Continuously variable pulse true-time delay system incorporating an acousto-optic Bragg cell and an electro-optic modulator

Abstract

Optically realized continuously variable true-time delay of microwave pulses is demonstrated in a heterodyne system involving an acousto-optic deflector and a specially designed electro-optic modulator. The system realizes the time delay by frequency dependent phase shifting of the spectral components of the signal (FDPC technique). A new feature of the system is the real continuous variation of the time shift achieved with the continuous frequency dependent phase shift, performed by a specially designed electro-optic modulator. Continuously variable time delay values between ±200 ns are measured.