A Low Frequency Electric Field Probe for Near-Field Measurement in EMC Applications


A low frequency electric field probe with high sensitivity was designed for locating radiated emissions source in electronic systems from 10 kHz to 100 MHz. This probe consists of a dipole at probe tip loaded with an op-amp built instrumentation amplifier, whose output then is amplified by a cascaded RF amplifier. The probe dipole is capacitively loaded by the instrumentation amplifier, resulting in a flat frequency response with high sensitivity at low frequency. The instrumentation amplifier also converts differential dipole output to single-ended signal without the need of an external hybrid. Additionally, the instrument amplifier suppresses common-mode noise picked up by the probe dipole. Measured data from probe above a microstrip trace shows flat frequency response of wanted field coupling and 30 dB - 40 dB suppression of unwanted field coupling from 10 kHz to 100 MHz.

Meeting Name

2017 IEEE International Symposium on Electromagnetic Compatibility & Signal/Power Integrity (2017: Aug. 7-11, Washington, DC)


Electrical and Computer Engineering

Keywords and Phrases

Amplifiers (Electronic); Differential Amplifiers; Electric Fields; Frequency Response; Operational Amplifiers; Probes; Radio Frequency Amplifiers; Flat Frequency Response; High Sensitivty; Instrument Amplifiers; Instrumentation Amplifier; Low Frequency Electric Fields; Low Frequency Measurements; Near-field Measurement; Single-ended Signals; Electromagnetic Compatibility; Electric Field Probe

International Standard Book Number (ISBN)

978-1-5386-2231-5; 978-1-5386-2229-2

International Standard Serial Number (ISSN)


Document Type

Article - Conference proceedings

Document Version


File Type





© 2017 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Aug 2017