MY184273A - Reduced size active antenna beam forming networks using cascaded butler matrices - Google Patents

Abstract

A reduced size active antenna beam forming network for vehicle communication is described. The active antenna beam forming network uses Butler matrices to improve higher signal to interference ratio. Signal entering one port of the Butler matrix is divided into equal parts before the signal is amplified by amplifiers and then recombined by another Butler matrix. There is an array of low noise amplifiers (34, 38) to amplify received signals; a Butler matrix (36) to divide signals into equal amplitude with progressive phase variations; an array of power dividers (40) to split signals; an array of high linearity low noise amplifiers (42) to amplify and create high linearity signals; and a second Butler matrix (44) to combine the narrow band signal. The radio signal detected by antenna (32) is received, amplified by amplifier (34), divided by Butler matrix (36), amplified by amplifier (38), split by power divider (40), amplified by amplifier (42) and combined by Butler matrix (44). The first Butler matrix (36) creates high gain narrow beam signal while the second Butler matrix (44) and high linearity low noise amplifier (42) reconstruct the antenna patterns of individual radiating elements. The resulting outputs have high linearity and broad beam width signals. (Figure 1)