On Wireless Board-to-Board Communication with Cascaded Butler Matrices

Antenna arrays fed by cascaded Butler matrix networks can be used to enable a very flexible wireless communication network between computer boards. However, the quality of the wireless links, particularly considering interference, depends on the design of the Butler matrices and on certain topology parameters, like the distance of boards, placement of antenna arrays, and the distance of antenna elements within the antenna arrays. In this paper, we model such a wireless multi-link board-to-board communication scenario and investigate the influence of these parameters. The Worst-Case Signal-to-Interference-and-Noise-Ratio (WCSINR) of a link is used as a measure of quality. We show that an optimization of the topological parameters significantly improves the (average) WCSINRs and yields a better performance of the communication links.