On the Design, Fabrication and Characterization of a Miniaturized and Optically Transparent CSRRs-Loaded Antenna Operating in C-Band for a Dual Optical-RF Purpose

A miniaturized and optically transparent CSRRs-loaded (Circular Split Ring Resonator) antenna operating in C-band is presented. Two miniaturization techniques were used to get a highly miniaturized microstrip antenna. By combining high-permittivity substrate with CSRRs-loaded ground plane, a reduction size over 70% was then obtained. The antenna dimension equals <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.1\lambda$</tex> at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$f_{r}=\boldsymbol{5.3}$</tex> GHz with a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$-3.9dBi$</tex> simulated gain. Optical transparency is achieved by printing a micrometric mesh metal films with pitch of 300 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mu m$</tex> and metal strip width of 10 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mu m$</tex> on both sides of sapphire substrate. Homemade prototypes were fabricated and characterized at microwaves: the operating frequency and radiation pattern were measured experimentally. Snapshots from an endoscopic camera were taken behind the transparent antenna as proof of concept. A new dual optical-RF application has therefore been developed.