Laser-aided amplitude compensation for SAW RAC devices

A post-fabrication trimming method using direct laser writing has proven to be effective in reducing phase errors in RAC (reflective array correlator) lines. This method has been applied to the compensation of amplitude errors. Amplitude trimming requires a lossy film to alter the amplitude response. Using a simple correction algorithm to pattern chrome cermet films, various amplitude corrections have been written by laser. Amplitude errors as large as 7 dB have been trimmed and errors have been reduced to a few tenths of a decibel. The use of laser amplitude and phase compensation has repeatedly produced devices with time sidelobe suppressions of 40 dB or greater