Shigeo Kawasaki

This paper presents the fabrication of an Active Integrated Phased Array Antennas (AIPAA) sensor system prototype utilizing Information, Communication & Energy transfer (ICEt) technology. Through the high-density integration of hardware components and software algorithms, this system enables adaptive adjustments in diverse scenarios, leading to optimal system performance. The proposed prototype demonstrates the capability to fulfill sensing, communication, and energy transfer tasks in various environments, including spacecraft exploration and river disaster warning systems. This research represents a significant step towards the development of advanced wireless sensor networks with ICEt technology for multifunctional applications.

© 2020 IEEE. In this letter, a frequency-tunable rectifier in the $C$-band designed by a hybrid semiconductor integrated circuit (HySIC) concept is proposed. A GaAs monolithic microwave integrated circuit (MMIC) and a Si radio frequency integrated circuit (RFIC) were utilized as the HySIC configuration in the rectifier design. For the purpose of initial confirmation of this design validity, the GaAs and Si chips were fabricated and packaged onto the copper tungsten plate with gold plating. As measured results, frequency-tunable range from 3.82 to 4.55 GHz was measured. Maximum radio frequency (RF)-direct current (dc) conversion efficiency and output dc power in the measured power range from-10.0 to 17.8 dBm were 28.7% and 17.3 mW, respectively.

© 2020 IEEE. The 24 GHz communication system was demonstrated with wireless multi-sensors by wirelessly powering at 5.8 GHz. The wireless sensors for health monitoring in a space vehicle work as the sensors of temperature, humidity, acceleration, illuminance, battery voltage and sound in this study. Under output power of 30W from a GaN transmitter, a GaAs rectifier of energy harvester was operated with more than 80% RF-DC conversion efficiency.

© 2020 URSI. This paper analyzes and optimizes the structure of gallium nitride (GaN) planar Schottky barrier diode (SBD) to maximize the rectifier RF-DC conversion efficiency (PCE) and the operating dynamic range. The analysis indicates a small series resistance and a small zero-bias junction capacitance were needed to improve the wide dynamic range performance of the rectifier circuit. The prototype single-shunt rectifiers using the proposed GaN SBDs for evaluation achieves a conversion efficiency of more than 80% at an input power of 40dBm at 5. 8GHz. The high efficiency design rectifier achieves 87% peak PCE with 23dB dynamic range. The wide dynamic range design rectifier achieves 78% peak PCE with 32dB dynamic range.