RADIATION FROM DIELECTRIC LEAKY-WAVE ANTENNAS WITH CIRCULAR AND RECTANGULAR APERTURES

The dielectric leaky-wave antenna considered here consists of multiple dielectric layers above a ground plane, with a simple source such as a dipole inside the layers. The layers act as a guiding structure for the radiating leaky wave field, which propagates radially outward from the dipole source. Such an antenna may produce either a broadside bea m or a scanned conical beam, depending on the chosen scan angle. For t he practical case of a finite-size aperture, the radiation pattern is determined by integration of the tangential fields over the aperture. For narrow-beam structures the leaky-wave field on the aperture may ex tend to large distances, and hence it is important to have an efficien t calculation of the radiation pattern for such cases. It is shown her e how to efficiently calculate the radiation pattern for a dielectric leaky-wave antenna having a finite-size aperture that is either circul ar or rectangular in shape. The derived formulas apply for a dipole so urce inside any type of dielectric layer structure, and thus include t he usual case of a microstrip antenna element on a single layer, as we ll as the more specific leaky-wave antenna structure considered here.