Millimeter-wave multi-beam antenna based on 2-D SIW beam-scanning network

A 94 GHz two-dimensional (2D) millimeter-wave beam-scanning network using low temperature co-fired ceramic (LTCC) technology has been proposed. It utilizes two Butler Matrixes, four 3-dB directional couplers and four phase shifters to provide eight groups of phase difference on one dimension and four groups on another dimension. Combined with 2×4 SIW slot antenna array, it can achieve eight beams on two dimensions and coverage from -60° to 60° in elevation plane. The gains of all beams are over 11.4 dBi. With the advantage of LTCC technology, the longitudinal size of the network is significantly reduced to 50% than a planar one. Meanwhile, the substrate integrated waveguide (SIW) structure can integrate the 2-D beam-scanning network and the antenna array in the same module which makes the whole system much stable.