Photonics-assisted THz wireless communication enabled by wide-bandwidth packaged back-illuminated modified uni-traveling-carrier photodiode
Yuxin Tian, Boyu Dong, Yaxuan Li, Bing Xiong, Junwen Zhang, Changzheng Sun, Zhibiao Hao, Jian Wang, Lai Wang, Yanjun Han, Hongtao Li, Lin Gan, Nan Chi, Yi Luo
Abstract
This paper presents a wide-bandwidth back-illuminated modified uni-traveling-carrier photodiode (MUTC-PD) packaged with standard WR-5 rectangular waveguide for high-speed wireless communications. With optimized epitaxy structure and coplanar waveguide electrodes, the fabricated 4-μm-diameter PD exhibits ultra-flat frequency response and high saturation power. Integrated passive circuits including low-loss bias-tee and E-plane probe are designed to package the PD into a compact module with waveguide output. The packaged PD module has demonstrated a flat frequency response with fluctuations within ±2.75 dB over a broadband of 140–220 GHz and a high saturated output power of −7.8 dBm (166 μW) at 140 GHz. For wireless communication applications, the packaged PD is used to implement 1-m free space transmission at carrier frequencies of 150.5 and 210.5 GHz, with transmission rates of 75 and 90 Gbps, respectively.