Table 1 - available via license: Creative Commons Attribution 4.0 International
Content may be subject to copyright.
Source publication
This paper proposes the stepped coaxial line sensor using the reflection coefficient in microwave range for complex permittivity measuring. The proposed probe is adapted from the conventional SMA connector which is cheap and easy to fabricate. The analysis model of the probe has been done by using FDTD method with the reference material such as the...
Context in source publication
Context 1
... cutting plane in Figure 1(b) is the interconnection of the con- ductor of the semi-rigid cable and the SMA connector. All dimensions of the probes are presented in Table 1, which are based on the size of the commercial micro- wave cable and connectors. Figure 2 shows the photo- graphs of probes. ...
Citations
... Other approaches can be used to derive the dielectric permittivity of food materials. For instance, inverse scattering procedures, guided-wave approaches, or transmission/reflection (T/R) techniques have been implemented [23], [24], [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39], [40], [41], [42], [43]. Even though several devices and methodologies are available, none of them can be immediately applied to the challenging goal of estimating the dielectric permittivity of the Carasau bread doughs during their industrial production. ...
... From the measurement of the scattering parameters, the complex dielectric constant is derived and, accordingly, the desired properties. The authors in [40] and [41] reported a method to measure the dielectric constant of a liquid material under test based on the measurement of the return loss (S 11 ). In [42], a two-port coaxial sensor is used to calculate the scattering parameters, which were converted to electrical parameters using the Nicolson, Weir, and Ross method, and then a least-square problem is imposed for the extraction of the dielectric constant. ...
Food quality is crucial in today's processing industry. The organoleptic properties of most foods materials are known to depend on their water content. The monitoring of food quality and moisture content calls for engineering solutions. To this aim, given their non-destructive nature and cost-effective features, microwave sensors are a valuable tool. However, for some peculiar food processing industries, suitable engineered microwave devices must be designed. Therein, we will focus on the case of Carasau bread industry. Carasau bread is a typical food product from Sardinia (IT). In this work, we will present the design, realization and characterization of a coaxial fixture, working between 0.5 and 3 GHz, for the determination of the complex dielectric permittivity of Carasau bread dough. Through a non-linear regression model based on particle swarm optimization routine, the scattering parameters are used to retrieve the electromagnetic properties of bread doughs. By making a comparison with the complex dielectric permittivity measured with an open-ended coaxial probe, an average error of 3% for the real part and 6% for the imaginary part have been found. The proposed device is driven by a Raspberry Pi that controls the acquisition of a Pocket-VNA, thus representing a cost-effective electronic system for industrial applications.
... A synthetic MRIbased head phantom has been fabricated and presented in [24] for MRI imaging purposes. They fabricated only white matter, gray matter, and CSF tissues by using various concentrations of copper sulfate (97.5% purity) and normal saline, but there were no measured outcomes for the dielectric properties of head tissues [25,26]. As a result, it is not guaranteed that it will be suitable for microwave head imaging applications. ...
... A synthetic MRIbased head phantom has been fabricated and presented in [24] for MRI imaging purposes. They fabricated only white matter, gray matter, and CSF tissues by using various concentrations of copper sulfate (97.5% purity) and normal saline, but there were no measured outcomes for the dielectric properties of head tissues [25,26]. As a result, it is not guaranteed that it will be suitable for microwave head imaging applications. ...
The paper presents the preparation and measurement of six-layered human head phantoms for the sensor-based microwave brain imaging system (SMBIS) for the diagnosis of tumors in the head. The head phantom has been constructed based upon three-dimensional arrangements filled-up with numerous biochemical combinations that imitate the six brain tissues: DURA, CSF, White Matter, Gray Matter, Fat, and Skin regarding permittivity within the wideband frequency band (1 GHz to 4 GHz). For imaging purposes, the malignant and benign tumor(s) are also fabricated and placed in different locations in the 3D skull model to validate the performance of the phantom. After being formulated, the dielectric properties are measured by utilizing a dielectric kit linked with a vector network analyzer. The measured dielectric properties are compared to real human head tissue’s dielectric properties. After that, the human phantom model, including tumors, is validated using a SMBIS. The investigational dielectric characteristics of the brain tissues showed good agreement with the dielectric properties of the real brain tissues of the head. The experimental imaging outcomes demonstrated the legitimacy of the proposed six-layered tissue mimicking phantoms that can be used as an alternate to the actual human brain tissue for the diagnosis of brain tumors in SMBIS.
... From the equivalent circuit of the proposed sensor, is the capacitance independent of the material and is the capacitance of the capacitor filled with the air. The admittance ( Y ) of this sensor depends on the complex relative permittivity ( ) of material as in Equation (6) [20][21][22]: ...
... From Equations (6) and (7), the relationship of the complex relative permittivity and reflection coefficient can be derived by measuring the three reference materials with From the equivalent circuit of the proposed sensor, C f is the capacitance independent of the material and C 0 is the capacitance of the capacitor filled with the air. The admittance (Y) of this sensor depends on the complex relative permittivity (ε r ) of material as in Equation (6) [20][21][22]: ...
A detection system for water adulteration in honey is proposed. It consists of a modified
SMA-connector sensor and a vector network analyzer. A modified SMA-connector sensor is applied to measure complex relative permittivity, electrical conductivity, and phase constant of honey samples with the open-ended method. The system is tested in the frequency range of 0.5–4.0 GHz at the sample temperature of 25 ◦C. The relationships between the complex relative permittivity, electrical conductivity, the phase constant, and the honey samples with different concentrations (0–30%w/w) are determined. The experimental results show that the real part of the complex relative permittivity is significantly proportional in honey samples with adulteration of water in the range of 0–30%w/w. The frequency of 0.6 GHz is a suitable frequency for detection with a real part of complex relative permittivity as an indicator. The frequency of 3.74 GHz is an appropriate frequency for detection
with electrical conductivity as in indicator while the frequency of 4.0 GHz is suitable for detection
with phase constant as an indicator. In addition, the data are analyzed with regression analysis.
This technique is also performed on natural latex samples to determine the dry rubber content. The frequency of 0.5 GHz is a suitable frequency with a real part of complex relative permittivity as an indicator while the frequency of 4.0 GHz is a suitable frequency with an imaginary part of complex relative permittivity, electrical conductivity, and phase constant as the indicators. The results demonstrate that it is possible to apply this technique to determine the dry rubber content in the natural latex samples as well.
... The measurement of the dielectric constant (Dk) and loss tangent (Tan δ) are conducted by using a dielectric probe from KEYSIGHT 85070E Dielectric probe kit with the software of 85070 to be installed with PNA-L N5232A 300KHz to 20 GHz Vector network analyzer (VNA). The probe test is indicated as one of the most popular and easy to use the method to obtained the [4]- [6], with the testing method considered as a non-destructive test that unaffected the measuring substrate with the capability of the probe method measurement is up to 20 GHz [7].As stated in [8], the previous researchers discovered that the water absorption rate for wood plastic composite (WPC) that used (oil palm decanter cake) with polypropylene (PP) alias between the average of 0.16 to 0.44 (different composition). In that previous research also, the conclusion discovered that the water absorption rate proportionates with composition increments. ...
This paper contributes the dielectric properties measurements on five mixture of biocomposite antenna substrates in water immersion condition. The fabrications process of the biocomposite antenna substrate uses the compounding flat press method between the Polypropylene acting as laminator and stem three of Leucaena Leucocephala as a filler. The dielectric properties measurements conducted by using the KEYSIGHT 85070E coaxial probe method, with the observe frequency range of 1 GHz to 20 GHz and ASTM D570 procedure for water immersion process. The percentages of the water absorption rate reported 0.026 % (PP100), 0.18 % (PB9010), 0.22 % (PB8020), 0.28% (PB7030) and 0.35 (PB6040), while the changes of the dielectric properties reported increase 10.31 % (PP100), 11.16 % (PB9010), 15.48 % (PB8020), 23.60 % (PB7030) and 36.35 % (PB6040) when compared with the dielectric properties measurements before 24 Hours ASTM D570 water immersion procedure. The changes of the water absorption rate and dielectric properties percentages in line with the increments of filler composition mixture. The data from this measurement useful to observe the aging shielding capability of the material against water and moisture content absorption for antenna substrate material.
... A dielectric probe from KEYSIGHT modeled as 85070E dielectric probe kit, operated by the 85070-software installed with PNA-L N5232A (300 KHz to 20 GHz), Vector network analyzer (VNA) is used to measure the dielectric constant (Dk) and loss tangent (Tan δ). The probe test is considered as one of the most popular and easy to use the technique to get the dielectric properties [38]- [40], which is considered as a non-destructive test that does not affect measuring substrate with the capability of the probe method measurement up to 20 GHz [41]. First, the probe is calibrated with 25 cm3 of sterile water. ...
In this research article, the preparation and measurement of a set of human breast phantoms for microwave breast imaging (MBI) as a method of tumor detection are presented. The developed artificial breast phantoms have realistic dielectric properties. Homogenous and most realistic heterogeneous breast phantoms have been fabricated based upon 3D structures filled up with different chemical mixtures that imitator the various breast tissue types (skin, healthy fat tissue, glandular tissue, and tumor tissue) regarding permittivity over ultra-wideband (UWB) frequency band (3.1-10.6 GHz). The primary challenge in fabricating such phantoms is in developing suitable mixtures of materials to emulate those properties across the frequency band of interest in hyperthermia and to fabricate the phantom with realistic anatomy. Once fabricated, the dielectric properties are measured using a dielectric probe connected with a modern vector network analyzer (VNA). The measured dielectric is compared to real human breast dielectric properties, and the primary imaging results are presented. The integrated design of the homogenous and heterogeneous phantoms permits to combine dynamically the tumor and breast phantoms for creating a test platform based on MBI systems. The experimental dielectric properties of the phantoms show good agreement with the literature and theoretical results. The Phantoms are constructed in such a way and the chosen materials demonstrate the properties to be stable over a long period. The experimental results demonstrate the validity of our proposed phantoms to be used in investigating as a supplement to the real human breast tissue with multiple object and comparatively high-resolution image.
... Measurements of the dielectric constant (Dk) and loss tangent (Tan δ) are conducted. The probe test is indicated as one of the most popular and easy to use methods to obtain the dielectric properties [40][41][42], and it is considered as a non-destructive test that doesn't affect the measuring substrate with a probe method measurement capability of up to 20 GHz [43]. ...
Microwave breast imaging has been reported as having the most potential to become an alternative or additional tool to the existing X-ray mammography technique for detecting breast tumors. Microwave antenna sensor performance plays a significant role in microwave imaging system applications because the image quality is mostly affected by the microwave antenna sensor array properties like the number of antenna sensors in the array and the size of the antenna sensors. In this paper, a new system for successful early detection of a breast tumor using a balanced slotted antipodal Vivaldi Antenna (BSAVA) sensor is presented. The designed antenna sensor has an overall dimension of 0.401λ × 0.401λ × 0.016λ at the first resonant frequency and operates between 3.01 to 11 GHz under 10 dB. The radiating fins are modified by etching three slots on both fins which increases the operating bandwidth, directionality of radiation pattern, gain and efficiency. The antenna sensor performance of both the frequency domain and time domain scenarios and high-fidelity factor with NFD is also investigated. The antenna sensor can send and receive short electromagnetic pulses in the near field with low loss, little distortion and highly directionality. A realistic homogenous breast phantom is fabricated, and a breast phantom measurement system is developed where a two antennas sensor is placed on the breast model rotated by a mechanical scanner. The tumor response was investigated by analyzing the backscattering signals and successful image construction proves that the proposed microwave antenna sensor can be a suitable candidate for a high-resolution microwave breast imaging system.
... The measured Y admittance is 1.71*10 -3 + j*2.72*10 -2 at the frequency operation of 931MHz, the calculated C 0 and G 0 are 5.96*10 -14 and 8.94*10 -9 , respectively. These parameters are referenced from the experiments [2] under a 25 º C temperature. From the equation (24) the initial value is ε c (0) = 78.0177 ...
... From the Table I Next, we test the calculation at three temperatures to compare to the calculation in [2] reference. ...
... (a) Photograph of the SMA probe, the copy right[2]. ...
This paper describes basic mechanisms to solve a complex permittivity of a nonlinear equation from the open-ended probe measurement in biomedical tissue. It's basic conception to solve and study the higher order nonlinear equations in biomedical engineering fields. The mechanisms are proposed the step-by-step as follows. Firstly, the equation is represented as complex function. Then, Newton's method is used to calculate the complex permittivity. The calculation, concerned parameters of the equation are obtained from an experiment of a reliable reference.
... However, they are used at microwave frequencies to determine the reflection coefficient for lossy mediums such as water [16]. This method requires a prior calibration due to the two wire measurement principle causing parasitic effects and has been reported to exhibit a maximum accuracy of 94% at 1 GHz and 80% at 2.45 MHz [17]. However, it has been shown that ε r can potentially be measured with interdigitated dielectrometry sensors (IDS) [18]- [22] in order to facilitate an on-line measurement system. ...
An accurate measurement of the relative permittivity, εr, of industrial oils using interdigitated dielectrometry sensors (IDS) is challenging due to the parasitic capacitance caused by the IDS spatial structure. In this paper, the investigated IDS structure consists of a substrate, a ground plane, an insulating layer below the electrodes and a soldermask above the electrodes having a periodicity of λ. This structure was simulated to determine the influence on the expected values of capacitance C, sensitivity S and deviation D (accuracy) for typical values of εr for industrial oils. It is shown that for particular structure ratios and values of εr, the parasitic capacitance can be compensated in order to provide an accurate measurement of εr. A standard rapid and cost efficient printed circuit board (PCB) technology is used to manufacture an IDS based on the simulations to verify the expected high accuracy in practice. Experiments conducted with this IDS structure on both new and degraded oils showed a high accuracy ≈ 99.5 %, verifying the simulations. These results have the potential to reduce the number of IDS design iterations in order to carry out highly accurate and precise measurements. This may go beyond the in-situ monitoring of oil degradation such as a number of related sensing applications employing interdigitated sensor platforms.
... The measurement of the dielectric constant (Dk) and loss tangent (Tan δ) are conducted by using a dielectric probe from KEYSIGHT 85070E Dielectric probe kit with the software of 85070 to be installed with PNA-L N5232A 300KHz to 20 GHz Vector network analyzer (VNA). The probe test is indicated as one of the most popular and easy to use the method to obtained the [4]- [6], with the testing method considered as a non-destructive test that unaffected the measuring substrate with the capability of the probe method measurement is up to 20 GHz [7].As stated in [8], the previous researchers discovered that the water absorption rate for wood plastic composite (WPC) that used (oil palm decanter cake) with polypropylene (PP) alias between the average of 0.16 to 0.44 (different composition). In that previous research also, the conclusion discovered that the water absorption rate proportionates with composition increments. ...
