Abstract
Two continuous 6-GHz signals were spatially synthesized by two optical beats, so that the microwave power was increased by 6 dB. Time delay difference between two optical beats were adjusted by altering the SMF length or LD wavelength. Also two continuous 20-GHz signals were synthesized by two optical beats and detected by Schottky Barrier Diode. Frequency of the synthesized 20-GHz signal was estimated from the measured time delay difference between two optical beats.