Computational Experience with a Dual Backtrack Algorithm for Identifying Frequencies Likely to Create Intermodulation Problems

This paper describes the results of a computational study using a particular enumeration procedure, called a backtrack algorithm, to find the lowest order of radio-frequency intermodulation. The average lowest order and its standard deviation, the average computer time and its standard deviation, along with other relevent statistics are obtained for a series of randomly generated problems with sets of five to 75 threat or source frequencies. Other parameters, such as the guard band, the maximum number of concurrent threats, and the size of the frequency band on the lowest order of intermodulation are varied during the computations. Statistics for these computer runs, along with those relating to terminating the algorithm when the lowest "acceptable" order is reached, are presented in some detail. Brief conclusions follow a listing of the results.