A Miniaturized Bandpass Frequency Selective Surface Exploiting Three-Dimensional Printing Technique

Abstract

This letter proposes a miniaturized-element bandpass frequency selective surface using three-dimensional (3-D) printing. The proposed design comprises convoluted metallic patterns on both sides of a dielectric substrate (interdigital capacitors on top, and meander lines on bottom) in an orthogonal arrangement. The novel feature of the structure lies in exploiting 3-D printing technique to selectively extend the dielectric thickness, thereby reducing the resonance frequency. This results in an improved miniaturization characteristic with unit cell dimensions of 0.056 lambda(0) x 0.056 lambda(0), where lambda(0) is the free-space wavelength corresponding to the resonance frequency 1.05 GHz (having 1.26 dB insertion loss) of the geometry. The topology also demonstrates excellent angular stability under oblique incidence (up to 75 degrees incident angle). We fabricated a 3-D printed prototype, and the measured response was consistent with the simulated result under normal incidence.