一种具有宽带双极化低散射特征的微带阵列天线

A Microstrip Array Antenna with Wideband Dual Polarization Low Scattering Characteristics

摘要:

针对阵列天线宽带散射缩减设计进行研究，设计了一种基于无源对消技术的低散射阵列天线，该新型微带阵列天线在宽频带内具有双极化低雷达散射截面（RCS, Radar Cross Section）性能；对基于两种散射性能不同的单元组成阵列的RCS性能进行了理论研究，进行了单元的散射幅度和相位对阵列RCS的影响分析；提出了一种加载T型缝隙的新型微带天线结构，该单元结构的辐射性能与散射性能能够进行独立调控和综合优化，该单元与传统微带贴片单元具有相似的辐射特性，并可在宽频带（带内和带外）内与传统微带单元产生有效相位差；将传统微带单元和加载T型缝隙的新型微带单元组成4×4阵列天线，仿真结果表明，提出的阵列天线在3GHz～7GHz（相对带宽80%）频带内实现了同极化RCS缩减，在3.3GHz～7GHz（相对带宽71.8%）频带内实现了交叉极化RCS缩减，缩减峰值分别为16.3dB和36.3dB，带内RCS缩减均值分别为14.1dB 和17.6dB；与传统微带阵列天线相比，提出的阵列天线增益下降小于0.1dB；提出的微带阵列天线具有高效率辐射和宽频带双极化低散射性能，为低散射阵列天线设计提供了新的思路。

Abstract:

The design method of array antenna wideband scattering reduction is researched, a low scattering array antenna based on passive cancellation technology is designed which has the performance of wideband dual polarization low radar cross section (RCS). The RCS performance of the antenna array consist of two kinds of elements with different scattering properties is studied theoretically. The influence of the scattering amplitude and phase of elements on the RCS of array antenna is analyzed. A new microstrip antenna element structure is designed by loading T-slot on the edge of the microstrip antenna radiation patch. By modifying the microstrip antenna element, its radiation performance and scattering performance can be independently regulated and comprehensively optimized. It has similar radiation characteristics with the reference microstrip antenna element and the effective phase difference between the two elements is produced in a wide band (in-band and out-of-band). The traditional microstrip antenna element and the new microstrip element loaded with T-slot are composed of 4×4 array antenna. The simulation results show that, the design array antenna achieves the reduction of co-polarization RCS in the frequency band of 3GHz ~ 7GHz (relative bandwidth 80%) and cross-polarization RCS in the frequency band of 3.3GHz ~ 7GHz (relative bandwidth 71.8%). The peak values of RCS reduction are 16.3dB and 36.3dB, and the mean in-band RCS reduction are 14.1dB and 17.6dB, respectively. Compared with the traditional microstrip array antenna, the gain loss of the proposed array antenna is less than 0.1 dB. Therefore, the proposed microstrip array antenna has high radiation efficiency and wideband dual polarization low scattering performance and a new idea for the design of low RCS antenna array is presented.