State estimation (SE) aims at monitoring the transmission and distribution networks to achieve stable and reliable grid operations. While the SE problem is non-convex, a local search method is used to achieve global optimum based on the belief that power system states are with limited variation in a short time scale. However, the recent and rapid deployment of renewables leads to strong power and state fluctuations in power grids, making local search method prone to local optimums with large estimation errors. Here, the authors propose to analyse SE with small measurement noises because highly accurate smart sensors are deployed in the past few years. By exploring a special structure of the performance metrics, the authors reformulate the SE problem in an extended state space. The new formulation is convex under the no-measurement-noise assumption. In order to use such a method when there are noises, the authors prove that a perturbation of globally optimal solution is asymptotically bounded by the measurement noise level. This prevents local optimums, which can create a large estimation error. Simulation results demonstrate that the method has a better performance compared to both weighted least square and the recent semidefinite programming-based approaches, especially when the noise is small.

Electromagnetic wave propagated via troposcatter is a valuable candidate for beyond line-of-sight detection. To improve the location accuracy of passive detection system based on troposcatter, path delay and angle bias caused by tropospheric refraction effect are estimated through the ray tracing method. As well, the Hopfield model is introduced to overcome ray tracing method's dependence on radiosonde data. Finally, consequences indicate that the Hopfield model can describe the tropospheric refraction better than other models. As well, the ray tracing method improved by the Hopfield model can effectively estimate path delay and angle bias.

A stacked dielectric patch resonator antenna with wide bandwidth and flat gain is proposed. For this design, two thin ceramic sheets with high permittivity are introduced to operate as approximate magnetic walls. Incorporated with another ground plane, two resonant modes can be excited to form a wide bandwidth, and a flat gain is also achieved within the band. Measured results demonstrate that the antenna obtains an impedance bandwidth of 18.2% and an average gain of 7.2 dBi.

In a wireless energy harvesting network with an energy-constrained decode and forward relay node, the authors propose a hybrid protocol (HP) which is a combination of power splitting relaying (PSR) and time switching relaying (TSR). The authors derive the analytical outage probability expressions of the HP over log-normal fading channel. The numerical results show that the HP scheme significantly outperforms the PSR and TSR schemes in terms of outage probability performance.

This study describes the use of a pre-low noise amplifier (LNA) third-order notch filter as a novel linearity enhancement technique for ultra-wideband complementary metal oxide semiconductor LNA current-reuse topology. The second/third order input intercept point (IIP2/3) has improved along the entire working bandwidth (BW) from 2.1 to 12.5 GHz. The suggested linearisation technique achieves maximum/minimum IIP2 improvement from 19.068 to 104.143 dBm at 6.4 GHz and from 22.5 to 57.42 dBm at 5.5 GHz, respectively. In addition, this work achieves maximum/minimum IIP3 improvement from −7.956 to 34.688 dBm at 6.4 GHz and from −9.986 to 8.281 dBm, respectively. Moreover, the suggested linearisation technique does not affect the total ultra-wideband (UWB)-LNA power consumption, which is only 6.7 mW. Furthermore, the linearised UWB-LNA average noise figure is 1.6535 dB at the entire working BW. The simulation is performed and optimised with an advanced design system utilising BSIM3v3 TSMC 180 nm model files at different temperature values.