Design of a miniaturized L-band four-bit digital phase shifter

The design of a miniaturized L-band four-bit digital phase-shifter having 14% bandwidth with low insertion loss is presented. The structure is based on loaded-line phase shifter combined with switched-line phase shifter, whereas, slow-wave line and bending line techniques are introduced for miniaturization purpose. Compared to traditional phase-shifter, the proposed structure is very compact in size i.e. 20mm×55mm. The measured results show that the designed phase shifter achieves better than ±5% differential phase stability, less than 2.2dB insertion loss, and better than 14dB return loss across the wideband 0.99-1.13 GHz.