Q-Band Short Backfire Antenna Arrays

This paper presents experimental results at Q-band for a waveguide-excited short backfire antenna. Two examples of the application of such a highly efficient radiator as elements in antenna arrays are given. It is shown that the use of quarter wavelength slots on the common main reflector rim of the array leads to substantial improvement in the directive gain and sidelobe level. A designed two-element array exhibits a directive gain of 25 dB and sidelobe level of -21 dB at 34 GHz whilst a four-element array shows corresponding values of 28 dB and -12 dB at the same frequency.