Performance analysis of ZnO and HfO₂ micro-pillars based capacitive antennas

Abstract

In this research paper, performance analysis of two different material-based micropillars capacitive antennas is proposed. The method involves formation of self-organized mask, micropillar formation by using process of etching and metal deposition (Au/Cr) on the top and bottom of micropillars. For fabrication of these capacitive antennas, we considered 2-inch p-type silicon (Si) wafers as a substrates material while upper and lower plates of capacitive antenna were fabricated by using gold as plating material on top and bottom. Both capacitive antennas were fabricated by taking the two different materials (ZnO and HfO₂) micropillars which acts a dielectric material between two upper and lower gold plates. For realization of both antennas firstly we have simulated both the antenna using CST Microwave studio software and thereafter fabricated by using appropriate microfabrication technique. Both the metamaterial-based capacitive antennas were designed by taking dimension of 35 × 26 mm on the 2″ Si substrate. The thickness (h) and dielectric constant (ε_r) of silicon substrate were taken as 0.270 mm and 11.7, respectively. The proposed antenna was designed to operate at frequency range of 1–10 GHz, which signifies that return loss (S₁₁) parameter must be less than −10 dB and voltage standing wave ratio must be less than 2. To validate the design, various parameters of RF antenna such as the return loss, gain, surface current distribution, and radiation patterns were obtained and compared for the fabricated antennas. The simulated and experimental results were found to show good agreement.

Keywords:

• Capacitive antenna
• gain
• return loss
• VSWR
• bandwidth
• micropillars

Acknowledgments

The authors would like to acknowledge and thanks Centre of Excellence in Nano-electronics (CEN) under Indian Nanotechnology User program (INUP), Indian Institute of Technology, Bombay for their necessary support and facility to carry out the research work.