Leaky-Wave Antenna With Wide Scanning Range Based on Double-Layer Substrate Integrated Waveguide

A leaky-wave antenna (LWA) based on the double-layer substrate integrated waveguide (SIW) that has a wide scanning range within a narrow bandwidth is proposed. The LWA consists of two layers, each of which consists of multiple elemental SIWs arranged in parallel at each layer while the direction of the SIWs in the two layers are at an oblique angle to each other. The elemental top layer SIWs are connected to those in the bottom layer though parallelogram-shaped slots, so that the two layers together form a double-layer SIW. Thin slots etched on the upper surface of each elemental SIW of the top layer act as radiating structures. As the phase difference between the radiating slots of adjacent elemental SIWs can be enlarged by the waveguide length, wide-angle beam scanning is achieved within a specific frequency bandwidth. The proposed LWA has a scanning range from -58 degrees to 49 degrees in a relative bandwidth of 6.45%, from 12.75 GHz to 13.6 GHz. The scanning rate (SR), defined as the scanning range divided by the relative bandwidth, is up to 16.5. The size of structure is compact, which is 4.0 lambda(0) x 3.6 lambda(0) x 0.04 lambda(0). The proposed LWA is suitable for radar or communication system applications.