A novel design of bandpass frequency selective surface (FSS) with high selectivity is proposed based on the antenna-filter-antenna (AFA) concept. Traditional AFA-based FSSs improve filtering performance by adding the order of resonator or the coupling paths. On account of the reciprocity theorem, transmission zeros are here introduced by the antenna's radiation null. The proposed FSS consists of two

A compact and broadband omnidirectional antenna is proposed for quad-polarization diversity. Novel reconfigurable structures of omnidirectional vertical polarization (VP) and horizontal polarization (HP) elements based on embedded design are put forward to achieve low-profile. A simplified equivalent LC cascaded circuit is modeled to better understand the broadband VP element and guide its design.

Asymmetric transmission (AT) through metasurfaces yields a direction-sensitive behavior for electromagnetic (EM) wave propagation. To date, majority of the reported works operate at normal incidences alone and are, therefore, highly prone to variations under oblique incidences. In contrast, the chiral metasurface presented in this letter is robust up to 60 $^{\circ }$ incident angle while yielding

A fully 3-D-printed wideband metamaterial absorber, characterized by an absorptivity above 0.95 in the X and Ku-bands and with a fractional bandwidth of 0.71, is presented in this letter. A 250 mm × 250 mm sample, with a total thickness of 6.3 mm (0.26λ 0 ), is fabricated exploiting the fused deposition modeling technique with commercial filaments. To achieve a wideband absorption, a hyperbolic metamaterial

A novel highly efficient leaky-wave antenna (LWA), based on a periodic set of holes created in a half-mode substrate integrated waveguide (SIW), is conceived for automotive radar. The computer-aided design of this partially filled SIW (PFSIW) LWA is carried out using a full-wave electromagnetic simulator. As a proof-of-concept, an LWA prototype having a plate size of 15 × 126 mm $^2$ is fabricated

A new 60 GHz band single-input switched beam antenna is proposed for the fifth-generation (5G) millimeter-wave network applications. The presented design is capable of electronically switching the main beam in two different directions via a proposed microstrip-line-to-slotline single-pole dual-throw (SPDT) switch based on commercially available p-i-n diodes. The antenna is fabricated in a low-cost

In this letter, a new structure of a dielectric-loaded substrate integrated waveguide H-plane horn antenna with gradient air slots, fed by a coaxial pin, is proposed. This novel structure aims at improvements in the radiation characteristics, including the gain, front-to-back ratio (FTBR), both E- and H-planes half-power beamwidth (HPBW), and sidelobe level (SLL). The measurements of the fabricated

A novel ultrawideband dual-polarized H-plane horn antenna incorporated with a Vivaldi array is proposed. Aiming at ultrawide low-frequency applications that require dual-polarization with a compact shape, the proposed antenna employs an all-metal shared aperture structure. Different from the conventional dual-polarized horn where dual polarization is achieved using two orthogonal modes of the same

This letter presents a novel patch antenna with a reconfigurable bidirectional pattern. By simply placing seven shoring pins underneath a circular patch, the proposed antenna enables the switch-overs between two orthogonal bidirectional beams and a quad-beam via controlling four p-i-n diodes. Characteristic mode analysis is applied here to provide physical insights on its working mechanism and also

The electric-line-source excited, pulsed electromagnetic (EM) field response on the surface of a highly contrasting thin sheet with dielectric and conductive properties is studied analytically in the time domain (TD) with the aid of the Cagniard–De Hoop technique. Closed-form TD expressions reveal anomalous highly oscillatory EM transients propagated over the surface of the layer. Illustrative numerical

This letter proposes a wideband and wide-angle conjugate impedance matching (WWCIM) method and a WWCIM layer, which are applied to the tightly coupled dipole array (TCDA). The impedance matching problem over an ultrawideband can be well solved by using this method when the scanning angle reaches 70° in the H-plane. At the port position, the impedances of the ultrawideband-phased array change sharply

This letter presents a waveguide-based linearly polarized magnetoelectric (ME) dipole antenna. The magnetic and electric dipoles are realized by a waveguide aperture and a pair of rectangular patches, respectively. The antenna employs a 3-D printing technique as the manufacturing method. Compared to the conventional ME dipole designs that operate in microwave band, the proposed antenna has a novel

Although the fifth-generation (5G) networks are deployed at millimeter-wave (mmWave) frequencies, little information about the multipath clustering statistics for mmWave outdoor-to-indoor (O2I) propagation has been reported. This letter attempts to overcome this deficiency somewhat by investigating cluster-based propagation statistics for mmWave O2I that are based upon measurements. The measurements

In this letter, a compact ±45° polarized base station antenna array fabricated using laser direct structuring (LDS) technique is presented. The proposed antenna array operates in fifth-generation (5G) NR band 41 (2496–2690 MHz). The simple antenna elements of the array consist of a modified patch radiator fed by Y -shaped probes realized by injection molding, which are amenable to efficient mass production

Based on the transmittance matrix ( T -matrix) approach, an efficient and stable rigorous coupled-wave analysis (RCWA) method for ultrathin multilayer gratings without solving eigenvalues is proposed in this letter. The numerical instability caused by the inversion of an ill-conditioned matrix in the traditional T -matrix approach is solved by implementing the proposed method. Besides, compared with

A novel method of designing a wideband dual-feed circularly polarized (CP) antenna is presented for different axial ratio (AR) requirements. By analyzing the output characteristic of the feed network for the dual-feed CP antenna, an approximate function is obtained and utilized to calculate the variances of the output magnitude and phase of the feed network under a required AR. Based on the analysis

In this letter, a compact substrate integrated waveguide (SIW) monopulse antenna array based on microstrip feed is proposed. The antenna cell is composed of two layers of dielectric substrates, the model of the dielectric substrate is Rogers 5880. The TE 20 mode is excited in the bottom SIW cavity, and the mirrored TE 20 mode is used to realize the function of a monopulse comparator, which makes the

A patch antenna coupling of a periodic leak-wave structure with tri-frequency capability is proposed. The periodic offset double-sided parallel stripline (DSPSL) leaky wave structure (LWS) is embedded in the direction of the whole ground of the microstrip patch substrate, then the capability of tri-frequency could be obtained by the different Floquet mode of the propagation constant. According to the

This letter describes the design of a broadband and FSS-based transmitarray (TA) antenna for 5G millimeter-wave applications. Two different elements are proposed to avoid the issues of the geometrical parameter resizing of the elements to obtain a 2 bit transmission phase of {−π, −π/2, 0, π/2} to achieve a TA antenna with wideband behaviors. Both of the two proposed elements show low insertion loss

This letter presents transmission enhancement methods for low-emissivity (low-E) windows at millimeter wavelength (mmWave) frequencies. These methods are required for installation of effective indoor customer premises equipment for mmWave fixed wireless access (FWA) services. Low-pass filtering frequency selective surfaces are patterned with low-E coatings by laser, and the effects are verified theoretically

An effective broadband electromagnetic interference (EMI) source reconstruction method is proposed in this letter. An equivalent dipole model incorporating the global optimization method is developed to reconstruct EMI sources on printed circuit boards (PCBs) based on the scanned magnetic near-field magnitudes of device under test (DUT). Different to conventional approaches, the locations and quantity

This letter proposes a low-profile substrate integrated waveguide (SIW) cavity backed self-quadruplexing antenna for wearable transceivers. The full-mode circular SIW cavity is split into four unequal quarter-mode SIW (QMSIW) cavities using the two slots on the upper layer of the cavity. The proposed antenna uses C-shaped and arc-shaped slots of different dimensions in each QMSIW resonator to operate

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

Provides a listing of current staff, committee members and society officers.

This letter describes the integration of microstrip slot array antenna with amorphous silicon solar cells. To appraise the antenna, a 2×2 circularly polarized microstrip slot array antenna integrated with amorphous silicon solar cells using a stacked design method was measured. The results show that the gain of the antenna is almost unchanged after the integration of the amorphous silicon solar cells

A wearable all-textile microstrip patch antenna (MPA) operating in the dual bands of medical body area network (2.36–2.40 GHz) and WiMAX (3.4–3.6 GHz), is proposed for body-centric communications. The omnidirectional radiation pattern with linear polarization for on-body link and unidirectional radiation pattern with circular polarization for off-body link are achieved by introducing reactance loading

Three different dielectric lens antennas are designed to enhance range of a commercially available 122 GHz radar system-on-chip transceiver with antennas in package. A Fresnel-zoned lens antenna, a plano-hyperbolic lens antenna with one-refracting surface, and a conventional plano-hyperbolic lens antenna with two refracting surfaces are compared. All lens antennas are made of Teflon (PTFE). Problem

Optically transparent flexible tag antennas are highly desired for some applications, where unobtrusiveness and capability of mounting on curved surfaces are required. On the other hand, circular polarization minimizes signal degradation due to polarization mismatch between the reader and tag antennas, thus ensuring good communication quality and accuracy. In this letter, we present an optically transparent

A dual-band structure-shared antenna with large frequency ratio is proposed in this letter by integrating two substrate integrated waveguide slot antennas (SIWAs) on the branches of dipole. In the proposed structure, dipole is fed by coaxial connector while SIWAs are fed by two microstrip lines. To improve the stability of the dipole and the isolation among three antennas, microstrip high-pass filter

Microwave power transmission has traditionally been used for long-distance applications so far. For the first time, we experimentally demonstrate efficient short-distance wireless power transfer based on microwave radiation. To overcome the directivity deterioration of an antenna as the transfer distance decreases in the near field, an electromagnetic rectifying surface is proposed for reflection-less

The rapid increase in the number of wireless devices in modern communication networks has significantly increased the number of interference sources, which severely impacts communication reliability. Adaptive interference cancellation is rapidly becoming a necessity for modern wireless networks. For interference cancellation, a digital beamformer adaptively adjusts its weight vector using an array

A low-profile circularly polarized wearable antenna with flexible performance and reduced specific absorption rate (SAR) based on graphene is presented. The antenna adopts highly conductive graphene film and polydimethylsiloxane substrate, which have good flexibility, mechanical stability, and light weight. The wearable antenna operating at 5.8 GHz with a profile of 0.05 λ is designed and fabricated

This letter presents a novel probe selection method for multiple-input–multiple-output (MIMO) over-the-air (OTA) testing. It can effectively reduce the number of probes used in anechoic chamber, which further reduces the ports of the channel emulator. Two basic channel models are used to validate the performance of this method. The simulation results demonstrate that it can reconstruct the channel

In this letter, EH 1 /EH 2 -mode periodic leaky-wave antennas (LWAs) are proposed for achieving backward-to-forward scanning capability. In order to suppress the open stopband, the impedance balanced condition based on the modal distribution circuit is derived. From the equivalent effects of loading slots, the composite slot loadings under the impedance balanced condition are introduced and designed

The hybrid analog and digital structure of large-scale antenna array offers a good tradeoff between cost and flexibility, which is a promising solution for millimeter-wave (mm-wave) system. This letter proposes a novel hybrid precoder (HP) design with an iterative beam split and detection algorithm, which works well for sparse mm-wave channels. The proposed strategy can extract the dominant propagation

A novel Ku -band pattern-reconfigurable array antenna is designed and experimentally tested, which is able to electronically form various radiation patterns, including a single pencil beam, dual beams, quad beams, and a single fan beam. It consists of 4 × 4 probe-fed O-slot patch elements. Two p-i-n diodes are integrated on the O-slot of each element, and by alternatively activating one of the p-i-n

A high-efficiency double-layer transmitarray (TA) operating at 14.25 GHz is proposed using low-loss dual-linearly polarized elements. Each element comprises only two layers of patches printed on a dielectric substrate and four vias. Cross dipoles and spiral dipoles with four L-shaped patches are used as the first and second unit cells, respectively. L-shaped patches are employed to increase the transmission

We address the electromagnetic problem involving small structures, and put forward an improved, explicit finite-difference time-domain (FDTD) algorithm based on the Newmark discretization with subgridding technique. This algorithm achieves a stable, low-reflection, and straightforward subgridding with an arbitrary grid refinement ratio by adopting hanging variables. The Newmark method is employed to

In this letter, a single-layer right-hand circularly polarized (RHCP) antenna with low-profile and improved gain based on quarter-mode substrate integrated waveguide (QMSIW) cavities array is proposed and experimentally validated. The proposed antenna consists of a central microstrip patch and four QMSIW cavities with the same dimensions, which are directly cascaded to the central patch. The E-field

In this letter, a phantom validation of a low-complexity microwave imaging device operating in free space in the 1–6.5 GHz frequency band is presented. The device, initially constructed for breast cancer detection, measures the scattered signals in a multibistatic fashion and employs an imaging procedure based on the Huygens principle. Detection has been achieved in both bone fracture lesion and bone

With increasing radio spectrum being allocated to wireless communications, multiband and ultrawideband systems are becoming much more prevalent. Such broadband systems are susceptible to interference, or can inadvertently radiate out-of-band emissions, so significant filtering is required at RF front-ends. With this motivation, a broadband conical monopole antenna with integrated tunable notch cavity

In this letter, we propose an improved Gaussian process regression (GPR) to accurately predict the monostatic radar cross section of conducting targets as a function of the incident angle and frequency. Inspired by physical optics, we assume the covariance function as the sum of linear periodic covariance functions. Experiments involving the simulated and measured data are carried out to assess the

Chaff cloud is widely used in target covering. It contains huge numbers of chaff elements. An optimization method is presented in this letter for determining the mixing ratio of the chaff elements for wideband jamming. The electromagnetic scattering is calculated first for single chaff element with different lengths using the method of moments. Then, the superposition method is adopted to obtain the

Lateral wave plays an important role in electromagnetic (EM) wave propagation in layered conducting media. The full utilization of lateral wave in marine layered media may provide an innovative way of transmedia wireless communication. However, the existing approaches for solving lateral wave are tedious and complicated. In this letter, a simple model was presented to obtain lateral wave and other

To extend the modeling area with artificial neural networks (ANNs) from finite periodic arrays to thinned arrays, where spacings between adjacent elements are crucial for array performance, an efficient model is proposed in this letter. Considering the spacings, a novel hidden node interconnection-radial basis function neural network (HNI–RBFNN) is developed to map the relationship between the array

In this letter, a flexible and frequency-reconfigurable bandstop frequency selective surface (FSS) is studied theoretically and experimentally. The FSS patterns are fabricated on an ultrathin flexible substrate through screen printing, a low-cost, high-efficiency additive manufacturing methodology. With the embedded varactors biased from 0 to 20 V, resonant frequency tuning from 3.5 to 5.7 GHz was

A broadband technique to extract the attenuation and phase constants of the slot mode in a rectangular waveguide from either simulation or measurement results is proposed in this letter. The method is based on processing the values of the reflection coefficient of several slotted waveguides with different lengths and the same termination and feeding. The accuracy of the method can be improved by increasing

In this letter, a broadband waveguide-to-coplanar waveguide with ground transition for large-chip-width substrate operating within terahertz frequencies is demonstrated. This transition adopts an integrated dipole antenna with coupling branches and disks topology. This compact transition reduces parasitic effects by wire bonding and is suitable for direct integration with terahertz monolithic integrated

We present a circular array of diversely polarized slot elements devoted to a portable direction-finding system in the UHF 868 MHz band. The detailed structure is presented as a combination of two printed circuits boards (PCBs) (FR4 substrate) holding the radiating slots and strip feeds located inside a metallic box housing. Experimental validations in terms of scattering parameters and embedded element

A single-layer microstrip patch antenna (MPA) under the operation of TM 10 and TM 20 modes for pattern diversity application without needing to rely on any feeding network is proposed for the first time in this letter. Initially, when a thorough analysis on mode excitation and inhibition of the MPA was deeply conducted, it demonstrated that its TM 10 and TM 20 modes could be independently excited by

In this letter, a magnetoelectric (ME) dipole antenna with low profile, broadband, stable unidirectional radiation is presented. Traditional Γ-shaped feeding structure is shunted, improved, and hence a dual-magnetic dipole is formed. Furthermore, a dual-electric dipole is also formed by etching a slot on top electric dipole patch. Therefore, an ME dipole antenna with a dual-complementary source is

A low-profile planar surface-wave antenna with metasurface is proposed for endfire radiation. The antenna has the advantages of low profile, high gain, and wide bandwidth of endfire radiation. The surface-wave structure is based on a substrate integrated waveguide (SIW) structure, which can be considered as a laterally-bounded conductor-backed coplanar waveguide (CPW) with a metasurface that is made

Angle-selective surface is defined as a surface construction that can exhibit angular selectivity allowing electromagnetic waves of certain angles to pass while blocking waves from other angles. It is theoretically revealed and demonstrated that a uniaxial dielectric-magnetic slab can serve as an excellent angle-selective surface. At the incidence of the Brewster angle, electromagnetic waves can pass

This letter proposes a new design of a dual-band dual-polarized base station antenna with a notch band for second-generation (2G), 3G, 4G, and the sub-6 GHz 5G systems. The antenna is composed of a four-leaf loop radiator, two-layer parasitic annular disk and a pair of crossed Y-shaped baluns. By introducing mouse-ear shaped arm to the edge of each radiator, a dual-band operating characteristic and

A dual-port metasurface (MS) antenna for pattern-diversity applications is proposed. The planar MS, consisting of 4 × 4 square patches, is excited by a driven patch. A pair of differential probe feed is used to drive the patch with broadside mode, while a stepped probe feed is employed in the center of the patch to generate conical mode. The capacitive-loaded stepped probe of the center feed is able

It is shown that the grating lobes issue of periodic leaky-wave antennas (P-LWAs) can be mitigated using parasitic monopoles placed between the antenna's unit cells. Due to the periodicity nature of P-LWAs, infinite number of space harmonics are excited, but only one space harmonic should radiate to achieve single-beam radiation. As the beam scans to the forward direction, a second space harmonic starts

A completely passive method of enabling 1-D beam-scanning for a monopulse antenna array with controllable sidelobe levels (SLLs) is presented in this letter. To achieve this unique function, a compact frequency-dependent phase-shifter composed of stripline resonators is proposed. This proposed phase-shifter provides similar sensitivity as conventional meander striplines, while its size is much smaller

A novel design of an electrically small, dual-band quasi-isotropic antenna with a microstrip balun is presented in this letter. A quasi-isotropic radiation pattern is realized from the total current flow over the proposed structure at two different frequency bands. The electrical size ka of the antenna is 0.49 with an extremely thin profile of 0.0014λ g . The antenna measurements reveal good uniformity

A novel method of using axial ratio (AR) contour to design a broadband circularly polarized (CP) antenna is presented in this letter. By resolving a radiated CP wave into two orthogonal far-field components, the resulted AR will be determined by the radiated power and phase differences between the two orthogonal components. Therefore, a series of AR contours can be obtained for different AR values

In this letter, a closed-loop cross-dipole antenna array (CLCDAA) is proposed for wideband orbital angular momentum (OAM) communication. The proposed antenna array is designed based on a closed-loop cross dipoles patch, several pillow-like parasitic patches, and a hybrid wideband feeding network. The design method of the feeding network is introduced using the analysis of the multiport network, and