A dual-band 90-degree SiGe HBT active phase shifter using band-pass and band-stop designs

摘要

A dual-band 90-degree SiGe HBT active phase shifter using band-pass and band-stop designs is presented in this paper. The active phase shifter employs differential configuration and has band-pass and band-stop filters in the load circuit. By switching two output ports of the differential amplifier, 90-degree phase shifting has been realized at dual bands. The implemented dual-band active phase shifter using 0.35 micron SiGe HBT has achieved a gain of 9.3 dB and a phase shift of 95 degrees at 0.74 GHz as well as a gain of 8.9 dB and a phase shift of 98 degrees at 0.88 GHz. This is the first time to present a dual-band active phase shifter using band-pass and band-stop designs.