Calibration Method of Multi-Beam Antenna Array Channels

This paper presents a procedure used to calibrate a multi-beam antenna array to compensate for channel amplitude and phase mismatch. The multi-beam smart antenna is based on Butler matrix. The calibration algorithm of N elements array antenna involves transmission of N time multiplexed orthogonal encoded signals. The received signals are coherently detected, accumulated in vector forms, and a set of correction factors are decoded from the received signal using the inverse of the encoded matrix. A Hadamard matrix is used as the encoding matrix. The simulation and analysis of calibration method are carried out with Matlab.