High‐efficiency broadband slotted waveguide array antenna

Abstract

This study describes design and development of a novel X‐band high‐efficiency broadband slotted waveguide array (SWA) antenna. Broadband nature of SWA has been achieved using differential feeding mechanism which bifurcates large resonating SWA into wideband sub‐arrays by creating virtual short. The performance of such type of broadband SWA is also compared with conventionally designed edge fed SWA and coupling slot fed SWA. The proposed broadband SWA features high efficiency, high power handling capacity and low fabrication tolerances as compared with conventional SWA designs. The design and prototype development of ten‐elements linear SWA with differential feeding mechanism is presented. The developed prototype array antenna demonstrates measured return loss (RL) performance better than 17 dB with 90.2% antenna efficiency over 7.6% bandwidth. The realised gain of 16.32 dBi at 9.65 GHz is measured and the proposed antenna also shows significant improvement in gain flatness. Ten elements linear broadband SWA has also been extended to 2 × 10 planar broadband SWA and its prototype development and characterisation has also been presented.