A novel design of non-bending narrow wall slotted waveguide array antenna for X-band wireless network applications

Abstract

Slotted waveguide antennas (SWAs) are widely used in various wireless applications such as space aircrafts, radars, and aircraft tracking systems. A specific type of SWA, which has slots in its narrow wall, has caught great interest due to its ability to produce horizontal polarization. However, due to the typically smaller size of the narrow wall compared to the resonant length of the slot, the slot inevitably extends onto the broad waveguide walls. This bending not only compromises the structural integrity of the waveguide but also complicates precise slot excitation modeling and increases fabrication complexity for planar arrays, often requiring metallic separators. This paper introduces a novel design that prevents edge slot bending on the wider waveguide walls by using a dielectric layer placed on the slots, effectively halving the slot’s resonant length. This ensures that the slot remains fully positioned on the narrow wall without bending onto the broader walls and also it protects the antenna from extreme heat and humidity. To validate the effectiveness of the proposed design, an array consisting of 12 slots with a Taylor synthesis-based amplitude distribution was designed, tested, and demonstrated to have side lobes below − 30 dB. Simulation results were found to be in good agreement with measurements.