Sub-Terahertz Radiation from a Photodiode-Integrated Patch Antenna Array

Enhancement of sub-terahertz radiation power from photonic emitters in an array scheme is investigated. The element of the fabricated array antenna was a UTC-PD integrated 300-GHz patch antenna. It was observed that the radiation angle of patch antenna array is about half as narrow as that of a single patch antenna. We also confirm that the radiation direction changed by 20 degrees when 27X/5 of phase difference was added to the input optical signal for each antenna element. These results indicated that power combining of the sub-terahertz radiation occurred in the patch antenna array. This shows that introducing an array structure is effective for obtaining strong terahertz and sub-terahertz radiation from photonic transmitters.