A SIW Leaky-Wave Beam Scanning Array

A new type of Butler matrix-fed two-dimensional (2-D) beam scanning antenna array using composite right/left-handed (CRLH) substrate integrated waveguide (SIW) leaky-wave antennas (LWAs) technique is proposed. It consists of 4 CRLH SIW LWAs and a wideband feeding Butler matrix as the beam forming network. The proposed array can scan its beams in two dimensions by changing the operating frequency and the input port of the Butler matrix (BM), respectively. The array is fabricated and measured. The main beams can scan in one plane from -60 degrees to 66 degrees continuously by sweeping frequency from 3.7 GHz to 4.7 GHz. In the orthogonal plane, it can point to 4 discrete angles (-36 degrees, -12 degrees, 16 degrees, 36 degrees) by feeding in the different input port of the BM. With a wider coverage of the upper half-space, the low cost, and the low profile, this proposed antenna array is very attractive for a variety of phased array applications, particularly those that require a flush-mounted structure.