A 4-Bit Multi-State Frequency Selective Surface with Dual Band Multifunction Response

A 4-bit multi-state frequency selective surface is proposed. Four PIN diodes are used to maneuver behavior of the structure with 7 different functional states. The four-bit binary state operations 0000, 1100, 0011 and 1111 offer transverse electric wave (TE)/transverse magnetic (TM) waves both transmit, TE transmit /TM shield, TM transmit/TE shield and TE/TM both shield, respectively at 2 GHz frequency. The pass band at 2 GHz frequency has -10 dB fractional bandwidth of 117%. The binary states 1101 and 1110 are symmetric which select the TE wave transmit/TM wave shield to the pass band at 3.45 GHz frequency with -10 dB fractional bandwidth of 49%, whereas binary states 1011 and 0111 allow the TM wave to transmit the band at 3.45 GHz and shields the TE polarized wave. The four symmetric binary states 0101, 0110, 1010 and 1001 provide transmission band at 3.45 GHz frequency for dual polarized plane wave incidence. The transmission of both the pass bands can be shielded by selecting the binary state equal to 1111. Prototype of the structure is fabricated and transmission coefficients for different states at normal and oblique incidence of the electromagnetic plane wave are measured which verifies the simulated response