In recent years, the microwave processes in artificial multiferroic media such as electromagnonic crystals have attracted increased research interest due to their potential applications for voltage-controlled spintronic devices. In contrast to the conventional magnonic crystals, the artificially created periodic structures are characterised by electrically and magnetically tunable band gaps in the

This work presents a new technique for the geometrical optics (GO) shaping of axisymmetric dual-reflector antennas. Both reflectors' generatrices are shaped by the continuous concatenation of conic sections, suited to provide simultaneous control of amplitude and phase of the aperture's GO field. With amplitude and phase control of the aperture field, the antenna designer has more options to achieve

A chipless radio frequency identification (RFID) system based on multi-resonant-based chipless RFID tags and fractional Fourier transform (FrFT) was simulated. Each tag codes a 3-bit unique identification (ID) in the form of a spectral signature in the interrogation signal. The signal is then backscattered to the processing unit (PU) for ID decoding. The simulated system accounts for two tags, 1 m

A technique is proposed for the enhancement of gain and circularly polarised (CP) bandwidth of a singly-fed CP dielectric resonator (DR) antenna. The specific geometry of DR is used to generate the orthogonal modes required for obtaining the CP response. The incremental harmonics of the fundamental and third-order modes, and , are generated by stacking of the similar DR layer topped with metallic patch

A novel gain/bandwidth enhanced leaky-wave microstrip line antenna with circular polarisation (CP) is proposed. Different from common leaky-wave antennas with an open, short or resistive termination, this antenna consists of a leaky-wave rampart-line antenna terminated with a CP patch radiator. The energy from the feeding point is first radiated by the rampart-line antenna, while the remaining part

As the interference bandwidth increases, the impact of interference coupling path dispersion on the cancellation performance can no longer be ignored in open space. Especially for the radio frequency interference adaptive cancellation system (RFIACS), the impact will be more serious. In response to this problem, this study establishes the time-domain model of a wideband RFIACS considering interference

This study addresses an analogue method for mitigating the non-linearities introduced by discrete supply modulation of a high-efficiency power amplifier (PA). A 10 W two-stage X-band gallium–nitride monolithic microwave integrated circuit ( PA with a peak power-added efficiency of 55%, is tested with drain supply modulation from 10 to 20 V with an increase in efficiency and substantial degradation

This study presents a wideband crossover developed using substrate integrated coaxial line (SICL) technology. The proposed SICL-based crossover isolates the two physically overlapping channels by routing the signal in a middle conductor of SICL through the transmission line created in the top and bottom ground plane using a metalised blind via. An equivalent model is proposed to study the role of substrate

Moving toward commercialisation of chipless radio-frequency identification (RFID) systems, there is a significant challenge for the detection of chipless tag in a practical application, in which the conventional calibration techniques such as background subtraction are insufficient or even impractical. In this study, first, a processing algorithm for an inverse problem based on the range estimation

This study proposes a design of a double-sided printed dipole (DSPD) antenna array with a low first sidelobe level (FSLL) for interference suppression. The proposed array consists of ten DSPD antennas based on the Rogers RO4003C substrate ( ɛr = 3.55). The FSLL has been compressed by imposing a single null at the centre of the first sidelobe. The excitation power distribution of the array has been

This study explains a novel wideband curvilinear Sierpinski fractal geometry (CSFG) based cylindrical dielectric resonator antenna. CSFG provides wider bandwidth by the combination of two important concepts: (i) reduction in volume to the surface area of the complete radiating structure, which in turn reduces the Q-factor; (ii) generation of two radiating modes inside the radiating structure HEM 11δ

In this study, a novel broadband rectenna system, capable of extracting energy from multiple RF sources is presented. The proposed topology employs a novel rectifying circuit comprising a two-port differential rectifier integrated with the hybrid coupler on a single board, which is the first structure of its kind possessing higher reliability. During measurement, the maximum efficiency of the proposed

This study introduces modelling of multi-adaptive neuro-fuzzy inference system (MANFIS) for predicting the bandwidth and notch frequencies of slotted ultra-wideband (UWB) antennas. Rectangular-shaped printed monopole antennas embedded with U-shaped slots are designed to realise triple band-notch characteristics. A MANFIS model is then developed to predict five output parameters (two cut-off frequency

In this study, the ultra-high-frequency (UHF) antenna for partial discharge (PD) detection is optimised to simultaneously satisfy the requirements of low return loss and high fidelity factor (FF) in the frequency band of interest by using the modified non-dominated sorting genetic algorithm II (MNSGA-II). Based on the labour division strategy, the MNSGA-II adopts an adaptive crossover and mutation

This study shows the potential of additive manufacturing for the fabrication of 3D Phoenix phase-shifting cell. With traditional microstrip printing technology, the cell has many advantages. Here, the authors demonstrate that the 3D printed version of the cell exhibits very good intrinsic performances in the 17–21 GHz frequency band. A deep insight into the operation mode of the cell is drawn in order

In this work, a compact antenna employing the substrate integrated waveguide (SIW) technology is investigated to achieve the characteristics of wideband and high gain. A pair of novel elliptical patches, which operate as an electric dipole, are loaded on the upper surface of the antenna. Two bow-tie-shaped slots are etched in parallel on the upper surface of SIW to obtain the features of magneto dipole

In this work, an ultra-wideband gradient metasurface (GM) is designed by using Pancharatnam–Berry (PB) phase. In the design process, a circular polarisation (CP)-maintaining metasurface (CMM) is proposed at first, which can realise ultra-wideband CP-maintaining reflection in the frequency band of 7.7–19.9 GHz, moreover, PB phase will be generated in its co-polarised reflection coefficient under CP

This study reports, for the first time, the use of coupled-line-based impedance matching in wireless power transfer (WPT) system. The transmitter and receiver of the WPT system are realised by microstrip feed line and symmetric coupled line at the top plane. The ground plane is realised with triangular-shaped defect along with the excitation slot mounted by an external capacitor. The defect in the

In this study, the authors propose an innovative solution based on mantle cloaking method to restore the performance of an implantable antenna, which is degraded due to the scattering from an adjacent metallic body. In an implantable device, the metallic body is generally used as a house for electronic circuitry. Initially, they investigate the deteriorating effects of metallic body on the antenna

In this study, a new type of horizontal radiation blade structure is proposed and applied to the very high frequency (VHF) broadband whip antenna. The influence of the radius, length, number of branches of horizontal radiation blade and its distribution on the whip body on the electrical performance of the whip antenna is analysed separately to design a more suitable structure, and then an algorithm

A super compact parasitic patch loaded patch antenna with enhanced gain and super wide band is proposed in this study for 5G millimetre-wave (mm-wave) applications. The proposed antenna has hybrid geometry and is constructed using circular and two rectangular driven patches with two semi-circular parasitic patches fed by stepped impedance microstrip line. The two rectangular stubs are incorporated

A novel microstrip lowpass filter design using rectangular split-ring resonators with dual splits are designed, analysed, and fabricated with exceptional performance such as ultra-wide stopband and sharp roll-off rate along with its compactness. The symmetrical suppressing cells are also employed to reject higher-order harmonics from the stopband without affecting selectivity. The expression for transmission

Broadband polarisation reconfigurable antenna based on crossed dipole and parasitic elements is proposed in this study, which can switch among three polarisation modes, i.e. linear polarisation, left-hand circular polarisation and right-hand circular polarisation. The proposed antenna consists of two crossed dipoles fed by a 3/4 square ring, two microstrip feeding elements etched at the centre of the

An ultra-wideband (UWB) array is presented for UHF-S band (0.19–2.3 GHz) communications with an emphasis on dual-linear polarisation and wide-angle scanning. The array achieves 12:1 impedance bandwidth for a voltage standing wave ratio (VSWR) <3 at broadside with low-angle scanning off broadside to 0°, 45°, 60° in the E -plane (VSWR < 3, 4, 3.1) and 0°, 45°, 60° (VSWR < 3, 3.8, 5.5) in the H -plane

The analytical theory describing the resonant excitation and coupling of volume and surface fields on the surface of two-dimensional complex electrodynamic structures is presented. The theoretical analysis is valid over a broad frequency spectrum from mm-wave frequencies through THz and even optical frequencies. An experimental study of planar periodic structures has been carried out using a vector

This article studies the compressed sensing (CS) technique applied in the THz linear sparse periodic array (SPA) imaging system, proposing the corresponding image reconstruction model. The THz-SPA imaging system has been tested in electromagnetic (EM) simulation, and then experimentally verified by using a simplified set-up that only uses one transmitting channel and one receiving channel. The reconstructed

In quasi-optical systems, the beam distortion and the cross-polarisation caused by the offset reflectors get a lot of attention. Also, the distortion was thoroughly studied in previous works. In this study, the authors give the detailed derivations of exact and approximate expressions of cross-polarisation and some simple explanations about energy conversion between co- and cross-polarisations in two-dimensional

This study presents a novel design of circularly polarised horn antenna in W-band with wide impedance bandwidth and 3 dB axial ratio (AR) bandwidth. By introducing a pair of grooves on the wall of a horn antenna, this simple and compact structure is capable of generating a circular polarisation (CP) wave without any extra polariser and is expecting a better power-handling capability. The full-wave

Terahertz technology is a hotspot in the current academic research. In this study, a 400 GHz broadband multi-branch waveguide hybrid coupler is designed, but it is very difficult to fabricate. In order to release the processing difficulty, a modified five-branch hybrid coupler has also been designed, fabricated and measured. The hybrid coupler consists of five modified branches and has been optimised

Losses are often the impairing feature of metamaterial true time delay line devices. In this study, the authors analytically demonstrate that ohmics losses in this kind of structures as well as impedance mismatch depend on the bandwidth. These results allow to consider wide band application for radar systems. It is verified experimentally that metamaterial delay line devices are fitted for wide band

In this work, a beam-steering array antenna for pattern stabilisation is presented. The antenna element consists of two layers with a unique structure of microstrip to coplanar waveguide (CPW) transition to cover a frequency range from 20 to 30 GHz and a stable pattern at all operating frequencies. To increase the gain of the antenna element, an elliptical broadband Fabry–Perot cavity structure is

This study presents a compact printed dipole antenna/tag loaded by metamaterial (MTM) inclusions for portable near/far-field communication/identification applications. It is shown that loading a printed dipole antenna by epsilon negative inclusions can lead to achieving the miniaturised, dual-band, low-profile antenna. To realise this concept, inductively loaded wire (ILW) has been proposed. To implement

The authors present a machine learning approach for the extraction of radiowave propagation models in tunnels. To that end, they discuss three challenges related to the application of machine learning to general wireless propagation problems: how to efficiently specify the input to the model, which learning method to use and what output functions to seek. The input that any propagation modelling tool

A proposed method for achieving active load-modulation technique without using a quarter-wavelength transmission line is discussed and evaluated. The theoretical analysis shows that the active load-modulation can be achieved without using a quarter-wavelength line, where the main amplifier sees a low impedance when the input signal level is low, and this impedance increases in proportion to the amount

This study proposes an ultra-wideband (UWB) metasurface-based beam-switching antenna system. A coplanar (CP) waveguide fed slot antenna (with 49% operating bandwidth) is coupled with a hexagonal metallic aperture to generate CP beam in the 10.2–10.8 GHz band. An octagonal split ring inclusion-based meta-element is designed to achieve 2π transmission phase variation with near-unity magnitude. The principle

Glucose monitoring is an important clinical procedure, especially for dialysis patients who need consistent monitoring of their glucose levels. Currently, the most extensively used method for glucose monitoring involves pricking the finger and sampling a small amount of blood. Given that this procedure is inconvenient and can cause pain and potential infection, there is demand for the development of

A new design methodology is presented for multi-band evanescent-mode band-pass filters (BPFs) realisation by integrating substrate-integrated waveguide structure with multiple short-circuited irises. The electro magnetic (EM)-behaviour of the distributed-element structure is modelled with the lumped-element equivalent circuit in a wide frequency range. Arbitrary transmission poles (TPs) and transmission

Due to the explosive increase of wireless devices, efficient over-the-air testing of such devices is highly desirable. The reverberation chamber (RC) offers efficient and cost-effective means to determine performance metrics of wireless devices, such as total radiated power (TRP). In this study, the distribution of the measured TRP in an RC is analytically derived, based on which the statistics (i

This study presents a frequency scanning Fabry–Pérot cavity antenna with a single 2D varying partially reflecting surface (PRS) operating from 9.4 to 10.6 GHz. A probe-fed stacked rectangular patch antenna is applied as the primary source. A PRS consisting of 9 × 9 cells, whose sizes vary with azimuth, is mounted upon the source to modulate the phase efficiently. Due to the opposite correlations between

This study presents a study on the radio channel modelling for realising reliable wireless communication in kitchen environments. The study allows optimising the wireless communication between a cooking pot and the kitchen hood in a smart home's kitchen. The delay, angular and path loss characteristics of the wireless channel are obtained from channel sounding measurements. The authors compared path

This work discusses the design of a microstrip patch antenna and its use as an orientation-agnostic radiator in an origami-inspired folding antenna array. The antenna is based on a perturbed circular patch design that is impedance matched to reside in a radial feed network for a 2 × 2 array. This 2 × 2 array can be switched to provide sum and difference pattern behaviour. Both the feed network and

In this study, an X-band low-profile monopulse array antenna with high aperture efficiency is proposed for tracking applications. It is consists of a 112-element patch array antenna, a monopulse comparator, and a full corporate feed network which is composed of the waveguide and microstrip dividers. The monopulse comparator and waveguide part of the feed are produced out of a single-layer substrate

A planar LTE/sub-6 GHz 5G multiple-input and multiple-output (MIMO) antenna integrated with mmWave 5G beamforming phased array antennas for future vehicle-to-everything (V2X) applications is proposed. The proposed antenna consists of two multi-band elements for LTE and sub-6 GHz 5G bands, two single-band elements for the sub-6 GHz 5G band, and four mmWave 5G beamforming phased array antennas. Two compact

In this study, a frequency selective surface (FSS)-based rasorber has been proposed by combining the designs of split-ring absorber and dual bandpass FSS, which are printed on the front and backside of 0.8-mm thick FR-4 substrate, respectively. The proposed FSS-based rasorber is a thin single layer structure and also exhibits the polarisation-insensitive behaviour due to its four-fold symmetry. The

To apply polarisation information of radar signal in radar reconnaissance equipment, a joint estimation algorithm of the radar signal direction of arrival (DOA) and polarisation parameters based on dual-polarisation antenna array has been researched in this study. The mathematical model of dual-polarised circular array has been given, and the joint estimation method of DOA and polarisation parameters

This communication investigates the convergence behaviour and accuracy of a near-field corrected iterative physical optics scheme for scatterings by imperfectly conducting and dielectric objects. The scatterings by large and complex impedance surface bodies such as fixed wing aircraft, rotatory wing aircraft, tank, vessel, and boat are computed and compared with those of a full-wave method. Several

A waveguide fed transverse slot has been analysed using the Method of Moments (MoM) formulation, wherein the internal admittance matrix elements have been evaluated from image theory and using the images of the slot due to waveguide walls. The contribution from all the images not in the same row as the slot has been evaluated using a closed-form expression and a rapidly converging series with negligible

The time-domain simultaneous signal and noise analysis of mm-wave/THz devices (diode) modelled as a transmission line is considered. For such devices, stochastic telegrapher's equations of a transmission line are extracted assuming a quasi-transverse electromagnetic mode. Since the analytical solution for these equations does not exist, numerical analysis of such equations is presented here in millimetre-wave

This article proposes a simple method of designing a highly efficient wideband parallel-circuit (PC) class-E/F 3 power amplifiers (PAs). A combination of the double-reactance compensation technique and fundamental as well as third-harmonic series-tuned resonators is used for the design of the PC class-E/F 3 PA output matching network. The step-by-step design flow and corresponding equations to calculate

Guided modes excited by a current source in a multilayer cylindrical structure is thoroughly investigated. The guidance condition in the multilayer structure is formulated. Based on this, three antenna configurations in cylindrical stratified media that are of strong practical interest are rigorously investigated: viz. a monopole antenna, a conformal axially-directed slot antenna and an azimuthal slot

This study presents the implementation of a waffle-iron filter in multi-layered substrate integrated waveguide technology, together with an approximate technique for measuring the stop-band scattering parameters of such a multi-mode waveguide filter. Two filters are designed for different stop-band widths, and tested. Two measurement techniques are presented – one utilising a set of measurements with

A broadband short-length lens antenna operating in W band is presented in this study. The lens is composed of a dielectric host material with numerous variable square holes drilling on it, which is fabricated using the three-dimensional printing method with high accuracy and low cost. Then, the lens is mounted directly on the end of a length-shortened horn antenna, obtaining a compact lens antenna

Aiming to improve the SWIPT (Simultaneous Wireless Information and Power Transfer) technologies, this work proposes a novel Dual-Output quasi-Yagi antenna (DOQY), designed by combining a single classic quasi-Yagi antenna (QY) and a dedicated frequency splitter in order to behave as two distinct antennas, one operating at 1.8 GHz mobile communication band for data communication and another at 2.4 GHz

In this study, high common-mode (CM) suppression balanced substrate-integrated waveguide (SIW) bandpass filter (BPF) and half-mode SIW (HMSIW) directional coupler are formed by two vertically stacked identical SIW or HMSIW single-ended ones and an aperture etched on the common ground between them. Under CM operation, the aperture is perfect magnetic conductor (PMC). When the height is less than λ g

This study proposes a coplanar waveguide-fed circular monopole antenna that is designed by ink-jetting conductive silver particle ink on photo paper. The antenna comprises a slotted circular patch and a reduced symmetrically slotted ground plane that is etched rectangularly. The slotted circular patch and ground plane provide the design flexibility with a broad bandwidth, substantial gain over 1.66–56

At present, it is a trend in wireless communication to integrate conventional separate components into a single one for further miniaturisation and whole performance optimisation. In this study, a novel filtering Doherty power amplifier topology is proposed, which incorporates a bandpass power divider for power division. The power divider is characterised by third-order bandpass response and good out-of-band

In this study, a compact configuration of frequency reconfigurable filtenna, designed by integrating a bandpass filter and with a monopole radiator, is demonstrated for achieving high-frequency selectivity along with compact size. The proposed filtenna can be efficiently tuned between ultra-wideband (UWB) and C-band states of operation. A bandpass filter, based on rectangular stepped impedance stub

In this study, a novel quasi-transverse electromagnetic (TEM) transmission line (TL) on a single-layer substrate is presented. The proposed structure comprises bilateral metalised vias and two longitudinal slots on the top and bottom plates, respectively. This two-conductor TL separated by the two slots allows the quasi-TEM mode and guarantees high isolation due to the vias which constrain the electromagnetic

The authors propose a new metamaterial-inspired substrate integrated waveguide (SIW) that utilises broadside-coupled complementary split ring resonators (BC-CSRRs) instead of metalised via holes, to confine propagation within the guiding channel. Due to the resonant behaviour of the BC-CSRRs, blocking of in-plane propagation is achieved in a straightforward and efficient manner. The final waveguide

Plane-wave scattering by metallic grating with artificial anisotropic substrate is a problem solved in this study for the design of broadband reflectarrays. For determination of the reflection characteristics of such structures, a generalised transmission line modelling is used for evaluating the dyadic Green's function. This function is utilised in a summation equation used for calculating the induced