Search NASA⌕ Search

Engineering topics

Stafford, J. M.

Publications and source records attributed to Stafford, J. M..

6 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

RFI Math Model programs for predicting intermodulation interference

Receivers operating on a space vehicle or an aircraft having many on-board transmitters are subject to intermodulation interference from mixing in the transmitting antenna systems, the external environment, or the receiver front-ends. This paper presents the techniques utilized in RFI Math Model computer programs that were developed to aid in the prevention of interference by predicting problem areas prior to occurrence. Frequencies and amplitudes of possible intermodulation products generated in the external environment are calculated and compared to receiver sensitivities. Intermodulation products generated in receivers are evaluated to determine the adequacy of preselector ejection.

Stafford, J. M.↗
NASA NTRS1971

Determination of nonlinear resistance voltage-current relationships by measuring harmonics

Test configuration measures harmonic signal amplitudes generated in nonlinear resistance. Vacuum-type voltmeter measures low frequency sinusoidal input signal amplitude and wave-analyzer measures amplitude of harmonic signals generated in junction. Input signal harmonics amplitude must not exceed that of harmonics generated in nonlinear resistance.

Stafford, J. M.↗