A Passively Switched Dual-Band FSS Slot Array

This paper introduces a technique for simultaneous dual-band operation of a slot based frequency selective surface (FSS). The dual-band function is achieved by the inclusion of series-resonant tuned circuits positioned at each slot centre, therefore functioning as a passive frequency selective switch. A surface offering pass-bands in the WLAN bands of 2.45 and 5GHz is presented and its performance evaluated both by computer simulation, and also practical measurements of a prototype surface. Results indicate a significant level of stability is achieved for centre frequency while operational bandwidths decrease and insertion losses increase somewhat with incident angle. The lumped components used are identified as a source of insertion loss.