Bias-Free Operational UTC-PD Pair for Optoelectronic Mixing

This study presents the first demonstration of a two-element uni-traveling carrier photodiodes (UTC-PDs) pair for optoelectronic mixing in wireless communication, utilizing bias-free operational UTC-PDs to effectively reduce system power consumption and complexity. One UTC-PD in the system converts the intermediate frequency (IF) signal into a bias modulation signal, which is then directed to a second UTC-PD that processes the local oscillation (LO) signal to achieve optoelectronic mixing. We achieved optoelectronic mixing with LO and IF signal frequencies of 20 and 2 GHz, respectively, resulting in a conversion loss (CL) of 21.9 dB at zero bias voltage.