Applications of the Nonlinear Circuit Analysis Program NCAP

The program NCAP has been developed during the last five years through the joint efforts of govern­ ment, industry, and universities to provide the EMC community with a useable procedure for analysing electronic equipment which must operate in a multi­ signal RFI environment. Several applications will be discussed to illustrate how EMC engineers can use NCAP. One application involves the use of NCAP to calculate third order intermodulation products in a discrete BJT tuned RF amplifier stage. In another application, NCAP is used to calculate RFI effects in a tuned AF JFET preamplifier caused by AM modulated RF signals with frequency components in the 0.1 to 100 MHz range. A third application involves the use of NCAP to calcu­ late RFI effects in a bipolar linear integrated cir­ cuit broadband amplifier. NCAP calculated results will be compared to experimental results for each circuit.