X-Band Tunable Frequency Selective Surface Using MEMS Capacitive Loads

Design of Active Frequency Selective Surface with Curved Composite Structures and Tunable Frequency Response

“…Related studies reported a high isolation from 5 dB to 25 dB and a high transmission loss from −1 dB to −10 dB between the reconfigured operating frequencies, because the corresponding FSSs controlled more than two diodes. Hence, we confirmed that the proposed structure has an improved operation in aspects such as high isolation and low transmission loss, if compared to the studies in [6][7][8].…”

“…The active circuit control to change the frequency response can include elements such as PIN diodes, varactor diodes, radio-frequency (RF) microelectromechanical systems, and other electronic control elements that directly modify the unit cell impedance. There is extensive research on AFSS control using these elements given its ease of construction [6][7][8][9][10][11][12][13]. However, the resulting AFSSs require many active elements to provide a stable frequency response, and they are affected by aspects such as incidence angle and polarization, which complicate the circuit structure [7,8,13].…”

“…Therefore, many studies focus only on improving the electric characteristics related to the flat dielectric substrate without considering the impedance or incidence angle [8][9][10][11][12][13]. Nevertheless, more research is needed on designs that employ curved-foam or composite structures and take into consideration the application, operation, and performance under real environmental conditions [6][7][8][9][10][11][12][13]. Although some studies have been conducted for FSS based on composite materials or three-dimensional structures, they were limited to passive and impractical structure [14,15].…”

Double bow-tie FSS for X-band and K$_{{u}}$-band operations with its parametric analyses

“…Among most of the FSS types, which are classified in different groups as [14]- [18], the bandwidth values of the proposed structures are in a satisfactory range for a group 3 type FSS, which are determined as "solid interior or plate types of various shapes" in [1]. The structures are easy to fabricate as compared to the studies such as [16], based on mems technology, and [18], based on loading additional elements such as varactors. The proposed structure has a polarization dependent behavior as expected when compared to the loop type FSS and hybrid FSS models.…”

Design of the Reconfigurable Frequency Selective Surface for X-Band Applications with Improved Isolation

“…[10], [13] . [14]～ [22] , 복잡한 바이어스 회로를 가 지고 있으며 [15], [16], [22] , 바이어스 회로 격리도 확보를 위한 집중소자를 추가로 사용하는 등 [20], [22] 높은 [10] . …”