Microstrip junctions are most widely used building elements of

microwave integrated circuits. Serve to connect microstrip devices, divide, or combine

power, those elements represent simple microstrip discontinuities characterized by

appropriate scattering matrices. Based on the knowledge of frequency-dependent

parameters of circuit elements and junctions connecting these elements, large microwave

devices can be easily analyzed by the circuit theory. That is why the accurate modeling

basic microstrip junctions in terms of S matrix elements is a problem of great

importance for modern microwave CAD.