A bidirectional dual-frequency antenna configuration

A compact arrangement incorporating - on opposite sides of a multilayer structure - two planar antennas or both a planar antenna and a transition from rectangular waveguide to microstrip line is presented. The elements on the different sides of a common ground plane may be designed either for the same or for different frequencies, thus including diplexing functions into the arrangement. Simulated and measured transmission performance and the radiation patterns of the device are given. The theoretical analysis is based on a modified spectral domain procedure. The design of a simple mixer taking advantage of the structure is demonstrated, and some other possibilities for application are given.