Radio Frequency Test Research Articles

A high throughput facility for the RF characterisation Of planar superconducting thin films

Abstract Accelerator laboratories worldwide are researching copper radio frequency (RF) cavities coated with superconducting thin films to exceed the limits of bulk niobium. The development and RF testing of thin films on small planar samples is vital before cavity depositions. A team at Daresbury Laboratory have developed a cost-effective facility using a novel 7.8 GHz Choke Cavity for the RF characterisation of planar samples. RF chokes ensure that no electrical contact is required between the sample and the cavity. The main advantages are: a simple sample design (90 − 130 mm diameter disk with no sample-cavity welding) and easy operation using a LHe-free cryostat. This enables high sample throughput, with up to 3 sample tests per week, making the facility suitable for quick, systematic scanning of deposition parameters. With the sample thermally and physically isolated from the test cavity, it is possible to measure the average surface resistance, R s, directly using an RF-DC compensation method. Facility commissioning has been performed with bulk and thin film niobium samples. These tests have demonstrated the ability to measure R s at temperatures in the range 4 − 20 K and sample peak magnetic fields up to 3 mT. The minimum resolvable R s is 0.5 μΩ with typical uncertainties of 9 − 15%. The design, operation and commissioning of this facility is reported in this paper.

Continuous Wave Mode Test of Conduction-Cooled Nb3Sn Radio Frequency Superconducting Cavities at Peking University

A liquid helium-free cryostat for radio frequency (RF) test of the superconducting cavity is designed and constructed. Gifford-Mcmahon (G-M) cryocoolers are used to provide cooling capacity, and the heat leakage at 4 K is less than 0.02 W. Vertical and horizontal tests of two Nb3Sn cavities are carried out in the cryostat with different surface treatments outside the cavities. Both of the cavities achieve stable continuous wave (CW) operation. A novel treatment, which cold-sprayed a 3.5 mm thick Cu layer onto the outside of the cavity, enables the maintenance of an average temperature of 5.5 K in the cavity at a RF loss of 10 W, implying that the thermal stability and uniformity of the cavity has been significantly improved. Through the synergistic control of four metal film resistors, a cooling rate of 0.06 K/min near 18 K is realized, and the cavity temperature gradient is reduced to 0.17 K/m, which effectively improves the RF performance of the cavity. The maximum Eacc of the cavity reaches 3.42 MV/m, and the Q0 is 1.1 × 109. An electromagnetic–thermal coupling simulation model for the superconducting cavity is established and is in good agreement with the experimental results. The simulation results show that the cavity with a Cu-spraying treatment and the thermal links of 5N Al can satisfy the Eacc of 10 MV/m under conduction cooling.

Characterizations for eWLB (Embedded Wafer Level Ball Grid Array) Antenna in Molded Package Integrations in 77GHz Automotive Applications

The worldwide IC market has had a significant growth rate in recent years, driving diversified package solutions in the segments of communication, computing, consumer, automotive, industrial, etc. Among these market segments, the automotive market is forecast to have the strongest CAGR (Compound Annual Growth Rate) of any of the end-use segments in the next 5 years, which results in more IC packages and components being designed into automotive vehicle systems such as infotainment, ADAS (Advance Driving Assistance System), instrumentation, body systems, battery control systems and so on. In these applications, the 77GHz short-range radar sensor application that can enable higher EIRP (Effective Isotropic Radiated Power) and adaptive cruise control performance has become more attractive to be commercialized. Due to the benefits of shorter interconnection length, lower conductive loss with smooth Cu surface as well as a lower dielectric constant and dielectric loss of materials in a fan-out wafer level package (FOWLP) technology, the FOWLP is proven as a suitable packaging solution to achieve the high speed and frequency requirements in 5G and mmWave applications. The eWLB Embedded Wafer Level Ball Grid Array) is a versatile FOWLP technology, providing a robust package platform in a space-efficient design with the very dense interconnection and routing of multiple dies as well as a smaller footprint and lower package profile providing a reliable package solution. Meanwhile, since the utilization of an antenna that is integrated into the packages has been studied as a lowcost solution because the packages can be tested in normal FR4 printed circuit board (PCB) instead of the RF function integrated PCB, the eWLB integrated with molded antenna chip packages (called eWLB antenna in molded package) technology is introduced in this paper. The characterizations for assembly process challenges are evaluated and illustrate the process optimizations of equipment handling, antenna molded chip package fabrication, reconstitution process control and warpage characterization of the molded wafer. In addition, the radio frequency (RF) test validation is performed to verify the performance of scattering parameter (S-parameter), radiation pattern, impedance and detection range of the antenna. In order to prove the reliable quality and yield of the evaluated eWLB antenna in molded packages, package-level reliability tests are studied. Through these results, it will show that this eWLB antenna in molded package integration is a robust and costeffective solution for 77GHz automotive applications.

DC‐bias and temperature included CSWPL model for RF power transistors

AbstractA novel frequency domain behavioral modeling method for gallium‐nitride (GaN) devices is presented in this article. By utilizing a multi‐dimensional polynomial function, the proposed technique interpolates DC‐bias voltage and temperature based on the Canonical section‐wise piecewise linear (CSWPL) model framework. A detailed description of the model's theory is provided. With data from 10‐W GaN devices, the model was implemented in commercial software and validated through both DC and radio frequency (RF) tests. A robust predictive ability is demonstrated by the obtained results, thus proving the accuracy of the developed modeling method. This model is superior to the standard CSWPL model in that it is capable of predicting transistor behavior at different bias voltages and temperatures using a single set of parameters, thereby greatly reducing the complexity of the model and the time required for extraction.

Machine Learning based calibration SDR in Digital Twin application

Software-Defined Radios are radio communications devices that have been growing and developing on a larger scale in recent years. Communications are intrinsically embedded in our day by day, thus presenting a higher motivation to use software-defined radios due to its attractive cost. However they present technical limitations. This paper addresses this problem, which is the non-linearity behaviour of gain and frequency in the LimeSDR-USB. That is, this equipment is used to produce a FM signal with an associated frequency and gain before being parameterised according to the internal parameters of each software-defined radio. Each software-defined radio presents a value of frequency and gain of its own, which correlates to the generated signals at the output level. To avoid this, machine learning networks were used, in which networks were trained to adapt to the non-linearity of these devices and correct it without the user noticing. This way, the user sets a desired frequency and gain in a signal, at the output of the software-defined radios, and a neural network calculates which values the software-defined radios should be parameterised, thus mitigating the non-linearity behaviour. This paper presents the evaluation of a laboratory prototype based on low-cost commercial software-defined radios equipment, to replace an expensive metrologically calibrated equipment used for radio frequency tests on a new concept of industrial test station, with description of the integration of Digital Twins, with their physical and virtual parts.

Evaluation the results of electromagnetic compatibility of a prototype device for ear stimulation in patients with tinnitus.

<b><br>Aim:</b> The aim of the study was to evaluate the results of electromagnetic compatibility of a prototype device for ear stimulation in patients with tinnitus.</br> <b><br>Material and methods:</b> The electromagnetic compatibility tests of the prototype device for electro- and magnetostimulation of the hearing organ were carried out at the Center for Attestation and Certification Tests OBAC Sp. z o. o. in Gliwice in 2020. The following product standards were used: PN-EN 60601-1-2:2015-11 - medical electrical equipment (general requirements for basic safety and essential functioning; PN-EN 55011:2012 - industrial, scientific and medical equipment [characteristics of radio frequency disturbances] ) PN-EN 61000-3-2:2014-10 - electromagnetic compatibility (EMC), permissible levels of harmonic current emissions (phase load current ≤ 16 A).</br> <b><br>Results:</b> The level of expanded uncertainty in the measurement of conducted disturbances in the range of 0.150-30MHz does not exceed the level specified in the PN-EN-55016-4-2:2011 standard. In the study of the emission of radiated disturbances up to 1GHz in the frequency range of 30-1000MHz (PN-EN 55011:2012 standard), it was found that the setting of the EUT during the tests was in accordance with the requirements of the standard. The level of expanded uncertainty in the measurement of radiated disturbances in the 30-1000MHz range does not exceed the level specified in the PN-EN 55016-4-2:2011 standard. The measured current harmonic levels (phase power supply current ≤16A) with a frequency range of 50Hz-2kHz do not exceed the permissible levels specified in the PN-EN 61000-3-2:2014-10 standard. The test of resistance to the magnetic field at the frequency of the power grid (PN-EN 61000-4-8: 2010 standard also showed that the setting of the EUT during the tests was in accordance with the requirements of the standard and the result was positive.</br> <b><br>Conclusions:</b> Testing of immunity to radiated radio frequency electromagnetic field (PN-EN 61000-4-3:2007 +A1:2008+A2:2011 standard) and testing of resistance to magnetic field at power frequency (PN-EN 61000-4-8 standard :2010) did not exceed the level specified in the standard and showed a positive result. The measured harmonic levels of the network current (phase supply current ≤16A) with the frequency range 50Hz-2kHz do not exceed the permissible levels specified in the PN-EN 61000- 3-2:2014-10 standard for a class A device.</br&gt.

Effects of RF Magnetron Sputtering Power on the Mechanical Behavior of Zr-Cu-Based Metallic Glass Thin Films.

Zirconium-based metallic glass films are promising materials for nanoelectronic and biomedical applications, but their mechanical behavior under different conditions is not well understood. This study investigates the effects of radio frequency (RF) power and test temperature on the nanostructure, morphology, and creep behavior of Zr55Cu30Al10Ni5 metallic glass films prepared by RF magnetron sputtering. The films were characterized by X-ray diffraction and microscopy, and their mechanical properties were measured by a bulge test system. The results show that the films were amorphous and exhibited a transition from noncolumnar to columnar morphology as the RF power increased from 75 W to 125 W. The columnar morphology reduced the creep resistance, Young's modulus, residual stress, and hardness of the films. The creep behavior of the films was also influenced by the test temperature, with higher temperature leading to higher creep strain and lower creep stress. The findings of this study provide insights into the optimization of the sputtering parameters and the design of zirconium-based metallic glass films for various applications.

Fabrication and RF test of the 500 MHz-RFQ linear accelerator for a transportable neutron source RANS-III

At RIKEN, a transportable accelerator-driven compact neutron source (RANS-III) is under development for an on-site nondestructive inspection of the degradation of old concrete and reinforcing steel. RANS-III consists of an ion source, a low-energy beam transport, a radio frequency quadrupole linear accelerator (RFQ linac), a radio frequency (RF) system, a high-energy beam transport, a target station and a neutron measurement system. Because the inner diameter of the RFQ linac is inversely proportional to the resonance frequency, the resonance frequency of the RANS-III RFQ linac in this study was chosen to be 500 MHz, which is 2.5 times that of the RANS-II RFQ linac. Therefore, the inner diameter and weight of the RANS-III RFQ linac were reduced to approximately half and one third, respectively, of those of the RANS-II RFQ linac. The RANS-III RFQ linac was designed to accelerate a proton beam with a 10 mA peak current and 100 μA average beam current from 30 keV to 2.49 MeV (Journal of Disaster Research 12(3) (2017) 585–592). Based on the evaluations, an RFQ linac for RANS-III was fabricated, and the RF characteristics of the cavity, such as the resonant frequency and electric-field distribution, were measured using a low-power test and tuned using fixed tuners. In addition, RF couplers and RF systems were constructed to inject RF power into the RANS-III RFQ linac, and RF input tests were performed.

Radiofrequency Coils for Low-Field (0.18–0.55 T) Magnetic Resonance Scanners: Experience from a Research Lab–Manufacturing Companies Cooperation

Low-field magnetic resonance imaging (MRI) has become increasingly popular due to cost reduction, artifact minimization, use for interventional radiology, and a better safety profile. The different applications of low-field systems are particularly wide (muscle–skeletal, cardiac, neuro, small animals, food science, as a hybrid scanner for hyperthermia, in interventional radiology and in radiotherapy). The low-field scanners produce lower signal-to-noise ratio (SNR) images with respect to medium- and high-field scanners. Thus, particular attention must be paid in the minimization of the radiofrequency (RF) coil losses compared to the sample noise. Following a short description of the coil design and simulation methods (magnetostatic and full-wave), in this paper we will describe how the choice of electrical parameters (such as conductor geometry and capacitor quality) affects the coil’s overall performance in terms of the quality factor Q, ratio between unloaded and loaded Q, and coil sensitivity. Subsequently, we will summarize the work carried out at our electromagnetic laboratory in collaboration with MR-manufacturing companies in the field of RF coil design, building, and testing for 0.18–0.55 T magnetic resonance (MR) clinical scanners by classifying them between surface-, volume-, and phased-array coils.

Detection and Identification of System Level Soft Failure Induced by Radio Frequency Interference in Small UAV System

A system level methodology is presented for soft failure detection and analysis in small unmanned aerial vehicle (UAV) system, induced by radio frequency interference (RFI). This method includes a radio frequency test system based on the equivalent dynamic test method, and soft failure detection and identification method based on ground control station observation records and system log analysis. By designing signal forwarding system for global positioning system, the equivalent dynamic flight state of the UAV is realized. Through the application of standard radiated susceptibility test methods, the effects of RFI with multiple interference levels covering the frequency range from 2 MHz to 3 GHz on small UAV systems have been investigated. RFI is coupled into the UAV system through the antenna coupling and cable coupling. Soft failure modes are classified and failure analysis is mainly carried out through system log analysis, combined with full-wave simulation analysis, the root cause of the soft failure is determined. The understanding of the soft failure mode and susceptibility is beneficial to the design of UAV system, improving the robustness of software and hardware.

A Systematic Method to Explore Radio-Frequency Non-Thermal Effect on the Growth of Saccharomyces Cerevisiae

Radio frequency (RF) non-thermal (NT) bio-effects have been a subject of debate and attracted significant interests due to potential health risks or beneficial applications. In this work, we report a systematic method for broadband investigation of RF NT effects on <i>Saccharomyces cerevisiae</i> yeast growth. The method includes a transverse electro-magnetic (TEM) device and a dielectric spectroscopy technique for RF frequency selection. A stripline-based TEM device has two 240-<i>&#x03BC;</i>L chambers 3D printed for cell cultures. The fabricated device operates up to a few GHz and produces uniform RF fields for cell exposure testing. A vector network analyzer (VNA) was used to provide &#x2212;20 dBm continuous-wave (CW) RF power. The heating effects on cell growth were estimated to be negligible. Frequency regions, where large permittivity differences between the medium and yeast cultures were obtained and used to select RF testing frequencies, <i>e.g.,</i> 1.0 MHz, 3.162 MHz, 10 MHz. These differences may indicate RF field gradients near cell membrane, and the gradients may affect local nutrient transport. Additionally, RF at 905 MHz is tested for comparison purpose. Yeast cells in the exponential growth phase were examined at four RF frequencies and compared with two controls. One control device held at the same temperature as the test device, while the other control was held at a temperature 1 &#x00B0;C higher. The results showed that the RF fields at 3.162 MHz reduced yeast growth rates by 15.1&#x0025;; however, the RF fields at 1.0 MHz enhanced cell growth by 13.7&#x0025;, while the observed 4.3&#x0025; growth rate increase at 10 MHz is insignificant and the RF fields at 905 MHz had no effects on the cell growth. These results showed a clear RF NT effects on <i>S. cerevisiae</i> growth that was frequency dependent. The hypothesized mechanisms of these effects, i.e., non-uniform RF fields near cell membranes and fluidic diodes in cell membrane ion channels may play important roles in nutrient transport, need to be further investigated.

Radio Frequency Coils for Hyperpolarized 13C Magnetic Resonance Experiments with a 3T MR Clinical Scanner: Experience from a Cardiovascular Lab

Hyperpolarized 13C magnetic resonance (MR) is a promising technique for the noninvasive assessment of the regional cardiac metabolism since it permits heart physiology studies in pig and mouse models. The main objective of the present study is to resume the work carried out at our electromagnetic laboratory in the field of radio frequency (RF) coil design, building, and testing. In this paper, first, we review the principles of RF coils, coil performance parameters, and estimation methods by using simulations, workbench, and MR imaging experiments. Then, we describe the simulation, design, and testing of different 13C coil configurations and acquisition settings for hyperpolarized studies on pig and mouse heart with a clinical 3T MRI scanner. The coil simulation is performed by developing a signal-to-noise ratio (SNR) model in terms of coil resistance, sample-induced resistance, and magnetic field pattern. Coil resistance was calculated from Ohm’s law and sample-induced resistances were estimated with a finite-difference time-domain (FDTD) algorithm. In contrast, the magnetic field per unit current was calculated by magnetostatic theory and a FDTD algorithm. The information could be of interest to graduate students and researchers working on the design and development of an MR coil to be used in 13C studies.

Investigations on the Use of Ensemble Methods for Specification-Oriented Indirect Test of RF Circuits

In order to reduce the costs of industrial testing of analog and Radio Frequency (RF) integrated circuits, a widely studied solution is indirect testing. Indeed, indirect testing is based on learning-machine algorithms to train a regression model that links the space of low-cost indirect measurements to the space of performance parameters guaranteed by datasheets, thus relaxing the constraints on expensive test equipment. This article explores the potential benefit of using ensemble learning in this context. Unlike traditional learning models that use a single model to estimate targeted parameters, ensemble-learning models involve training several individual regression models and combining their outputs to improve the predictive power of the ensemble model. Different ensemble methods based on bagging, boosting or stacking are investigated and compared to classical individual models. Experiments are performed on three RF performances of a LNA for which we have production test data and model quality is discussed in terms of goodness-of-fit, accuracy and reliability. The influence of the training set size is also explored. Finally, the efficiency of classical and ensemble models is compared in the context of a two-tier test flow that permits to tradeoff test cost and test quality.

Characterization of a COTS-Based RF Receiver for Cubesat Applications.

This paper reports the experimental results of a test campaign performed on the radio-frequency (RF) receiver prototype operating at a 2025–2110 MHz frequency range, designed and fabricated for CubeSat applications. The prototype has been tested through a board-level test approach for the verification of the functional requirements and a component-level one for specific characterization measures. The tests have shown the following results: a −115–−70 dBm sensitivity range, 390 MHz intermediate frequency, a 0 dBm output power level with ±1 dB error, a 2.34 dB noise figure, and a 4.86 W power absorption. Such results have been largely achieved implementing an automatic gain control system by cascading two Commercial Off-The-Shelf (COTS) amplifiers. Moreover, an innovative technique based on RF test points has been successfully experimented and validated to measure the S-parameters of a custom low-pass filter integrated on the receiver, showing the possibility of even characterizing the single COTS components exposed to radiation through a unique board-level test setup. The technique may have a great impact on the cost reduction of electronic boards for space applications, since it would avoid using expensive evaluation boards for each COTS component that needs a radiation test.

Towards light weight multifunctional hybrid composite housing for satellite electronics

The present paper provides an overview of the fabrication and testing of multifunctional hybrid composite radio frequency (RF) electronic housing for satellite applications. An oversized hybrid composite block containing carbon fiber (CF) and multiwall carbon nanotubes (MWCNTs) as reinforcement in epoxy matrix were fabricated through hand layup and compression molding technique. Fabricated block was machined to desired size and shape to form multifunction hybrid composite housing for satellite electronics. DC electrical resistivity was measured on sample panels to assess the influence of MWCNTs on CFRP and 30 times decrease in volume resistance was observed. EMI shielding effectiveness (SE) and Radiated Emission Electromagnetic Compatibility (EMC) tests were performed on developed prototype RF electronic housing. Results showed that the addition of MWCNT in CFRP has increased the overall electrical conductivity leading to higher EMI SE than neat CFRP without MWCNTs. Moreover, the developed electronic unit also qualified the RE EMC test in 10 kHz to 18 GHz range. The increment in electrical characteristics was attributed to formation of MWCNTs conductive network inside the epoxy matrix. Hybrid composite housing was also subjected to vibration test and compared with aluminum alloy (AA 6061-T6) housing, which is typically used in satellite structure. Finite element analysis (FEA) for vibration test was also carried out on both housings and obtained results are in great agreement with experimental findings. It can be concluded that hybrid composite housing can replace the metallic counterpart with an added advantage of 50% lighter in weight for satellite electronics applications.

Development and testing of radio frequency modulated electron Gun at VECC, Kolkata

A superconducting electron linac (e-Linac) photo-fission driver is under construction at VECC for the upcoming rare isotope beam facility called ANURIB. The first stage consists of an injector linac based on 1.3 GHz superconducting radio frequency technology designed for accelerating 10 MeV, 2 mA CW electron beam. An rf modulated thermionic electron gun (E-Gun) has been developed and tested for this injector linac. The E-Gun will allow continuous beam operation up to 300 keV with around 3 pC charge per pulse at 650 MHz. Electron beam with RF modulation is extracted from the gun and intensity, energy, size of the DC beam as well as trans-conductance of the electron source are measured. The design of some major components for the electron gun and low energy beam transport line is discussed and results of beam tests are presented.

European XFEL Superconducting Cryomodules Characterization Toward Modules Acceptance and Future LLRF Operation

This paper describes some achievements of the low-level radio frequency (LLRF) tests performed to evaluate the superconducting cryomodules in preparation of their installation in the European X-ray Free Electron Laser (XFEL) accelerator. The software developed to characterize the cryomodules tested at the Accelerator Module Test Facility (AMTF) will be presented. The purpose of these tests is to evaluate some of the key parameters of the eight Tera Electronvolt Superconducting Linear Accelerator cavities, housed in every cryomodule. These parameters include: cavity quench gradients, cavity fundamental resonant modes, performance of the slow and fast frequency tuners, and characteristics of the input power coupler. These results impact the final decision on the cryomodule acceptance and its installation inside the linear accelerator (linac). In this approach, the MicroTCA.4-based LLRF system is used to control and assess the cryomodule performance. Middle layer servers are developed to verify the tests initial conditions, carry the test, and log the results in a dedicated database. The tests results provide a basis for the cryomodule validation, but also serve as a reference useful during the commissioning and operating phase of the accelerator.

Analysis and Experimental Test of Electrical Characteristics on Bonding Wire

In this paper, electrical characteristic analysis and corresponding experimental tests on gold bonding wire are presented. Firstly, according to EIA (Electronic Industries Association)/JEDEC97 standards, this paper establishes the electromagnetic structure model of gold bonding wire. The parameters, including flat length ratio, diameter, span and bonding height, were analyzed. In addition, the influence of three kinds of loops of bonding wire is discussed in relation to the S parameters. An equivalent circuit model of bonding wire is proposed. The effect of bonding wire on signal transmission was analyzed by eye diagram as well. Secondly, gold bonding wire design and measurement experiments were implemented based on radio frequency (RF) circuit theory analysis and test methods. Meanwhile, the original measurement data was compared with the simulation model data and the error was analyzed. At last, the data of five frequency points were processed to eliminate the fixture error as much as possible based on port embedding theory. The measurement results using port extension method were compared with the original measurement data and electromagnetic field simulation data, which proved the correctness of the simulation results and design rules.

Radio Frequency Processing of Radio Frequency Power Coupler for Quarter Wave Resonator in Rare Isotope Science Project

Radio frequency (RF) power couplers for quarter wave resonators (QWR) have been developed for rare isotope science project (RISP) in Daejeon Korea. The power coupler is required to deliver up to 2 kW RF power at 81.25 MHz to the QWR cavity in continuous-wave (CW) mode. The prototype of QWR RF power couplers are fabricated and tested. The coupler test bench has been developed in order to conduct RF processing. The RF processing consists of two section, pulse mode and CW mode. The multipaction (MP) band of the QWR coupler has been measured during RF processing. After the RF processing, the RF test has been performed keeping 2.0 kW RF power during 8 hours. As the results of the RF test, the prototype of couplers for QWR has been qualified to assemble with the cavity for cryomodule test.

Synthesis and Use of Bio-Based Dielectric Substrate for Implanted Radio Frequency Antennas

Equipped with precision sensors/antenna modules combined with integrated processing and telemetry circuitry, wireless implants that are both biocompatible and biodegradable are important devices for monitoring patient’s conditions and patient’s safety. In this article we report on the development, design, and testing of a bio-based monopole radio frequency (RF) sensor/antenna module for potential use in human health applications. The module is built on a dielectric substrate biocomposite made of 0.5:1.0 ratio of polylactic acid (PLA) to sunflower carbon substrate (SCS) produced via pyrolysis of seeds shells. Findings for the SCS include optimized reactor yields around 7.9 wt.% at 500°C, a 0.27:1.0 fixed to elemental carbon content, dielectric constant near 3.4, loss factor between 0.0 and 0.4 measured in the 1 to 6 GHz frequency range. The PLA-SCS biocomposite exhibited comparable dielectric properties to those of pure SCS, a 17% elastic modulus increase, and over 500% increase in hardness. Numerical simulation of the designed sensor/antenna module agreed fairly well with the experimental validation results. Tests of the fabricated sensor/antenna module on water, soil and muscle tissue phantom, as well as implanted inside muscle tissue phantom, via the reflection coefficient (S11) and in a communication link via the transmission coefficient (S21) confirmed use and applicability of the developed antenna.