InP-based ultra-fast photodetectors for millimeter-wave sub-harmonic mixers

A novel scheme for efficient optoelectronic down-conversion of millimeter-wave signals is presented. A Coplanar Waveguide-integrated Uni-Traveling Carrier Photodiode with a Traveling wave design was used as the optoelectronic mixer. For fundamental mixing at a frequency of 100 GHz a conversion gain of -32 dB was found that is a significant improvement compared to previously published results. For sub-harmonically pumped mixing lower gain was measured depending on the harmonic order. Flat IF response was found for a wide range of frequencies.