Closed-Loop Iterative Self-Calibration of Initial Phase in Phased Arrays

Area of Science:

• Electrical Engineering
• Signal Processing
• Antenna Theory

Background:

• Phased arrays require precise initial phase calibration for optimal performance.
• Existing calibration methods can be time-consuming and complex, especially for large-scale systems.

Purpose of the Study:

• To develop a fast and efficient closed-loop iterative automatic initial phase calibration scheme.
• To improve beam focusing and side-lobe suppression in large-scale phased arrays.

Main Methods:

• Obtaining complex readback data from all array elements with known calibration source direction and signal frequency.
• Calculating and removing theoretical phase, then performing conjugate multiplication with a reference element to eliminate common phase errors.
• Iteratively updating a phase compensation table using the relative phase residual for rapid automatic calibration.

Main Results:

• Achieved digital computation time of approximately 1.6 ms for a 256-element array.
• Demonstrated rapid convergence of the phase compensation table.
• Improved peak response by ~14.69 dB and reduced the highest side-lobe level by ~12.72 dB.

Conclusions:

• The proposed algorithm effectively improves beam focusing and side-lobe suppression.
• Provides a novel implementation scheme for initial phase calibration of large-scale phased arrays.
• Offers a significant advancement in phased array calibration efficiency and performance.