Transparent microstrip line with IZTO/AG/IZTO multilayer electrode

Abstract

This article presents a transparent microstrip line made of a transparent multilayer electrode (IZTO/Ag/IZTO) to investigate its feasibility in high frequency usage. The average transmittance of the transparent multilayer electrode is 81% in the range of visible wavelength and average conductivity is ∼2 × 106 S/m. The transparent microstrip lines, which are deposited on transparent acryl and glass substrates are fabricated and compared with the copper microstrip lines, which are printed on conventional microwave substrates, FR‐4. The transmission coefficient (S21) and reflection coefficient (S11) of the proposed microstrip line have been measured and reported. In addition, transparent microstrip lines on transparent ground planes have also been fabricated and measured with three IZTO/Ag/IZTO (IAI) electrodes (Thickness of Ag = 10, 12, 14 nm). © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:1161–1164, 2017

Optically transparent microstripline with micro‐ and wired‐metal mesh

“…In this paper, optically transparent microstriplines are fabricated using two types of conductive metal meshes, micro‐metal mesh film (µ‐MMF) and wired‐metal mesh (WMM), on a transparent acryl substrate. µ‐MMF and WMM have sheet resistances of 0.08 and 0.01 Ω/sq, respectively; these are lower than that of IZTO/Ag/IZTO (2.52 Ω/sq) reported in our previous work . The optical transmittances of µ‐MMF and WMM are 60% and 75% higher, respectively, than that of IZTO/Ag/IZTO (80%) reported in our previous work .…”

“…The measured optical transparency of µ‐MMF and WMM is 62% and 71%, respectively. The measurement results of insertion losses show that these microstriplines with metal meshes have lower in the overall frequency band, up to 6 GHz, than those of reported previous transparent microstriplines with a multilayered TCO material (IZTO/Ag/IZTO), because metal meshes have much lower resistance than that of IZTO/Ag/IZTO. Furthermore, the insertion losses of transparent microstriplines with µ‐MMF and WMM for the longest length of L = 50 mm are maximum of 0.42 and 0.83 dB up to 6 GHz, respectively, and these values are nearly identical with those of the typical microwave substrate (FR‐4).…”

“…µ‐MMF and WMM have sheet resistances of 0.08 and 0.01 Ω/sq, respectively; these are lower than that of IZTO/Ag/IZTO (2.52 Ω/sq) reported in our previous work . The optical transmittances of µ‐MMF and WMM are 60% and 75% higher, respectively, than that of IZTO/Ag/IZTO (80%) reported in our previous work . For performance comparison as a transmission line, two microstriplines using copper sheets on a typical microwave FR‐4 substrate and a transparent acryl substrate are fabricated and measured.…”

“…The transmittance of the double layer (overlapped area) is the square of that of the single layer. Their sheet resistances are 0.0829 and 0.0135 Ω/sq, respectively, which are much lower than that of IZTO/Ag/IZTO, as shown in Table …”

“…Therefore, multilayered TCO materials that show better electrical properties and low sheet resistance have been explored as alternatives to single‐layered ITO thin films . We have previously studied transparent RF passive components (antennas and transmission lines) fabricated using a multilayered TCO material (IZTO/Ag/IZTO) with sheet resistance of 2.52 Ω/sq and relatively high transmittance of 80% . We have also studied a micro‐metal mesh film (µ‐MMF), as another transparent electrode material, made of an 8‐µm‐thick amorphous copper layer with better sheet resistance of 0.08 Ω/sq and optical transmittance of 60% for patch antenna applications …”