A novel in-situ calibration technique for a high resolution E-Field probe

The potential of E-Field probes as diagnostic tools in operational microwave circuits and devices has been widely recognised but little used. Progress in this area has always been hampered by the lack of an absolute calibration technique. As such, these measurements are usually only useful for relative measurements over a range of electrical conditions where the probe remains stationary. This paper describes a probe design which can be calibrated in-situ each time the probe is moved. The calibration technique is demonstrated by measurements of RF waveforms at the device plane of a medium power (10W) GaAs PHEMT power amplifier.