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.

In this letter, the computation of the Green's function for one-dimensional (1-D) periodic structures is presented via a fast and accurate algorithm based on the philosophy of Kummer's decomposition (KD). The KD uses an optimal value for a quasi-periodicity parameter. An approximate optimal balance between direct summation and acceleration is constructed when necessary. The algorithm has been designed

In this letter, a three-dimensionally printed one-sixteenth fractional spherical homogeneous dielectric lens antenna on a metallic corner reflector is designed. This lens antenna is fed by an open-ended rectangular waveguide for high-gain radiation. The main design concept is to produce an equivalent spherical dielectric lens that is excited by multiple virtual sources arising from the multiple images

A low-profile wideband dual-polarized antenna with an improved high-impedance surface (HIS) reflector is proposed. Dual-polarized radiation is excited by feeding a set of crossed dipoles. Low profile is achieved by utilizing an improved HIS reflector. Good impedance characteristics are realized by inserting small square cells among the primary hexagonal cells of the HIS. Two shorting pins and four

In this letter, a novel circularly polarized (CP) slotted substrate integrated waveguide (SIW) cavity antenna using a hybrid TE 202 mode (HTM) and the eigen TE 202 mode (ETM) is proposed and studied. The antenna is designed for Ku-band satellite wireless link applications. It utilizes two different and orthogonal TE 202 modes (ETM and HTM) with slots etched on the surface to form left-hand CP radiation

Three wideband monopolar patch antennas (MPAs) integrated into a Y-shape structure for multi-input–multi-output (MIMO) operation in 3300–4200 MHz for fifth-generation (5G) access points are presented in this letter. Each MPA has an antenna height of 10 mm (about 0.11 λ at 3300 MHz) and a top-patch length of 22 mm (about 0.24 λ at 3300 MHz). Each MPA is capacitively excited through a feed strip at its

A novel very low frequency (VLF) communication system using one pair of magnetoelectric (ME) antennas has been proposed. The ME antennas are strain-mediated acoustic resonators operating at their electromechanical resonance in the VLF band. The measured near-field radiation pattern reveals ME antennas are equivalent to dipole antennas. The magnetic field radiated by the ME transmitter has been predicted

This letter presents the design and study of a novel aperture coupled cylindrical dielectric resonator antenna (cDRA). Unique aspects of the proposed antenna design are that proposed aperture can excite six different hybrid radiating modes (HEM 11 δ , HEM 11 δ +1 , HEM 12 δ -like , HEM 12 δ , HEM 13 δ , HEM 14 δ ) in the cDRA; first time, quad-band quad-sense circular polarization is obtained in the

In this letter, we present a design of a linear array of tilted dipoles to achieve radiation patterns with asymmetric angular filtering characteristics. To realize the asymmetric radiation, the dipole elements are spaced by a distance larger than half a wavelength, thus allowing for grating lobes to occur in the visible region. Moreover, the dipoles are loaded with artificial dielectrics to increase

This letter presents an efficient approach for the electromagnetic analysis of complex scenarios involving transmitting antennas moving along predetermined trajectories. In order to efficiently reduce the size of the problem for each position of the antenna, we propose a technique based on macro basis functions that are dynamically generated using a ray-tracing analysis. The multilevel fast multipole

Achieving wide circularly polarized (CP) bandwidth in a simple probe-fed microstrip antenna is essential for many practical applications. Existing knowledge guides exploring a thick substrate-based patch design. However, it suffers from two major inherent issues: squinting of beam and high cross-polarized (XP) radiation. No solution is available so far. This letter successfully addresses both issues

Using the method of moments, we investigate two types of circularly polarized loop array antennas with and without a coplanar feedline (CF). The loops and the CF are located above a ground plane at a height of a quarter-wavelength. First, we analyze decoupling two-element array antennas. It is found that the antennas with and without the CF show reduced cross-polarization levels of −15 and −16 dB,

Sparse linear arrays based on a novel subarrayed scheme are proposed and synthesized in this letter. The array with a fixed aperture size is partitioned into several uniformly spaced subarrays while number, spacing, and excitation in each subarray are optimized with multiple constraints. Compared with conventional sparse linear array with all the elements excited independently, the sparse linear array

This letter analyzes the impact of interuser distance and angular separation on the channel correlation and achievable sum-rate for a massive multiple-input–multiple-output (MIMO) system in non-line-of-sight (NLOS) conditions. The investigation is based on outdoor measurements on a channel sounding system capturing the dynamic channel of two user arrays. The letter analyzes correlation and sum-rate

This letter presents a center-feed high-gain and high-efficiency 4 × 4-element slot array antenna in the 60 GHz band. The antenna feed network is designed using only a single-layered square quad-ridge cavity structure, which is excited through a rectangular slot that has the same size as that of a standard WR-15 rectangular waveguide. The proposed antenna avoids any conventional power dividers in the

In this letter, a probe-fed reconfigurable dual-/triple-band circularly polarized (CP) Spidron fractal dielectric resonator antenna (SFDRA) is proposed. Initially, a dual-band CP SFDRA is designed. An eigen-mode simulation of an isolated SFDR concludes that the quasi-TM $_{11\delta }$ and quasi-TM $_{21\delta }$ are excited in the lower band, whereas the quasi-TE $_{12\delta }$ mode is excited in the

A low-profile compact dual-band L-shape monopole antenna is designed for microwave thorax imaging. The antenna operates at 433 and 915 MHz in Industrial, Scientific, and Medical band with a compact size of 30 mm × 20 mm × 1.5 mm, which is suitable for wearable devices. It radiates toward in-body direction. The monopole is bent to L-shape for miniaturization. A meandering shorted branch and an open

A wideband millimeter-wave (mmW) circular aperture horn antenna with a conical radiation pattern realized by the metallic three-dimensional (3-D) printing technology is presented in this letter. The proposed structure consists of a coaxial waveguide and a quadruple-ridged conical horn. The horn antenna is fabricated using a direct metal laser sintering (DMLS) technology, and both manual polishing and

This letter presents an optical transparent antenna array integrated with solar cell. Metal-meshed structure is used in the transparent antenna array, which achieves a balance between radiation efficiency and optical transparency. The meshed patches have equidistant distribution in the array and are fed by coaxial probes. A meshed ground, which has the same grid size as the meshed patch, is introduced

A novel wide-beamwidth rectangular dielectric resonator antenna (DRA) is proposed. By loading two pairs of higher-permittivity dielectric slabs symmetrically on two opposite surfaces of the rectangular DRA in one direction parallel to the feeding slot, the E-plane radiations from two opposite surfaces of the DRA are restrained. Dimensions and the relative permittivity of the dielectric slabs are adjusted

In this letter, a novel multiple-input–multiple-output (MIMO) antenna operating at 3500 MHz band is presented for 5G mobile terminals. The proposed antenna includes four blocks. Each block consists of two face-to-face elements with total size of 25 × 3.5 mm 2 . Rather than excited separately, the two elements are excited simultaneously. Pattern diversity is achieved by using in-phase and out-of-phase

A new differential frequency-reconfigurable antenna based on dipoles is presented in this letter. The basic structure of the proposed antenna consists of two pairs of vertical arms forming two dipoles, the feeding structure, mode switching structure, and p-i-n diodes. By switching “ on ” and “ off ” p-i-n diodes, the antenna can resonate at two states, and thus work centered at 3.5 and 5.5 GHz, respectively

The design and operation of a compact antenna array offering circularly polarized (CP) radiation for picosat and other small satellites for communication applications is presented. The proposed array combines the folded-shorted patches (FSPs) and meandering for antenna miniaturization. Realization of CP is achieved by a compact and planar feed circuit consisting of a network of meander-shaped 90° and

Various ultrawideband (UWB) band-notched antennas are developed to avoid interference between UWB and other nearby narrow frequency bands that falls within the UWB spectrum. However, all band-notched UWB antennas developed generate ringing in the time domain, and a great amount of distortion is present in transmitted (or received) UWB pulses. The distortion level is dependent on band-notching strength

This letter aims to develop an innovative, fast, and effective technique to design radial line slot antennas (RLSAs) capable of obtaining nonconventional radiation properties by means of combining analytic approaches with optimization techniques. This technique allows to obtain much more complicated designs than the classical ones, including maximum directivity/gain and sidelobe level (SLL) control

This letter presents two 2 × 2 polarization-insensitive dual-polarized rectenna arrays with different power combining strategies for wireless power transmission applications. With a dual-polarized antenna array, the incident wave can be received and decomposed into the horizontally and vertically polarized components, which are equally redistributed by a hybrid coupler. By this means, the efficiency

Short-circuited reflection method is usually used to characterize the dielectric property of materials. When using the method, the extraction of the vector reflection coefficient (VRC) of the metal-backed sample is the key to determine the complex permittivity of the sample. Traditionally, the VRC is measured by a vector network analyzer associated with the transmission line or the antenna. In this

A differential-fed gain-enhanced dual-polarized dielectric patch antenna operating at higher order TM 121 and TM 321 modes is investigated in this letter. The introduction of grounded bars in a conventional square dielectric patch resonator (DPR) is a key technique in the proposed design. It not only moves the higher order TM 121 mode upwards to enhance the gain of the antenna, but also enables the

The magnetoquasistatic (MQS) field coupling theory is presented for long ranges between a transmitting device located outdoor to a receiving device located indoor. The theory is validated based on measurements in a large indoor house environment ( $>$ 8000 ft $^2$ ) with the transmitting device located far outside the house ( $>$ 11 m from outer wall). We discuss the system and demonstrate position

This letter provides correction comments to an article published in 2015, by Ghosh et al. in which the authors have proposed a circular-split-rings-based ultrawideband ultrathin metamaterial absorber and claimed 90% absorption between 7.85 to 12.25 GHz. It is found that the authors have misinterpreted a cross polarizer as a broadband absorber by neglecting its cross-polarized reflection. It is found

Presents corrections to equations in the above named paper.

A simple radio frequency (RF) testing system that can be conveniently built and used for measuring radio propagation in tunnels is introduced. With the proposed testing system, RF power attenuation with distance in a train tunnel was measured at four frequencies (455, 915, 2450, and 5800 MHz) for both horizontal and vertical polarizations. Two analytical modeling methods-the ray tracing and modal methods-are

Microwave breast imaging performance is fundamentally dependent on the quality of information contained within the scattering data. We apply a truncated singular-value decomposition (TSVD) method to evaluate the information contained in a simulated scattering scenario wherein a compact, shielded array of miniaturized patch antennas surrounds an anatomically realistic numerical breast phantom. In particular

We propose a 3-D-printed breast phantom for use in preclinical experimental microwave imaging studies. The phantom is derived from an MRI of a human subject; thus, it is anthropomorphic, and its interior is very similar to an actual distribution of fibroglandular tissues. Adipose tissue in the breast is represented by the solid plastic (printed) regions of the phantom, while fibroglandular tissue is

We present a 3-D microwave breast imaging study in which we reconstruct the dielectric profiles of MRI-derived numerical breast phantoms from simulated array measurements using an enclosed array of multiband, miniaturized patch antennas. The array is designed to overcome challenges relating to the ill-posed nature of the inverse scattering system. We use a multifrequency formulation of the distorted

We present a miniaturized, dual-band patch antenna array element that is designed for use in a 3-D microwave tomography system for breast imaging. Dual-band operation is achieved by manipulating the fundamental resonant mode of the patch antenna and one of its higher-order modes. Miniaturization and tuning of the resonant frequencies are achieved by loading the antenna with non-radiating slots at strategic