Figure - available from: Microwave and Optical Technology Letters
This content is subject to copyright. Terms and conditions apply.
Source publication
This letter proposes a high isolation two‐element multiple input multiple output (MIMO) antenna by using a wideband pixel neutralization line (NL). The design procedures are simplified as follows: (1) Obtaining the Y‐parameters of the original two‐element antenna with a grid of microstrip stubs, and discrete ports are inserted among microstrip stub...
Similar publications
Ziel der vorliegenden Arbeit ist die Entwicklung eines bildgebenden Radarsystems für die Füllstandmessung von Schüttgütern. Hierzu wird zunächst das räumliche Auflösungsvermögen von Radarsystemen mit mehreren Sende- und Empfangskanälen (engl. Multiple Input Multiple Output (MIMO)) analysiert und eine effiziente Signalverarbeitung vorgestellt. Ansch...
Citations
... Optimizing the configuration and arrangement of antenna elements within the array to achieve desired radiation patterns, beam steering capabilities, and side lobe suppression [9], utilizing multilayer stack configurations to add functionalities such as polarization diversity, frequency selectivity, and impedance matching [10,11]; mutual coupling often deteriorates an antenna array's radiation characteristics, to mitigate this, the element separation should be at least λ/2 (from center to center) to avoid mutual coupling and grating lobes [12], techniques to reduce mutual coupling include implementing electromagnetic band gap (EBG) structures [13], applying neutralization techniques [14], integrating stub transitions into the feeding microstrip line [15], etching slots or slits into the ground to create Defected Ground Structures (DGS) [16,17]. ...
This study focuses on creating and analyzing pentagonal microstrip patch antenna arrays with one, two, and three elements for use in the 10 GHz X-band range, utilizing a metamaterial (MTM) superstrate technique. The MTM superstrate, composed of open circular ring cells, is tailored for a 1×2 array with a 10×8 cell arrangement covering an area of 45×36 mm². A 1×3 array has a 14×12 cell configuration spanning 63×54 mm². Positioned beneath the radiating elements and optimized with a quarter-wave transformer for impedance matching, the superstrate significantly enhances antenna performance. The MTM superstrate alters the radiation pattern and increases the gain by approximately 2 dB, demonstrating a gain improvement of around 27% for high-gain applications in the X-band frequency range. For the 1×2 array, the gain increases from 7.52 dB to 9.58 dB, representing a 27.38% improvement, while the input reflection coefficient improves from -48.6 dB to -58.068 dB, reflecting a 19.5% enhancement. Similarly, for the 1×3 array, the gain rises from 9.69 dB to 11.6 dB, showing a 19.73% increase, and the input reflection coefficient improves from -57.46 dB to -60.64 dB, indicating a 5.54% improvement and a good radiation efficiency of about 79.11%. This work involves designing and simulating the proposed antenna arrays using the Computer Simulation Technology (CST) software.
... Until now, there are many methods to improve the isolation of the antenna layer, including spatial multiplexing [12], polarization diversity [13][14][15] physical isolation [16], near-field cancellation [17,18], mode orthogonality [19,20], defected ground structure (DGS) [21], electromagnetic band gap (EBG) [22], neutral line [23], array layout [24], antenna decoupling surface [25], and so on. Several co-circular polarization (Co-CP) MSTAR antennas with identical right-handed circular polarization (RHCP) or left-handed circular polarization (LHCP) radiation for transmit and receive have been considered in the past [10,17,18,20,26]. ...
... Hence, our task is to focus on reducing the two more strongly coupled paths and , which come from the horizontal and vertical directions of the antenna, respectively. Considering that the volume of the MSTAR antenna cannot be increased, the planar EBG and DGS techniques are used to suppress the coupling between transmit and receive in the horizontal and vertical directions and have been extensively demonstrated in the literature (e.g., [21,22]). ...
Separated transmit and receive antennas are employed to improve transmit-receive isolation in conventional short-range radars, which greatly increases the antenna size and misaligns of the transmit/receive radiation patterns. In this paper, a dual circularly polarized (CP) monostatic simultaneous transmit and receive (MSTAR) antenna with enhanced isolation is proposed to alleviate the problem. The proposed antenna consists of one sequentially rotating array (SRA), two beamforming networks (BFN), and a combined decoupling structure. The SRA is shared by the transmit and receive to reduce the size of the antenna and to obtain a consistent transmit and receive pattern. The BFN achieve right-hand CP for transmit and left-hand CP for receive. By exploring the combined decoupling structure of uniplanar compact electromagnetic band gap (UC-EBG) and ring-shaped defected ground structure (RS-DGS), good transmit-receive isolation is achieved. The proposed antenna prototype is fabricated and experimentally characterized. The simulated and measured results show good agreement. The demonstrate transmit/receive isolation is height than 33 dB, voltage standing wave ratio is lower than 2, axial ratio is lower than 3 dB, and consistent radiation for both transmit and receive is within 4.25–4.35 GHz.
... Table 2 compares this work with the existing conventional decoupling schemes. Compared to the results of Cheng et al. 3 and Li et al., 5 we have implemented a simpler decoupling scheme. Additionally, compared to the results of Sun et al. 8 and Zhang et al., 9 we have further explored decoupling between asymmetric antennas that work in the same frequency band. ...
This article proposes a method to solve the decoupling problem between asymmetric antennas based on common mode and differential mode cancellation theory. The coupling between two asymmetric antennas can be analyzed and mitigated by exciting two signals simultaneously. To verify the feasibility of this theory, a pair of asymmetrically coupled planar inverted‐F antennas are proposed in this paper. Simulation and experimental results show that this method provides a good theoretical foundation for decoupling between asymmetric antennas. Compared with traditional decoupling techniques, it can obtain good performance, and the design scheme is simple and easy to implement.
This paper proposes a novel decoupling technique achieved by adjusting the position of feeding probes of antennas. Two inherent radiation modes (patch mode and monopole mode), with different patterns and polarizations, are simultaneously excited by the same feeding probe. High isolation is realized based on manipulating the relationship of two-mode couplings by moving the feeding positions. Since the two radiation modes are generated by the same antenna element, the proposed MIMO antenna features a simple structure and compact size. For verification, a two-element array with center-to-center spacing of 0.404 λ0 (λ0 is the wavelength in the air) is prototyped and characterized. Simulation and experimental results show that the proposed novel technique can offer higher port isolation (>18.1 dB), increased efficiency (>70%), and a lower envelope correlation coefficient (ECC < 0.1) in the operating frequency band (11.61–12.49 GHz).
