Novel Wideband Multilayer Butler Matrix Using Cb-CPW Technology

Abstract

Abstract-This paper presents a novel design of a 4 × 4 twolayer wideband Butler matrix using a CB-CPW wideband multilayer directional coupler as well as a novel CB-CPW wideband elliptic directional coupler. With this configuration, the proposed matrix was designed to avoid crossovers as in conventional Butler matrices, thus reducing its size, losses and the design complexity while leading to a broad bandwidth of 3 GHz. To evaluate the performance of the proposed matrix, experimental prototypes of the directional elliptic coupler, the CB-CPW multilayer directional coupler and Butler matrix were fabricated and measured. Furthermore, a 4-element antenna array was connected to the matrix to form a beamforming antenna system at 5.8 GHz. As a result, four orthogonal beams were realized in the band 4.5-7.5 GHz.

Novel UWB CB-CPW butler matrix for wireless applications

“…For wideband applications, few configurations of Butler matrix have been suggested [4][5][6][7]. In [4], a 4×4 double layer UWB Butler matrix using microstrip-slot technology has been proposed.…”

“…The main advantage of the proposed configuration is the elimination of crossovers that normally occur in conventional Butler Matrix. In our previous work [6,7], wideband Butler matrices have been introduced using CB-CPW technology. The reported results show a band from 4 to 8 GHz.…”

“…This matrix is advantageously used to offer a very wide bandwidth better than reported in [6][7] to cover the en entire FCC bandwidth (3.1-10.6 GHz).…”

Compact Wide‐Band Branch‐Line Coupler with Meander Line, Cross, and Two‐Step Stubs

“…Size reduction, bandwidth enhancement, cost reduction, and multiband operation are the predominant requirements for branch‐line coupler (BLC) designs. BLCs are requisite components in many modern wireless communication systems; they are for instance employed as major building component of Butler matrices . They are also extensively utilized in designing many microwave circuits such as balanced mixers and amplifiers , switched multiplexers , filters , and power combiners/dividers .…”

Compact Planar Microstrip Crossover for Beamforming Networks

“…The traditional way used in beamforming networks to isolate the signals on the intersection is to use a three-dimensional structure, e.g., bond wires, air bridges or multi-layer structures [3][4][5][6][7]. The use of those non-planar structures increases the fabrication complexity and cost significantly.…”