Surajit Kundu
National Institute Of Technology Sikkim, India
Title: Radiation improvement of ultra-wideband antenna using frequency selective surface for impulse radar applications
Biography
Biography: Surajit Kundu
Abstract
Statement of the Problem: Impulse Radar such as Ground Penetrating Radar (GPR) is commonly used as EM scanner to produce the pseudo images of buried objects. Depth and lateral resolutions of such scanning techniques can be improved by enhancing the working bandwidth. Planar antennas in the commercial Ultra-wideband (UWB) are potential candidate to improve the resolutions due to the wide spectrum coverage from 3.1 to 10.6 GHz. However the soil attenuation increases with increase in frequency which restricts the depth of coverage. One unique way to solve this issue is addressed here by integrating UWB frequency selective surface (FSS) to the antenna for gain augmentation.
Methodology & Theoretical Orientation: Antenna radiation can be enhanced in various ways such as array configuration using metallic reflector but these methods are not suitable for UWB. Metamaterial inspired periodic electromagnetic band gap materials can act as partial reflective surface when integrated below the antenna and enhance the antenna radiation in the broadside direction by reflecting the antenna s back radiation. Due to the linearly decreasing reflection phase response of reflective surface the reflected waves become co phased with the transmitted wave in broadside direction and added constructively to improve the radiation and thus gain augmentation in the entire UWB without degrading other antenna pameters. The high gain UWB Antenna-FSS composite structure can be very effective for sub surface scanning applications.
Findings: Uniplanar and dual layered FSS structures are designed and integrated to the ultra and super wideband antennas. The characteristics of antenna with and without FSS are studied by simulation and experimental measurements where good correlation between the simulated and measured data validates the performance. The transient and frequency domain analysis of Antenna-FSS integrated structure is carried out in vicinity of different surfaces such as dry soil wet soil wood etc. where the fitness of proposed structure for GPR application is attained.
Conclusion & Significance: The conventional impulse radar antennas have certain limitations that can be improved by incorporating UWB antenna-FSS. The detailed study and comparative analysis with other reported work ensure the applicability of this solution