On-Chip High Impedance RMS Voltage Measurements at 265–300 GHz

A wideband (265-300 GHz) and high impedance root-mean-square (RMS) detector for on-chip voltage measurements is demonstrated in a 45-nm bulk CMOS process. The detector responsivity is ~70V/W at 10-nA bias. Adding the detector increases the loss of a 140-μm long GCPW thru structure by less than 0.2 dB up to 300 GHz. The compact RMS detectors are placed under a grounded coplanar waveguide feed to a patch antenna with virtually no area penalty, and used to measure the standing wave voltages. The minimum detectable signal of detector is ~-37 dBm with a dynamic range of ~40 dB.