The 50 most-cited articles in Electronics Letters, 2016

A memristive Chua's circuit regarded as a paradigm is reconsidered to exhibit its extreme multistability in this Letter. Memristor initial state‐dependent dynamics is analysed and the coexistence of infinitely many attractors related to memristor initial states is revealed by numerical simulations and circuit simulations. The dynamical behaviour just reflects the emergence of extreme multistability in the memristive circuit.

A fast and accurate video anomaly detection and localisation method is presented. The speed and localisation accuracy are two ongoing challenges in real‐world anomaly detection. We introduce two novel cubic‐patch‐based anomaly detector where one works based on power of an auto‐encoder (AE) on reconstituting an input video patch and another one is based on the power of sparse representation of an input video patch. It is found that if an AE is efficiently trained on all normal patches, the anomaly patch in testing phase has a more reconstruction error than a normal patch. Also if a sparse AE is learned based on normal training patches, we expect that the given patch to AE is represented sparsely. If the representation is not enough sparse it is considered as a good candidate to be anomaly. For being more fast, these two detectors are combined as a cascade classifier. First, all small patches on test video frame are scanned, those which have not enough sparse representation are resized and sent to next detector for more careful evaluation. The experiment results show that the method…

A novel S‐shaped periodic defected ground structure (PDGS) is proposed to reduce mutual coupling between antenna elements. Coplanar placed antenna elements work at the same frequency band with centre frequency 2.57 GHz. Centre‐to‐centre distance between the antenna elements is 50 mm which is ∼0.43λ. The PDGS is three S‐shaped defected ground structure units placed between microstrip antenna elements. By using the proposed PDGS, more than 40 dB mutual coupling reduction between microstrip antenna elements is achieved.

A frequency selective surface with absorptive/ transmissive property is represented. It allows waves at high frequency around 10 GHz to transmit with very low insertion loss by using the resonance between a parallel microstrip LC structure. It also possesses a wide absorption over lower band by inserting lumped resistors into elements. The absorption band is over 3–9 GHz. A prototype is fabricated and its absorptive/ transmissive performance is measured.

Quantum‐dot cellular automata (QCA) is an emerging field‐coupled nanotechnology that promises to outperform existing CMOS technology. Single‐layer QCA designs of full adder, full subtractor, ripple carry adder, and ripple borrow subtractor is proposed. The proposed designs are improved over both existing single‐layer designs and multilayer designs.

A new linear sparse array based on the nested array is proposed, which enjoys all the good properties of the two‐level nested array, and can provide more degrees of freedom (DOF). The new array is constructed by two uniform linear arrays (ULAs) and an additional sensor. The sensor locations, the array aperture, and the achievable DOF from its difference co‐array (DCA) are all benefited for closed‐form expressions. Furthermore, the resulting DCA is kept as a hole‐free ULA. The optimal numbers of sensors in the two ULAs provided the total number of physical sensors are derived. This new array can resolve more sources and achieve better angle estimation performance than the two‐level nested array. Simulation results validate these conclusions.

A structure of a compact ultra‐wideband monopole antenna has been presented. The antenna consists of a microstrip‐fed rectangle radiator as well as a ground plane with a rectangle slit and an L‐shaped stub. The critical factor in achieving a small size is a careful design procedure involving numerical optimisation of all geometry parameters of the antenna aiming at explicit size reduction while maintaining acceptable electrical performance. The final design exhibits dimensions of only 9.45 × 18.5 mm and a footprint of 175 mm 2 . Experimental validation and comparisons with competitive designs are also provided.

A novel approach to suppress the ambipolar behaviour and enhance RF parameters is proposed for the first time. For this, the dielectric and gate material work function engineering is used to suppress the ambipolar behaviour individually. Further, the combination of gate dielectric and gate material work function engineering is used to suppress the ambipolar conduction in huge amount and to eliminate the hot carriers effects. Apart from these, the proposed work improves the ON‐state current and RF figures of merit for symmetric devices.

A new printed MIMO system with eight elements for a 5G mobile terminal is investigated. The MIMO system consists of printed planar inverted‐F antenna elements operating at GSM1900 (1880–1920 MHz), LTE2300 (2300–2400 MHz) and LTE2500 (2540–2620 MHz). The antenna elements have a compact size of 14 mm × 15 mm and are deployed on the non‐metalised part of a PCB with dimensions 136 mm × 68.8 mm × 1 mm. By only utilising radiation pattern diversity, good isolations and envelope correlation coefficients for both MIMO systems are achieved. The mean effective gains of the antenna elements are also presented.

A novel MIMO sharp band‐notched antenna with high isolation for UWB applications is presented. The antenna consists of two antenna elements with an overall area of 18 × 36 mm 2 . A T‐shaped stub is extruded in the ground plane to improve isolation and an L‐shaped stub to introduce band‐notched function C‐band (3.62–4.77 GHz). The designed antenna possesses a low mutual coupling of <−20 dB over the operating band from 2.9 to 20 GHz. The performance of this antenna is studied in terms of isolation between the two ports, radiation pattern, efficiency, realised gain, and envelope correlation coefficient.

Closed ring resonator (CRR)‐based quad‐band metamaterial absorber is presented. The unit cell of proposed absorber consists of four separate CRRs which are diagonally connected to square patches enclosed within an individual CRR. The structure is fabricated on 0.8 mm‐thick FR4 substrate. Simulated peak absorptivities of 98.5, 97.7, 94.8, and 96% are obtained at 4.34, 6.68, 8.58, and 10.64 GHz, respectively. The measured and simulated absorption characteristics of the proposed absorber are in good agreement. The proposed absorber is wide angle and polarisation insensitive and has identical absorption characteristics for both transverse‐electric and transverse‐magnetic polarised radiations.

Radiating twisted beams, orbital angular momentum (OAM) based radar provides a new perspective for present radar techniques. However, estimation methods now used has a demerit of resolution. Thus, we raised multiple signal classification (MUSIC) algorithm to improve resolution ability based on this innovative concept. The echo model based on uniform circular array for MUSIC was first built. In contrast to uncorrelated signals in classical MUSIC algorithm, echo signals from targets are fully coherent with each other. Spatial smoothing technique was subsequently utilised in OAM regime to tackle it. Simulation results showed the super‐resolution capacity of MUSIC to detect objectives compared with the traditional fast Fourier transform method.

A very simple ring‐oscillator voltage‐controlled oscillator (VCO) structure for use in VCO‐ADC applications is presented. It has a greatly improved linearity compared with previously published VCOs. Measurement results of a 1 V, 65 nm CMOS prototype confirm the effectiveness of the proposed approach.

Successful 54 Gbit/s on–off keying (OOK) transmission over 2.2 km of multimode OM4 fibre is demonstrated. The decisive advantages of the single mode over multimode vertical cavity surface emitting laser (VCSEL) in transmission experiments are shown.

A broadband circularly‐polarised monopole antenna is proposed. The broadband property of the antenna is basically achieved not only by the chifre‐shaped monopole radiator, but also its asymmetric feed. The circular‐polarisation characteristics are greatly enhanced by adjusting the location of the monopole microstrip‐feed. The antenna delivers good performance on impedance matching and circular polarisation. The measured results demonstrate that the impedance bandwidth is 72% and the 3‐dB axial‐ratio bandwidth reaches 41.6% with a central frequency of 2.5 GHz.

An error‐free wireless transmission of a 9 Gbit/s on–off keying modulated signal as well as a 4 k video signal is demonstrated using resonant tunnelling diodes as active elements in both the transmitter and the receiver. The employed system and the modulation scheme enabling the high data rate are discussed.

The realisation of a GaN high voltage vertical p – n diode operating at >3.9 kV breakdown with a specific on‐resistance <0.9 mΩ cm 2 is reported. Diodes achieved a forward current of 1 A for on‐wafer, DC measurements, corresponding to a current density >1.4 kA/cm 2 . An effective critical electric field of 3.9 MV/cm was estimated for the devices from analysis of the forward and reverse current–voltage characteristics. This suggests that the fundamental limit to the GaN critical electric field is significantly greater than previously believed.

A resonant‐tunnelling‐diode terahertz oscillator capable of wide‐band direct modulation was fabricated, and wireless data transmission at a 500‐GHz range was demonstrated. An error‐free transmission up to the data rate of 22 Gbit/s and a transmission with a bit error rate less than the forward error correction limit up to 34 Gbit/s were achieved.

The experimental results from a fabricated integrated circuit of fractional‐order capacitor emulators are reported. The chip contains emulators of capacitors of orders 0.3, 0.4, 0.5, 0.6 and 0.7 with nano‐Farad pseudo‐capacitances that can be adjusted through a bias current. Two off‐chip capacitors are used to set the bandwidth of each emulator independently. The chip was designed in Austria microsystems (AMS) 0.35μ CMOS.

A compact, broadband and single‐fed circularly polarised implantable patch antenna is numerically evaluated and experimentally demonstrated for industrial, scientific, and medical band (2.45 GHz) biomedical telemetry application. By inserting a cross‐shaped slot with unequal‐length arms in the ground plane, the proposed antenna can obtain improvement for both impedance bandwidth and axial ratio (AR) bandwidth, without increasing the backward radiation. The simulated −10 dB impedance and 3 dB AR bandwidths are 16.15% and 6.09%. The measured impedance bandwidth is 14.03%. The overall antenna size (including the superstrate) is 10 × 10 × 1.27 mm 3 .

A new approach for current sensor fault detection and isolation (FDI) for permanent magnet synchronous motor (PMSM) drives is presented. Contrary to the classical approaches for sensors fault diagnosis, based on residual generation through observers or parity equations, the proposed technique uses the average normalised machine‐phase currents. The main advantages of this approach are that it does not need any information about the PMSM or inverter models, and it involves low tuning efforts, that make it suitable for real‐time implementation with good reliability. The good performance and the robustness of the proposed FDI approach are illustrated through experimental results.

3D‐printing has been used for rapidly prototyping a low‐cost and light‐weight dielectric Fresnel zone plate lens. This lens was comprised of four dielectric zones and they were fabricated in one process with the tailored permittivities. Measurements show that this lens provides 7.3–12.8 dB gain enhancement over the frequency band from 8 to 12 GHz.

A practical condition monitoring method is proposed for the fault diagnosis of railway point machines (RPMs) by considering the difficulty of obtaining in‐field failure data. Failures in RPMs have a significant effect on railway train operations, and it is very crucial to detect abnormal conditions in RPMs. However, it is generally difficult to obtain in‐field failure data for a classifier training step. A diagnosis method using dynamic time warping is proposed to manage the variation in durations of RPM movement without a training step. On the basis of the experimental results with RPMs operated in Korea, it is believed that the proposed method without a training step can detect abnormal electric‐current shapes more accurately than previous training‐based methods.

A new class of bias‐compensated affine‐projection‐like (APL) algorithms is proposed, in which a bias‐compensation vector is derived to eliminate the bias caused by the noisy input. In addition, a new estimation method for the input noise variance is proposed which does not require the input–output noise variance ratio in advance. Simulations in a system identification context show that the proposed algorithms achieve significant improvements in steady‐state misalignment as compared with the conventional APL algorithms.

Wideband radar cross‐section (RCS) reduction of a microstrip patch array antenna is proposed and investigated. The design is based on replacing the solid metal ground of the antenna with a frequency selective surface (FSS) consisted of miniaturised hexagonal loop elements. The stop band of the FSS is coincident with the antenna working frequency band which is from 3.3 to 3.4 GHz. The FSS acts as the ground plane in the stop band and is transparent to the incident waves in the other frequencies. Therefore, preserving the antenna propagation characteristics, wideband RCS reduction is achieved from 4 to 16.5 GHz for vertical and horizontal polarisations. It is shown that using this FSS has a negligible effect on the impedance bandwidth, pattern and gain of the antenna. Also, there is a good agreement between the simulation and measurement results.

A high voltage ratio DC–DC converter is proposed which is comprised of four stages. First, an impedance network along with a switching network have been used to boost the input voltage. The boosted voltage waveform is then followed by an isolation transformer to provide another degree of freedom and obtain higher boost ability. Finally, a voltage multiplier rectifier is utilised to rectify the secondary voltage of the transformer. No switching dead‐time is required, which increases the reliability of the converter. The proposed converter benefits from the continuous input current. Besides, a comparison with the existing step‐up topologies indicates that the number of passive elements and hence the weight and size have been reduced. The operating principles were analysed and the experimental tests on a 260 W prototype reveal that a high efficiency above 91% can be achieved.

A miniaturised implantable antenna with dual‐band operation the Medical Implant Communications Service (MICS) (402–405 MHz) and Industrial, Scientific, and Medical (ISM) (2400.0–2483.5 MHz) bands is presented. The size of the proposed antenna is 31.5 mm 3 (8.75 mm × 7.2 mm × 0.5 mm) which is the smallest size compared to previous implantable antennas. A serpentine‐shaped radiating patch and open‐end slot placed on the ground plane are used for miniaturisation. The performance of the antenna was evaluated from measurements and is based on good agreement with simulations.

Automatic diagnosis of epilepsy using electroencephalogram (EEG) signals is a hot topic in medical community as traditional diagnosis relies on tedious visual screening by highly trained clinicians from lengthy EEG recording. Hence, a new methodology to automatically detect epilepsy from EEG signals considering complex network as the principal dynamics of the epileptic EEG signals can be perfectly described by complex network is introduced. A novel edge weight method for visibility graph in the complex network for detection of epilepsy syndrome is presented. The effect of new edge weights for one key characteristic (such as, average weighted degree ) of complex network is investigated. Finally, the extracted feature set is evaluated by two popular machine learning classifiers: support vector machine (SVM) with several kernel functions and linear discriminant analysis. The experimental results on Bonn University datasets show that the proposed approach is able to characterise the epilepsy from EEG signals generating up to 100% classification performance by SVM with polynomial kernel.

A Bouc–Wen model is presented and identified based on the bat‐inspired algorithm to describe the hysteresis of the piezo‐actuated stage. Based on the established Bouc–Wen model, a sliding mode controller is proposed to suppress the hysteresis non‐linearity of the piezo‐actuated stages. In order to solve the buffeting problem in the process of control, the sign function is replaced by the sigmoid function. Experiment is performed to validate the effectiveness of the proposed sliding mode controller, and the results show that the maximum error of the motion tracking control of the piezo‐actuated stage is 0.3264 μm.

A novel broadband chessboard surfaces with double layer structure to reduce the radar cross‐section (RCS) of an object is presented. By combining two artificial magnetic conductor (AMC) cells and a novel structure, 73% frequency bandwidth of −10 dB RCS reduction compared with a metallic plate has been obtained. In order to increase the bandwidth in chessboard structures, boards with high thickness are required, cheaper boards’ thickness are limited. An RO4003 board on an air substrate has been used. This technique, in addition to accommodating the designer with a new parameter, decreases the costs and increases the bandwidth greatly and also simulation results and measurements are in good correspondence.

Biomedical signals transmitted over the internet are usually tagged with patient information. Data hiding techniques such as steganography ensures the security of such data by hiding the data into signals. However, data hiding results in signal deterioration that might affect diagnosability. A novel technique which uses curvelet transforms to hide patient information into their ECG signal is presented. Curvelet transform decomposes the ECG signal into frequency sub‐bands. A quantisation approach is used to embed patient data into coefficients whose values are around zero, in the high‐frequency sub‐band. Performance metrics provide the measure of watermark imperceptibility of the proposed approach. BER is used to measure the ability to extract patient data. The proposed approach is demonstrated on the MIT‐BIH database and the observations validate that its performance is superior compared with the random locations approach. Although the performance of the proposed approach decreases as patient information size increases, the peak signal‐to‐noise ratio values are high. Therefore, the…

Non‐invasive blood glucose measurement has attracted great interest from researchers deploying various techniques where microwave sensing is one of them. Microwave resonators are utilised as sensors for measuring the glucose levels. A body part is placed on the sensor for a reading and the measurement principle lies in the change of the dielectric properties of blood with varying levels of glucose. The fingertip is a popular measurement site as there is a good amount of fresh blood supply. The position of the fingertip on the sensor has an effect on the sensor response due to the change in the propagation path of the EM field inside the finger. Moreover, fingerprints also affect the sensor response as the irregular ridges and valleys in the fingerprint introduce air gaps altering the effective permittivity seen by the sensor. The effects of fingerprints as well as finger positioning on the sensor is explored and explained.

A new non‐intrusive ac voltage measurement technique based on stray electric filed energy harvesting is presented whereby the voltage of ac power lines can be measured without removing insulation and therefore without direct contact with conductors of the power lines. The energy of electric field around the power lines is picked up and stored in a capacitor by a wire wound around insulated 3‐wire household power lines or by a conductor plate placed in the vicinity of overhead high‐voltage power lines. Autonomous switches are used to monitor the stored electric field energy in a storage capacitor and to generate pulse train. Experimental results show that the repetition rate of the output pulse is a linear function of the line voltage. Since the voltage of insulated 3‐wire household power line can be measured without removing insulation and the voltage of high‐voltage power transmission line can be measured without any contact to the conductor of the power line, the proposed technique can be widely applied to smart grid system.

The first practical demonstration of readily useable fibre Bragg gratings in long lengths (>20 m) of polymer optical fibres (POFs) is reported; this is an increase in fibre length that exceeds two orders of magnitude for use in the C‐band. A low loss perfluorinated fibre and a femtosecond‐laser, direct‐write method to inscribe gratings at two different wavelengths are used. Gratings are fabricated to operate at ∼800 nm, where the optical loss is minimal, and in the C‐band, commonly used with traditional optical fibres for the majority of telecommunication applications. The development of POF Bragg gratings inscribed in long fibre lengths is the first important step for the integration of practical sensing devices and could promote the use of multiplexed POF sensors. The sensors were tested and characterised and demonstrate their compatibility with a commercial Bragg grating demodulator.

To multiplex multiple orbital angular momentum (OAM) beams, a compact half‐mode substrate integrated waveguide leaky‐wave antenna (LWA) for generating multiple high‐order OAM modes is presented. The LWA is based on a cavity resonator with two feeds of ±90° phase difference. The principle and mode analysis of the resonator are discussed, and the generation of high‐order OAM beams is proved by the measurements.

A 30 bit high‐density circular chipless RF identification tag based on C‐shaped open end polarisation independent slots is presented. The encoding capacity of this design is enhanced in a compact size. Patch diameter of the tag is 24 mm. Circularly polarised incident plane waves are used for excitation. Data capacity of 30 bits is achieved in the frequency band of 3.1–11.7 GHz. Spectral signature‐based radar cross‐section results are also measured for flexible and temperature sensor integrated design. The prototype is inkjet printed on Kapton ® HN heat resistant conformal sheet.

Non‐orthogonal multiple access (NOMA) is emerging as a promising multiple access technology for the fifth generation cellular networks to address the fast growing mobile data traffic. It applies superposition coding in transmitters, allowing simultaneous allocation of the same frequency resource to multiple intra‐cell users. Successive interference cancellation is used at the receivers to cancel intra‐cell interference. User pairing and power allocation (UPPA) is a key design aspect of NOMA. Existing UPPA algorithms are mainly based on exhaustive search method with extensive computation complexity, which can severely affect the NOMA performance. A fast proportional fairness (PF) scheduling based UPPA algorithm is proposed to address the problem. The novel idea is to form user pairs around the users with the highest PF metrics with pre‐configured fixed power allocation. System‐level simulation results show that the proposed algorithm is significantly faster (seven times faster for the scenario with 20 users) with a negligible throughput loss than the existing exhaustive search…

A novel quantum‐dot cellular automata (QCA) design for the non‐restoring binary array divider is presented, which is constructed using the proposed coplanar QCA Exclusive‐OR gate and full adder. The results show that proposed designs have better performances than the best existing structures in terms of common design metrics. The presented 3 × 3 and 4 × 4 dividers are able to achieve 65, 75, 45% and 41, 27, 41% reductions in cell count, latency, and area, respectively.

A low‐power technique to reduce the power consumption of the dynamic comparators is presented. Using this technique, the pre‐amplification phase of the comparator is stopped without any effect on the dynamic behaviour of the comparator. Therefore, the power consumption of the pre‐amplifier stage which is the main part of the total power consumption is reduced significantly. Simulation results in various comparators reveal that the proposed technique reduces the total power consumption by more than 50%.

A dual‐band dual‐sense circularly polarised (CP) square slot antenna is presented. The proposed antenna consists of a L‐shape patch and two rectangular strips around two opposite corners on the lower ground. By adjusting the size of them, a broadband dual‐band dual‐sense CP antenna can be obtained. It can radiate right‐hand circular polarisation at 3.0 GHz and left‐hand circular polarisation at 5.5 GHz at + z direction. The measured results of impedance bandwidths for S 11 < −10 dB are 38.8% (2.51–3.72 GHz) and 27.5% (4.83–6.37 GHz). The 3 dB axial ratio bandwidths are 37.4% (2.50–3.65 GHz) and 16.3% (5.02–5.91 GHz).

A triple band‐notched UWB monopole antennas is presented for flexible electronics. To enhance the flexibility, ultra‐thin liquid crystal polymer with 50 μm thickness is used as the substrate. The antennas are constituted by swallow tail radiation patch and trapezoid ground. Moreover, band‐notched characteristic is realised by etching different sized elliptic single complementary split‐ring resonators on the radiation patch. An improved triple band‐notched UWB antenna with notched‐frequency bands at 3.7–4.2 GHz, 5.15–5.35 GHz, and 5.725–5.825 GHz are designed by a novel capacitance compensation method. The measured radiation patterns indicate that the antennas are an omni‐directional antenna both at flat and bent circumstances. The occupied area of antenna is 27 × 21 mm.

A compact dual‐band balanced bandpass filter with high common‐mode (CM) suppression is proposed. Two layers of substrate are vertically stacked to realise the miniaturisation. The first differential‐mode passband can be obtained by the dominant modes and the second can be achieved by utilising the higher‐order modes. The desired coupling coefficients of both bands are achievable by properly setting positions and sizes of the coupling slots etched on the layer interface. Meanwhile, four slotlines are etched on the bottom layer of the substrate to improve CM suppression and band‐to‐band isolation. A four‐order prototype is designed for demonstration. Good agreement between simulated and measured results is obtained.

A coding diffusion metasurface is designed and fabricated for ultra‐wideband radar cross‐section (RCS) reduction. Two kinds of unit cells based on square ring patch are employed to generate the ‘0’ and ‘1’ elements of the coding metasurface. By precise design of the unit cells, a 180° ± 37° reflection phase difference between these cells is achieved over 8.01–22.76 GHz, leading to dramatically reduce the scattering field level by more than 10 dB. To obtain the diffusion far‐field pattern of the metasurface, the optimisation algorithm is utilised to calculate the optimal layout of the digital elements. Both full‐wave simulation and measurement results verify the capability of the proposed metasurface.

Self‐similarity is an attractive image property that has been successfully applied to object recognition due to its robustness to severe target appearance variations. However, less attention has been paid to explore self‐similarity for visual tracking, mainly because it is difficult to learn self‐similarity information between different features suitable for visual tracking. To address this issue, a simple, yet effective approach is presented to learn self‐similarity information among the local features extracted from the different regions of the target. The target is first divided into some non‐overlapping regions, in which each region is described by the histogram of gradient (HOG) features. Then, an explicit polynomial kernel feature map is constructed, which is capable of characterising the self‐similarity information among all the local regions in the targets. Finally, based on the feature maps, a linear support vector machine (SVM) is learnt via an online dual coordinate descent method that offers fast convergence guarantee. Experiments on a large tracking benchmark dataset…

A novel composite right/left‐handed substrate integrated waveguide (SIW)‐based leaky wave antenna (LWA) is proposed. Square‐ring‐slot radiators are adopted to introduce series capacitor as well as the energy leakage, and four grounded vias within the slot ring contribute to part of the shunt inductor. Moreover, low cross‐polarisation levels in the beam scanning plane are achieved due to the differential excitations of the radiators located along the centre line of the SIW working at TE10 mode. The antenna is fabricated and measured. Both simulated and measured results show that the proposed antenna is a balanced LWA operating in the frequency band 13.5–17.8 GHz. Continuous beam scanning characteristic is acquired within the scanning region −57° to +30°. In addition, low cross‐polarisation levels less than −27 dB are obtained, and measured results are in good agreement with simulated ones.

An energy‐optimal coverage path planning algorithm is proposed for environment survey. First, 3D terrains are modelled by tensor product Bezier surfaces for a mesh representation. Then, a power estimator is derived to calculate the consumed energy for a piecewise spatial path. Based on the digital surface model, an energy consumption map is constructed for the whole area by means of a weighted directed graph. Finally, an energy‐optimal path can be achieved through traversing the map by a genetic algorithm. Numerical experiments demonstrate the effectiveness and efficiency of the proposed algorithm.

High quality fully integrated power supplies could notably improve the performances of the noise‐sensitive building block in the UWB communication systems. Double buffers are inserted into the cascode flipped‐voltage‐follower (FVF) topology to enable designing the dominant pole at the output node for better power supply rejection (PSR) and less voltage variation during load transient. An enhanced super source follower (E‐SSF) is proposed to further reduce the output impedance of the buffer that drives the power transistor. The FVF‐based low dropout regulator (LDO) with E‐SSF achieves a worst‐case PSR of −18.9 dB across the full spectrum and a transient response time of 312 ps. The proposed LDO is designed in a 28 nm CMOS process and consumes 100 μA quiescent current with 1.0 V input and 0.8 V output voltages. In total, 120 pF on‐chip capacitors are used for filtering.

An energy harvesting (EH) and information processing network based on two‐way multiplicative relay is proposed. In the proposed scheme, two nodes communicate with each other via an energy constrained multiplicative relay node. The relay node uses power splitting‐based relaying protocol for EH and information processing. The numerical results show that the proposed scheme outperforms the legacy amplify‐and‐forward EH relaying technique.

Massive multiple‐input multiple‐output (MIMO) systems are being proposed for next generation broadband wireless systems. However, as the complexity of implementation grows with the number of antenna elements, their feasibility is a challenging task. Consider very low complexity, 1‐bit digital‐to‐analogue converters (DACs) for the downlink of massive MIMO systems. The impact of the resultant severe non‐linear distortion effects is analysed when a low‐complexity maximum ratio transmission technique is employed for user separation. The non‐linear distortion levels decrease with the number of transmit antennas allowing good performance, even with 1‐bit DACs are shown.

A polarisation diversity antenna for an ultra‐high‐frequency RFID tag is presented. The antenna consists of two dual‐planar inverted‐F antennas arranged in a cross‐configuration, and mountable on a metallic object. The antenna can work together with a linearly polarised reader antenna that has an arbitrary polarisation direction. The proposed tag antenna has a nearly uniform read range between 9.1 and 10.2 m, regardless of the polarisation direction of the reader's transmit field.