Performance Enhancement of Unconventional Slotted Waveguide Antenna Arrays at Ku Band

Slotted waveguide antenna (SWA) arrays are highly valued for their compact structure, high power handling capability, directivity, and efficiency, making them ideal for advanced radar and communication systems. In broad-wall SWAs, side lobe levels (SLLs) are influenced by slot displacement from the waveguide centerline and slot inclination angles, impacting array performance. This paper introduces a novel design approach for meandered SWA arrays optimized as frequency scanning antennas (FSAs), achieving enhanced gain, scanning coverage, and SLL suppression. The design incorporates an innovative meandering feeding mechanism, significantly improving frequency scanning performance over the Ku band (15.1-16.5 GHz). The array includes 16 radiating slot elements paired with an E-plane horn antenna in elevation plane, narrowing beam width, and optimizing radiation control. Using the discrete Taylor distribution to meet SLL requirements, this approach effectively balances low SLL with high gain. Simulations conducted in CST Microwave Studio confirm the array's performance, showing 70 degrees scanning coverage, over 21 dBi gain, and an SLL reduced to -21 dB. Both simulated and measured results designate that the proposed meandered SWA array architecture is appropriate for next-generation frequency scanning systems, offering a compact, power-efficient, and high-precision solution for demanding applications.