The theory of passive intermodulation generation on

printed transmission lines has been proposed. The new model for

a terminated section of the transmission line with distributed

nonlinear resistance has been developed and verified against the

published experimental data. The closed form relation between

the macroscopic nonlinear resistance and microscopic nonlinear

surface resistivity of strip conductors has been obtained for

microstrip lines. Effects of microstrip line width, length and

matching on passive intermodulation generation have been

studied in detail.