This Letter presents a dual linearly polarised microstrip antenna for base station applications. Firstly, a dual-polarised metasurface-based antenna element employing differential feeding technology is proposed. The proposed antenna element achieves a simulated bandwidth of 11.6% for | S 11 | < −15 dB, mutual coupling better than 30 dB, and the cross-polarisation discrimination level over 35 dB. Secondly

A compact and wideband slot antenna backed by a square substrate integrated waveguide (SIW) cavity is presented. By exciting the dual-slotted SIW cavity with an offset coaxial feed, a transverse electric (TE) 110 resonant mode along with two hybrid modes as combinations of TE 110 and TE 120 resonances can be generated within a close range. The triple resonances contribute to producing a wideband response

In this Letter, an asynchronous spike-driven processor based on gated recurrent neural network algorithm for electrocardiogram (ECG) cardiac arrhythmias detection has been designed. Based on the processor, the proposed ECG detection model, containing a many-to-many gated recurrent unit layer and a fully connected layer, can achieve a high classification overall accuracy of 97.8% using the MIT-BIH arrhythmia

Vein texture elements in images are sometimes degraded due to centrally symmetric blur, e.g. due to motion of hand or camera not being in focus, which significantly affects recognition systems performance. Multiscale local phase quantisation (MLPQ) can effectively improve system accuracy in the presence of blur by dividing vein images into non-overlapping blocks and extracting multiscale local phase

In the current image processing field, medical image segmentation needs a lot of groundtruths, and the process of making these groundtruths is time-consuming and laborious. Thus, a novel retinal vessel segmentation algorithm without groundtruth is proposed in this Letter. The hierarchical clustering algorithm is first used to binary classify vessel and non-vessel pixels. Then classification results

A compact and robust physically unclonable function (PUF) for secure key generation is proposed. With the help of a cross-coupled amplifier, the leakage-current mismatch between the two transistors was digitised to produce a unique chip identification. The measurement results show that the proposed PUF has the best-in-class randomness and uniqueness, as well as the following features: (i) an ultra-small

A novel multi-stage pipelined extended-counting (EC) for 3D-stacked CMOS image sensors is presented, which combines the benefits of a pipelined ADC, a first-order ADC and the EC principle in order to simultaneously achieve a high resolution and a high frame rate for 3D-stacked imagers. By assigning each stage of the pipeline to a sub-column of pixels while choosing another input stage of the pipeline

This Letter presents an optimised cascaded integrator comb (CIC) filter sharpening algorithm embedding a fifth-order finite impulse response filter, which improves the worst-case alias rejection and simultaneously compensates the passband droop. The sharpening filter is designed without multipliers, which reduces hardware complexity. The results of a fourth-order CIC filter design practice show that

This Letter proposes a single event double-upset (SEDU)-fully-tolerant latch, referred to as FBSET, mainly featuring four interlocked branch circuits implemented by stacking three PMOS and one NMOS transistors or three NMOS and one PMOS transistors to achieve low power dissipation. The latch exhibits up to 84.56% area-power-delay product saving compared with recently reported latches. Simulation results

In this Letter, step-controllable radio frequency (RF) micro-electro-mechanical systems (MEMS) tunable capacitor with ultra-wide tuning range using netted membrane structure has newly proposed, fabricated, and characterised for highly miniaturised and reconfigurable RF devices and systems applications. The proposed tunable capacitor could step-wise increase the capacitance by introducing a few slits

As one of the most fundamental tasks in computer vision, semantic segmentation assigns per pixel prediction of object categories. Training a robust model for semantic segmentation is challenging since pixel-level annotations are expensive to obtain. To alleviate the burden of annotations, the authors propose a weakly-supervised framework for zero-shot semantic segmentation, which can segment images

This work considers a discrete-time multi-server queue with batch arrivals of packets having a deterministic length. By a novel analysis, the packet delay distribution is computed with a very light computational workload.

In this Letter, the physical layer security for a novel reconfigurable intelligent surface (RIS)-assisted non-orthogonal multiple access (NOMA) system in a multi-user scenario is investigated, where the authors consider the worst case that the eavesdropper also utilises the advantage of the RISs. More specifically, they derive analytical results for the secrecy outage probability (SOP). From the numerical

This Letter presents a new design of balanced-to-unbalanced (B2U) filtering magic-T based on circular patch resonator. Without additional circuit, the prescribed in-phase and out-of-phase specifications of the magic-T are achieved by elaborately studying and exploring the electric field distributions of the degenerate resonant modes in the circular patch resonators. Meanwhile, the desired filtering

In this Letter, a new design of dual-band patch filter is proposed with greatly improved bandwidth and miniaturised size based on one single modified circular patch resonator. In this design, a metallic via is introduced in the centre region of the patch to develop the modified resonant TM 01 mode (TM′ 01 mode), while two types of slot perturbations are adopted to separate a pair of degenerate modes

The authors present a model-free policy-based reinforcement learning model that introduces perturbations on the pattern of a metasurface. The objective is to learn a policy that changes the size of the patches, and therefore the impedance in the sides of an artificially structured material. The proposed iterative model assigns the highest reward when the patch sizes allow the transmission along a constrained

A broadband active metasurface is designed around quantum-cascade (QC) gain material for use in a broadband tunable QC vertical external-cavity surface-emitting laser (VECSEL). The metasurface is based on a unit cell containing two resonant waveguide elements that couple with the periodicity of the metasurface to produce a multi-resonant reflection spectrum. Simulated reflectance spectra exhibit full-width

A power factor correction (PFC) charge-pump (CP) bridgeless converter for LEDs is presented. In the input stage, coupled inductors, together with CP capacitors, are integrated into a half-bridge inverter, thus characterising the single stage. This topology even being bridgeless due to the positioning of the load operates with a bus voltage below the bending voltage. The CP configuration is used to

In this Letter, considering the configuration of small antenna array aperture used for special usage, the authors proposed a target trajectory estimation method by unambiguous phase differences with prior knowledge on target velocity from a single fixed passive sensor. First, they developed the maximum likelihood estimator of the target trajectory parameters based on unambiguous phase differences and

In this Letter, a 1.2 kV SiC power MOSFET with a partially widened retrograde P-well (RP) structure and N -implanting region is proposed to enhance the device's reliability. Compared with the conventional SiC power MOSFET, the short circuit (SC) ability of the proposed structure can be improved effectively without sacrificing other performance. Simulation results reveal that a 40% reduction of the

Dual-channel thin-film transistors (TFTs) show excellent effective mobility ( μ eff ) and reliability, including negative-bias-illumination stability. To enhance the performance of these devices, post-thermal annealing in air is performed for 2 h at the low temperature of 250°C. To investigate the effects of low-temperature thermal annealing, indium–zinc-oxide/gallium–indium–zinc-oxide (IZO/IGZO) dual-channel

Extreme learning machine (ELM) is a single layer feed-forward neural network with advantages of fast training and good generalization properties. However, when the size of the hidden layer is increased, both of these advantages are lost as the redundant information may cause overfitting. Traditional way to deal with the issue is to introduce regularisation which promote sparsity but in the output layer

The time-of-arrival (TOA) estimation method is an important ranging and positioning technology for indoor localisation and navigation. In this Letter, a novel TOA estimation method for smartphones based on a built-in microphone sensor is proposed, which utilises the propagation delay between optical and acoustic signals to achieve distance estimation. Unlike other TOA estimation technologies based

This Letter proposes a stochastic model of the wearable sensor nodes of a wireless body area network (WBAN) based on Markov decision process (MDP). The proposed technique tackles the problem of maximising the likelihood of data transmission while minimising the computational cost and energy. Suitable transmission strategies subject to the energy level of the nodes and channel conditions are needed

Ceramic (Ba 0.55 Sr 0.45 Ti 1.01 O 3 ) – polypropylene polymer ER182 composites-based materials were applied for sub-THz range antenna lens application in telecommunications. Typical plano-convex -shaped lenses were simulated and measured with a standard rectangular waveguide at 220–330 GHz frequency band and applied on 150 mm on-air distance. The lens fabricated with ER182 polymer material increased

Parabolic equation models discretised with the finite-difference method have been a research topic for a long time. Through the simulation of electromagnetic wave propagation characteristics in typical scenarios, it is pointed out that the fast algorithm needs to be developed for the solution of two-level Noye–Hayman (NH2) implicit method to meet the accuracy and computational requirements of electromagnetic

Providing an easy-to-use and non-invasive heart rate estimation system for home healthcare is imperative for detecting health deterioration in the early stages and for providing preventive treatments. To this end, we propose a ballistocardiographic method that estimates heart rate by analysing face videos and exploiting cyclic head motions caused by blood pumping through the carotid arteries during

A kind of impedance transformer with high impedance ratio based on tapped coupled-resonator filter theory is proposed. Differently with the published ones, the proposed filtering transformer incrementally takes impedance property of the filter into consideration. Thus, the high impedance ratio can be achieved. By proper design of impedance and type of resonator, two prototypes with impedance ratios

This communication describes a gate leakage compensation technique to ensure wide-temperature operation and wide-supply regulation of traditional self-cascode based voltage references in deep nanometre nodes ( ). Extensive simulations in 28 nm ultra-thin buried oxide fully depleted silicon-on-insulator CMOS process show that the proposed 4-transistor topology can operate down to 0.2 V, generating a

This Letter presents an electromagnetic modelling of an active integrated antenna array for 5G mobile communication. Here, the authors propose a functional method for active-integrated antenna array synthesis, based on the method of moments combined with the generalised equivalent circuit (MoM-GEC) in conjunction with a genetic algorithm for the synthesis of a 2D array with switched phase states. Their

This Letter presents a 29-/35 GHz dual-band high-gain hybrid π-network-based phase shifter. The hybrid π-network realised by combining electrical tuning through capacitors and magnetic tuning through transformers extends the phase shift range. Furthermore, the phase shift modules are inserted between the vertically stacking transistors to realise the embedded phase shifting with the minimum loss. The

In this Letter, a compact and high-performance ultra-wideband (UWB) bandpass filter based on half-mode substrate integrated waveguide (HMSIW) is proposed. A novel slow-wave structure with lowpass characteristics is developed and loaded on the HMSIW to obtain the UWB frequency response and realise size-reduction. Moreover, two rectangular slots are etched on the transition structures of the microstrip-to-HMSIW

A new compact multilayer dual-band balanced-to-balanced filtering power divider (FPD) based on substrate integrated waveguide (SIW) resonator is proposed in this Letter. Originating from the field distributions of resonant modes in the square SIW cavity, TE 201 -mode and TE 203 -mode are utilised to achieve desired differential-mode (DM) transmission and high common-mode (CM) suppression. Meanwhile

Low profile broadband substrate-integrated waveguide to rectangular waveguide (RWG) transitions have been proposed for RF verification of W-band automotive radar. The transition is designed on a PCB, which is assembled between the radar board and instrument waveguide port. In the design of the transition, a magnetoelectric (ME) dipole is introduced to excite the basic mode of RWG, and a bowtie slot

A balanced substrate-integrated waveguide (SIW) filter based on a virtual electric wall (VEW) is presented and studied in this Letter. By introducing VEW on the symmetry plane for replacing the metallic-via-array, conductor losses from metal sidewalls can be avoided. As proof-of-concept example, a six-pole balanced filter using asymmetric inductive windows is designed and fabricated with a measured

In this Letter, an active area optimisation technique to improve the performance parameters of the film bulk acoustic resonator (FBAR) is proposed. The active area of the back trench membrane-based FBAR is optimised to remove the spurious modes, higher harmonic modes, and to confine the acoustic signal at its central part during the resonance. The effect of thickness variation of SiO 2 layer on the

This Letter describes a method to quantify online and in real-time, the level of degrading of the series parasitic resistance R s of a photovoltaic (PV) panel. This method aims to obtain the herein proposed M -factor, which results from the calculation of the slopes of the I–V curve in the boundaries of its maximum power-point. For this purpose, the slight modification of the maximum power-point tracker

This study has been made to improve the detection capacity of radar using phase coded waveforms especially the Golay set sequence while keeping the sidelobe ambiguity function to the possible minimum. This Letter begins with a description of Golay complementary sets construction from a graph and a determination of the parameters on which they depend to be optimised after. Then, the simulated annealing

A GaN-based gate driver circuits have been successfully designed and fabricated using a commercially available 6-inch GaN-on-Si platform. The driver circuits consist of three-stage direct-coupled FET logic (DCFL) inverters featuring monolithically integrated depletion-mode (D-mode) and enhancement-mode (E-mode) high electron mobility transistors (HEMTs). At room temperature (RT), at a supply voltage

AsTeGeSiN threshold switching devices, which have recently gained attention for their reliable operation, are investigated for the degradation mechanism under constant voltage stress (CVS). Threshold switching devices are essential for 3D stacking of high-density memories. The degradation mechanism can be divided into two conduction regions, i.e. before and after the threshold voltage ( V th ) by applying

A new coupling scheme of a 4.28-THz quantum-cascade laser is constructed by employing two off-axis parabolic reflectors. Two parallel terahertz beams are coupled out from the symmetrical facets of the wire laser. The total effective laser power of the terahertz beams is measured by a thermal power-meter under the modulation state. The highest value of the laser effective output power is about 1.4 W

In this work, monolithic mode-locked GaSb-based lasers at 1.7 µm emission wavelength with heterodyne measurement of the frequency comb are presented. Mode-locking operation was confirmed by measuring the optical beatnote at the round-trip frequency of 9.56 GHz and analysing the frequency comb. Mode-locking operation occurred from 0.1 to 3.3 V reverse bias voltages at the absorber section and driving

An iterative adaptive approach (IAA) based algorithm is presented to realise coherent integration for the random pulse repetition interval radar. The proposed method firstly removes the effect of Doppler ambiguity via phase compensation, and then accomplishes target focusing via conducting the azimuth IAA and range inverse fast Fourier transform. Theoretical analysis and numerical experiments have

As a typical signal processing problem, direction-of-arrival (DOA) estimation has been adapted to a wide range of applications in radar-based systems. A high DOA resolution requires a large number of antenna elements which increases the overall cost. To minimise the cost, it is desirable to choose an optimum sub-array from a full array. To enable cognition, the subarrays are selected based on the present

Coprime arrays can highly increase degree-of-freedom by operating the second-order virtual signal. However, the corresponding virtual array is discontiguous, and thus most existing direction-of-arrival estimation approaches fail to utilise all received information. To avoid performance loss, the authors intend to convert the discontiguous array into a contiguous one in this Letter and propose two virtual

In this Letter, a new scheduling scheme for belief propagation (BP) is proposed to reduce the decoding latency. All the stages update messages at the same time, it improves the reliability and accelerates the decoding convergence. The authors also remove the last stage of factor graph to reduce computational complexity. Simulations show that the average decoding latency of a (1024,512) polar code is

The mobile network operators should expand their network capacity as service traffic increases in mobile networks. It is important to balance network capacity and traffic volume in terms of service quality and operating costs, and this network balance can be quantified by the capacity margin, which is defined as the difference between network capacity and traffic volume. There are two approaches to

Owing to the rapid and facile deployment of unmanned aerial vehicles (UAVs), the third-generation partnership programme has recently shown considerable interest in UAVs for assisting current terrestrial base stations. Hence, the feasibility of using UAVs has been vigorously investigated for enhancing the performance of traditional ground-based communications, e.g. coverage and quality-of-service enhancement

To reduce the sidelobe level (SLL), a ten-element non-uniform microstrip array antenna at 14.25 GHz frequency was designed. This Letter proposes an improved differential evolution algorithm, expanding the optimisation variable from one, the array element spacing, to two, the array element spacing and the excitation amplitude. Then a series linear array antenna with non-uniform spacing and unequal excitation

A novel feedforward-coupling ring oscillator (FRVCO) is presented. A comparative study in terms of oscillation frequency and phase noise is conducted between the proposed model and the traditional FRVCO. Due to the improved delay cell, high oscillation frequency, low phase noise and uniform multi-phase output can be achieved. Compared with the traditional FRVCO, under the same design parameters, the

This Letter presents a self-capacitance sensing (SCS) technique for touch screen panel with the alternating panel charge sharing (APCS) that effectively suppresses low-frequency noise and achieves a better signal-to-noise ratio (SNR). With the proposed APCS-based SCS, SNR is improved in measurement by 7.65 dB compared to the conventional panel charge sharing-based SCS.

Mobile robot path planning is an important part of the mobile robot field. The swarm intelligence optimisation algorithm has certain advantages in solving such multi-objective optimisation problems, so this Letter proposes to apply the pigeon-inspired optimisation (PIO) algorithm to the path planning problem. However, the traditional PIO algorithm is suffering from the problems of easy to get into

Ferroelectric tunnel junctions have recently attracted a lot of research interest, not only for memory operation but also for e.g. neuromorphic computing. Retention characteristics of these devices are of utmost importance in many applications. The authors have recently demonstrated the feasibility of double-layered ferroelectric tunnel junctions where the ferroelectric hafnium zirconium oxide acts

This Letter presents an alternative analysis method to derive the voltage–current transmission matrix of transmission line sections. By contrast with the approach usually adopted in many microwave engineering textbooks, the proposed method, instead of coping with the telegrapher's equations and their solutions, computes efficiently the relationship between the voltages and currents at the input and

RGB-D-based human action recognition aims to learn distinctive features from different modalities and has shown good progress in practice. However, it is difficult to improve the recognition performance through directly training multiple individual convolutional networks (ConvNets) and fusing features later because complmentary information between different modalities cannot be learned. To address

This Letter presents a method for training convolutional neural networks (CNNs) that detect targets of interest in hyperspectral images. Collecting suitable and abundant training data has been the main obstacle to the successful application of CNNs to hyperspectral target detection. To solve the problem, the authors propose a scheme to generate synthetic training data. Publicly available spectral reflectance

In this study, the authors present a novel visual tracking method using the pixel-wise posterior estimation and minibatch Monte Carlo sampling. To avoid background pixels in the noisy bounding box representation, they estimate the posteriors in a pixel-wise manner. To boost the pixel-wise posterior estimation, they adopt minibatch Monte Carlo sampling, where only a small portion of pixels are used

This Letter presents an ultrasonic waveguide sensor for measuring fluctuations in a liquid level using leaky longitudinal wave L(0,2) in a coolant loop system. A 20% cold-worked D9 fuel pin clad tube of 1000 mm long, 6.6 mm outer diameter and 0.45 mm wall thickness was used as a waveguide on which the L(0,2) mode was transmitted/received along the axial direction at 500 kHz. When the waveguide got

A wide locking range (LR) injection locked frequency tripler (ILFT) based on a dual-band voltage controlled oscillator (VCO) is proposed in this Letter. By rationally designing the transformer parameters, the VCO can easily realise the adjacent dual-band operating characteristics. The ILFT has dual LRs which can easily overlap each other at a fixed bias. A subharmonic signal is also injected through

This Letter proposes a high data rate optical transmission system for data centre interconnects, where the authors employ vertical cavity surface emitting lasers (VCSEL) and graded index few-mode fibre (GI-FMF) having modal bandwidth of around 24.3 GHz.km to enhance the link capacity and range. Additionally, they consider PAM-4 modulated data transmission at the rate of 2 100 Gbps using a pair of VCSELs