Q-band dielectric-loaded short backfire antenna arrays

Experimental results at Q-band are presented for a waveguide-excited short backfire antenna having a dielectric-loaded main reflector rim. Results show that loading the rim with dielectric produces an appreciable improvement in the directive gain and sidelobe level. The favorable influence on the array characteristics of the dielectric-lined array main reflector rim is demonstrated using two examples of the application of such a highly efficient radiator as array elements. It is concluded that in terms of cost, the use of dielectric for enhancing the gain of such arrays is more attractive than that of quater wavelength slots.