New technique for designing wideband one layer frequency selective surface in X‐band with stable angular response

Abstract

In this article, a new method is presented for designing frequency wideband unit cell to use in frequency selective surfaces (FSSs). A double slot square loop (DSSL), which has 2 resonant frequencies, is selected as a primary FSS unit cell and its frequency bandwidth is increased with the proposed method. The effect of the applied innovation on frequency response of DSSL unit cell is investigated by equivalent circuit presented in this paper. Simulated frequency response of the designed unit cell shows that frequency bandwidth of this unit cell increases in comparison with that of primary unit cell. A FSS structure with the designed unit cell is fabricated and its measured return loss confirms that, the frequency bandwidth of the proposed structure is about 50% in X‐band. In addition, frequency response of this FSS structure is stable during 45 degree angle deviation of the incident wave from normal axis of the FSS surface. High frequency bandwidth, low fabrication complexity and stable angular response are the favorable characteristics of the proposed FSS structure which make it suitable for using in microwave filters.

A low profileRFshieldingFSSwith enhanced ultrawide bandwidth range and angular stability

“…The key features of the proposed FSS are as follows: In comparison with, 17–25,27–36 the proposed FSS reflector for shielding application is very compact (0.052 λ 0 × 0.052 λ 0 × 0.0075 λ 0 ) in this wideband range from 2.84 GHz to more than 20 GHz. In comparison to other related prototypes, this two‐dimensional single metallization layer has the highest FBW of more than 150 % as reported in the literature. Furthermore, the peak SE is close to 60 dB. Because of its four‐fold symmetry, the proposed selective layer exhibits a good polarisation‐insensitive response and high angular stability for both TE and TM modes up to 75 ° . We verified the equivalent circuit‐model response with the full‐wave simulation response for complete wideband in accordance with the operating frequency in the proposed design. …”

“…• In comparison with, [17][18][19][20][21][22][23][24][25][27][28][29][30][31][32][33][34][35][36] the proposed FSS reflector for shielding application is very compact (0.052λ 0 Â 0.052λ 0 Â 0.0075λ 0 ) in this wideband range from 2.84 GHz to more than 20 GHz. • In comparison to other related prototypes, this twodimensional single metallization layer has the highest FBW of more than 150% as reported in the literature.…”

Optically Transparent Tri-Wideband Mosaic Frequency Selective Surface with Low Cross-Polarisation

“…On the other hand, for FSS with a trace width lower than 0.8 mm, only narrow bandstop response (FBW < 30%) with high angular and polarised stability was attained; see [56,57]. As for the bandpass frequency response, both opaque and transparent MFSS recorded higher FBW of 59.25% and 62.78%, respectively, when compared to the FSS proposed in [58] that recorded only 50% bandpass response. In comparison with transparent MFSS proposed in past studies (see [28][29][30][31][32][33]), the transparent MFSS proposed in this present study displayed the advantage of having wideband bandstop and bandpass responses, as well as the ability to provide high optical transparency above 70.3%, but angular stability limited to only 25 • .…”

Design of a triple band notched polarization independent compact FSS at UWB frequency range

“…20 A double slot square loop FSS is implemented for dual stop band characteristics. 21 A square loop and a folded arm square loop structure are printed at the top and bottom of the substrate for triple band stop characteristics at WiMAX, WLAN, and X-band. 22 However, these structures do not provide good angular stability.…”