A Unified Variational Solution to Microstrip Array Problems

A very general variational procedure is used to compute single or coupled microstrips under the quasi-TEM approximation. The capacitance model is found by means of a unique fundamental cell. The method is essentially an extension of Smith´s, but may be used to study a wider variety of problems, such as nonuniform strip arrays, coplanar striplines, and broad-side coupled strips. Moreover, it is also possible to compute the coupling capacitance between nonadjacent strips.