A Numerical Method for the Design of n-Microstrip Filters

A numerical method is reported for the design of filters composed of arbitrary n-microstrip structures like hairpin, meander, half-wave coupled parallel lines and more generally hybrid structures. In order to improve the design accuracy the dispersion, the losses and the dicontinuities in the structure are taken into account. The optimization routine is based on the Fletcher-Powell method with a numerical evaluation of the gradient vector of an appropriate objective function. the indipendent variables being the physical sizes of the microstrip lines.