A compact terahertz frequency selective surface with fast roll-off characteristics

Abstract

A simple and compact terahertz (THz) frequency selective surface (FSS) with high selectivity is presented for the cases of normal incidence. The guidelines for the design along with the operation mechanism are presented in detail from the view of equivalent circuit. The design is implemented by mapping the lumped components in a topology circuit of microwave filter with two transmission zeros to structures of FSS, while the mapping is realized by slotting cross-shaped aperture in the grid. An intensive study on equivalent circuit model predicts the existence of transmission zeros and poles. It can afford two transmission zeros and two transmission poles ranging from 350 GHz to 450 GHz with the band separation of 1.05 and 1.07, thereby exhibiting fast roll-off characteristics. The two transmission zeros can be controlled independently by simply changing structure parameters of the unit cell. The proposed FSS is superior in terms of roll-off rate as well as the balance between selectivity and overall thickness. The measured results of the prototype are consistent with the simulation results, which validates the robustness of the design.

Intelligent electromagnetic mapping via physics driven and neural networks on frequency selective surfaces

“…To uncover the EM mappings between various structures and beam properties in an intuitive and simple way, Marcuvitz [34] proposed the classical equivalent circuit model (C-ECM), in which the structures with infinite length were intuitively regarded as cascades of lumped elements. Since then, the theory of equivalent circuit models (ECMs) has been extensively optimized and introduced into analyzing complex structures [9,[35][36][37][38][39][40][41][42][43][44][45]. Unlike the C-ECM, later models concentrated on finite length structures, which were still based on the C-ECM but beyond the application scope.…”

Absorptive/transmissive frequency selective surface with multiple transmission zeros for reduced transition bandwidth

“…In [16], a cascade configuration of gridded square loops was utilized for creating two transmission zeros between adjacent passbands. To obtain multiple transmission zeros, a composite structure of complementary square rings and etched slot lines was provided in [17]. Alternatively, the multi-layer coupling method of bandpass and bandstop FSS [18] has also been investigated.…”