Calibration And Extrapolation Of Phase-Modulated Comb Phase-Standards

High bandwidth dense frequency-comb phase-standards present a difficult calibration challenge. Calibration of the phase-modulation sidebands, coupled with the calibration of the unmodulated time-invariant phase-standard allows the sideband phase-response to be extrapolated to higher frequencies. The aim is to reduce test equipment cost by using both real-time and equivalent-time oscilloscopes. Preliminary measurement results are presented.