Integrative Transmitarray With Gain-Filtering and Low-Scattering Characteristics

摘要

This article presents a design concept of integrative transmitarray antenna (TAA) with gain-filtering and low-scattering characteristics. The integrative TAA element combines a bandpass frequency-selective surface (FSS) element and a square dielectric post with antireflection pyramidal structures (SDPP), achieving the simultaneous control of in-band transmitted waves and out-of-band reflected waves. The FSS element provides the phase-shifting and gain-filtering capabilities around the center operating frequency f(0). Meanwhile, the SDPP elements with different heights are utilized to reduce the scattering cross section (SCS) based on the phase cancellation principle. To realize wideband and wide-angle SCS reductions, also to mitigate the in-band radiation degradation, the optimal SDPP arrangement is determined with subarray segmentation. In the experiment, a 42 x 42-element integrative TAA is designed. Against only the FSS TAA, the simulated results show that loading the optimal SDPP array can realize the scattering reduction in a 10:1 bandwidth up to 60 degrees, including similar to 5/similar to 10 dB SCS reductions in 0.5-1.5 f(0)/1.5-5f0, respectively. Moreover, the integrative TAA achieves gain-filtering responses with out-of-band suppression levels higher than 20 dB. After fabricating the FSS TAA and the SDPP array by the technologies of standard PCB fabrication and 3-D printing, respectively, the proposed design is further demonstrated by experiments.

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