Rectangular Microstrip Patch Antenna: Design and Analysis using 111-Nitride Substrates

Abstract

In this paper, I have theoretically designed different microstrip patch antenna using commercially available substrates and 111-Nitride substrates. The rectangular microstrip patch antenna has conspicuous for microwave device or cellular device in many wireless applications. Due to their advantages of light weight, low volume, low profile planar configuration, low fabrication cost on large scale production with a special process, capable of dual and triple frequency operations, mechanically robust when mounted on rigid surfaces rectangular patch antenna has great potential to use in mobile handset. In this work, commercial substrates are used as Taconic, Rogers & FR-4 and - 111-Nitride substrates are used as InN, AIN & GaN. And those substrates based rectangular microstrip patch antenna have been theoretically designed and analyzed. The antenna performances are evaluated using Ansoft High Frequency Structure Simulator (HFSS). These include the theoretical analysis and calculation of input impedance (Zi), voltage standing wave ratio (VSWR), return loss (RL), directivity, gain and efficiency. Ill-Nitride substrates are also compared with commercially available substrates and found better in all aspects for wireless applications.

The dielectric constant (r) (frequency dependent parameter) for different substrates has a great influence on antenna perfonnance and those values are used as CFR.I 4.4, EMN =8.4, g, , =8.8 and =5.3 respectively. Physical parameters of each substrate like mass density, thermal conductivity, dielectric loss tangent and relative permeability are also catered ilTespective of availability during simulation for making it little realistic. During calculation & simulation, substrate height (h) & operating frequency (f0) are selected as 0.8 mm & 1.9 GHz. The value of Zi, VSWR (peak) and RL (peak) for Ill-Nitride substrates are found within the limit of standard values like Zi is around 500, VSWR (peak) 2.5 and peak value of R1. <-10dB. Overall antenna radiation efficiency, total directivity and gain are found better. During analysis of commercially available substrates, it is found that all those values are not compatible for mobile device applications with f0 = 1.9 GHz & h = 0.8mm.

The above studies, design parameters and analysis indicate that the proposed Ill-Nitride based rectangular microstrip patch antenna especially GaN substrate may be a promising candidate for mobile device applications.