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

Diffraction at a strip with one face soft (electric) and the other hard (magnetic) is studied. New results obtained by the method of moments (MoM) are compared with the asymptotic theory of edge diffraction (TED) for the totally soft and hard strips. Attention is given to diffraction of oblique incident waves including the grazing diffraction. Novel analytic estimations for the forward and backward

The objective of this study is to try to find a canonical solution to realise transversal bandpass filters (BPFs), especially transversal BPFs with high order. For this purpose, first, a new configuration composed of coupled lines and transmission lines is proposed. After a series of simple transformations and approximations executed, the proposed configuration is simplified to a circuit with four

In this study, the differential substrate integrated waveguide (SIW) slot antenna array is proposed with intrinsic common-mode (CM) rejection. Through field analysis, it is found that the SIW is a natural differential transmission line which can only transmit differential signal due to the characteristics of hybrid electromagnetic boundary perfect electrical conductor and perfect magnetic conductor

In this study, a single-layer balanced wideband phase shifter with a wide phase shift range of 45°–315° and acceptable common-mode (CM) suppression is proposed. The main branch has a simple ladder-like structure and the reference branch utilises a coupling structure. The main branch electrical length is constant for any desired differential-mode (DM) phase shift. Assuming a specific return loss (e

In this study, a reconfigurable, two-element, multiple-input multiple-output (MIMO) printed inverted-F antenna (PIFA) is presented with an enhanced isolation ability. The MIMO antenna system is designed using three different reconfiguration techniques that are based on positive-intrinsic-negative diodes, radio frequency micro-electromechanical switches and varactors. Their impact on the performance

In this study, first, the problem of time reversal imaging of an embedded dielectric or metallic cylinder inside another dielectric cylinder is studied. The direct problem is carried out numerically using the finite-element method. The background dyadic Green function (DGF) is computed analytically by computing radiated fields of an infinitesimal electric dipole near an infinitely long dielectric cylinder

A theoretical analysis is presented for miniaturised filters with an extended stopband and extended common-mode (CM) rejection, using loaded closed-loop resonators. A numerical method is presented to solve the equations extracted from the ideal transmission line model. Selection of critical resonator parameters to minimise filter area while simultaneously maximising the differential-mode (DM) stopband

A new microstrip tri-band filtering power divider (FPD) with favourable filtering and isolation performance based on the tri-mode fork-type resonator is presented in this study. By constructing the coupling scheme between the input transmission line and two pairs of symmetric fork-type resonators, a nice tri-passband filtering power division response can be easily achieved without an additional matching

Dirac dispersion cones enable remarkable wave phenomena in electronics as well as electromagnetic systems. In this work, the authors experimentally demonstrate for the first time the Dirac leaky wave antennas (DLWAs) at millimetre-wave (mm-wave) frequencies. The demonstrated DLWAs are implemented in the substrate integrated waveguide technology, delivering unprecedented features at high frequencies

In this study, a bioinspired computation (BIC) optimisation technique to synthesise the geometric dimensions of a lozenge-shaped broadband frequency selective surface (FSS) for electromagnetic wave filtering in satellite communications systems, for the X (8–12 GHz) and Ku (12–18 GHz) bands, is presented. A hybrid BIC technique, that combines the general regression neural network with a multi-objective

In this study, an improved alternating projection algorithm is presented for the pattern synthesis of a dual-polarised conformal array. An extra desired pattern is introduced to find an appropriate solution in the process of projecting the desired solution set to the feasible solution set. Virtual interferences are introduced to modify the solution iteratively based on the deviation between the obtained

The design and implementation of a full-duplex radio system capable of real-time analogue self-interference cancellation at radio frequency (RF) and baseband stages are presented. The system consists of a dual-patch three-port orthogonally linear polarised antenna system (without a circulator/duplexer), a homodyne dual receiver, and a differential amplifier at the baseband. The interference outputs

A wide-band push–push common-collector Colpitts voltage-controlled oscillator (VCO) using impedance peaking network and gain enhancing technique is proposed in this work. The impedance peaking network is introduced to increase the coupling factor of the differential inductor in the inductor capacitor (LC) tank without sacrificing the quality factor. The impedance peaking technique could guarantee the

This study investigates the comparative design method of a wireless power system to power sensors in an extended range when a Class E inverter is used at a certain frequency. It is known that the compatibility of the Class E inverter and the WPT system is the premise to incorporate them together. The relationship among different system parameters is discussed to ensure the soft switching of the Class

In this paper, a novel technology based on double-layer metasurfaces is proposed in order to broaden the bandwidth of microstrip antennas, which has been verified in X-band linearly polarised and circularly polarised antennas. Referring to the conventional metasurface antenna that employs slot-coupled feeding, these designs add an extra metasurface between the radiation patch and the ground plane so

A dual-linear polarisation reconfigurable broadband omnidirectional antenna is proposed. The radiating structure consists of a slotted ring and an inner square loop, which can generate omnidirectional radiation based on characteristic mode analysis. A dipole feeding network is designed and four PIN diodes are loaded into the feeding network to change the current flow direction. The final dimensions

In this study, a design, simulation, fabrication, and measurement of the TEM-TE 11 mode converter antenna (MCA) like a pelican beak are investigated. The working frequency of the pelican beak-shaped MCA (PBMCA) is the frequency in the range of 3.9–4.6 GHz (700 MHz bandwidth). Due to increasing the antenna cross-section, the probability of the electrical breakdown dramatically reduces. Electrical breakdown

To overcome the narrow axial ratio (AR) bandwidth inherent in conventional linearly to circularly polarised converters, this research proposes a metasurface (MS) with a diamond-shaped configuration that can mitigate the effect of surface wave (SW) along the MS edge and achieve a wider 3 dB AR bandwidth. The diamond-shaped MS structure is realised by slanting a square MS by 45°, and it consists of constituent

A compact single M-shaped probe fed circularly polarised filtenna (filtering antenna) without extra filtering circuit is presented in this study, in which three pair slots with different lengths are etched on its parasitic patch to produce radiation nulls at both band edges of its operating band. Furthermore, a single M-shaped probe feeding structure is used to improve the selectivity, especially for

This study presents a compact 154 GHz receiver fabricated in a 0.13 µm SiGe BiCMOS process, which is composed of a three-stage low-noise amplifier and an improved micromixer. In order to mitigate the intrinsic DC and RF imbalance of the basic micromixer, the resistor compensation is implemented at one branch of the RF paths, which achieves superior performance. Consisting of a common-emitter and two

In this study, the authors present a P-band phased array front-end for radar applications, implemented using a 0.18 SiGe BiCMOS process, thereby enhancing robustness over process-voltage-temperature (PVT) variations. It comprises a low noise amplifier, 6-bit attenuator, 6-bit phase shifter, power amplifier, T-R switches as well as control circuits. As the key here is to achieve high resolutions in

In this study, a dual-broadband reflective polarisation converter with high efficiency for both linear-to-linear and linear-to-circular polarisations based on a metasurface is proposed. Owing to the characteristics of strong anisotropy and multi-order plasmon resonances, the proposed polarisation converter can rotate an y / x polarised electromagnetic wave to its cross-polarised ( x / y ) direction

We propose a self-quadruplexing four-element multiple-input-multiple-output (MIMO) antenna system with frequency agility. Four separately-fed orthogonal U-slots are cut from the same cavity to locate the radiating patches. The frequency tuning is realized by inserting four varactors into the radiating structures. Metalized vias are used for antenna miniaturization and to reduce the coupling between

This study presents a circularly-polarised substrate-integrated waveguide end-fire antenna and four-antenna arrays for 5G beam-steering mobile devices at 28 GHz. Polarisation is achieved through implementation of a substrate-integrated waveguide notched-septum polariser. It is then loaded with a dielectric lens to improve gain, axial ratio bandwidth, and circular polarisation (CP) purity. To suppress

In this study, a novel time-domain multiple reflection method for determining the electrical properties and thickness of the sample has been proposed. The unique advantage of this method is that it employs only reflection coefficient data for the reconstruction of the properties. The proposed scheme is validated by determining the permittivity, thickness, and loss tangent values of different samples

A generalised probe method is proposed for fast and accurate complex permittivity measurements. The method is based on the simulated reflection coefficients using the finite difference frequency domain method. A database is set up, which consists of the simulated complex reflection coefficients of the unknown material under test. A fast searching algorithm is performed to match the measured reflection

An array antenna design based on a gridded parasitic patch stacked microstrip antenna element is presented. The radiating part in the top layer of one antenna element has nine rectangular metal patches placed in a grid with three rows and three columns with a separation of 0.1 mm between the patches. Two means of realising the array are investigated. In a regular concept, the parasitic patches of individual

Analogue predistorter (APD) has gained a new significance due to the need for high bandwidth in the fifth generation (5G) communication. As predistorted signal is generated in the analogue domain, it is free from data converter bandwidth limitation and presents an attractive linearisation solution for power amplifier (PA) in the 5G base station. Furthermore, it also finds its application in the multicarrier

This study presents a novel radial uniform circular array (UCA) antenna for quad-mode orbital angular momentum (OAM) multiplexing in the 5.2   GHz band. The antenna can simultaneously generate four OAM modes (±1, ±2) using two radial UCAs printed concentrically on a single substrate. Each UCA is connected to an individual dual-mode feeding network, and generates a pair of complementary OAM modes. The

In this study, a series of rat-race couplers with bandpass filtering responses and impedance transforming characteristics are presented based on novel coupled-line structures. Firstly, a novel filtering rat-race coupler core circuit is proposed by introducing coupled-line structures into conventional rat-race coupler. Then, a series of rat-race couplers with enhanced filtering responses and stopband

In this study, a broadband and high gain dielectric-rod end-fire antenna are proposed for applications on both the K and Ka bands. By employing the double-ridged waveguide (DRW) feeding structure which is composed of a coaxial line to tapered DRW transition, a parabolic tapered DRW, and a parabolic-tapered flared parallel waveguide section, the impedance bandwidth of this proposed antenna is broadened

Epoxy resin (ER) composites reinforced with micro-sized oil palm empty fruit bunch (OPEFB) were fabricated to improve the biodegradability of electromagnetic interference connector gasket. The dielectric properties, transmission coefficient | S 21 |, reflection coefficient | S 11 |, reflection loss, power loss and shielding effectiveness were studied at a frequency range of 8–12 GHz. OPEFB–ER composites

This study presents a novel dual-band filtering power divider (DB-FPD) structure with independently controllable bandwidths for dual-band application. The proposed DB-FPD structure is constructed by shorted G- and T-shaped patch resonators, and meandered slot lines are etched on shorted patch resonators to generate resonance in the upper band. The 3 dB fractional bandwidth (FBW) of designed DB-FPD

This work presents improvements for inclined thin wire simulation in finite-difference time-domain (FDTD). Modelling of the corners of staircase geometries is proposed by adding the accumulated charges at an edge region. This correction is important due to the delay of the electromagnetic fields propagation on the stairs. To test the validity of the proposition, the v-dipole fed by a resistive voltage

A compact high-isolation planar eight-way power divider using a zero-phase isolation circuit is presented. The composite right- and left-handed transmission line is applied to achieve good input impedance matching, and the hybrid coplanar waveguide (CPW)/microstrip line is used to get a compact circuit size in the eight-way power-dividing circuit. In addition, the zero-phase microstrip line is applied

A broadband circularly polarised (CP) stacked antenna with a sequential-phase feed technique is proposed in this study. The antenna contains a square ring that is encircled by four driven patches. The gap-coupled feed method is used to transfer energy from the square ring to the driven patches. Moreover, four stacked patches are placed above the bottom layer to enhance the impedance and CP bandwidths

Modern electronic industry requires simultaneous monitoring of electronic devices from their production, usage, up to their recycling. Therefore, the traceability system is becoming more and more popular in this modern electronic industry. In this study, such a system working in the ultra-high frequency range was demonstrated. A functional part of the system (sensor) was produced using different technologies

A high gain, low specific absorption rate, oval-shaped monopole antenna is presented. It is backed by an all-textile 3 × 3 array of electromagnetic bandgap (EBG) unit cells. The antenna is printed on the thin Rogers ULTRALAM 3850 substrate, while the EBG array is composed of the conductive ShieledIT Super and dielectric substrate felt. The design operates at 2.45 GHz of the Industrial, Scientific,

Multilayer radar absorbing material (MRAM) is composed by superimposing different dielectric material layers with various thicknesses for reducing the reflection of electromagnetic (EM) wave. In this study, a novel triple-objective optimisation scheme based on Pareto-integrated artificial bee colony (P-ABC) algorithm is presented for the fully-optimised design of four broad-band and broad-angle MRAMs

To guarantee shipping safety, it is crucial to build a reliable wireless communication network. This study presents characteristic analysis of shipping wireless channel based on measurements. The authors conduct five channel measurements for two important water mobile communications, covering inland river and sea scenarios. Channel characteristics, e.g. power delay profile, amplitude distribution,

In this study, a low cost, broadband and high gain multilayer multiresonator microstrip antenna (MSA) is designed. It consists of one metallic fed patch at the bottom layer and two circular patches (1B2 T) are printed on the bottom side of the top FR4 substrate layer, which is air suspended. Two configurations with the bottom patch of circular and elliptical shapes are compared. The elliptical 1B2 T

This study deals with the affine transformation that is used to convert the triangular element grid of a planar phased array antenna into a square one. By means of this kind of transformation, it is possible to apply the iterative Fourier transform (IFT) method to synthesise low sidelobe tapers for array antennas featuring a triangular grid. Combination of the IFT method with an affine transformation

In this study, a novel compact radio frequency identification (RFID) tag antenna with a combination of a dipole and the double-layer symmetric electromagnetic band gap (DLS-EBG) structure is proposed for metallic objects in ultra-high-frequency (UHF) band. The DLS-EBG unit cell consists of a symmetrical double-layer structure and offset vias for tag miniaturisation. The equivalent circuit model of

Differentially fed six-beam switchable reconfigurable antenna is proposed in this study. The antenna consists of radiators, parasitic elements, cross-shaped feeding network and the ground plane. The radiators are formed by two pairs of gear-shaped cross dipoles. By changing the excitation differential ports to drive one of two pairs of dipoles, and by enabling different reflectors, the beam can be