Design and simulation of a flexible beamforming interface for MIMO receivers using a Butler labyrinth

Abstract

This article focuses on the design and simulation of a new component for analog beamforming based on the Butler labyrinth. The proposed component enables the analysis of four-antenna beamforming in systems with two receive channels. The problem was to design a component that would enable simulation of a MIMO receiver with an accurate account of the analog beam-former effects on the digital signal processing level. The entire process is described-from layout design to the final DSP level integration and simulation. The performance of the simulated Butler component is compared to that of an ideal, theoretical one. The differences in the results indicate the importance of taking into account the effects of the layout level design on the DSP simulation level. The new component proves valuable for the bottom-up approach in the design and simulation of a wireless system.

An ultra‐wideband 3 × 3 Butler matrix with unique Vivaldi array structure for high‐range resolution radars

“…is the most accurate compared to other methods. [5][6][7][8][9][10][11][12][13] As a key component for beamforming tracking, a switched beam system usually consists of an antenna array that can generate multiple fixed beams with enhanced precision. Beamforming tracking systems are known to be able to detect a target with high-range resolution when applied with ultra-wideband (UWB) methodology.…”

“…So far, several studies have been reported that deal with generating the line-of-sight pattern with a 3 Â 3 Butler matrix. 7,[10][11][12][13] In this article, a UWB 3 Â 3 modified Butler matrix built on a unique structure of Vivaldi antennas has been developed to overcome the problems such as diagnosis of a high-range resolution target, low gain in the whole UWB, line-of-sight pattern generation, and high SLL to achieve satisfactory beam-steering conditions. However, Vivaldi antennas that can operate at a bandwidth/center frequency ratio of more than 100% are subject to high SLLs when placed side by side in an arrangement of the array, as they will have a large size for the upper frequencies of the operating band.…”

“…The auto‐tracking technique of beam‐steering array antennas based on passive microwave components (coupler, phase shifter, etc.) is the most accurate compared to other methods 5–13 . As a key component for beamforming tracking, a switched beam system usually consists of an antenna array that can generate multiple fixed beams with enhanced precision.…”

“…The inability to generate a line‐of‐sight pattern is one of the inevitable problems in standard Butler matrix feed networks. So far, several studies have been reported that deal with generating the line‐of‐sight pattern with a 3 × 3 Butler matrix 7,10–13 …”