A novel T-shaped optically controlled microwave phase shifter

A novel T-shaped optically controlled microwave phase shifter is presented in this paper. The phase shifter consists of a T-shaped microstrip line with a gap in the shunt arm. The gap is filled with silicon and its conductivity is modulated by photo-excitation. The preliminary design of phase shifter is carried out using the transmission line model. Further Method of Moments is used to accurately model the photo-excited microstrip gap. The phase shifter parameters are optimized to achieve high phase shift with minimal insertion loss and ON-to-OFF amplitude change.