Abstract: Dielectric lenses (6) with an outer dimension of about 0.5 to 1.5 times a wavelength are arranged on front faces of respective slots (3) of a waveguide slot array antenna (1). The dielectric lenses (6) are formed in a panel structure where they have been connected integrally through a dielectric panel (7) so that they cover a front face of the antenna. Spherical waves radiated from the slots are converted into a flat wave by the dielectric lenses, and a composite wave of radiation waves from the respective slots becomes a flat wave which hardly includes ripples, so that an antenna gain is remarkably improved as compared with a case that dielectric lenses are not provided.

Abstract: Dielectric lenses (6) with an outer dimension of about 0.5 to 1.5 times a wavelength are arranged on front faces of respective slots (3) of a waveguide slot array antenna (1). The dielectric lenses (6) are formed in a panel structure where they have been connected integrally through a dielectric panel (7) so that they cover a front face of the antenna. Spherical waves radiated from the slots are converted into a flat wave by the dielectric lenses, and a composite wave of radiation waves from the respective slots becomes a flat wave which hardly includes ripples, so that an antenna gain is remarkably improved as compared with a case that dielectric lenses are not provided.