An optical down-converter for phase detection

Summary form only given. Commercial off-the-shelf optoelectronic components can easily be implemented for remoting microwave signals great distances providing essential microwave functionality while also offering less weight, smaller size, less prime power, and fewer components at the remote location. A two-channel down-converting optical system capable of detecting the relative phase of incoming microwave signals can be used in direction finding applications as well as in modulation and demodulation of complex microwave communication signals. This is, to our knowledge, the first ever two-channel optically down-converting phase detection system. The system configuration uses cascaded modulators, optical amplification, balanced detection, and low noise preamplifiers to obtain a noise figure of 8.5-14 dB over the operating frequency range 2-18 GHz.