A broadband E-field sensor

A broadband (10-kHz-350-MHz) E-field sensor based on an electrically small antenna for measurements of transient fields has been developed. The antenna is coupled to a receiver using a wideband buffer amplifier. The sensitivity of the sensor depends on the size of the antenna, while the broadband performance is determined by the size of the antenna, the input impedance of the amplifier, and the coupling between the two devices. The sensor is calibrated in a TEM (transverse electromagnetic) cell using CW (continuous-wave) and pulsed fields. Results of an analysis and calibration of the sensor are presented. For a sphere of 9.6-cm diameter coupled with a 1-M Omega microprobe, the sensor provides a flat response with sensitivity of 1 mV/(V/m) from 10 kHz to 350 MHz. The risetime of the output pulse is less than 500 ps. The dynamic range of the sensor is expected to be on the order of 80 dB.<>