A Two-Dimensional Beam Scanning 60 GHz Antenna Array Based on SIW Butler Matrix

A two-dimensional (2-D) scanning 60 GHz multibeam antenna arraybased
$4\times 4$
Substrate Integrated Waveguides (SIW) Butler matrix (BM) is proposed. The antenna is composed of a dual series fed patch antenna subarray and 2 groups
$4\times 4$
Butler matrices. Butler matrices are arranged in the input ports at both sides of the antenna sub arrays. The 2-D multibeam antenna is achieved a wideband with 15% and maximum gain of 18.8 dBi at 60 GHz. When the 4 ports on the same side are fed, the beam is directed (30°, 30.1°), (−55°, 50.5°), (55°, 50°), and (−30°, 30°). When fed by the four ports on the other side, the beam direction (30°, -30.1°), (−55°, -50.5°), (55°, - 50.5°), (−30°, -30.1°).