A tunable miniaturized-element frequency selective surfaces without bias network

A novel bandpass miniaturized-element frequency selective surface with tunable frequency characteristic is presented in this paper. The structure is composed of two Meander-line arrays printed on opposite sides of a dielectric substrate and varactor diodes are positioned between the neighboring Meander-line. By biasing the varactors with the Meander-line themselves, the ability to electronically tune the frequency response is realized. This configuration also eliminates the need for any additional network, and therefore resolves the design difficulties associated with the spurious response of the bias network. Full-wave numerical simulation results about transmission characteristic are showed. From the simulation results, which can be seen that a wide tuning frequency range can be achieved and a good stability with different incident angles and different polarizations are obtained. Its physical size is also far less than one wavelength.