High-Performance Probe for Over-the-Air Measurement

We present a low-cost, and compact probe that can be used in an over-the-air (OTA) measurements. The probe is a slot antenna with a ground plane. To simplify detection, the near-field signal of an antenna under test is mixed with an LO at the probe location. The mixer is a self-biased diode quad on the probe. Results are in good agreement with the simulation showing that a range of 35 dB of RF signal power can be detected. This can be used in near-field analysis such as an over-the-air antenna measurements.