부산대학교 도서관

A wideband hybrid phase shifter (PS) with low phase and amplitude error is presented, consisting of a 180° reflection-type PS (RTPS) and a phase invertible variable gain amplifier (PIVGA). The effects of a nonideal coupler and reflective loads on the limitation of RTPS’s bandwidth are analyzed. To achieve a wide operation bandwidth and a compact chip area, the 180° RTPS is realized by cascading three stages of 60° RTPS with capacitive load (CL). A PIVGA follows the RTPS to achieve a full 360° phase-shift range (PSR) and compensate for the loss of RTPS. The proposed wideband 6-bit PS is implemented in a 40-nm CMOS process with a core area of 0.11 mm2. It achieves 39.3% (22.5–33.5 GHz) fractional bandwidth (FBW) with low rms phase and an amplitude error of less than 2.8° and 0.45 dB, respectively. Moreover, the average gain of the proposed PS is 2.5 dB at 28.5 GHz with $S11$ and $S22$ both lower than −8 dB from 22.5 to 33.5 GHz.