Multi-dimensional scanning multi-beam array antenna fed by integrated waveguide Butler matrix

A one-port two-dimensional (2-D) radiating antenna element is proposed and then used to form a substrate integrated waveguide (SIW) multi-beam antenna array. Leaky- wave antenna (LWA) consists of periodic arrangement of slot pairs designed on the top ground plane of the waveguide. Two-port LWA has frequency dependent radiation characteristics from −24° to +15° including the broadside direction. The output port of the LWA is loaded by antipodal linearly tapered slot antenna (ALTSA) to radiate all the remaining amount of power in the orthogonal direction. 4×4 Butler matrix based beam forming network (BFN) is proposed for the phase scanning of a 1×4 one-port LWA array and forms four independent simultaneous beams in the second dimension. The antenna and BFN are fabricated by using the SIW technology to implement highly efficient, compact, multi-dimensional scanning multibeam antenna array.