Compact circulator based phase shifter at C-band in BiCMOS

This paper presents an active BiCMOS circulator based phase shifter suitable for spatial diversity transceivers in the C-band. Up to 10 GHz, a phase control range of at least 90 deg and a gain of 0 plusmn 0.5 dB can be realized. The circuit uses a single supply of 1.8 V and draws a maximum current of 4.6 mA. The proposed phase control principle neither needs inductors nor varactors yielding a simple phase control and very compact core size of only 0.023 mm
²
.