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Antenna and Package Design for 61- and 122-GHz Radar Sensors in Embedded Wafer-Level Ball Grid Array Technology
Abstract
This paper suggests the usage of an optimized structure of the embedded wafer-level ball grid array technology for millimeter-wave antennas-in-package. Multiple antenna arrays in a second redistribution layer have been designed, evaluated, and integrated with different transceivers to form very compact sensor packages for 61- and 122-GHz radar applications. The resulting packages contain a complete radar front end while featuring dimensions of $8 mmx 8$ mm. The packages are easy to assemble and replaceable. Theoretical considerations, numerical results, and measurements have been carried out for the single components. For the verification of the sensor packages, a system demonstrator was developed, and measurements have been performed in continuous-wave mode. At both frequencies, promising system performance regarding range and distance errors could be confirmed without the usage of complex processing and calibration algorithms.
... resolution has various fields of applications, such as highprecision vibration measurements in industrial scenarios [8], vital sign detection [9], and non-destructive or biomedical spectroscopy [3], [10], [11]. The upcoming sub-terahertz communication standard IEEE 802. ...
... On the other hand, the package serves as a dielectric carrier for passive structures, such as interconnects, filters, or antennas, within the redistribution layer (RDL) [21], [29]. The thin-film RDL can be machined with very high accuracy, enabling precise manufacturing of passive package components [9]. The RDL's high-frequency suitability was thoroughly investigated and demonstrated in [21], [29]. ...
... The RDL antenna performance highly depends on the distance to GND. A change in height due to process variations in the assembly has dramatic consequences in terms of antenna efficiency, matching, and radiation pattern [9]. As a consequence, a modified eWLB package setup, introduced in [9], is shown in Fig. 1(b). ...
This paper presents a broadband low-loss fanin wafer level ball grid array (WLB) vertical through-moldvia (TMV) interconnect that enables highly integrated systemin-package (SiP) applications beyond 220 GHz. The dedicate advantage of the proposed approach is to further minimize the separation between package components (e.g., antenna in package (AiP)) and on-chip receiver or transmitter chain. To demonstrate the robustness of the TMV interconnect design, the necessity for co-simulation of the integrated circuit (IC) package and the IC itself during the package-design is shown. Therefore, an in-depth analysis of the suppression of parasitic mode oscillation inside silicon is carried out. Furthermore, the parasitic radiation loss at the TMV interconnect discontinuity is given and a verification of the proposed TMV due to high agreement of simulation and measurement results is demonstrated. The interconnect has been verified with a measured 10 dB return loss bandwidth of 38 GHz and a de-embedded insertion loss of less than 2.8 dB at 275 GHz, which enables a compact low-loss broadband signal transition from active IC components in the backend-of-line (BEOL) to passive components in package. Compared to fan-out WLB, the developed fanin WLB solution enables higher integration density of active and passive components with the shortest interconnects for minimal insertion loss. Thus, the proposed fan-in TMV packaging provides a very compact, easy-to-assemble and cost-efficient alternative for SiP designs for future broadband communication and sensing solutions.
... Compared with AoC, AiP solution is more attractive due to its higher gain and efficiency, improved system performance, and reduced cost in sub-terahertz band [5]. In recent years, AiPs are mainly fabricated with low temperature co-fired ceramics (LTCC) [6], [7], [8], high-density interconnect (HDI) [9], [10], [11], and wafer-level package (WLP) [12], [13], [14], [15]. ...
... In addition, the thickness of the package can be greatly lowered, which contributes to improve thermal and electrical performance. However, the popular fan-out WLP process, such as embedded wafer level ball grid array (eWLB) technology [12], [13], [14], typically has restrictions on the design flexibility of antennas. It is a challenge to design a D-band broadband antenna in WLP process. ...
... A few D-band antennas in wafer-level package have been proposed in recent years [12], [13], [14], [15]. Almost all the designed antennas suffer from narrow impedance bandwidth because of the limited space and fixed process flow. ...
This paper presents a broadband stacked patch antenna array in wafer-level package based on benzocyclobutene (BCB) process for D-band wireless communications. The BCB material is not only used as a substrate for the antenna, but also as an interconnection layer, enabling low-loss interconnection with RFICs through vias and transmission lines. By introducing a BCB polymer-filled back cavity and carefully developing the feeding network, the designed antenna achieves a relative bandwidth of 18.9%. In addition, the
$2 \times 2$
stacked antenna array features a stable high-gain broadside radiation pattern. The pairwise antiphase feeding technique is adopted to suppress the cross-polarization level. In order to acquire high-speed data transmission, a dual-polarization MIMO implementation is presented. The port isolations are greater than 35 dB across the whole operating band.
... Here, the aforementioned FOWLP or eWLB approach has been applied in a similar fashion. In addition, the redistribution layer of the package has been used to integrate the antennas into the package [66], [68], [84]. An example of a bistatic 60-GHz industrial radar transceiver with antennas in an eWLB package is shown in Fig. 5(c). ...
... This approach involves increased losses and bandwidth limitations at the antenna interface, but in return allows for a large aperture. For short-range applications, however, a systemin-package (SiP) approach has been followed [68], [89], [90]. As an example, Fig. 6(a) shows a scalable 120-GHz radar transceiver [67] that has been packaged into an FOWLP, shown in Fig. 6(b), to realize a highly integrated bistatic radar SiP with integrated antennas and low-loss interface [68]. ...
... For short-range applications, however, a systemin-package (SiP) approach has been followed [68], [89], [90]. As an example, Fig. 6(a) shows a scalable 120-GHz radar transceiver [67] that has been packaged into an FOWLP, shown in Fig. 6(b), to realize a highly integrated bistatic radar SiP with integrated antennas and low-loss interface [68]. In an even more extreme integration step, the 120-GHz antennas can even be integrated on the silicon chip itself [91]. ...
This invited paper reviews the progress of silicon-germanium (SiGe) bipolar-complementary metal-oxide-semiconductor (BiCMOS) technology-based integrated circuits (ICs) during the last two decades. Focus is set on various transceiver (TRX) realizations in the millimeter-wave range from 60 GHz and at terahertz (THz) frequencies above 300 GHz. This article discusses the development of SiGe technologies and ICs with the latter focusing on the commercially most important applications of radar and beyond 5G wireless communications. A variety of examples ranging from 77-GHz automotive radar to THz sensing as well as the beginnings of 60-GHz wireless communication up to THz chipsets for 100-Gb/s data transmission are recapitulated. This article closes with an outlook on emerging fields of research for future advancement of SiGe TRX performance.
... After the precursor reaches the point of cleaning material, it will adsorb chemical substances and react with the active surface, and finally make a recording film. Membrane damage will not only reduce the effectiveness of the skin, but also shorten the functional life of the skin and affect the function of the skin [23]. When the polymer concentration and viscosity are low, the fibers obtained in beads and beads mainly have no bonds between molecular chains or the physical connection itself is not strong enough to withstand external stress and breakage. ...
Sustainable design does not emphasize the safety of the ecosystem, but builds a systematic innovation process, taking into account customer needs, environmental benefits, social benefits, and corporate development. This article is based on the preparation of a modified carbon nanotube polyvinylidene fluoride composite film to analyze its application value in packaging design, aiming at analyzing the performance of the modified carbon nanotube and the polyvinylidene fluoride composite film during the preparation process, and applying its various characteristics to the process of packaging design optimization concept. The article is mainly divided into two parts: preparing modified carbon nanotubes and preparing polyvinylidene fluoride composite films. Among them, the photomechanical properties of carbon nanotubes, the relationship between the composition of the composite material and the dielectric properties, the dielectric response and relaxation behavior, the hydrophilicity of the composite membrane, and the membrane separation technology were discussed, and the carbon nanotubes were constructed. Incorporating carbon nanotubes into carbon fiber hybrid materials, and combining carbon nanotubes with polymer materials, works extremely well. The structure model is prepared, the molecular pore size, hydrophilicity, etc. are recorded, and surface modification, chemical modification, blending modification, and other methods are applied to analyze and evaluate the data. The experimental results show that in the application of modified carbon nanotubes and polyvinylidene fluoride composite films and packaging design, the interactive function of toughening modification increases 2.44 points; through enhancement modification, packaging design reduction increases by 2.5 points; and through the compatibilization modification, the functionality of the packaging design has increased by 1.88 points.
... In addition to joint transmit waveform-receive filter optimization in form of cognitive transceiver architectures, novel processing and learning algorithms are required for detection, tracking and classification of weak or low radar cross section (RCS) targets, especially for enabling human-machine interface applications. Advancement of silicon and packaging technology [Frank et al., 2018] has led to miniaturization of radar form-factor accelerating the wide adoption of radar sensors as a sensing technology in industrial, consumer and new automotive applications. Several human-machine interface (HMI) applications include detection, tracking and classification of humans or human motions or materials objects in the field of view. ...
The topic of detection, tracking and classification of weak targets in interferencedominated environment using radars is studied in this thesis. The problem is approached from the perspective of both resource-friendly radar systems and resourcelimited radar systems. In the case of resource-friendly radar systems, cognitive architectures that can progressively sense the environment and adjust its operating waveform-receiver filters are analyzed. The study of joint optimal transmit waveform and receive filters such that they operate optimally in the presence of weak targets and interference has been of huge interest in both academia and industry. Recent advances in adaptive waveform synthesis have focused on joint design and implementation of knowledge-aided receiver signal processing techniques and adaptive transmit signals. This closed loop radar framework that mimics mammals’ neurological capability to tune system parameters in response to cognition of the environment is commonly referred to as "cognitive radar" or "fully adaptive radar". In this thesis, the output signal to interference noise ratio maximizing jointly optimal transmit waveform and receive filter for a single-input, single-output radar design in the presence of extended target and colored interference is presented. The ambiguity function, processing gain and Cramer-Rao bound for such waveformfilters are derived. Apart from the optimal waveform dictated by the joint optimization strategy, it is desired that the radar transmit waveforms possess constant time envelope to drive the power amplifiers at saturation. This constraint requires reconstruction of constant envelope signals, which is addressed using proposed relaxed iterative error reduction algorithm. In general, iterative algorithms are sensitive to the initial seed, which is solved by deriving a closed-form solution making stationary phase assumption. In the case of multiple-input multiple-output (MIMO) radars, the interference between signals can significantly limit the radar’s ability for observation of weak targets in presence of stronger targets and background clutter. For the multi-channel radars, in this thesis orthogonally coded Linear Frequency Modulated (LFM) waveforms is proposed, wherein consecutive complex LFM signals in a frame are coded by orthogonal codes, namely Golay complementary, Zadoff Chu, direct spread spectrum, space-time block coded, discrete Fourier transform and Costasbased sequences. The orthogonal codes to modulate the LFM across symbol form fixed library waveforms leading to partial adaptation instead of arbitrary waveform dictated by "fully adaptive radar". The ambiguity function for such orthogonallycoded MIMO radar is derived, and the waveforms are analyzed in terms of their ambiguity function and imaging performance. With the advancement in silicon and packaging technology, radars have evolved from high-end aerospace technology into relatively low-cost Human-Machine Interface (HMI) sensors. However, the sensor in such industrial and consumer setting should have a small form-factor and low-cost, thus they cannot sustain cognitive architectures to detect and classify weak human targets. To improve detection and classification performance for HMI applications, novel processing and learning algorithms are proposed. In practice, there are several challenges to learningbased solutions using low-cost radars particularly with respect to open set classification. In open set classification, the system needs to handle variations of the input data, alien operating environment and unknown classes. Conventional deep learning approaches use a simple softmax layer and evaluate the accuracy on known classes, thus on closed set classification. The softmax layer provides separability of classes but does not provide discriminative class boundaries. Hence, many unknown classes are erroneously predicted as one of the known classes with a high confidence, resulting in poor performance in real world environments. Other challenges arise due to the inconspicuous interclass difference between features from one class and other closely-related class and large intra-class variations in the radar data from the same classes. To address these challenges, novel representation learning algorithms along with novel loss functions are proposed in this thesis. Unlike conventional deep learning approaches using softmax that learns to classify, deep representation learning learns the process to classify by projecting the input feature images to an embedded space where similar classes are grouped together while dissimilar classes are far apart. Thus, deep representation learning approaches simultaneously learn separable inter-class difference and compact discriminative intraclass, essential for open set classification. Specifically, the proposed representation learning algorithms are evaluated in the context of gesture sensing, material classification, air-writing and kick sensing HMI applications.
... Embedded-wafer-level-ball-grid array (eWLB) technology [5], [6] combines a small chip area and a large antenna aperture using fan-in and fan-out areas in a low-cost approach. On the surface a redistribution layer (RDL) is formed that connects the pads of the chip to solder balls placed in a grid This work is licensed under a Creative Commons Attribution 4.0 License. ...
This work presents a novel sensor packaging and a novel transition concept for radar applications above 150 GHz based on glass material. By using laser induced deep etching (LIDE) technology, glass vias and cavities are fabricated without degrading the mechanical stability of glass, as micro-cracks are completely avoided. Especially at high millimeter wave (mm-wave) frequencies, precise structuring on low dielectric loss materials and a high integration density are essential for low loss transitions. In this paper, an ultra compact FMCW radar monolithic microwave integrated circuit (MMIC) at 160 GHz is used to demonstrate this packaging technology. In addition, the high frequency signal is guided by a low loss transition to a deposed antenna via a dielectric waveguide (DWG) providing the antenna front end with mechanical flexibility. Thus, using plated through glass vias (TGVs) and a circulating solder ring, the package is hermetically sealed. The optical transparent glass package has a size of only
${5.8}\,\rm {mm}\times {4.4}\,\rm {mm}\times {0.9}\,\rm {mm}$
. A minimum measured insertion loss of 2.85 dB at 162 GHz from chip to DWG is achieved. The complete radar system with a range resolution of 12 mm is demonstrated via radar measurement.
... The final version of record is available at https://ieeexplore.ieee.org/document/9411122 using a standard eWLB process, whereas the 122 GHz eWLB antennas shown in [8] have been realized using a modified and hence costlier manufacturing process. Fourth, the realized gain achieved for a single radiating element is expected to be higher than the 122 GHz eWLB antenna shown in [7]. ...
... Additionally, an embedded wafer-level ball grid array (eWLB) sensor package with integrated antenna structures is used as feed as well. Further details on the sensor packages and antenna structures are provided in [15]. The feed is centred underneath the transmitarray for both scenarios. ...
This Letter presents the design of a low-profile and low-cost transmitarray antenna operating at 122 GHz. The transmitarray design is based on unit-cells with 1-bit phase resolution. A single RO4350B substrate layer is used to form the unit-cells resulting in a total thickness of 0.326 mm. A wideband shift in the transmission phase of 180° is generated by rotating one metal layer of the unit-cell by 180°. The simulation of the transmitarray with 30 × 30 elements and a feed distance of 35 mm shows a maximum directivity of 28 dBi at 122 GHz. Steering angles of 0° and 15° are investigated. Measurements of the fabricated transmitarrays are performed with an open waveguide and a package antenna as feed showing similar results but slightly different maximum relative gain values of 11.8 and 9.5 dB for the 0° version. The measured main beam directions are in good agreement with the simulations and the design values.
This paper presents a broadband low-loss fan-in wafer level ball grid array (WLB) vertical through-mold-via (TMV) interconnect that enables highly integrated system-in-package (SiP) applications beyond 220 GHz. The dedicate advantage of the proposed approach is to further minimize the separation between package components (e.g., antenna in package (AiP)) and on-chip receiver or transmitter chain. To demonstrate the robustness of the TMV interconnect design, the necessity for co-simulation of the integrated circuit (IC) package and the IC itself during the package-design is shown. Therefore, an in-depth analysis of the suppression of parasitic mode oscillation inside silicon is carried out. Furthermore, the parasitic radiation loss at the TMV interconnect discontinuity is given and a verification of the proposed TMV due to high agreement of simulation and measurement results is demonstrated. The interconnect has been verified with a measured 10 dB return loss bandwidth of 38 GHz and a de-embedded insertion loss of less than 2.8 dB at 275 GHz, which enables a compact low-loss broadband signal transition from active IC components in the backend-of-line (BEOL) to passive components in package. Compared to fan-out WLB, the developed fan-in WLB solution enables higher integration density of active and passive components with the shortest interconnects for minimal insertion loss. Thus, the proposed fan-in TMV packaging provides a very compact, easy-to-assemble and cost-efficient alternative for SiP designs for future broadband communication and sensing solutions.
Radar-based gesture recognition systems are a promising concept for new human–machine interfaces. However, the systems are sensitive to user-dependent gesture patterns, sensor noise characteristics, background environments, and unknown gestures or background motions. To overcome such challenges, we propose a variational autoencoder architecture-based deep metric learning, which is optimized using a novel loss function combining a statistical distance triplet loss and the center loss. By learning the statistical distance between distributions, the proposed solution, compared with triplet loss, is able to better learn the nonlinear characteristics in the data, is less sensitivity to training strategy, and is capable of creating close knit embedding clusters. Moreover, it is experimentally demonstrated that the proposed gesture recognition system using radar spectrograms has improved classification accuracy and random gesture rejection accuracy compared with the state-of-the-art deep metric learning approaches. Furthermore, we proof the real-world capability of the system by implementing a real-time demonstrator, which allows playing “Tetris” with hand gestures.
In this article we present the design of a 120 GHz 2
$\times $
2 dipole array in a 130 nm SiGe technology, which employs dual mode substrate wave cancellation to improve radiation efficiency and to avoid uncontrolled radiation from the chip edges. We show a systematic analysis of the involved dielectric slab modes TM
<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub>
and TE
<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub>
and their effects on the radiation pattern and efficiency. Based on this, the position and orientation of the array elements are derived for optimal cancellation of substrate waves and different feeding techniques are compared. The dipole array shows a measured realized gain of 1 dBi [including ground signal ground (GSG)-pad, Balun, and matching-capacitor, all on-chip], an
$S_{11}$
-bandwidth of 18 GHz, and a realized gain bandwidth of 16 GHz. Very good correlation between simulations and measurements is achieved through careful modeling of the probe effects. The presented results provide useful insight on the design of on-chip dipole arrays for future millimeter-wave applications in standard SiGe or CMOS technologies.
High-performance IC-to-antenna interconnection is one of the key enablers for the mass production of high-end millimeter wave (mmW) radar systems above 100 GHz. In this work, a radar system with an on-package antenna array working at 122 GHz is presented. The antenna is placed on top of the molded package and the antenna-to-chip interconnection is realized by through-polymer via (TPV) technology. The detailed fabrication process of the radar antenna-in-package (AiP) with TPV is discussed. The results from the functional tests of the radar AiP are presented and benchmarked to a commercial quad-flat no-leads (QFN) package with an open antenna cavity. The detection margin between the echo signal and the constant false alarm rate (CFAR) threshold is approximately 10 dB higher for the TPV radar AiP compared with the benchmarked commercial QFN package.
A high-integration and low-cost transmitter packaging solution for 0.2-THz system-in-package (SiP) application is newly presented using high-temperature co-fired ceramic (HTCC) technology. To improve 3-D integration, internal vertical air-filled interconnection waveguides buried in the HTCC package are explored and fabricated. A compact MoCu waveguide bandpass filter (BPF) is designed and integrated into the package to suppress the harmonic output of the mixer. To demonstrate the potential SiP application in the future 0.2-THz radar systems, based on the proposed solution, two 0.2-THz transmitters using frequency multipliers/mixer are designed, fabricated, and measured. All the components are buried in HTCC, and the overall size is
$36\times 14\times9.8$
mm
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and
$54\times 14.5\times9.8$
mm
<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>
, respectively. Both the transmitters show good performance, and the measured output power is better than 8 and 5 dBm, respectively.
In this article, a millimeter-wave bidirectional active integrated coplanar waveguide slot antenna with ball grid array (BGA) interconnection is proposed. Symmetric multistage step impedance resonator matching network and tapered shaped structures are utilized to ultrawideband compensate the reactance behavior of the vertical BGA transition, which can be employed to reduce the interconnection length among different modules. By gradually changing the width of the semielliptic slot, an ultrawideband radiation behavior is achieved with a small impedance variation from one resonate mode to another. The proposed 1
$\times $
4 passive antenna array can operate from 25 to 40 GHz with a gain of 13.1 dB. Compared with the conventional active integrated antenna structures, good advantages of wide bandwidth and high gain are obtained with the proposed technique. The prototype of the presented active antenna array is fabricated and measured with a wide impedance bandwidth of 29.1–40 GHz and can be more suitable for high-solution radar sensor.
This study presents a design of a 94-GHz high-performance and highly compact frequency-modulated continuous-wave radar sensor. In this sensor, an
$X$
-band CMOS-based all-digital phase-locked loop chip,
$W$
-band SiGe-based transceiver monolithic microwave integrated circuit (MMIC), and
$W$
-band GaN-based MMIC power amplifier (PA) are heterogeneously integrated (HI). Each part of the 130-nm bipolar complementary metal-oxide-semiconductor (BiCMOS) SiGe-based transceiver MMIC is designed to include a low-noise amplifier, PA, octupler, mixer, and lange coupler. The fabrication process of our in-house silicon-based MEMS photosensitive composite film is developed to provide very high-density integration and very low insertion loss of interconnections between chips. The HI front end of the radar sensor is measured on-wafer with a high output power of 22 dBm. Moreover, a low double-sideband noise figure (NF) of 10.2 dB is obtained. Bonding–substrate integrated waveguide (SIW)–WG transitions between the heterogeneously integrated front end and the antenna are specially designed and verified. A 2.3-dB degradation is observed, where 19.7 dBm is measured at the transmitter WG WR-10-flange. Thus, the sensor offers a 55-dB dynamic range at a 2-m position with an expectation of a long-distance target-detection range. The radar sensor has an 11.7-cm range resolution and is only
$60\times 40\times $
8 mm
<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>
in size, with a weight of only 78 g.
Drahtloses Erfassen verschiedener physikalischer Größen, wie Temperatur, Kraft und Drehmoment, ist bereits heute eine wichtige Aufgabe der industriellen Messtechnik und wird durch die fortschreitende Automatisierung auch in anderen Gebieten stetig relevanter. Einen vielversprechenden Ansatz stellen dafür resonante Hochfrequenz-Sensoren dar, beispielsweise basierend auf akustischen Oberflächenwellen (SAW-Sensoren). Diese rein passiven Sensoren sind extrem robust und können auch unter schwierigsten Umgebungsbedingungen eingesetzt werden. Bisher scheitern jedoch viele Anwendungen dieser zukunftsträchtigen Technologie an den aufwendigen und teuren Lesegeräten, die zum Abfragen der Sensoren benötigt werden. Die vorliegende Arbeit stellt deshalb ein neues drahtloses Ausleseverfahren für resonante Sensoren vor, bei dem erstmalig das Prinzip der instantanen Frequenzmessung (Augenblicksfrequenz- bzw. Momentanfrequenzmessung) verwendet wurde, um das Antwortsignal des Sensors auszuwerten. Durch diesen interferometrischen Ansatz lassen sich hohe Messwertaktualisierungsraten mit deutlich reduziertem Hardwareaufwand realisieren. Um Nichtidealitäten sowie Einflüsse von Temperatur und Alterungseffekte der analogen Hardwarekomponenten zu minimieren, wurde eine In-situ-Linearisierung verwendet, die bekannte Referenzsignale einspeist, um damit systematische Fehler in den nachfolgenden unbekannten Messungen digital zu kompensieren. Ein Kernpunkt dieser Arbeit stellt die detaillierte theoretische Untersuchung zur Systemauslegung sowie den Systemgrenzen und Fehlerkompensationsmöglichkeiten des vorgeschlagenen Verfahrens dar. Dazu wurden alle Einzelkomponenten inklusive möglicher Quereinflüsse im Gesamtsystemkontext evaluiert und neben internen Fehlerquellen auch externe Störeinflüsse betrachtet. Dabei wurden entscheidende neue Erkenntnisse für den praktischen Einsatz dieses innovativen Messkonzeptes erlangt, die sich zum Entwurf eines optimierten Gesamtsystems nutzen lassen. Um die Realisierbarkeit des Konzepts zu zeigen, wurden Laboruntersuchungen durchgeführt und ein Systemdemonstrator im 2,4-GHz-Frequenzband entworfen und evaluiert. Dieser konnte mit einfacher Schaltungstechnik eine 3-Sigma-Präzision der Frequenzmessung unter 2 Millionstel (ppm) bei 1000 Messungen pro Sekunde erreichen. Zusammen mit der unkomplizierten Signalverarbeitung werden dadurch neue Maßstäbe hinsichtlich kostengünstiger Realisierungsmöglichkeiten gesetzt und enormes Potential für verschiedene industrielle, automotive und medizinische Anwendungen demonstriert.
This paper presents the design and characterization of linearly polarized low-cost transmitarray antennas with ± 70° azimuth beamforming range in V-band in order to add beam steering functionality to existing radar front ends. The transmitarray antennas are composed of 13 × 13 planar unit-cells. The unit-cells consist of two layers of RO4350B laminate and provide a one bit phase resolution. The desired unit-cell behavior has been validated by simulations and measurements. Eight transmitarrays with different phase distributions have been designed and fabricated to realize different beam steering angles in azimuth. The experimental characterization of the radiation patterns shows the desired performance in the frequency range from 59 GHz to 63 GHz. Additionally, steering angle combinations in azimuth and elevation up to 40° have been realized and successfully demonstrate by measuring the 2D radiation pattern.
In this paper, a packaging solution for millimeter-wave system-on-chip (SoC) radio transceivers is presented. The on-chip antennas are realized as primary radiators of an integrated lens antenna which offer high bandwidth and high efficiency. The package concept includes a high permittivity silicon lens which serves additionally as heat sink and a quad flat no-lead package which is mountable on a standard printed circuit board (PCB). The electrical and thermal properties of the package are investigated through simulations and calibrated measurements. The concept is verified by realizing a complete radar sensor. The manufactured SoC radar frontend is soldered on a standard PCB which includes the baseband circuitry for a frequency-modulated continuous wave radar and finally, measurements are performed to compare the superposed radiation patterns of the transmit and receive antennas with simulations. IEEE
Enormous technological progress accomplished over the last several decades has facilitated the use of millimeter-wave (mmW) frequencies for mass-produced products such as automotive radars, industrial sensors, highspeed data communication links, and medical devices. The main enablers are new semiconductor technologies, with constantly improving cut-off frequencies reaching several hundred gigahertz. However, the dominant limiting factor for the mass production of low-cost mmW systems above 100 GHz is that suitable packaging technologies are not yet available. Still, a dramatic increase in research and development is taking place in the area of mmW packaging. The goal of this article is to provide a short overview of the topic and then present one particular approach in detail: the idea of integrating a complete mmW front end, including the antenna, into one small solderable surfacemount device (SMD).
A highly miniaturized and commercially available millimeter wave (mmw) radar sensor working in the frequency range between 121 and 127 GHz is presented in this paper. It can be used for distance measurements with an accuracy in the single-digit micrometer range. The sensor is based on the frequency modulated continuous wave (CW) radar principle; however, CW measurements are also possible due to its versatile design. An overview of the existing mmw radar sensors is given and the integrated radar sensor is shown in detail. The radio frequency part of the radar, which is implemented in SiGe technology, is described followed by the packaging concept. The radar circuitry on chip as well as the external antennas is completely integrated into an 8 mm $x$ 8 mm quad flat no leads package that is mounted on a low-cost baseband board. The packaging concept and the complete baseband hardware are explained in detail. A two-step approach is used for the radar signal evaluation: a coarse determination of the target position by the evaluation of the beat frequency combined with an additional determination of the phase of the signal. This leads to an accuracy within a single-digit micrometer range. The measurement results prove that an accuracy of better than $±$6 μm can be achieved with the sensor over a measurement distance of 35 mm.
Six-Port microwave interferometers are a low-cost as well as low-power type of radar sensor with a high phase accuracy, which can be used for precise displacement measurements. Near field effects strongly influence the signal characteristics of a reflection of the electromagnetic wave near the antenna, especially if the target is low reflective. In this paper a calibration procedure based on phase error correction by segmental polynomial approximation is proposed that utilizes these effects. After validating the functionality of the calibration algorithm and its improvement by comparison to a comparable state-of-the-art procedure, two further near field measurements are presented. A cardboard as well as a plastic plate are used as low reflecting targets to show the applicability of the proposed calibration procedure for diverse measurement scenarios.
Microwave technology plays a more important role in modern industrial sensing applications. Pushed by the significant progress in monolithic microwave integrated circuit technology over the past decades, complex sensing systems operating in the microwave and even millimeter-wave range are available for reasonable costs combined with exquisite performance. In the context of industrial sensing, this stimulates new approaches for metrology based on microwave technology. An old measurement principle nearly forgotten over the years has recently gained more and more attention in both academia and industry: the six-port interferometer. This paper reviews the basic concept, investigates promising applications in remote, as well as contact-based sensing and compares the system with state-of-the-art metrology. The significant advantages will be discussed just as the limitations of the six-port architecture. Particular attention will be paid to impairment effects and non-ideal behavior, as well as compensation and linearization concepts. It will be shown that in application fields, like remote distance sensing, precise alignment measurements, as well as interferometrically-evaluated mechanical strain analysis, the six-port architecture delivers extraordinary measurement results combined with high measurement data update rates for reasonable system costs. This makes the six-port architecture a promising candidate for industrial metrology.
Non-invasive automatic crack detection and characterization of packaged ceramic tiles is an integral part of industrial processes. Inefficiencies in quality monitoring of packaged tiles is quite unbearable in terms of manufacturing, time, money and consumer satisfaction. As a result, there is an increasing demand for the use of smart visual inspection systems to ensure the high quality of products in the manufacturing line. Although different techniques have been proposed by various researchers, accurate monitoring of the packaged ceramic tiles remains particularly challenging in order to cut down number of false alarms, which could otherwise result in fiscal or reputation loss to the company. Therefore, this study explores the possibility of application of millimeter wave based non-invasive crack detection of packaged ceramic tiles using an ingeniously designed V band (60 GHz) imaging radar system. A statistics-based adaptive algorithm has been proposed for crack detection of packaged ceramic tiles with the main consideration of achieving minimal false alarm. A total of 40 different ceramic tiles with different crack and non-crack configurations were considered. The proposed algorithm was tested and satisfactory performance has been achieved.
A 77-GHz transmit-array on dual-layer printed circuit board (PCB) is proposed for automotive radar applications. Coplanar patch unit-cells are etched on opposite sides of the PCB and connected by through-via. The unit-cells are arranged in concentric rings to form the transmit-array for 1-bit in-phase transmission. When combined with four-substrate-integrated waveguide (SIW) slot antennas as the primary feeds, the transmit-array is able to generate four beams with a specific coverage of $pm 15^{circ}$. The simulated and measured results of the antenna prototype at 76.5 GHz agree well, with gain greater than 18.5 dBi. The coplanar structure significantly simplifies the transmit-array design and eases the fabrication, in particular, at millimeter-wave frequencies.
Two separate transmitarrays that operate at 77 GHz are designed and fabricated. The first transmitarray acts as a quarter-wave plate that transforms a linearly polarized incident wave into a circularly polarized transmitted wave. The second transmitarray acts as both a quarter-wave plate and a beam refracting surface to provide polarization and wavefront control. When the second transmittarray is illuminated with a normally incident, linearly polarized beam, the transmitted field is efficiently refracted to 45 °, and the polarization is converted to circular. The half-power bandwidth was measured to be 17%, and the axial ratio of the transmitted field remained below 2.5 dB over the entire bandwidth. Both designs have a subwavelength thickness of 0.4 mm (λ°/9.7). The developed structures are fabricated with low-cost printed-circuit-board processes on flexible substrates. The transmitarrays are realized by cascading three patterned metallic surfaces (sheet admittances) to achieve complete phase control, while maintaining high transmission. Polarization conversion is accomplished with anisotropic sheets that independently control the field polarized along the two orthogonal axes. The structures are analyzed with both circuit- and fields-based approaches.
This paper presents the first flip-chip-packaged and fully integrated Doppler micro-radar in 90-nm CMOS for noncontact vital-sign and vibration detection. The use of a smaller wavelength compared with previous works achieves the highly compact system for portable devices, and the radar design considerations at 60 GHz are discussed from both system and circuits points of view. The compact 60-GHz core (0.73 mm2 ) provides a 36-dB peak down-conversion gain and transmits a radar signal around 0 dBm at 55 GHz. Quadrature generation at the intermediate frequency stage of the heterodyne receiver gives a power- and area-efficient solution to the null detection point issue, ensuring robust detection. By using single-patch antennas and without a high-power amplifier, the system demonstrates the first-pass success of human vital-sign detection at 0.3 m. The small mechanical vibration with a displacement of 0.2 mm can be detected up to 2 m away. At 60 GHz, target displacement comparable to wavelength results in strong nonlinear phase modulation and increases detection difficulties. A signal-recovery algorithm is proposed to improve the accuracy of vital-sign detection.
A broadband coplanar waveguide (CPW) to coplanar strip (CPS) transmission line transition directly integrated with an RF microelectromechanical systems reconfigurable multiband antenna is presented in this paper. This transition design exhibits very good performance up to 55 GHz, and uses a minimum number of dissimilar transmission line sections and wire bonds, achieving a low-loss and low-cost balancing solution to feed planar antenna designs. The transition design methodology that was followed is described and measurement results are presented.
The coplanar waveguide (CPW)-to-coplanar stripline (CPS)
transition is analyzed theoretically and experimentally in this paper.
To characterize this transition in the lower frequency band, a simple
equivalent-circuit model that consists of uniform and nonuniform
transmission lines is established. The elements of this model can all be
obtained by the closed-form formulas; hence, this model is suitable for
computer-aided-design application. This model is then applied to design
and analyze the CPW-to-CPS transitions with various structure
parameters. In the higher frequency band, the partially prism-gridded
finite-difference time-domain (FDTD) method is employed to take into
account the bond-wire effect as well as the surface-wave leakage and
space-wave radiation associated with the transition. In this study,
results based on equivalent-circuit model, FDTD simulation, and
measurement are compared. Good agreement among these results supports
the usefulness of the proposed equivalent-circuit model and also
validates the FDTD method. By using the equivalent-circuit model to
optimize the transition configuration, the CPW-to-CPS transition with
broad bandwidth and low insertion loss may be achieved
This paper presents a compact integration design of a low-cost bondwire-interconnection scheme between a 60-GHz CMOS vital-signs Doppler radar sensor chip and a millimeter-wave patch-array planar antenna (17-dBi gain). The interconnection has the form of an inductance-capacitance-inductance structure configured as a T-matching network. It consists of a short microstrip line as a small capacitance and parallel bondwires as inductance. Open-ended stubs are additionally applied in the design to improve the ground connection at 60 GHz. To enhance the robustness of the impedance-matching bandwidth to withstand possible bonding length variations, additional series and shunt transmission lines are also deployed. The proposed low-cost integrated circuit-to-board interconnection design requires no additional processing (e.g., cavity etching of the carrier board). In the experimental measurement, compared with the radar sensor connected with a 7-dB-loss V-band cable to the planar antenna in a previous report, the implemented compact bondwire-interconnected CMOS radar antenna module can enhance the detection range from 75 to at least 105 cm [and potentially up to 120-150 cm if the radar chip output power (0 dBm) is the same as 3 dBm]. This shows the potential facilitation for the incorporation of the 60-GHz radar sensor chip into portable devices for wireless remote physiological monitoring healthcare applications.
This paper presents the design of a V-band logarithmic power detector (PD) and the integration with a 60-GHz CMOS vital-signs Doppler radar sensor to be incorporated with a microprocessor control unit (MCU) for fast automatic clutter cancellation. The PD adopts the successive detection logarithmic amplifier (SDLA) topology and achieves a high dynamic range by replacing the limited amplifiers with millimeter-wave (MMW) linear amplifiers. From the measurement results, the PD exhibits a dynamic range and logarithmic errors higher than 35 dB and within ± 2 dB from 50 to 62 GHz. The whole integrated radar sensor chip is fabricated by a 90-nm CMOS process with a chip size of 2 mm x 2.34 mm and a dc power consuming of 243 mW. The radar chip and a 60-GHz 17-dBi patch-array antenna are integrated by bondwire interconnection on a compact single carrier board for experimental test. By incorporating the MCU to the radar chip board, the fast automatic clutter canceling can achieve more than 25-dB clutter cancellation. Moreover, it shows a successful vital-signs detection for a distance more than 1.2 m.
In this paper, a high-range 60-GHz monostatic transceiver system suitable for frequency-modulated continuous-wave (FMCW) applications is presented. The RF integrated circuit is fabricated using a 0.13-μm SiGe BiCMOS technology with fT/fmax of 250/340 GHz and occupies a very compact area of 1.42 x 0.72 mm². All of the internal blocks are designed fully differential with an in-phase/quadrature receiver (RX) conversion gain of 14.8 dB and -18.2 dBm of input-referred 1-dB compression point and a transmitter (TX) with 6.4 dBm of output power. The 60-GHz voltage-controlled oscillator is of a push-push type Colpitts oscillator integrated into a frequency divider with an output frequency between 910 MHz and 1 GHz with the help of 3-bit frequency tuning mechanism for external phase-locked loop operations. Between the TX and RX channels, a tunable coupler is placed to guarantee a high isolation between channels which could withstand any fabrication failures and provide a single differential antenna output. On the TX side, two power detectors are placed in order to monitor the transmitted and reflected powers on the TX channel by passing through a branch-line coupler for built-in-self-test purposes. The total current consumption of this transceiver is 156 mA at 3.3 V of single supply. Considering the successful real-time radar measurements, which the radar is able to detect the objects in more than 90-m range, it proves the suitability of this monostatic chip in high-range FMCW radar systems.
A 170 GHz fully integrated single-chip heterodyne frequency modulated continuous-wave (FMCW) imaging radar using a 130 nm SiGe BiCMOS technology (fT/fmax = 220/280 GHz) is reported. This system demonstrates a wide bandwidth of 27.5 GHz (16.3%) at a center frequency of 168 GHz. A design methodology to maximize the tuning range of the voltage-controlled oscillator (VCO) is presented. A co-design of the VCO, coupler, and antenna is performed to minimize the chip area and the dc power consumption. The transmitter radiates a peak power of -1 dBm with a dc-to-RF efficiency of 1.42%. At the receiver side, a subharmonic mixer is used for signal down-conversion. The system achieves a measured sensitivity of 87 fW with a total dc power consumption of 67 mW. The prototype is capable of forming 2-D and 3-D images with a range resolution of 7 mm. To the best of our knowledge, this fully integrated imaging radar demonstrates the highest sensitivity and radiation efficiency among all imaging systems around 200 GHz. Moreover, the system is capable of practical 2-D and 3-D imaging with significantly lower dc power consumption compared to the state-of-the-art FMCW radars.
This paper describes a multi-purpose radar system suitable for applications with different requirements on dynamic range, resolution, and miniaturization degree. It utilizes a scalable sensor platform that includes a wideband 30.5-GHz voltage-controlled oscillator (VCO) as well as 61- and 122-GHz transceivers (TRXs) in a silicon-germanium BiCMOS technology. The proposed architecture enables the cascading of multiple TRXs and allows the implementation of MIMO radar systems in two different frequency bands by using a single VCO. The higher transmit output power of 11.5 dBm as well as receive gain of 24 dB make the 61-GHz TRX suitable for applications requiring a high dynamic range. The lower wavelength allows the integration of on-chip antennas in the 122-GHz TRX and enables, thus, a high miniaturization degree. The higher LO scaling factor makes the 122-GHz TRX also more attractive for high-resolution applications. A sweep bandwidth of 2.5 GHz generated by the VCO is scaled up to 10 GHz and results in a range resolution of 3 cm. The proposed TRXs are equipped with binary phase shift keying modulators as well as an I/Q receiver and can be utilized to build a flexible software-defined radar platform for range and distant-selective vibration sensors utilizing frequency-modulated continuous wave as well as pseudo-random noise radar techniques.
In this paper, a CMOS multichannel transceiver (TRX) is proposed for angular identification in automotive car radar applications. Two transmitters (TXs) and six receivers (RXs) are placed on the same die using 65-nm CMOS technology with chip size 3.5 × 3 mm
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. To generate a millimeter-wave (MMW) frequency-modulated continuous-wave signal, an injection-lock frequency sextupler cascaded a 1-to-8 Wilkinson power dividing network with wideband isolation is designed as the LO-chain to convert external source from 12.5-13.7 to 75-82.2 GHz for both the TXs and RXs. Each TX achieves above 11-dBm output power and the RXs achieve 30-dB conversion gain from 75 to 82 GHz, and the total power dissipation of whole chip is 1.43 W. Compared with other published multichannel TRXs in silicon germanium (SiGe) process, this paper demonstrates compatible performances and the potential of multichannel TRX using CMOS for MMW automotive car radar application.
We present highly integrated 60-GHz radar transceivers for industrial sensor applications. The bistatic and monostatic transceivers are implemented in the SiGe bipolar technology and packaged using the embedded wafer-level ball grid array technology that allows for direct embedding of the antennas in the package redistribution layer. In this way, very compact and efficient radar frontends comprising all millimeterwave components can be implemented in an 8 × 8 mm
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package. These frontends were soldered on a standard low-cost printed circuit board based on FR4 material. For verification of the proposed frontends, an frequency-modulated continuous wave (FMCW) radar system was developed and set up within this paper. Theoretical considerations and simulations as well as corresponding measurements were carried out for the evaluation of the designed system. The demonstrator results of these embedded radar sensors show an excellent system performance at a high integration level.
This paper presents a 60-GHz CMOS direct-conversion Doppler radar RF sensor with a clutter canceller for single-antenna noncontact human vital-signs detection. A high isolation quasi-circulator (QC) is designed to reduce the transmitting (Tx) power leakage (to the receiver). The clutter canceller performs cancellation for the Tx leakage power (from the QC) and the stationary background reflection clutter to enhance the detection sensitivity of weak vital signals. The integration of the 60-GHz RF sensor consists of the voltage-controlled oscillator, divided-by-2 frequency divider, power amplifier, QC, clutter canceller (consisting of variable-gain amplifier and 360 phase shifter), low-noise amplifier, in-phase/quadrature-phase sub-harmonic mixer, and three couplers. In the human vital-signs detection experimental measurement, at a distance of 75 cm, the detected heartbeat (1-1.3 Hz) and respiratory (0.35-0.45 Hz) signals can be clearly observed with a 60-GHz 17-dBi patch-array antenna. The RF sensor is fabricated in 90-nm CMOS technology with a chip size of 2 mm 2 mm and a consuming power of 217 mW.
This paper presents a 77-GHz radar system using a transmitter (Tx) and receiver (Rx) integrated with on-chip waveguide feeders in 65-nm CMOS. The newly proposed on-chip waveguide feeder shows the insertion loss of about 2 dB and more than 30% bandwidth. Additionally, both the Tx and Rx are integrated with internal ×10 frequency multipliers. Therefore, a radar system can be easily implemented without sensitive millimeter-wave packaging technology by mounting the Tx and Rx chips on the waveguide aperture. The interconnections for the low-frequency reference and baseband signals can be realized on the low-cost FR-4 printed circuit board. The radar system shows 9-dBm output power and 13-dB down-conversion gain from the waveguide port.
A 16-element phased-array receiver has been developed for advanced W-band automotive radars. The phased-array receiver is based on a single SiGe chip with RF beamforming capabilities, which is packaged using low-cost bond-wire techniques and attached to a 16-element linear microstrip array. The antenna results in a directivity of 29.3 dB and a gain of 28.0 dB at 77-81 GHz, and can be scanned to ±50° in the azimuth plane in ~ 1° steps. The packaging details are presented together with the steps taken to ensure a wideband impedance match and low coupling between the phased-array channels. Gain measurements done at 79 GHz agree well with simulations. The 16-element phased array receiver was used with a 2-element frequency-modulated continuous-wave transmitter at 76.5-77 GHz and high-resolution millimeter-wave images were obtained. The work shows that complex millimeter-wave phased arrays can be packaged using traditional bond-wire techniques, and can be a powerful solution for advanced automotive radars.
Six-port interferometers are of great interest for displacement and vibration measurements in industrial as well as medical applications. However, they show offsets as well as amplitude and phase imbalances in their differential in-phase and quadrature signals, leading to inaccuracies of the measured displacement. If a very slow moving or vibrating target has to be monitored, an additional phase shifter for calibration is needed, so that the system's errors can be compensated. A method for calculation and compensation of errors is presented and a compact and cost-efficient implementation of a phase shifter for 24 GHz Six-port interferometers is shown.
In this article, we present a study about the impact of embedded wafer level ball grid array (eWLB) on characteristics of antenna. The antenna in package is a promising solution for integration of antennas and eWLB technology enables integration of passive components and antennas into the redistribution layer (RDL). The antenna radiates perpendicular to the package in broadside into the package. There are different parameters such as size, shape, and thickness of the eWLB package which affect the radiation pattern significantly. Moreover, the materials properties of package like relative permittivity (εr) and loss tangent (tanδ) impact the impedance bandwidth, gain and efficiency of antenna and have to be taken into account. The other important parameter to design the antenna in package is the distance of antenna to the reflector. We present the feasibility of an antenna with backside metallization as an integrated reflector in an 8 mm × 8 mm eWLB package. The measurement and simulation results show that eWLB is an attractive candidate for mm-wave applications.
In this paper, we present simulation and measurement results of single-ended and differential vertical interconnections realized using the thin-film redistribution layer (RDL) and through encapsulant vias (TEVs) of the embedded wafer level ball grid array (eWLB) package. We demonstrate that the fan-out area of the eWLB can be used advantageous for the design of passive devices using TEV structures. We show simulation and measurement results of inductors and transformers built up by RDL and TEV structures. Thus, these structures are designed in the fan-out volume of the eWLB mold compound. We discuss the electrical performance of the 3D interconnections and embedded passives realized using TEVs. The presented examples demonstrate that the eWLB technology is an attractive candidate for system integration because this technology enables the design of 2D passives in RDL and 3D passives using RDL and TEV.
In this article we present an antenna array concept in embedded wafer level ball grid array (eWLB) package for mm-wave applications. The eWLB package has a excellent performance for high frequency and the additional fan-out area around the silicon chip enables the realization of passives and antennas. Moreover, integration of the antenna in package increases the efficiency and reduces cost. For some applications a single antenna in package is unable to achieve the required gain and directivity. Combining several antenna elements as an array in a package can be a possible solution. A two elements differential dipole antenna array in an 8 mm × 8 mm eWLB package at IMS (Industrial, Medical and Scientific) band about 61 GHz is analyzed and successfully implemented. A 100 Ω differential feeding system is designed for the array. The measured reflection coefficient is -25 dB and the designed antenna array has a gain of 11 dB and radiates in broadside.
This paper presents an on-chip double-dipole antenna by applying micromachining techniques based on a standard SiGe BiCMOS process. It enables the fully integration of millimeter-wave transceiver and antenna into a single chip. A parametric study has been made in simulation which reveals the influence of the key design parameters over the radiation efficiency and directivity. A prototype has been fabricated and measured to verify the design. The measured peak gain is 8.4 dBi at 130 GHz with a simulated efficiency of 60 %. The 3-dB gain bandwidth is 122 – 140 GHz.
In this article, we present the feasibility of an antenna concept at the ISM (Industrial, Scientific and Medical) band for a two-channel 61 GHz transceiver in embedded wafer level ball grid array (eWLB) technology. The eWLB is an innovative package solution for high-frequency and high-performance applications. We present both simulation and measurement results of antennas which are integrated in the thin-film redistribution layer (RDL) of an eWLB package. Two λ/2-dipole antennas are used for transmitter (TX) and receiver (RX). The package including the antennas is soldered on a RF board in order to measure radiation pattern and scattering parameters (S-parameters). The measured isolation between two antennas is -25 dB and they have a return loss of -26 dB. The observed gain of a single antenna is about 8 dBi and the antenna input impedance bandwidth is 5 GHz. We investigate the impact of package size on the antenna radiation pattern. We present the analysis of the antenna-package interactions and determine the optimum distance of the antennas in package to the reflector on board.
In this paper, a 3-D integrated 77-GHz automotive radar front-end is presented. Embedded wafer level packaging (EMWLP) technology is proposed to eliminate the use of wire bonding, which not only introduces significant radio frequency loss, but also occupies large footprint for high-pin count die. The transceiver bare die is embedded in a reconfigured molded wafer with compression molding process. Double-sided multiple redistribution layers are formed to fan-out the transceiver input/output signals and through mold via is employed to realize the vertical interconnection. With these promising features, the EMWLP technology can be extended to a 3-D integration. A substrate integrated waveguide slot antenna is integrated on top of the EMWLP module and a lens is used to enhance the antenna directivity. The performance of the fully integrated radar front-end is tested and the measurement results show good package performance with RF loss around 5 dB for most of the samples. Temperature cycling reliability test was also performed by letting the fully integrated prototype goes through 1000 temperature cycles with JEDEC standard. The measured package loss spread across samples after 1000 cycles of TC test is about 13 dB, which is mainly due to the antenna warpage affecting the RF path's signal integrity.
This paper presents an antenna-in-package (AiP) solution with embedded wafer Level ball grid array (eWLB) packaging technology. The primary antenna is realized in the redistribution layer of the eWLB package. It is composed of two patches driven by differential signals and supports seamless connection with differential output monolithic microwave integrated circuits in a compact package. A dielectric rod lens was designed to optimize the radiation performance of the whole package. The final lens has the dimensions 10 mm × 10 mm × 10.5 mm. Our measurements show that the whole package (chip+AiP) including the lens reaches 16-dBm effective isotropic radiated power for the frequency range from 71.4 to 81.7 GHz. The radiation beam is relatively symmetric for both the E- and H-plane. The proposed AiP solution has great potential for millimeter-wave applications.
This paper presents the design of a directional folded dipole antenna integrated in an embedded wafer level ball grid array (eWLB) package, the comparison of different antenna designs and the influence of the silicon die and neighboring antennas within the package to the radiation behavior. The co-integration of the antenna and the silicon-based monolithic microwave integrated circuit (MMIC) in a system in package (SiP) approach is a convenient solution to suppress lossy radio frequency (RF) transitions and to simplify the design and the manufacturing of radio frontends significantly. The proposed SiP is focused on 77-GHz automotive radar applications. The MMIC contains the 77-GHz signal source and a transceiver with amplifier and mixer. The gain of different antennas in different constellations within the package is shown.
The embedded wafer level ball grid array (eWLB) is a novel packaging technology that shows excellent performance for millimeter-wave (mm-wave) applications. We present simulation and measurement results of single-ended and differential transmission lines realized using the thin-film redistribution layers (RDL) of an eWLB. We demonstrate the capabilities for the integration of passives on example of a configurable 17/18 GHz down-converter circuit realized in silicon-germanium (SiGe) technology with a fan-in eWLB differential inductor used for the LC tank. We compare the performance of differential chip-package-board transitions realized in an eWLB and in other common package types. We report an optimized compact chip-package-board transition in the eWLB. We obtain a simulated insertion loss as low as −0.65 dB and a return loss below −16 dB at 77 GHz without external matching networks. We introduce the concept of antenna integration in the eWLB and show examples of single-ended and differential antenna structures. Finally, we present for the first time a single-chip four-channel 77 GHz transceiver in SiGe integrated in the eWLB package together with four dipole antennas. The presented examples demonstrate that the eWLB technology is an attractive candidate for mm-wave applications including system-in-package (SiP).
A novel 77-GHz directional folded dipole antenna integrated in an embedded wafer level ball grid array (eWLB) package is presented. For the characterization of the antenna a frequency multiplier is embedded, which scales the 4.25-GHz input signal up to 76.5 GHz and allows the use of a commercial signal source. The antenna structure is manufactured at the metallic layer, in the fan-out area of the package, and directly connected to the monolithic integrated frequency multiplier. The gain of the antenna is about 7 dBi, measured over a large bandwidth of about 8 GHz. The combination of the frequency multiplier with the on-package antenna is a promising approach to future radar modules in a single eWLB package for automotive radar applications. Such a module avoids 77-GHz transitions to the PCB and hence simplifies the design and manufacturing of the radar sensor significantly.
The feasibility of an antenna-in-package (AiP) concept is demonstrated for automotive radar sensors at the 77 GHz-band. Infineon's embedded wafer level ball grid array (eWLB) is employed as packaging technology. We developed a printed dipole antenna (PDA) and a printed loop antenna (PLA) in 8×8 mm<sup>2</sup> eWLB packages that include 3×3 mm<sup>2</sup> dummy Si chips. The fabricated eWLB packages are soldered onto evaluation boards that are designed and fabricated on an RF substrate. The measurements and the simulations are in a good agreement and predict a promising solution for the realization of cost efficient antenna-in-package concepts.
We report our recent investigation of a novel uniplanar transition
between microstrip lines and coplanar strips (CPS) which is to be
utilized in our velocity-matched distributed photodetector (VMDP). Both
FDTD simulations and X-band experiments show broadband, low return loss
performance of this newly proposed structure, with a measured 3 dB
insertion loss bandwidth of 68 percent for the case of a balanced
back-to-back microstrip-to-CPS transition
Embedded wafer level ball grid array (eWLB)
- M Brunnbauer
- E Furgut
- G Beer
- T Meyer
Pea-sized mmW transceivers: QFN-based packaging concepts for millimeter-wave transceivers
- T Zwick
- F Boes
- B Göettel
- A Bhutani
- M Pauli
A 77-GHz antenna in package
- fischer