FM Receiver Measures Field Intensity

One of the limiting factors in measuring field intensity at the fringe area of an antenna is that the white noise level may be equal to or greater than the carrier signal. In addition, this noise level may vary with time of day, thereby rendering calibration for ambient-noise level an uncertain procedure. This paper describes a field-intensity measuring technique that overcomes this limitation. The silencing action of an FM receiver is used to accurately measure the magnitude of an RF signal regardless of the level of random noise present.