IMPATT diodes were designed and integrated with microstrip patch antenna on–chip in standard CMOS technology to extract the efficiency beyond avalanche frequency. By
comparing the on-chip simulations and measurements of an IMPATT diode integrated in a CPW to an integrated one with a microstrip patch antenna at the same biasing conditions, the results demonstrated an efficiency ranging from ~ 0.01% to 0.016% without and with the added surface roughness losses, respectively. Such variation is strongly associated with the uncertainty provided by the increase of conduction losses ranging between 40%~80% beyond the avalanche frequency.
