Accession Number : ADD001340
Title : Automatic Noise Figure Indicator.
Descriptive Note : Patent,
Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C
Personal Author(s) : Campbell,Kenneth J
Report Date : 28 Jun 1974
Pagination or Media Count : 7
Abstract : The patent relates to an automatic noise figure indicating system which impresses noise of known amplitude on the RF input of a receiver under test and uses the audio output of the receiver to measure its noise figure. The injected noise is cyclically impressed upon the receiver at a determinable switching frequency, the output of the receiver being alternately connected to first and second low-pass filters in synchronism with the switching. A high-pass filter suppresses the switching frequency and prevents its detection in the noise figure indicating system. A means is provided for developing an analog signal as a function of the power ratio between the two signals produced by the first and second low-pass filters. The analog signal is visually presented by an indicator appropriately calibrated in terms of noise figure.
Descriptors : *Measuring instruments, *Patents, Noise(Electrical and electromagnetic), Automatic
Subject Categories : Test Facilities, Equipment and Methods
Distribution Statement : APPROVED FOR PUBLIC RELEASE