Since its inception, multiple-input multiple-output (MIMO) has become a magical technology that continues to break new grounds and deliver the needed upgrades in mobile communications. The emerging 5G systems are also being labelled by many as the massive MIMO generation. This somewhat oversimplified view is perhaps a reflection of the great impact MIMO has had on our generation of mobile communication

This Letter presents the design of a low-profile and low-cost transmitarray antenna operating at 122 GHz. The transmitarray design is based on unit-cells with 1-bit phase resolution. A single RO4350B substrate layer is used to form the unit-cells resulting in a total thickness of 0.326 mm. A wideband shift in the transmission phase of is generated by rotating one metal layer of the unit-cell by . The

Shipboard platforms have numerous antennas crowding topside space. Consolidating these antennas would require having antennas with multi-frequency capabilities. A Gregorian parabolic stacked antenna provides multi-frequency capabilities on a single pedestal which reduces the number of antennas required on a US Navy shipboard platforms. This Letter depicts the simulated design and radiation pattern

Rapid and accurate detection of COVID-19 is a crucial step to control the virus. For this purpose, the authors designed a web-based COVID-19 detector using efficient dual attention networks, called ‘EDANet’. The EDANet architecture is based on inverted residual structures to reduce the model complexity and dual attention mechanism with position and channel attention blocks to enhance the discriminant

This Letter presents a millimetre-wave CMOS oscillator, which achieves 4.9 dBm output power with 16% peak power efficiency. A phase noise of at 1 MHz offset frequency and 26.7% tuning range around 57.5 GHz centre frequency were verified experimentally. To the best knowledge of the authors, the output power, efficiency, and phase noise performance are the best among fundamental CMOS oscillators in the

Efficiency-enhanced and high-precision input common-mode feedback control (ICMFB) is proposed for a fully differential readout circuit of the MEMS capacitive sensor. This ICMFB improves the efficiency and performance of input common-mode voltage control using a smaller feedback capacitor. The noise performance of the readout circuit is improved as a decrease of a feedback capacitor. The correlated

This Letter presents a global shutter image sensor based on PIN photodiodes intended to be used for optical coherence tomography (OCT) in the spectral domain, where the light is brought to the photodiodes via optical waveguides monolithically integrated on top of electronics in a photonic layer. Photodiodes are optimised to have the peak responsivity in the wavelength range between 800 and 900 nm,

Camera-based object detection in low-light/night-time conditions is a fundamental problem because of insufficient lighting. So far, a mid-level fusion of RGB and thermal images is done to complement each other's features. In this work, an attention-based bi-modal fusion network is proposed for a better object detection in the thermal domain by integrating a channel-wise attention module. The experimental

Convolutional neural networks for image steganalysis demonstrate better performances with employing concepts from high-level vision tasks. The major employed concept is to use data augmentation to avoid overfitting due to limited data. To augment data without damaging the message embedding, only rotating multiples of or horizontally flipping are used in steganalysis, which generates eight fixed results

Depth-image-based rendering (DIBR), as the most popular view synthesis method, is commonly used in the application of multi-view and free-viewpoint videos. However, the quality evaluation of DIBR-synthesised videos remains largely unexplored, which may hinder the development of more advanced view synthesis technology. With this motivation, this Letter presents a new quality metric for DIBR-synthesised

Identification of time delay is a prerequisite for the realisation of control compensation. The existing researches generally assume that the system input should be monotonic, which is unsuitable for online identification due to system saturation. To solve this problem, relaxed input conditions are developed in this Letter. Then a modified least-square algorithm with forgetting factors, which has a

This Letter introduces an optimisation method that is based on parallelism to simulate the behaviour of foraging ants using spiking neural P (SN P) systems. The proposed method is designed by collaborating several SN P systems to obtain a polynomial time optimal solution. The complexity and reliability of the method have been verified. A theoretical analysis has been performed on the measures of complexity

Two screen printing inks were developed for the low-temperature fabrication of printed and flexible thick film negative temperature coefficient thermistors able to operate at room temperature. The first of the two screen printing inks developed utilised cobalt ferrite (CoFe 2 O 4 ) as the temperature sensing material with the second ink incorporating manganese ferrite (MnFe 2 O 4 ). These were then

This Letter presents a new real-time and compact current-mode temperature sensor for system-on-chip thermal monitoring. The proposed temperature sensor provides a low-cost readout scheme that utilises a current switching comparator and dual-control bucket searching algorithm. It does not require an ADC or charged capacitor with large area and power dissipation. The dynamic element matching and threshold-setting

An anti-parallel (AP) diode pair based on a Fermi-level managed barrier (FMB) diode was developed for the sub-harmonic mixing of terahertz waves. A quasi-optical module integrating an AP–FMB diode pair and a trans-impedance amplifier exhibited a very low noise-equivalent-power of 9 × 10 −19 W/Hz at an input signal frequency of 304 GHz with a very low local oscillator power of 30 μW.

This Letter presents a miniaturised multi-channel millimetre-wave filter bank implemented by stripline and substrate integrated waveguide (SIW). Since the orthogonal transverse electric mode and transverse electromagnetic mode can coexist in the same hybrid structure cavity and be transmitted almost without mutual interference, embedding stripline into SIW to miniaturise the size of the filter bank

Photonics-based radar enables a large operation bandwidth that is particularly favourable for high-resolution synthetic aperture imaging. However, how to implement fast and high-accuracy imaging with photonics-based broadband radar is still an open question. In this Letter, the performance of photonics-based inverse synthetic aperture radar imaging with frequency-domain and time-domain algorithms are

Owing to the existence of non-line-of-sight (NLOS) signals in global navigation satellite system (GNSS) challenged environment, the real-time kinematic (RTK) position precision is seriously damaged. In order to improve the position accuracy, the authors propose a robust positioning method which tackles this problem by detecting the NLOS through a decision tree and estimating the double-differenced

In this Letter, the authors report a flexible CMOS chip converted by a novel chip transformation process. To realise a truly flexible CMOS chip, a two-step etching process was employed in the transformation process: (i) vapour etching to remove inter-dielectric layers followed by polymer encapsulation and (ii) plasma etching to remove the substrate of the chip. The I–V results measured after the chip

A reverse conducting (RC) insulated gate bipolar transistor (IGBT) with p-float and n-ring surrounding trench-collector is proposed. The p-floats surrounding sidewalls of trench-collectors suppress snapback and also avoid snapback when there are semiconductor/trench-collector interface charges ( Q f ). The n-rings surrounding the top of the trench-collectors speed up the forward recovery and ensure

Active noise control is an expanding field that requires a suitable synthesis of secondary perturbations. Unfortunately, most schemes for noise cancelling do not take into account that the input signal that drives the adaptive filter can be noisy. In this Letter, it is theoretically shown that noise perturbations in the excitation data degrade the performance of the standard filtered-x least mean squares

A new, direct and practical scheme is proposed for determining the model orders of a system, its signal and disturbance using key properties of Kalman filter (KF). Unlike conventional methods, it enjoys the unique property of being both necessary and sufficient. The system is described by the Box–Jenkins model, whose accessible input and output are corrupted by unknown zero-mean white Gaussian-distributed

In this Letter, based on certain binary Golay complementary pairs and deletion function, a new construction of binary near complementary sequences with low peak-to-average power ratio is proposed. The length of these sequences takes the form (where a , b and c are non-negative integers) and has not been reported before.

In this Letter, a new beamforming technique called sliding beamforming is proposed for target detection when a strong jamming signal is present. The basic philosophy of the sliding beamforming is to repeat an antenna-pair beamformer in a sliding manner across the array to completely eliminate the jamming signal while preserving the gain of the array. For uniform linear antenna arrays, only a single

The third generation partnership project has recommended π /2-binary phase-shift keying (BPSK) in discrete-Fourier-transform-spread orthogonal frequency division multiplexing (DFT-s-OFDM) for low peak-to-average power ratio (PAPR) uplink transmission. Recently, the rotation angle of 7 π /6 for rotated BPSK has been proposed by J. Kim et al. to achieve optimal PAPR performance. However, the authors

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