An F-Band n-Probe Standing Wave Detector for Complex Reflection Coefficient Measurements in 40-nm CMOS

摘要

This article presents an F-band-integrated standing wave detector for complex reflection measurements. The complex reflection coefficient is derived from a standing wave, measured by 312 power detectors coupled from underneath a transmission line (TL), taking the loss of the TL into account. For the proposed method of reflection coefficient derivation, the tradeoff between TL length and number of probes is shown through simulation. The standing wave detector is fabricated in the 40-nm CMOS process, and the measurements show complex reflection coefficient for input powers down to -20 dBm at 120 GHz while only consuming 112 mu W of dc power. In measurements, the complex reflection detection is shown for multiple impedances achieving an absolute phase error of 8.3 degrees with a sigma of 1.5 degrees and a magnitude error of 0.33 dB with a sigma of 0.21 dB, compared to a VNA reference measurement.