Improved Rotating-Element Electric-Field Vector Method for Fast Far-Field Phased Array Calibration

Abstract

We present a fast far-field phased array calibration/beamforming method. An improved version of the rotating-element electric-field vector (REV) method, which is used to calibrate array antennas by measuring the power received at a far-field point while varying the phase of each element, is proposed. Two major improvements were made. First, a simpler algorithm was used to determine the calibration value of the conventional REV method, without disconnecting an antenna element during the calibration process. Second, a solution for a specific case was added for a more accurate categorization to use the correct formula. This improved rotating-element electric-field vector (IREV) is experimentally verified. Curve fitting and sinusoidal regression were used to reduce the number of measurements required for fast calibration/beamforming. Arrays of a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\times 6$ </tex-math></inline-formula> phased array system comprising a 4-bit phase shifter and a 6-bit variable-gain attenuator (VGA) were calibrated using only measurements of the far-field received power. Calibrations were performed when the horn and array antennas were perfectly aligned with each other and when the latter was tilted at an angle of 12° relative to the former.