A low phase error X-band eight-channel SiGe PIN diode phased array receiver

A low phase error X-band eight-channel SiGe PIN diode phased array receiver for 9.5–11.5 GHz application has been proposed and fabricated in a commercial 0.18-µm SiGe BiCMOS process. High performance PIN diode switches used in phase shifters ensure low phase error for all phase states. The 9.5–11.5 GHz receiver, which consists of LNAs, VGAs, PIN diode passive phase shifters and active combiners, achieves over 10 dB measured average gain, less than 5 dB NF (at max. gain and ref. phase state) per channel. The RMS gain error is less than 1 dB and the RMS phase error is less than 4.8° at 9.5–11.5 GHz for all phase states. To the authors' best knowledge, this receiver achieves the lowest RMS phase error in multi-channel X-band phased array receivers using passive phase shifting method.