160 GHz harmonic-rejecting antenna with CMOS rectifier for millimeter-wave wireless power transmission

An on-chip antenna operating at 160 GHz frequency is designed for mm-wave wireless power transmission (WPT). To enhance the power conversion efficiency and reduce the area cost, a double compact microstrip resonant cell (DCRMC) low-pass filter (LPF) is embedded into the CPW-feeding structure. Compared to the reference antenna, 8 dB return loss suppression is observed for the 2^nd harmonic. Observed from simulations, the proposed harmonic-rejecting antenna can achieve a gain of 5.3 dBi. In addition, an on-chip mm-wave rectifier is designed to convert the captured AC power to DC. Fabricated in a 40 nm standard CMOS process, the CMOS rectifier occupies an area of 0.11 mm². 8.5% of rectifier´s power conversion efficiency (PCE) is achieved in the measurement under condition of 500 Ω load and -2.46 dBm RF input. To the authors´ knowledge, this is the highest operating frequency ever reported for a rectenna.