An 8-18 GHz 90 degrees Switched T-Type Phase Shifter

This paper proposes a novel 8-18 GHz 90 degrees switched T-type phase shifter (TPS). In contrast to the conventional TPS, the proposed TPS adds a compensation capacitance to greatly enhance the phase shifting capacity. Moreover, the designed structure also integrates a filtering compensation network, which can effectively achieve a flat relative phase shift in a wide band. The proposed 90 degrees TPS is fabricated using 0.15 mu m GaAs pHEMT technology. The TPS achieves homogeneous phase shift at 8-18 GHz, with the measured phase error of less than +/- 1.5 degrees. The insertion loss of the proposed phase shifter is 1.3-2.6 dB, and the chip size is merely 0.53 +/- 0.86 mm2. Thanks to these excellent performance characteristics, the designed phase shifter is well-suited for ultra-wideband wireless communication and radar systems.