Novel 4‐bit second‐order multifunction frequency selective surface

Abstract

An innovative four-bit second order multifunction active frequency selective structure controlled via four PIN diodes with nine different combinations is introduced . The proposed design is equipped with electromagnetic switching, frequency switching and polarization selection at two passbands. The coding states 0000 and 1111 offer transmission to the passbands centred at 1.96 and 4.98 GHz frequencies and shield to the bands centred at 4.98 and 1.96 GHz for transverse electric (TE)/transverse magnetic (TM) waves, respectively. The coding state 1010 offers transmission to the TE and TM waves at 1.96 GHz and 4.98 GHz, respectively and shields the TM and TE waves at 1.96 GHz and 4.98 GHz, respectively. Contrarily, the coding state 0101 offers transmission to the TE and TM waves at 4.98 GHz and 1.96 GHz, respectively and shields the TE and TM waves at 1.96 GHz and 4.98 GHz, respectively. The coding states 1000/0100 and 1101/1110 allow transmission to the TE wave at 1.96 and 4.98 GHz frequencies, respectively and shield to both the passbands at TM wave. Conversely, the coding states 0001/0100 and 1011/0111 allow transmission to the TM wave at 1.96 and 4.98 GHz frequencies, respectively and shields to both the passbands at TE wave. The coding state 1100/0011 provides shield to all the frequencies below 7.7 GHz. The designed structure is validated through the measured response of the fabricated prototype.