The temperature dependence of the dielectric parameters of tissues and tissue-mimicking phantoms is very important for non-invasive temperature measurement in medical applications using microwaves. We performed measurements of this dependence in the temperature range of 25?50°C using distilled water as a reference liquid commonly used in dielectric property studies. The results were compared with

A miniature dual-band bandpass filter with interlocked stepped-impedance resonators (SIRs) is presented in this paper, which was designed for the student design competition held in European Microwave Week 2019. This bandpass filter is required to have two concurrent passbands, namely, the first passband at 900?1000 MHz and the second passband at 1427?1518 MHz bands, which cover six designated band

In this paper, an orthogonal frequency-division multiplexing (OFDM) waveform radar sensing approach is demonstrated based on field measurements at C-band. We demonstrate a concept that is based on the exploitation of typical wireless communication transmissions to perform passive, distributed radar sensing. Our concept is based on an OFDM radar that operates in the modulation symbol domain and can

This paper presents a high-efficiency linear GaN K-band transmitter for broadband high peak-average power ratio (PAPR) signals. A GaN MMIC 18.5?24 GHz three-stage power amplifier with over 4 W peak output power, 20 dB saturated gain, and 40% peak PAE is supply-modulated with a four-level discrete dynamic supply GaN MMIC. For 100 MHz signals with , we demonstrate an average efficiency improvement f

In this paper, different techniques for the generation of additional transmission zeros (TZs) in planar waveguide filters are investigated. In the classical theory, TZs are generated only by destructive interference of non-adjacent cavities, limiting the available number of TZs to the filter order itself. However, more approaches for the generation of TZs are known, including bypass-coupling in ov

High-order sub-harmonically injection-locked oscillators have recently been proposed for low phase-noise frequency generation, with carrier-selection capabilities. Though excellent experimental behavior has been demonstrated, the analysis/simulation of these circuits is demanding, due to the high ratio between the oscillation frequency and the frequency of the input source. This work provides an a

This paper presents a notched band ultra-wideband bandpass filter using a single perturbed quint-mode half-mode substrate-integrated waveguide cavity. The cavity is perturbed by loading four stubs at two corners of the magnetic walls of the single cavity. The variable parameters of stubs are selected to move down the first five resonant modes to the predetermined passband during the design process

This paper presents a compact octagonal array of microstrip patch antennas for direct broadcast satellite (DBS) (12.2?12.7 GHz) services. The proposed single element of this array is a new fractal antenna, having considerably high gain and can heavily suppress cross polarization along the main beam direction. The single element is derived from a 2D spiral geometry. The corporate feed network of th

For the requirements of low mutual-coupling MIMO antennas for WLAN, a new complementary split-ring resonator (CSRR) unit cell is introduced in this paper. A microstrip-fed Vivaldi antenna array is designed for WLAN applications, where compact triple-band gap-complementary split-ring resonator unit cells are loaded between two antennas to examine the effect of unit cells on the rate of mutual-coupl

The goal of this study is to analyze the specific absorption rate (SAR) distribution of the projected 5G frequencies below 6 GHz and at Wi-Fi frequency (2.45 GHz) on a human head, for eyewear device applications. Two separate tri-band printed dipole antennas for this purpose are designed and fabricated at operating frequencies of 2.45/3.8/6 GHz for prototype-1 and at operating frequencies of 2.45/

In this paper, a novel alternating direction method of multiplier (ADMM) is proposed to solve the inverse scattering problems. The proposed method is suitable for a wide range of applications with electromagnetic detection. In order to solve the internal ill-posed problem of the integral equation and make the reconstructed images more closer to the ground truth, first, the augmented Lagrangian met

In this paper, an algorithm for extracting and localizing a radar pulse in a noisy environment is described. The algorithm combines two powerful tools: wavelet denoising and the short-time Fourier transform (STFT) analysis with statistical-based threshold. We aim to detect radar pulses transmitted by any radar in blind mode regardless of the intra-pulse modulation and parametric features. The use

In the first part, the scattering characteristics of an isolated dielectric coated conducting rod have been investigated. The types of considered coatings for the scattering analysis are realistic materials including barium strontium titanate, magnetodielectric, gallium arsenide, and silicon carbide. It is found that the gallium arsenide coating can be used to significantly reduce the scattering f

A four-way suspended-stripline power divider is presented in this letter. The power dividing network is designed by using the suspended stripline, while the isolation network is designed by using the microstrip line. The vias are used to connect the power dividing network and the isolation network. The even- and odd-mode analysis method is applied to design the presented power divider. The simulat

The airborne radomes have to cater superior electromagnetic (EM) performance with bandpass characteristics of stealth application. In this regard, a hybrid A-sandwich radome is proposed in this paper. The proposed radome consists of a novel strongly coupled frequency selective surface (FSS) core sandwiched between two dielectric layers (acts as skin) to form an A-sandwich structure. The dielectric

This paper presents the filter design in the student design competition of EuMW 2019. This contest motivates students for the design and implementation of a dual-band bandpass filter able to get outstanding performance, where different implementation technologies, such as microstrip, coplanar, multilayer microstrip, substrate integrated waveguide, and some others can be effectively employed. Filte

The effective resistivity () is a figure of merit commonly used to assess the radio-frequency performance of a substrate from the measurements of coplanar waveguide lines. For highly resistive substrates, such as the trap-rich (TR) substrate, the extracted decreases by several orders of magnitude at millimeter-wave frequencies. The explanation for this decay is twofold. First, the imaginary part

This paper reports on quasi-elliptic dual-band bandpass filters (BPFs) that were designed for the Filter Student Design Competition of the 2019 European Microwave Week. The proposed lumped-element (LE) BPF concept is based on two dual-band transversal cells and one multi-resonant cell that allow the realization of symmetric and asymmetric dual-band transfer functions shaped by six poles and five t

Electromagnetic scattering from the sea surface is of great significance in radar detection, target recognition, ocean remote sensing, etc. By introducing the action spectrum, the modified spatio-temporal variation wave spectrum is used to establish a nonlinear sea surface with currents in this paper. Traditional capillary wave modification facet scattering model (CWMFSM) can only calculate the ba

This paper proposes a differential sensor based on a pair of open split ring resonators (OSRR) operating in reflection. The output signal is thus the differential reflection coefficient of both resonators, intimately related to their dielectric loading. Thus, for identical loads in both sensing resonators, the individual reflection coefficients are equal, thereby providing an ideally null output s