Transparent Microstrip Patch Antennas with Multilayer and Metal-Mesh Films

This letter presents transparent microstrip patch antennas made of two types of transparent conductive films, which are multilayer film (MLF; IZTO/Ag/IZTO) and metal-mesh film (MMF; Cu). The sheet resistance levels of the MLF and MMF are 2.52 and 0.18 Ω/□. The transparencies of the MLF and MMF are over 80% and 60% at a 550-nm wavelength, respectively. The design and dimensions of the antennas follow the conventional simple microstrip patch antenna. A transparent acryl substrate is used for the proposed transparent antennas. The conductive parts of the proposed antennas are also made of copper sheets (CS; case 1) for the performance comparison to two types of transparent antennas made of MLF (case 2) and MMF (case 3). The resonance frequency band of the antennas is 2.4-2.5 GHz for Wi-Fi service. The case-1, case-2, and case-3 antennas have peak gains of 4.75,-4.23, and 2.63 dB and have radiation efficiencies of 66.32%, 7.76%, and 42.69% at the center frequency of the Wi-Fi service band (2.45 GHz), respectively.