A Low Profile X-Band Slotted Waveguide Array Antenna for Radar Applications

An X-band low profile slotted waveguide array antenna measuring just over a foot has been designed for surface navigation and air traffic radars. At 9.41 GHz, the horizontally polarized antenna provides a realized gain of 17.3 dBi and half power beamwidths of 4.7° and 110° in E and H planes respectively. The antenna offers a front to back ratio of above 20 dB from 9-12 GHz and a total efficiency of 96.11% at 9.41 GHz. Through parametric studies, a non-linear relationship between the length and performance parameters including reflection coefficient, gain, beamwidths, and front to back ratio of an SWA has been established. The proposed design contains 20 slots arranged over two rows in a single waveguide section and offers an optimum tradeoff between size profile and antenna performance.