Coupled line multiports

The properties of multiple coupled line structures are reviewed for applications in microwave circuits. In order to demonstrate the applications of the coupled line multiports, some representative examples are given. These include the application of the multiple coupled line theory in the analysis and design of components such as a spiral inductor, a coupled line two port representing a DC block-filter, a three-microstrip three-port channel selection filter, a three-waveguide optical coupler, and the study of crosstalk, delay, and distortion in a coupled interconnect including losses and dispersion. Other applications of such linear systems include the analysis and design of interdigitated structures for application in MMICs (monolithic microwave integrated circuits), and photodetectors, and various four, six, and other multiport directional couplers and power dividers