In view of the problems such as low fault location accuracy of existing cable-overhead-hybrid transmission lines and difficulty in identifying the traveling wave head, this paper presents a newfashioned fault location technology for cable-overhead-hybrid transmission lines. Accurate calibration of the traveling wave head is achieved by improving the HOVMD-TKEO method. And based on this, the fault accurate location of overhead-cable hybrid line is realized by wave velocity normalization method. Finally, the feasibility and accuracy of this method is verified by PSCAD/EMTDC simulation analysis of 110kV cable-overhead-hybrid transmission lines.

Trillions of Internet of Things devices require rigorous design trade-offs regarding size, cost, and energy efficiency, leading to design challenges for clock modules. This paper proposes a low-power all-digital frequency locked loop (ADFLL) featuring a digital frequency detector with minimum D-type flip-flop usage and a lock detector with hysteresis lock/unlock decision zone, suitable for system-on-chip applications. The ADFLL is verified in the field-programmable gate arrays (FPGA) and is implemented as an on-chip clock generator in a radio frequency identification tag using 130nm CMOS technology with 0.185×0.26mm² size. The generated clock has ±0.25% frequency accuracy with good temperature and process robustness.

Gallium Nitride High Electron Mobility Transistor (GaN HEMT) monolithic microwave integrated circuits (MMICs) play a pivotal role across diverse applications, including deep-space satellite communication systems, phased array radar, and imaging and sensing systems. In response to the evolving demands of these rapidly advancing applications, there has been a growing imperative to develop monolithic high power amplifiers (HPAs) for system-on-a-chip scenarios in recent years. Taking advantage of high performance GaN HEMT technology and high-Q factor on-chip passive components, this paper introduces and implements a novel monolithic HPA with a high drain voltage of 48V, capable of delivering a high output power. The proposed GaN MMIC utilizes field plate 0.35µm AlGaN/GaN-SiC HEMT technology with a ft∼22GHz. The HPA leverages cascaded multi-stage amplification architecture and power combining network. The implemented HPA demonstrates notable performance metrics, including an average power gain of 23dB and an average saturated output power of 200W across a bandwidth from 8GHz to 10.5GHz in experimental measurements. The designed HPA occupies a compact chip area of 4.10×5.46mm².

This paper presents the design of an ultra-wideband RF power amplifier (RFPA) with high output power and high power added efficiency (PAE) in the 0.45-4.5GHz band. By adjusting the circuit in the low-pass filter matching network, the influence of parasitic devices is effectively suppressed, thus ensuring bandwidth and efficiency. The overall circuit structure is compact, has strong anti-interference ability, and can realize the combination of distributed modular components. The experimental results show that the output power of RFPA is stabilized in the range of 40.2-41.8dBm in the frequency band of 0.45-4.5GHz, and the drain efficiency is higher than 40%. This design will provide important technical support for the performance improvement and expansion of wireless communication systems.

A Self-Powered Multi-Input Optimized Synchronous Electric Charge Extraction (MI-OSECE) circuit for multiple Piezoelectric Transducers is presented in this paper. When the voltage of the Piezoelectric Transducers (PZT) reaches its peak value, the self-powered synchronous switches in the proposed circuit extract the partial charges and invert the remainder on the clamped capacitance C_p of PZT to achieve improved output power. In addition, it can be extensible to harvest energy from multiple PZTs with a single inductor configuration. The experimental results show that the proposed MI-OSECE circuit can harvest energy from multiple PZTs simultaneously; the Peak Output Power Ratio (POPR) and the factor BW_0.9 of the proposed circuit can reach 3.4 and 0.83, respectively, illustrate the harvesting ability and load adaptability of the proposed circuit.

In this letter, a wideband microwave absorber with high angular stability is proposed based on the integrated design of frequency selective surface (FSS) and lattice structure. The proposed absorber is composed of a resistive FSS sheet embedded within two lattice structures. With the aid of the upper lattice structure, the wave impedance of the absorber is compensated at oblique incidence and the angular stable absorption is achieved. The performance of the absorber is investigated with an equivalent circuit model and full-wave simulations. The 80% and the 90% absorption bands are ranging from 1.4GHz to 6.2GHz and 1.5GHz to 6.1GHz, with a fractional bandwidth of 126.3% and 121%, respectively. Meanwhile, the absorption rate keeps above 80% within 65° for both TE and TM polarizations and remains above 90% within 50° incident angle. For further verification, a prototype has been fabricated and measured. Good agreements between the simulated and measured results can be observed. Considering the wideband absorption characteristics and high angular stability, the proposed absorber can be applied to construct EM wave shelters.

A Snapback-Free and Low-Loss Reverse Conducting LIGBT with Integrated Multi-functional Trench Gates (MTG-LIGBT) is a device that eliminates the snapback phenomenon of the SA-LIGBT and offers a low loss which realized by its multi-functional trench gates as demonstrated by the TCAD SENTAURUS. Two trench gates and a planar gate together form a FIN-NMOS, which significantly reduces turn-off loss E_OFF. Due to the presence of the multi-functional trench gate, the P-type substrate of FIN-NMOS can be lightly doped. And then reverse conduction can be achieved through punchthrough. Consequently, The MTG-LIGBT achieve a snapback-free state and own a superior trade-off relationship between V_ON and E_OFF.