Efficient Estimation of Active Element Patterns for 2-D Planar Array Antennas via Directional Decomposition

An efficient approach for estimating active element patterns of 2-D planar array antennas is proposed in this letter. Active element patterns enable accurate reflection of mutual coupling and truncation effects in finite arrays; however, extracting all patterns incurs larger computational cost as the number of antenna elements increases. To address this issue, this letter proposes a directional decomposition method that efficiently estimates simulated active element patterns by decomposing 2-D array problems into simpler 1-D array problems. Through directional decomposition, the computational complexity for numerical analysis reduces from O(M2 B(N3 xN3 y )) to O(M2 B(N3 x + N3 y )) for Nx × Ny 2-D planar array. Numerical validation with open-ended waveguides confirms that the proposed method can estimate active element patterns with high accuracy. The synthesized beam patterns show mean squared errors below 0.1 dB in the main lobe region for various beam steering cases. Computation time for numerical analysis reduces to less than 0.1% compared to the conventional active element pattern method for the 11×9 elements planar array used in validation.