Characterisation of planar passive circuits using source method and different trial functions

A source method is developed for analysing discontinuities in planar microstrip circuits. It is proposed to model the circuit by rigorous methods including the source method and using different sets of trial functions; roof top, sinusoidal and an entire trial functions. These numerical functions are computed by determining TE-TM modes of a ridged waveguide using the transverse method. The performance of each set of trial functions used with the source method is evaluated. The numerical results obtained, giving the transmission and reflection coefficients for STEP discontinuities, are compared with previously published data.