A Domino Tiling Method for Circularly Polarized Subarrayed Phased Array Antenna Based on Modified Maximum-Entropy Model
Hong Lin, Lun Wei Mou, Cheng Jia Li, Yu Jian Cheng
Abstract
In the majority of current research on phased array subarrayed tiling, the circular polarization characteristics of the array are often neglected, which results in a deterioration of the axial ratio (AR) of a circularly polarized subarrayed antenna during scanning. This article presents a domino tiling method for the circularly polarized subarrayed phased array antenna (PAA). In the proposed method, domino subarray tiling with constrained arrangement rules is achieved by a modified maximum-entropy model. The resulting subarray tiling exhibits a modular alternating horizontal and vertical layout, where the subarrayed sequential rotation feeding can be introduced to improve the AR. Moreover, it has a relatively simple subarrayed feeding network, which is easy to implement. The array pattern synthesis for the proposed design, achieving high directivity and low sidelobe levels (SLLs), is performed by convex optimization. To validate the effectiveness of the proposed method, a circularly polarized element is designed to configure the validating subarrayed antenna. Both simulated and experimental results of the validating subarrayed antenna show good AR performance, regardless of the boresight direction or scanning angles. Specifically, the AR s of the validating subarrayed antenna for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\theta $ </tex-math></inline-formula> = 0° and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\theta $ </tex-math></inline-formula> = 45° are both below 1.2 dB at the center frequency. Additionally, the proposed method exhibits potential for wideband operation in circularly polarized subarrayed phased arrays.