High-Power High-Responsivity Modified Uni-Traveling-Carrier Photodiode Used as V-Band Optoelectronic Mixers

A modified uni-traveling-carrier photodiode-based V-band optoelectronic mixer is demonstrated. The relative optical local oscillator (LO) and optical intermediate frequency (IF) signal levels and the reverse bias can be optimized for maximum up-converted power. It was found that the optimum optical IF percentage relative to the total incident optical power was approximately 1/3 for all photocurrent levels while the optimum reverse bias increased linearly with photocurrent. A simple analytical model that explains these observations is developed. A high up-converted power of -4.7 dBm was achieved at 60 GHz and photocurrent of 70 mA. The maximum up-converted power is primarily limited by the saturation characteristic of the photodiode.