Transmission line analysis of a rectangular microstrip patch antenna coupled to an open-ended microstrip line

A highly-flexible and computation-efficient transmission line method is presented to model a rectangular patch antenna coupled to a microstrip line. Using this transmission line approach the input impedance, resonant frequency, return loss, coupled and radiated power can be determined simultaneously. From the analysis results it is shown that the resonant frequency and input impedance have a strong connection to the coupled line. Both the coupled and radiated powers can be increased to useful levels when the matching section is properly designed after the resonant input impedance has been determined at the antenna feeding port.