Design of Waveguide Short-Slot Two-Plane Couplers for One-Body 2-D Beam-Switching Butler Matrix Application

摘要

A waveguide short-slot two-plane coupler is proposed as a component of 2-D beam-switching Butler matrix. The hybrid and cross coupler operations are designed by including the 2-D polarity symmetry, the propagation constant, and the coupling with the ports of the modes in the coupled region. Their designs are confirmed by experiments. The achieved bandwidth is approximately 2%, restricted by the frequency characteristic of the modes in the coupled region. Since the short-slot two-plane hybrid coupler itself acts as the 22-way 2-D beam-switching Butler matrix, the beam switching is also verified by measurements. The general configuration of the 2-D beam-switching Butler matrix is also proposed by using the short-slot two-plane couplers.