Photonic Microwave Phase Shifter Based On Silicon Microring

Radio frequency (RF) phase shifters have been playing an increasingly important rolein phased-array beamforming systems and smart antenna applications. Conventional RFphase shifters have limitations in terms of operational bandwidth and phase-shift tuningrange. Recently, the use of photonic elements to control the phase shift has raised attentiondue to the advantages of flexible tunability, high bandwidth, and light weight offered byoptical systems.This paper mainly studies the two kinds of RF phase shifter respectively based on thethermal nonlinear effect and plasma dispersion effect of silicon microring.In the first part, we analysis the principle and properties of microring, confirm thefeasibility of the photonic phase shifter based on the microring. The characters of all-passmicroring and up/download microring are compared, and conclusion is that the former oneis better in loss and range of phase shift, which means better for utilizing in photonicphase shifter.In the second part, we research into a phase shifter based on the thermal nonlineareffect of a silicon microring. A photonic phase shifter with0.3-4.7-radphase-shift tuningrange for a40-GHz signal is demonstrated, we improve it by DBS modulation mode anduse the carrier light as the pump of TPA effect in the microring. In this way, we cut off alaser and got a similar result as existing scheme.At the last part of this paper, we concept-prove aphotonic microwave phase shifterusing a silicon microring resonator based on plasma dispersion effect, providing a0.2-2.2-radphase-shift tuning range for a40-GHz signal, and we could get larger range bycascading more microring simply.