A miniature switching phase shifter in 0.18-µm CMOS

A miniature 3-bit switching phase shifter using standard 0.18-μm CMOS process is presented in this paper. By using thin-film meander-line to shrink the size of inductor, the chip area can be reduced to 0.285 mm². This circuit demonstrates an RMS phase error of smaller than 5.3° and an RMS amplitude error of smaller than 1.3 dB from 21-29 GHz. The average insertion loss and return loss at 24 GHz are 11 and 7 dB, respectively. To the authors´ knowledge, this phase shifter achieves lowest RMS phase error and insertion loss among all Si-based switching phase shifters above 10 GHz.