An Optically Transparent Metasurface-Based Resonant Cavity Fed by Patch Antenna for Improved Gain

Abstract

An optically transparent metasurface (MS) is proposed to design a resonant cavity fed by a patch antenna operating at 5.6 GHz. In the proposed MS, a transparent micro metal mesh conductive (MMMC) film is used as the transparent conducting film (TCF), and it has a high optical transmittance of more than 75% and a low sheet resistance of 0.7 Ω/sq. The MS is composed of a layer of glass substrate and a layer of MMMC film. The unit cell of MS consists of a square patch using MMMC film patterned on a square glass substrate. The transparent MS, patch antenna, ground plane, and air-filled half-wavelength cavity form a resonant cavity antenna, to achieve an improved gain. The MS is designed, optimized and analyzed using the EM simulation software CST. Results show that the MS can improve the simulated boresight gain from 4.7 to 13.2 dBi by 8.5 dB, without affecting the impedance bandwidth (IMBW) much. The losses of MS with different values of sheet resistance are also studied, showing the MS using MMMC with sheet resistance of 0.7 Ω/sq has very small losses.

mmWave High Gain Planar H-Shaped Shorted Ring Antenna Array

“…However, the required dimension is still large and the precise use of multiple via increases the difficulty in both fabrication and performance tuning. In addition, metasurface, cavity backed, cavity resonance antennas are considered for high gain array antenna [ 11 , 12 , 13 ], but they require a high profile or a large occupation of extra layers limiting the integration with beamforming ICs. Lastly, complementary dipole and slot array structure, and phased array quasi-Yagi antenna have been proposed [ 14 , 15 ], but the high profile and complicated coupling aperture feed network seems to be the bottleneck.…”