A Miniaturized Ultrawideband Active Electric Probe with High Sensitivity for Near-Field Measurement

A miniaturized ultrawideband active electric probe with high sensitivity for near-field measurement is proposed in this paper. The probe is designed with a four-layer PCB with mainly two chips, an amplification chip (HMC797APM5E) which can work from dc to 22 GHz and a power management chip (HMC980LP4E). The probe can work from 9 kHz to 18 GHz with 15 dB average gain compared to the passive probe. And the flatness is about ±4 dB in terms of |S21| (transfer factor) from 2.5 GHz to 18 GHz. The maximum size of the probe is 64 mm 41.5 mm with 1 mm spatial resolution, and the width of the tip is only 4.1 mm, so the probe can handle most test environments. On the whole, the probe is very efficient for near-field measurement to detect weak signals in a wide bandwidth.