Abstract
Antenna-coupled electrode electro-optic (EO) modulators operating in the 28-GHz band were analyzed,
designed, and fabricated for applications to next generation (5G) mobile wireless communication systems
and to the precise antenna measurement systems. By scrutinizing antenna-coupled electrodes with
3-D field analysis software, an electric field enhancement factor of approximately 8000 times the irradiated
wireless 28-GHz field was obtained for optical modulation, which enables a compact wireless-optical
signal convertor without an external power supply. We fabricated our designed EO modulator using
a 50-μm-thick z-cut LiNbO3 crystal film and a 250-μm-thick SiO2 glass base substrate, and successfully
demonstrated signal conversion characteristics from the 28-GHz band wireless to optical signals in the
experiment.
