The directivity of a horn antenna as a true-time-delay array element of an optical beam-forming network is enhanced by using a graded index dielectric lens. The proposed refractive index distribution of the lens is designed to mitigate the phase error at the antenna aperture while keeping the antenna reflectionless. Ray-tracing-based optimization is carried out to achieve the best design parameters and modify the horn’s body. Realization of the lens is also demonstrated by discretizing the refractive index of the lens into several layers. The half-power beamwidth value of an example horn antenna is divided by four using the proposed lens. The functionality of the proposed lens is verified by conducting ray-tracing and full-wave simulations using COMSOL.

通过使用渐变折射率介电透镜，喇叭天线作为光束形成网络的真实时延阵列元件的方向性得到增强。建议的透镜折射率分布旨在减轻天线孔径处的相位误差，同时保持天线无反射。进行基于光线追踪的优化以实现最佳设计参数并修改喇叭主体。透镜的实现也通过将透镜的折射率离散成几层来证明。使用建议的透镜将示例喇叭天线的半功率波束宽度值除以 4。通过使用 COMSOL 进行光线追踪和全波模拟，验证了所提出的透镜的功能。