Comparison of CPW and microstrip line fed antennas using MWCNT material for X-band applications

Abstract

This article, describes the comparative study of two different feeding methods for copper and
MWCNT material based antennas, namely CPW feed and microstrip feed designed for X-band
applications. In this work, four antenna models were fabricated such as 1.copper with microstrip feed,
2.copper CPW feed, 3. MWCNT with microstrip feed, and 4. MWCNT CPW feed. Evaluated the
performance of all the above models with parameters like, return loss (S11), bandwidth, gain, and radiation
efficiency. Also, a comparison between materials and feeding techniques is considered for analysis. The
four antennas are fabricated on FR-4 substrate having a dielectric constant of 4.4, tan ? 0.02, and are
simulated using the Ansys HFSS tool. The spin coating method is used to fabricate MWCNT antennas.
Among the four antennas, a CPW feed MWCNT antenna provides 33% higher impedance bandwidth in
the frequency range of 8GHz -11.5GHz in comparison with a stripline feed copper-based antenna. The
CPW feeding technique provides wider bandwidth compared to the microstrip feed line, The CPW feed
has less coupling and more lossy compared to the microstrip feed line, hence it results in less Q- factor,
as consequence enhances bandwidth. One of the applications of carbon nanotube-based antennas is in the
Synthetic Aperture Radar (SAR) applications.