This paper addresses the analysis and design of a new class of metasurface leaky-wave antennas (LWAs) that inherently have low monostatic radar cross section (RCS) for normal incidence parallel polarization. The impedance profile of these antennas is modulated with a square wave to achieve leaky-wave behavior with low RCS. The low RCS performance is justified by the concepts of generalized Snell's law of reflection and array theory. When the reflection phase difference between consecutive periods is near 180°, the power reflected in the specular direction is minimal. It is also shown that modulating the surface impedance with a square wave still results in a high-gain fan beam similar to that of a sinusoidal modulation; however, the trade-off for obtaining a low RCS is an increase in the sidelobe level due to radiation from higher-order harmonics. A similar trade-off exists between the gain/beamwidth and RCS reduction. A prototype of an LWA with low RCS was fabricated and measured; an excellent agreement was observed between simulations and measurements.

中文翻译：

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小雷达截面棋盘漏波天线的分析与设计


本文讨论了新型超表面漏波天线 (LWA) 的分析和设计，该天线本质上具有低单基地雷达截面 (RCS)，适用于法向入射平行极化。这些天线的阻抗分布采用方波进行调制，以实现低 RCS 的漏波行为。广义斯涅耳反射定律和阵列理论的概念证明了低 RCS 性能。当连续周期之间的反射相位差接近180°时，镜面反射方向上反射的功率最小。还表明，用方波调制表面阻抗仍然会产生类似于正弦调制的高增益扇形光束；然而，获得低 RCS 的代价是由于高次谐波辐射导致旁瓣电平增加。增益/波束宽度和 RCS 降低之间也存在类似的权衡。制造并测量了具有低 RCS 的 LWA 原型；模拟和测量之间观察到了极好的一致性。