A RIGOROUS STUDY OF MICROSTRIP CROSSOVERS AND THEIR POSSIBLE IMPROVEMENTS

A theoretical study of microstrip crossovers is presented. For an air- bridge interconnect in a crossover configuration, the equivalent circu it examined exhibits low-pass filter characteristics. To reduce the re turn loss in the passband, insertion of discrete shunt capacitors is p roposed and investigated. These shunt capacitors are treated as linear lumped elements and connected by via-holes of rectangular cross secti on. It is emphasized that air-bridges, via-holes and lumped elements u sed in this particular application are all rigorously included in a fu ll-wave spectral-domain analysis.