Varactor‐Tunable Frequency Selective Surface With an Appropriate Embedded Bias Network

Abstract

In this work, a varactor‐tunable frequency selective surface (FSS) is proposed; it is based on a common FSS composed of annular ring slot cells, in which four varactors are loaded on each annular ring slot to dynamically tune its resonant frequency in real time. In addition, an appropriate embedded bias network is added to introduce a same direct current bias voltage for each varactor. Numerical simulations demonstrate that the resonant‐frequency of the proposed FSS can be tuned over a 77.2% wide frequency range from 2.73 to 6.16 GHz by altering the capacitance of the varactors from 1.0 to 0.1 pF; moreover, the embedded bias network has little effect on the band‐pass response, and the minimum of the reflection coefficients is less than −24 dB at all times. Finally, one effective experimental validation is carried out. The proposed tunable FSS possesses the merits of wide tuning range and high transmittance; thus, it has great potential applications in the design of tunable radomes or adaptive screening of unwanted wireless transmissions.

Modeling the Resonant Behavior of Continuously Reconfigurable FSS Based on Four Arms Star Geometry

“…Reconfigurable FSS frequency response, including varactor effects and bias lines, can be numerically simulated using commercial software [13], [25], [26]. However, the required computational processing time imposes limits, principally for optimization techniques.…”

Thermally Tunable Frequency‐Selective Surface Based on VO2 Thin Film

“…[ 6 ] However, VO 2 is still not applied in tunable FSS for these wavelengths, since for this purpose, thin films with the comparable surface area are required. Tunable FSSs for centimeter wavelengths are usually made using microelectromechanical switches, [ 7 ] magnetic materials with tunable permeability, [ 8 ] and more conventional PIN diodes [ 9,10 ] or varactor diodes [ 11,12 ] integrated into each unit cell of the FSS. The parameters of FSS with the listed elements are controlled by applying voltage bias, providing means for fast switching times up to nanoseconds.…”