Investigations on substrate integrated waveguide antennas for gain and bandwidth improvement

Abstract

In thesis, Substrate Integrated Waveguide (SIW) based antennas namely, circular log-periodic SIW antenna, half mode substrate integrated isosceles trapezoid (HMSIIT) with extended ground antenna and square cavity SIW self diplexing antenna. Parametric analysis is done for various substrate thickness, dielectric constant and dimensions the measurement results are compared with published literature. The development of wireless communications systems requires high gain, wide bandwidth and low loss antennas. The bulky metallic structure and coaxial line provide good radiation characteristics, but the size of the antenna is large. For achieving high gain, wide bandwidth and good radiation characteristics in the planar antenna are challenging one. There are various existing schemes are focuses on deducing the development of high gain, bandwidth and good radiation characteristics antennas. The most fascinating challenges in planar antennas consist of large size, narrow bandwidth, losses, and degradation in antenna s radiation characteristics and complexity. The emergent SIW techniques are extensively used in the antennas. It provides low loss, high gain, bandwidth and good radiation characteristics. The simulated results are proven with SIW based designed antennas and are analyzed using ANSYS high-frequency structure simulator (HFSS) (Version 17.2). In this concise presentation, three different antennas namely circular log-periodic SIW antenna, Half Mode Substrate Integrated Isosceles Trapezoid (HMSIIT) with extended ground antenna, square cavity SIW self diplexing antenna are investigated. By incorporating SIW technology with the antennas, multiband and wideband characteristics are achieved with improved radiation characteristics. The designed work is divided into three main phases. The first phase aims to design circular log-periodic SIW antenna for gain and bandwidth improvement and to analyze its reflection characteristics.