Phosphosilicate glass waveguides for phased-array radar time delay

摘要

Optical waveguides have great potential for signal distribution and processing at microwave signal frequencies. One application is to perform true-time-delay beam steering of phased-array antennas. Low-loss phosphosilicate glass waveguides can be formed on large silicon substrates to serve as delay lines. Such waveguides can be efficiently coupled to single-mode optical fibers. Since the waveguides are made of a passive optical material, micromechanical integrated-optic switches are being developed to perform the time-delay switching function. Fabrication of both waveguides and switches can be done using VLSI processing techniques. The combination of passive waveguides and micromechanical switches should make the time delays and switch operation relatively insensitive to temperature variations.