A kind of circularly-polarised radial line slot antenna for high-power microwave application is proposed by contriving a kind of radial line slow-wave structure, an improved circularly-polarised radiator unit and a reflection cancelling slot. An antenna prototype with a length of 12 cm and an aperture diameter of 54 cm is designed, which has a gain of 29.0 dBi and an axial ratio of 1.12 at 9.42 GHz. The high-power experiment proves that this antenna has a power-handling capacity of more than 600 MW.

Two compact triple-band monopole antennas consisting of a single-loop resonator (SLR) fed with coplanar waveguide (CPW) and microstrip transmission lines, respectively, are proposed. The SLR exhibiting three resonances is used to achieve the three operating frequency bands ranging from 2.4 to 6 GHz. The proposed triple-band antennas exhibit very well eight-like radiation patterns and low cross-polarisations, which have potential applications for wireless communications.

A differential feeding technique for a broadband planar antenna-array is presented. The antenna structure is composed of four parallel linear series-fed arrays of four microstrip patches. To cancel the beam tilt versus frequency, one side of the array is fed with in-phase signal, whereas the same out-of-phase signal feeds the opposite side of the array. A rat-race balun is especially designed to generate those two signals. In comparison with other feeding techniques, there is no need for a resistive load which is actually a problem at millimeter (mm)-wave frequencies. To validate the concept, a 60 GHz prototype etched on the TacLamPlus substrate is designed and measured.

A compact dual-port multiple-input multiple-output (MIMO) antenna is proposed for 2.4 GHz wireless local area network systems. The radiation element consists of a monopole and a patch ring with two cuts, through which a coplanar waveguide port and a slotline port are constructed. The current distributions of the proposed antenna for both ports excited are simulated and analysed, respectively. According to the measurement results of the manufactured antenna prototype, the isolation between these two ports over the operating frequencies is better than –35 dB and the cross-polarisation radiation levels are less than –45 dB at the main direction. Finally, the proposed antenna has excellent isolation not only at the feed ports, but also in the radiation patterns.

A planar inverted-F antenna (PIFA) is presented, which has a dual-resonance feed structure that enhances impedance bandwidth considerably. The proposed antenna fully covers LTE13/GSM850/GSM900 without significant modification of the antenna element fabricated in a small ground clearance. The antenna's impedance bandwidth under VSWR = 3:1 is 733–974 MHz, with a good realised efficiency.

A slot antenna with a notched band at 5.5 GHz is proposed for UWB applications. The basic UWB antenna comprises of a rectangular radiating patch and a ground plane with a tapered shape slot and printed on 1.6 mm-thick FR4 dielectric substrate. To realise a notch band, two symmetrical slits are etched on the slot of the ground plane. Experimental results show that the proposed antenna exhibits wideband performance from 3.08 to more than 11 GHz with a notched frequency band centred at 5.5 GHz which can effectively mitigate the interference between the WLAN and UWB systems. It is also confirmed from the measurements that the insertion of slits does not affect the antenna performance, except at the notched frequency band.

A highly sensitive, rapid and convenient biosensor based on film bulk acoustic resonator has been developed for detection of pesticide residues in agricultural products. When the pesticide molecules are bound to the immobilised antibodies on the resonator sensing surface, the resonant frequency is obviously reduced because of additional mass. Trace pesticide in the solutions was detected through real-time monitoring of the resonant frequency during antigen–antibody reactions on the resonator surface. Using the proposed biosensor, realised is a convenient and rapid detection process (less than 1 min) and a remarkable low detection limit (ppb level) for the pesticide. On the basis of the sensing performances, the film bulk acoustic resonator shows promising applications for food safety guarantees.

Presentsed is an optimised design for the RF CMOS low-noise amplifier (LNA) as the analogue front-end circuit for the brain–machine interface's transceiver with an emphasis on the tradeoff between gain, noise and power consumption. A 360 nm cascode LNA operating in 404 MHz of the Medical Implant Communication Service frequency band is designed to demonstrate good performance achievable in the microwatt range. Overdrive voltage of the transistors is approximately 100 mV to exploit the high g_m /I_D achieving low power consumption, while avoiding performance degradation associated with the subthreshold region.

The stationarity of the body area network (BAN) channel when the subject is sleeping is examined. The authors question the validity of first- and second-order distribution fits to BAN channel gain. Wide sense stationarity tests have an upper bound at 70% probability for a maximum data length of 5 s. For data lengths greater than 5 s, the probability of stationarity rapidly diminishes. It is shown that the BAN channel is inherently non-stationary, and independent of the subject, sensor location and activity.

A pre-emphasis transmitter with improved data zero-crossing accuracy is described. It is achieved via data re-synchronisation using a set of extended true single-phase clock latches before output combining, constituting a robust, area- and power-efficient solution. Fabricated in 65 nm CMOS, the full-rate one-tap pre-emphasis transmitter measures a total jitter of 33.12 ps up to an 8 Gbit/s data rate, and 25.04 to 38.75 ps under a 0–14 dB reconfigurable pre-emphasis range. The achieved output swing is as large as 550 mV_pp, and the active area is just 0.007 mm².

A simple yet very effective slew rate enhancement (SRE) method is proposed. The proposed SRE feedback is normally off and is activated only when an excessive transient signal in the output stage indicates the onset of slewing. Therefore, the method does not degrade the small signal performances or the linearity of amplifiers as do most existing SRE techniques. The new SRE applies to both single-stage and multi-stage, both single-ended and fully differential amplifiers. Simulation results of an example implementation show more than 700% slew rate boost with less than 2.5% power consumption overhead.

A new grid map-merging technique which consists of virtual emphasis by one-way observation, curvature-based map matching and particle swarm optimisation is proposed. The proposed technique can improve not only the accuracy of map merging, but also the flexibility of multi-robot systems. The improved performance is verified by showing higher similarities than the existing map-merging techniques in experiments.

The problem of deriving less conservative stability and stabilisation conditions for a class of discrete-time Markovian jump linear systems with partly unknown transition probabilities is investigated. To do so, traditional conditions under consideration are first formulated to be with homogeneous polynomial dependence on partly unknown transition probabilities, and then be converted into a finite set of linear matrix inequalities via a relaxation process that can incorporate all possible slack variables coupled with transition probabilities.

A simple shielding evaluation method of small shield cans using a transverse electromagnetic cell and a specially designed test printed circuit board is proposed. Numerical modelling of the measurement setup using a commercial three-dimensional electromagnetic field simulator is also introduced to verify the measurement. From measurement and simulation, reliable results for shielding evaluation of the shield cans were obtained.

An efficient distortion-correcting algorithm for the intra-coding of a depth map is presented by considering the property of the flat area in a depth map. The influence of the distortion of reference pixels on the rate-distortion (RD) cost function of the macro-block (MB) in a flat region of a depth map is analysed. Then, the RD performance of the flat region is improved by correcting the distortion of the first MB in the flat area on the basis of this analysis. Experiments show that the performance of the synthesis view of the proposed method can achieve average peak signal-to-noise ratio (PSNR) of 0.32 and 0.30 dB compared with the JMVC8.5 and the plane segmentation-based intra-prediction method, respectively.

A method for correcting both errors and erasures of Reed-Solomon (RS) codes using error-only and erasure-only decoding algorithms is proposed. First, the method removes the effect of erasures from syndromes, then it uses error-only and erasure-only correcting processes to correct errors and erasures, respectively; thus, the overall decoding complexity can be reduced substantially. Furthermore, with hardware implementation, the most time-consuming operations in these two processes can be calculated concurrently to obtain a significant reduction of decoding latency.

An improved estimation scheme for disturbance due to the dead time and inverter nonlinearity in an inverter-fed permanent magnet synchronous motor (PMSM) drive is presented. The proposed scheme is based on a signal processing and harmonic component extraction and does not require any additional circuits nor parameter information. Furthermore, it is faster to estimate the disturbance as compared with the conventional method based on harmonic analysis. The effectiveness of the proposed scheme is verified through comparative simulations.

A wideband substrate integrated waveguide (SIW) power divider with enhanced out-of-band rejection is proposed. Periodic butterfly radial slots are etched on top layer of SIW to realise a pass-band combining with high-pass characteristics of SIW. An experimental circuit has been fabricated by the standard printed circuit board process. Simulated results are compared with measured data and good agreement is reported.

A simple and energy-efficient photonic system to generate continuously tunable, low phase noise, sub-THz waves based on COTS components is presented. The optical scheme is based on the use of a commercial vertical cavity surface emitting laser under gain switching modulation that provides a very flat optical frequency comb generator (OFCG) with 23 modes in a 20 dB bandwidth. The laser only needs 15 dBm continuous wave radiofrequency input power and 9 mA of bias current to provide this OFCG. Two optical injection locking stages filter and amplify the two desired modes that are detected in a photodiode to produce the desired sub-THz signal at the frequency difference of these two selected modes. As an example, demonstrated is the generation of a very stable 88.2 GHz tone with lower linewidth than 10 Hz using a reference of 4.2 GHz to generate the OFCG.

A bandpass filter with an elliptic response is presented based on a complementary compact microstrip resonant cell (CCMRC). It can be designed by following the traditional coupled resonator theory. An example filter is fabricated and measured. It is shown that the proposed elliptic response CCMRC has high selectivity, compact size, low insertion loss and a wide upper stopband, making it promising in microwave applications.

A measurement technique whereby one can measure the relative phase fluctuations and frequency stability of two oscillators operating at different frequencies, both well above the operating bandwidth of any available phase noise measurement test set, is presented and verified experimentally.

A polarisation-sensitive sub-terahertz-wave detector has been developed by integrating an InP/InGaAsP Schottky barrier diode and a modified bowtie antenna. The fabricated quasi-optical module could detect signals at frequencies ranging from 30 GHz to 1 THz. The measured sensitivities were 1080 V/W at 250 GHz, 250 V/W at 400 GHz and 86 V/W at 600 GHz for a zero-bias condition. The principal polarisation axis angle for signal detection was confirmed to be stable within ±1.5° in a frequency ranging from 80 to 600 GHz, while the degree of polarisation was more than 95%.

A scattered sequential sampling algorithm for the automatic construction of stable and passive scalable macromodels of parameterised system responses with a well-conditioned refinement strategy using path-simplexes is proposed. The method is tailored towards the local scalable macromodelling schemes on scattered grids. A pertinent numerical example validates the proposed approach.

Reported is the deposition and characterisation of lead zirconium titanate (PbZr_0.4Ti_0.6O₃) (PZT) and lead calcium titanate (Pb_0.7Ca_0.3Ti0₃) (PCT) deposited on a gold electrode with a gold top electrode to form a capacitor structure. Pulsed laser deposition was utilised to deposit the thin films. The thin films were characterised for their dielectric constant and loss tangent variation with temperature as well as the pyroelectric coefficient. The thin films were poled to improve the pyroelectric effect. The highest pyroelectric coefficient was found to be 280 µC/m² K for PZT film and 400 µC/m² K for the PCT film after poling.

60 Gbits over 2 m, 50 Gbits over 50 m and 40 Gbits was transmitted over 100 m of OM4 multimode fibre using four-level pulse amplitude modulation and a directly modulated 850 nm vertical cavity surface emitting laser (VCSEL).

The operation of a self-oscillating switched-mode circuit topology for low-voltage thermal energy harvesting is analysed and experimental efficiency results are presented. Circuit self-start-up function as well as high-efficiency power transfer are obtained by using only one transformer without additional inductors. It is shown that even without using a maximum power point tracking (MPPT) tracking circuit, it is possible to achieve efficiencies up to 65% over a relatively broad input voltage range which can be optimised by properly varying the transformer turns ratio n.

The aim of this reported work is to estimate travel time on urban road sections. The concerned roads are the ones with no dedicated sensing infrastructure and for which the only potentially available source of data is sparse GPS probe data. Presented is a new approach to solve this problem by using an applied particle filter method and historical probabilities distributions of travel time per road section.

Speech capture in the presence of non-stationary interfering signals, e.g. music or other competing talkers, is a challenging problem, and in a recent work, distributed microphones have been employed for this purpose. In this reported work, consideration is given to the problem of power allocation in a distributed microphone system, where a directional wireless microphone is placed close to each interferer and provides an estimate of the statistics of the undesired signal for suppression at the primary microphone. The optimal transmit power allocation is derived such that the mean squared error in estimating the desired signal is minimised subject to a total power constraint. It is shown that signal-to-noise performance improves at the primary microphone using optimum power allocation in comparison with an equal power allocation scheme.

A two bi-directional-way relaying method that enables simultaneous communication without inter-pair interference within two time slots is proposed. A common sensor node B exchanges information with two sensor nodes S ₁ and S ₂ via two relaying scenarios. In the first scenario, the relaying system contains two relays, R ₁ and R ₂, in two overlapping clusters. In the second scenario, the relaying system has only one relay, R, in the same cluster. Under the amplify-and-forward protocol, the authors propose the use of a pulse amplitude modulation signal, instead of a general complex signal, for presenting informational messages of all sources. The authors then propose a phase-shift transmission scheme. As a result, two-bi-directional relaying transmission is available within two time slots, but without any interference. Simulation results show that in terms of achievable rate, the proposed scheme outperforms the conventional method which uses a general complex signal and four time slots.

The dependence of power amplifier (PA) backoff on resource allocation for non-contiguous carrier aggregation is investigated. To be specific, assuming two non-contiguous carriers, the power spectral density (PSD) of the third-order intermodulation distortion (IM3) is approximated as a function of power allocation and PSD allocation. Based on the closed-form expression, it is proven that the PSD of IM3 is maximised when the resource allocation is inversely proportional to the PSD allocation. The PA simulations verify that such resource allocation also maximises the PA backoff.

The channel availability of cognitive radio is often estimated through a two-state ON/OFF model of primary users’ (PUs) behaviour. The ON/OFF model estimates channel availability with respect to the presence of PUs. Multiple secondary users (SUs) may be aware of channel availability, and try to opportunistically access the channel when it becomes available. Hence, the ON/OFF model may overestimate channel capacity from the perspective of SUs, since the channel could be occupied not only by a resuming PU, but also by contending SUs. Proposed is a joint channel availability estimation through a Markov chain model which takes into account, within a single model, PU behaviour and the SU's carrier sensing with multiple access/collision avoidance contention access, without leading to the state explosion problem. Simulations performed show that the joint channel availability equation is able to estimate channel capacity with mean errors of around 2%.

Aiming at signal detection in α-stable (SαS) noise, a receiver with a new zero-memory nonlinearity limiter (ZMNL) is designed. The proposed ZMNL serves to transform the SαS noise into a standard Gaussian one by using the bi-parameter Cauchy-Gaussian mixture (BCGM) model to approximate the SαS density. Simulation results indicate that the proposed receiver outperforms the conventional sub-optimal receivers for α > 1.5.