A wideband photonic microwave phase shifter using polarization-dependent intensity modulation

We present a tunable and wideband microwave photonic phase shifter based on polarization-dependence of the LiNbO3 Mach-Zehender modulator (MZM). In the proposed device, an orthogonal single sideband modulation is implemented by using a MZM and an optical band-pass filter. With the polarizer to synthesize the polarization orthogonal optical carrier and sideband, the phase of the optical microwave signal output from the polarizer can be tuned from 0 to 360° by simply adjusting the polarization direction of the lights whereas the amplitude keeps constant. A full range tunable phase shifting in the frequency range of 10-35 GHz is achieved.