Design of a wideband equal power divider and multiple phase shifter for variable polarization

A hybrid microwave passive network having equal power division and variable phase shifting ability within a wideband is proposed. The hybrid network consists of a wideband noncoupled-line microstrip balun network and two 90° phase shifters derived from the same balun. The microstrip network has an advantage of equal power division and 10 dB return loss within a wide bandwidth from 2.6 GHz to 4.1 GHz. The four output ports of the network provide 0°, 90°, 180°, and 270° phase shift with respect to the input signal throughout the operating band. The amplitude and phase imbalance between the four output ports are within 0.9 dB and ±8°, respectively, along with the port isolations are below -15 dB. The overall dimensions of the device are made compact (3.2λ × 2λ × 0.032λ) at the center frequency of 3.3 GHz and designed on low cost FR-4 (εr = 4.4) substrate.