Wireless millimeter-wave-lightwave signal converter using stacked patch-antennas embedded with a micrometer-gap and electro-optic crystal

We have proposed a new electro-optic signal converter which enables us to convert wireless millimeter-wave signals to lightwave signals. This is based on a LiNbO3 guided-wave optical modulator combined with vertically-stacked planar patch antennas embedded with a narrow (∼5 µm) gap. Utilizing the stacked structure, the antenna gain, antenna area, and electric field for optical modulation are increased, so that the signal conversion efficiency is increased by 3.65 dB at 60 GHz.