Port (circuit theory)

Beam (structure)

Engineering

Transformation matrix

Computer science

Antenna (radio)

Classical mechanics

Directional antenna

Power dividers and directional couplers

Physics

Optics

Electronic engineering

Kinematics

Hybrid coupler

Topology (electrical circuits)

Electrical engineering

IEEE Transactions on Microwave Theory and Techniques

A multibeam beam-forming network (BFN) for generating 2-D multibeam array antenna (MAA) is proposed using single-layer substrate integrated waveguide (SIW) technology. Firstly, a new topology for building 16 x 16 BFNs is proposed, which successfully transforms the traditional topology from a 3-D configuration to a 2-D (or uniplanar) one. Two major challenges are tackled during this transformation, namely, the planarization of basic components and the reduction of excessive intersections between multiple paths. To this end, a novel design of eight-port hybrid couplers, as critical components of this BFN, is developed to transform a 3-D to a 2-D structure. Furthermore, a new design of eight-port crossover, which can address four path intersections simultaneously, is proposed to reduce the total number of path intersections from 16 to only 4. The proposed topology for 16 x 16 BFNs allows all the basic components, including eight-port hybrid couplers, eight-port crossovers, and phase shifters, to be placed within a single-layer configuration. Fed by the proposed uniplanar 16 x 16 BFN, a 2-D MAA with 16 (4 x 4) beams, which is capable of switching the beams in both elevation and azimuth directions, is realized. Compared with the previous 2-D Butler matrix (BM) designs using multilayer technology, it is for the first time that a uniplanar design of 16 x 16 BFN is proposed and realized, which significantly simplifies the design and fabrication complexity.

Uniplanar Beam-Forming Network Employing Eight-Port Hybrid Couplers and Crossovers for 2-D Multibeam Array Antennas