Low‐loss frequency selective surface for multi‐band THz transmission measurement

Abstract

Frequency selective surface is a key component in a quasi‐optical system enabling multi‐band operation. This work presents the design, fabrication and measurement of a low‐loss frequency selective surface in a quasi‐optical system for terahertz transmission measurement to separate 220 to 260 GHz and 325 to 340 GHz bands. High‐precision milling technique was employed for fabrication. The measurement was conducted using a terahertz time domain spectroscopy and a home‐made quasi‐optical test bench. Good agreement was achieved between the measured results and simulated ones. The design and measurement methods can be applied to frequency selective surfaces working in other millimeter wave bands.

Design and simulation of a new narrow terahertz bandpass filter

“…7). Also, according to studies of circular filters by using the CST software [27][28][29][30], the transmission coefficient is 95-100%.…”

“…Through a comparison of the properties of the proposed spider bandpass filter and the plus bandpass filter, it emerges that the former has a higher transmission coefficient (almost 100%) and lower noise (unwanted frequency) at all the frequencies in the range of 0.1-3 THz. The noise (unwanted frequencies) of a the proposed asterisk, b plus [7] and c circular [27][28][29] bandpass filters Fig. 10 Dimension of the proposed spider bandpass filter…”

Reconfigurable screen-printed terahertz frequency selective surface based on metallic checkerboard pattern

“…These thin, periodic structures, composed of both conductive and non-conductive materials and generally exhibiting features on the order of the wavelength size, are capable of transmitting or reflecting electromagnetic waves at specific frequencies [6]. Their versatility has led to extensive applications in manipulating THz waves, including polarization conversion [7], transmission measurement in quasi-optical systems [8], remote sensing [9], monochrometers [10], and more. For more adaptive solutions, there has been a surge in demand for reconfigurable frequency-selective surfaces (RFSSs) in various applications, including frequency agility, beam steering, polarization control, and dynamic filtering [11][12][13].…”

“…In the THz region, RFSSs have recently found applications using various tuning approaches, including a polarizer based on vanadium dioxide [12], a mechanically tunable filter using a polydimethylsiloxane substrate [21], modulators based on FSS-graphene stacked structures [22], a mechanically reconfigurable bandpass filter [23], electronically controlled flexible THz modulator [24], and thermally tunable FSS based on barium strontium titanate thin film and metamaterials [25]. Numerous fabrication techniques, including photolithography [12,22], milling [8], and laser ablation [26], have been employed for THz FSS fabrication, each chosen based on design requirements and materials. Despite their precision, these methods are time-consuming, expensive, and limited to small-scale production.…”