Broadband 180° bit phase shifter using a λ/2 coupled line and parallel λ/8 stubs

In this paper, a broadband 180° bit phase shifter using a new switched-network was presented. The new network is composed of a λ/2 coupled line and parallel λ/8 open and short stubs, which are shunted at the edge points of a coupled line, respectively. According to a desired phase shift, it provides a controllable phase dispersive characteristic by the proper determination of Z_m,Z_s, and R values. The 180° bit phase shifter operated at 3 GHz was fabricated and experimented using design graphs which provide the required Z_m,Z_s values, and I/O match and phase bandwidths. The experimental performances showed broadband characteristics.