A Miniaturized Dual-Band FSS With Stable Resonance Frequencies of 2.4 GHz/5 GHz for WLAN Applications

In this letter, we propose an anchor-shaped loop unit-cell structure for compact frequency selective surfaces (FSSs) with dual-bandstop behavior in two wireless local area network (WLAN) frequencies 2.4 and 5.0 GHz. The proposed FSS possesses 230- and 300-MHz bandwidths with insertion loss less than -20 dB around the two central operating frequencies 2.4 and 5.0 GHz, respectively. In addition, the FSS exhibits excellent miniaturization with 0.065 lambda x 0.076 lambda unit cells, where lambda represents the free-space wavelength. Furthermore, the unit-cell structure provides a stable performance for both TE- and TM-polarizations under incident angles 0 degrees-60 degrees. A prototype of the proposed FSS is fabricated and measured. Good agreement between the simulated and measured results is obtained.