Presents the table of contents for this issue of the publication.

Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.

This Inaugural Special Issue of IEEE Microwave and Wireless Components Letters (MWCL) includes 51 papers from the 2021 IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium (IMS), Atlanta, USA, GA, June 7–10, 2021.

This work introduces a multilayered organic package with embedded antennas that enables the integration of a scalable wideband phased array module supporting the n257, n258, and n261 5G frequency bands (24.25–29.5 GHz). The package comprises: 1) an $8\times 8$ array of dual-polarized antenna elements with 5.1-mm spacing; 2) RF, intermediate frequency (IF), dc, and digital interconnects to support radio-frequency

Prospective authors are requested to submit new, unpublished manuscripts for inclusion in the upcoming event described in this call for papers.

Prospective authors are requested to submit new, unpublished manuscripts for inclusion in the upcoming event described in this call for papers.

These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal.

This page or pages intentionally left blank.

Presents the table of contents for this issue of the publication.

Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.

A precise-integration time-domain (PITD) method with a thresholding scheme is proposed to reduce the computation cost of the matrix exponential for solving electromagnetic (EM) problems. The finiteness of EM wave speed is used to analyze the structure of the matrix exponential, revealing that the dense matrix exponential can become sparse. A thresholding scheme for eliminating tiny and thus unimportant

The design of an additively manufactured circular waveguide 3-dB hybrid directional coupler is proposed and demonstrated. Asymmetric corner radius perturbations at the in-plane orthogonal junction of the four waveguides along with curvilinear inductive posts designed to interact with the TE 11 mode of the circular waveguide are used to facilitate directivity and isolation. Capacitive waveguide perturbations

In this letter, a novel variable power divider, which provides wide-range variable power division, is proposed. The proposed power divider consists of a magic-T, variable phase shifter, and 90° delay line. The operating principle of the proposed circuit is theoretically discussed, and a 5-GHz band prototype using a planar magic-T is designed and experimentally evaluated. The measured power division

A $W$ -band metallic waveguide module capable of spatial power combining of linear microstrip array is presented. The module employs two uniquely devised split-channel blocks to obtain a uniform field distribution in an oversize merged channel and couple an equal amount of power to ten microstrip elements aligned in the direction of the waveguide $E$ -plane. The array of microstrip thru lines, each

A 60-GHz polar vector modulator with a lookup table (LUT)-based calibration for a variable gain active phase shifter is presented. It consists of an input buffer, an I/Q generator, a vector summing amplifier, and 6-bit phase/gain digital-to-analog converters (DACs). It is very difficult to obtain accurate gain and phase characteristics of a polar vector modulator due to circuit imperfections, such

Using a new kind of folded waveguide (FWG) with modified circular bends and two-stage depressed collector, we have designed a $W$ -band-pulsed traveling wave tube (TWT) operating at substantially lowered-voltage with high power and efficiency. A prototype tube has been tested at voltage of 15.66 kV and 30% duty cycle, showing output power over 180 W and gain over 36 dB in 91–97-GHz frequency range

This letter presents an innovative stacked cell, where the common source device is split in to two smaller devices leading to a more compact and symmetric structure, with almost negligible parasitics associated with the transistor connection. This novel configuration is rigorously compared, for the first time, with the two classical approaches commonly adopted to physically connect the two devices

This letter presents a wideband on-chip frequency detector implemented in a 65-nm CMOS technology. The frequency detector is composed of a fish bone like transmission line and a series of distributed power detectors with a parallel-to-serial readout circuit. A slow wave structure is employed in the transmission line for improved area efficiency. The frequency is extracted from the waveform profile

A low-noise active leakage canceller (ALC) for radio frequency identification (RFID) transceiver is reported. The proposed ALC suppresses the strong transmitter (TX) leakage at the receiver (RX) input through continuous leakage tracking by employing an I/Q harmonic rejection switched-capacitor digital power amplifier (I/Q HR SC DPA). Compared to the analog feedback loop-based ALC, the proposed ALC

We propose the body floating and self-bias technique, in which the body of the transistor is connected to its drain through a resistance (13.6 $\text{k}\Omega $ in this work). A low-power 3–9-GHz CMOS low-noise amplifier (LNA) using the technique for sub-6-GHz 5G systems is reported. An enhancement in $S_{21}$ and noise figure (NF) of the LNA is achieved due to the forward body-to-source bias ( $V_{\mathrm

A disordered-cavity-based metaimager (DCM) that can be used for coincidence imaging is proposed in this letter. The proposed DCM possesses narrow frequency gap, low correlation coefficients, and high efficiency. Due to the all-in-one design, the DCM has good robustness and is insensitive to fabrication errors, which is suitable to be fabricated using the 3-D printing technique. The DCM working from

This letter proposes a calibration method to properly measure the incident power in a directional coupler (DC) when the measurement configuration has low directivity. The proposed method is based on measurements of short-circuits placed at different distances to calibrate the DC response. Results show that the method is clearly robust and provides accurate measurements even for directivities as low

Prospective authors are requested to submit new, unpublished manuscripts for inclusion in the upcoming event described in this call for papers.

These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal.

Presents the table of contents for this issue of the publication.

Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.

This letter reports proof-of-principle demonstration of 3-D printable, low-cost, and compact terahertz (THz) spectral splitters based on diffractive optical elements (DOEs) designed to disperse incident collimated broadband THz radiation (0.5–0.7 THz) at a prespecified distance. Via inverse design, we show that it is possible to design a diffractive optic that can split broadband incident spectrum

This letter presents a compact, wideband, planar, E-arm folded magic tee at $Ku$ -band for monopulse slotted waveguide antenna array applications. A novel impedance matching structure, an L-shaped septum, is implemented at the magic tee junction, which results in wide impedance bandwidth at all ports. The height of this septum is the same as that of the waveguide height, which allows the design to

An analysis of the second-order mixed-coupled bandpass filter (BPF) of a general form is carried out. The resonators in this BPF are presented by a resonant frequency $f_{0}$ and a susceptance slope parameter $b$ . The position of the transmission zero (TZ) generated by the mixed coupling is determined. A correspondence is established between the mixed coupling representation as the sum of magnetic

In this work, a serpentine microrectangular coaxial delay line (MRCDL) operating from dc to Ka -band is realized based on MEMS-Casting (MEMS-C) process. As an emerging technology, the MEMS-C process provides a low-cost, rapid, and one-time prototyping approach for manufacturing the proposed MRCDL. Besides, the single-crystal quartz with low permittivity and low loss tangent is used to fill the MRCDL

This letter presents a novel class of compact dual-mode bandpass filters based on half-mode substrate-integrated waveguide (HMSIW) cavities. By using both TE 102 and TE 301 modes of the HMSIW rectangular cavity as resonant modes and TE 101 mode as nonresonating mode, a novel HMSIW doublet with two poles and two transmission zeros (TZs) is implemented. The TZs can be located at one side or both sides

This letter proposes a wideband filtering differential phase shifter with enhanced harmonic suppression. Through the original transmission line model, the numerical relationship between the prescribed amplitude/phase response and the initial design parameters can be readily established. Then the simple transformation from the transmission line to its T-type lowpass network is utilized to suppress the

A novel dual-mode (DM) dielectric waveguide (DW) filter with controllable transmission zeros (TZs) is presented. The DM filter is based on a cascaded implementation, utilizing individual DM DW cavities. The filter is practically realized by embedding three circular blind holes at different positions in the surface of a dielectric silver-coated square cavity. By changing the relative position of the

A compact multifunctional switchable filter based on parallel-coupled lines with three different filtering functions is presented in this letter. By using p-i-n switches to connect or disconnect microstrip line and shorted coupled lines, three different modes, i.e., wideband bandpass filter (BPF), bandstop filter (BSF), and dual-band BPF, can be realized. For demonstration, the switchable filter prototype

We propose a second-order $RC$ -only voltage-mode active all-pass filter (APF) as an analog time-delay cell. The core circuit of the proposed APF is canonical and consists of only one transistor, one resistor, and two capacitors. Therefore, this design is area efficient, and it is suitable for low-gigahertz frequency applications, where conventional $LC$ designs are not practical, due to large inductor

An improved millimeter-wave nonlinear model for InP heterojunction bipolar transistor (HBT) is proposed in this letter. The frequency dispersion effect has been taken into account in the Agilent HBT model in Agilent ADS software. Model verification is carried out by comparison of measured and simulated dc and S-parameters up to 110 GHz.

This letter presents the design approach for a compact, single-stage, wideband MMIC power amplifier. A method is proposed to compensate for the output capacitance of the active device over a frequency range as wide as possible, with minimum impact on the achievable output power, which leads to a two-element compensating network. A three-section transformer is then adopted for a real-to-real transformation

This letter proposes a low-phase-noise high-efficiency power oscillator with digitally controlled output power and frequency. The transformer-based matching network resonator is implemented to balance the quality factor and matching efficiency. The active core and the transformer are jointly optimized to achieve the required output power while achieving the low phase noise and high power efficiency

A standard substrate integrated waveguide (SIW)-based bandpass filter (BPF) suffers from bulkiness that limits its application in the implementation of compact size low phase noise oscillator. Instead, in this letter, an eighth mode SIW (EMSIW) resonator-based BPF is utilized to realize a miniaturized low phase noise oscillator for $X$ -band applications. Additionally, an equivalent circuit model of

A tunable resonant multiband transmit/receive (T/R) switch is proposed and fabricated in 45-nm silicon on insulator (SOI) CMOS to cover the frequency band from 24 to 47 GHz allocated for 5G mobile communication systems. For the Tx path, the measured insertion loss is 0.85 and 0.8 dB at 28 and 39 GHz, respectively. The OP1dB is 22 and 28.5 dBm at 28 and 39 GHz, respectively. The OIP3 is 40 and 41 dBm

A wideband and highly efficient power amplifier (PA) is designed using a simple and systematic approach. This method employs an optimization process to set the input impedance of the matching networks in optimal regions on the Smith chart, obtained using conventional load-pull/source-pull simulations, in both the fundamental and second harmonics. The developed design method led to a GaN PA whose measurements

This letter presents the design and characterization of a Doherty power amplifier for K-band applications based on the GaAs 150-nm pseudomorphic HEMT (pHEMT) technology of Qorvo. For the output power combiner, a wideband design approach, based on embedding the output capacitance of the active devices in the combiner, is applied. A state-of-the-art bandwidth of 4 GHz is achieved: in the 21–25-GHz range

This study presents a compact rectifier array with an adaptive power distribution network (APDN). The rectifier array comprises rectifier cell 1 for both high-power mode and high-frequency band; rectifier cell 2 for both low-power mode and low-frequency band; and a power distribution network, which adaptively distributes power according to the input power and frequency. The proposed APDN is merged

Wearable and elastic surface coil using a conductive and stretchable textile for magnetic resonance imaging (MRI) of breast was designed. A high-conductive silver thread was woven with elastofiber to create two elastic textile coils. Three phantoms with varying sizes and a resolution plate were also designed to validate the coil performance. Signal-to-noise ratios (SNRs) were calculated for the phantoms

A microwave rectifier composed of a pair of Schottky diodes with dynamic capacitive self-compensation is proposed in this letter. The impedance of a Schottky diode usually varies with the input power. A method using paired diodes for capacitive self-compensation is presented to enhance the rectifier’s dynamic power range. The imaginary part of one diode’s impedance is compensated using another identical

High-frequency (HF) transmitter implemented with the multioctave power amplifier (PA) is faced with the problem of high-order harmonics owing to the nonlinearity of the PA. In this letter, a complexity-reduced harmonic-cancellation digital predistortion (CR-HC-DPD) is proposed and a narrow pulse sampling (NPS) method is adopted for model identification. Compared with the previous HC-DPD scheme, the

These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal.

In this letter, we propose a novel technique for rapid and accurate yield estimation of microwave passive components using model-order reduction (MOR)-based neuro-transfer function (neuro-TF) models. In the proposed technique, the frequency responses of microwave components are represented by transfer functions in the pole-zero-gain format. The poles, zeros, and gain in the transfer functions are computed

The absorbing boundary condition (ABC) is very common to be used to truncate the computational domain in the hybridizable discontinuous Galerkin (HDG) method. However, if solving waveguide transmission problems with multimode scattering, the ABC is not very applicable due to the wave impedances varying with the frequency. Considering the perfectly matched layers (PMLs) boundary can absorb well the

This letter proposes a new surrogate-based multiphysics optimization technique for microwave devices incorporating artificial neural networks (ANNs) and trust-region algorithm. In the proposed technique, at each optimization iteration, we build an accurate and efficient ANN surrogate model using multiple multiphysics training samples around the optimized solution from the previous iteration. A parallel

Nonradiative dielectric waveguide (NRD guide) is a promising platform for realizing compact millimeter waveguide circuits. NRD guide devices have been simulated by several numerical simulation approaches so far and these approaches treat 3-D structure because electric and magnetic fields in NRD guides vary in whole directions. In this letter, we propose a 2-D full-vectorial finite element analysis

Optically transparent conductors (TCs) have been implemented and adopted into next-generation transmission lines and other RF structures from UHF to millimeter-wave (mmWave) applications. A current method of evaluating the performance of optically TCs uses a figure of merit (FOM) which is frequency agnostic. A new FOM for optically TCs at RF, microwave, and millimeter-wave frequencies is presented

In this letter, a compact wideband bandpass filter (BPF) with a wide stopband is proposed based on the substrate integrated defected ground structure (SIDGS) and folded stepped-impedance resonator (FSIR). Such a SIDGS resonator can not only allocate a specific resonance with compact size but also introduce the different harmonic positions compared with a traditional microstrip line resonator. Meanwhile

In this letter, a novel reconfigurable filter concept, which is called assembly reconfigurability through rotation, is proposed for the first time to implement a high-Q filter with adjustable frequency response. Two separated printed circuit boards (PCBs) are designed and assembled together to build a double-layer substrate integrated waveguide (SIW) filter. Guided by coupling matrix synthesis, the

This letter presents the design of compact triple- and quad-band power dividers (PDs) based on substrate integrated waveguide (SIW) technology. The proposed PDs are designed as a rectangular cavity, one pair of unequal complementary split-ring resonators (CSRRs) and U-shaped slots (USSs). Initially, a dual-frequency SIW PD is implemented using unequal CSRRs on the top surface of the SIW cavity. This

In this letter, a novel design of a narrow bandpass frequency selective surface (FSS) based on the utilization of the coupled method, which resonates at Ka -band frequencies between 29 and 30.3 GHz, is proposed and experimentally evaluated. A high selectivity was achieved, by coupling two metallic layers, which were based on the structure of a cross aperture and a rectangle grid patch, respectively

In this letter, we present an innovative filter configuration employing transversal coupled triple-mode spherical resonators while capable of realizing transmission zeros (TZs). Transversal coupling involves simultaneous source and load-controlled couplings to all the three modes of the spherical resonator. Spherical resonators inherently have very large quality factor (Qu) and exhibit a farther spurious

Modeling the temperature-dependent nonlinearity of intrinsic capacitances in AlGaN/GaN high electron mobility transistors (HEMTs) improves model accuracy. In this letter, extraction results indicate that the current modeling methods cannot accurately reflect the variations of nonlinearity in intrinsic capacitances with temperature. This letter analyzes the causes of unmodeled phenomena and characterizes

This letter introduces for the first time a fully integrated analog vectorial modulator (VM) in gallium nitride on silicon (GaN-on-Si) monolithic microwave-integrated circuit (MMIC) technology, operating in $Ka$ -band, and an analytical calibration technique suitable for VM. An extensive characterization of the prototype, with both static and dynamic modulating signals, validates both the design and

In this letter, a novel reconfigurable 0°/90° phase shifter is proposed. Compared with the conventional phase shifters, the proposed one uses fewer reconfigurable devices and becomes more compact. Two states of a meander line are used to generate the 90° phase shift, making it suitable for the 2-D beam steering 2-bit array application. A phase shifter prototype on F4B was measured to validate its design