Wideband 180 Degree Phase Shifter with Low Phase Error

A wideband 180 degree phase shifter is proposed to operate in 3-5 GHz bandwidth. It is designed on the base of transitions between microstrip and coplanar waveguide (CPW) lines. Thus, a sequence of microstrip -to (CPW) -to microstrip transitions are used to realize the structure. This phase shifter has a good return loss (S11<-10 dB and a low transmission loss (21 value of 6 degrees phase error in the output signal. Numerical Simulation and measurement results are provided to verify these claims. Results show acceptable performance of the structure to use in relevant applications such as binary phase shift keying (BPSK) modulators and feeding networks in phase array antennas. Moreover, its simple and low cost structure makes it a good candidate in mentioned applications compared to conventional phase shifters implemented by integrated circuits (IC).