Design and Performance Analysis of a Fractal Micro-strip Patch Antenna with Defected Ground Structure

Abstract

Microstrip Patch Antennas (MPA) are very popular in wireless communication systems due to their compactness, low profile, light weight, and ease of fabrication. The conventional microstrip antennas, however, have drawbacks like limited bandwidth, low gain, and single-frequency operation, which limit their applications in satellite communication, radar, and other advanced wireless systems. For the above problems, the design and analysis of a fractal patch array antenna with Defected Ground Structure (DGS) techniques to improve the performance of the antenna, and the design of a fractal antenna are discussed. The fractal geometries, such as the Sierpinski Triangle and Koch Curve, are used due to their self-similarity and space-filling properties, allowing for compact multiband and wideband antenna operation. The DGS is used to redistribute the ground-plane current distribution, which, in turn, improves the impedance matching, lowers the surface-wave losses, and increases the radiation efficiency. The proposed antenna is designed and simulated using the electromagnetic simulation software ANSYS HFSS. The important parameters that are required for the antennae like return loss, Voltage Standing Wave Ratio (VSWR), radiation pattern, gain and bandwidth are analyzed. The optimized antenna has a minimum return loss (S11) of about -55 dB at 8.6 GHz, a peak gain of 8.4 dBi, a VSWR of 1.02, and an impedance bandwidth of nearly 4.5 GHz in the -20 GHz operating frequency range. The proposed antenna applies to the modern multi-band wireless, radar, and satellite communication systems.