Abstract: A planar dielectric substrate supports a stripline conductor therein. A conductive housing has one or more recesses for receiving a dielectric and a conductive cover is mountable over the dielectric in contact with the housing to enclose the dielectric and isolate the stripline from adjacent structures. The housing and cover have aligned slots disposed on opposite sides of the dielectric and transverse to the stripline for providing coupling of signals between the stripline and the slot. An aperture is formed in the housing in communication with the slot.Other embodiments of the invention include impedance matching means for either or both of the stripline and the aperture for optimizing the efficiency measured in terms of VSWR of the radiator.