Theory study on a photonic-assisted radio frequency phase shifter with direct current voltage control

A photonic-assisted radio frequency phase shifter with direct current voltage control is proposed using a polymer-based integrated Mach-Zehnder modulator. A closed-form expression of radio frequency (RF) signal power and phase is given. Theoretical calculation reveals that by carefully setting the bias voltages, RF signal power variation lower than 1-dB and phase accuracy less than 3° can be achieved and are not degraded by perturbation of modulation index once the bias voltage drift is kept within -3% ～ 3%.