Effects of superstrates on the resonant frequency of rectangular microstrip antennas

✍ Scribed by Raj Kumar; P. Malathi

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 244 KB
• Volume: 49
• Category: Article
• ISSN: 0895-2477
• DOI: 10.1002/mop.22954

✦ Synopsis

Abstract

This article presents the extended expression to calculate the environmental effect on resonant frequency of multilayer rectangular microstrip antennas. The expression has been investigated for effective dielectric constant ε~eff~ and resonant frequency f~r~. The effective dielectric constant ε~eff~ of Present Method has been compared with full wave numerical technique with and without loading. These are in good agreement within 1% accuracy. It has been observed that % change in f~r~ due to cover and substrate thickness is around 3.2% and 20%, respectively, as their thickness is varying 19 times of its initial value. This variation is drastic for h~3~/h~2~ = 0.01. The maximum % variation in f~r~ for one substrate and two superstrate is around 5% as h~4~ varies from 1 mm to 5 mm. In case of unwanted air (h~3~), the % variation in f~r~ of present method in comparison to experimental value is less than 1.0% for small air‐gap and 0.4% for large air‐gap for various spaced dielectric (ε~r4~), which reveals that the effect of superstrate in f~r~ is small than substrate above the ground plane. The resonant frequency in suspended substrate microstrip antenna with and without superstrate is 21.8% and 28.15%, respectively, as h~1~/h~2~ varies from 0.065 to 1.94. The resonant frequency of all the possible configuration is in good agreement with the experimental results. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2946–2950, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22954