Light-emitting diode as radio-frequency detector: development of RFI-free electromagnetic field sensor

Author

Neelakanta, P.S. ; DeGroff, Dolores

Author_Institution

Dept. of Electr. Eng., Florida Atlantic Univ., Boca Raton, FL, USA

Volume

25

Issue

23

fYear

1989

Firstpage

1606

Lastpage

1608

Abstract

A unique RFI-free electromagnetic field sensing technique using an LED as an RF detector is described. A double heterojunction (AlGaAs/GaAs) LED is used as an RF rectifier coupled to an EM probe; it delivers proportional light output with significant efficiency even at low (rectified) drive currents. DC biasing of the LED to the threshold of conduction can be achieved by an optically powered photodiode pair. Use of fibre-optic links from the detector to the receiver and in the optically powered bias arrangement eliminates the possibilities of RFI. Presented here are the sensitivity and frequency response of a test probe measured over 3-30 MHz under near-field conditions.

Keywords

electromagnetic compatibility; fibre optics; field strength measurement; light emitting diodes; optical links; radiofrequency interference; 3 to 30 MHz; AlGaAs-GaAs light emitting diode; DC biasing; EM probe; HF; LED RF detector; RF detector; RF rectifier; RFI-free electromagnetic field sensor; fibre-optic links; frequency response; near-field conditions; optically powered bias; optically powered photodiode pair; proportional light output; radio-frequency detector; sensitivity; test probe;

fLanguage

English

Journal_Title

Electronics Letters

Publisher

iet

ISSN

0013-5194

Type

jour

DOI

10.1049/el:19891078

Filename

138822