Microwave imaging of hidden crevasse in glacier terrain using metamaterial loaded eight-slot Vivaldi antenna

摘要

In this paper, a novel microwave imaging methodology based on the simplified experimental setup for identifying hidden crevasse in a glacier or polar terrain is proposed. For scanning the glacier terrain, a new eight-slot Vivaldi antenna (ESVA) with high directivity (16 dBi) and wide bandwidth is proposed. The proposed antenna is designed for the wide frequency range of 1.5-10.5 GHz in order to achieve the improved spatial resolution for the detection of the hidden crevasse. To improve the lower frequency response (1.5-6 GHz), a novel anisotropic zero-index metamaterial (AZIM) cell is introduced. By placing the AZIM cells on the proposed ESVA, a further 2 dB increase in the directivity is achieved. The proposed antenna is designed and simulated using the CST Microwave studio, and its various parameters are optimized for better performance. The designed antenna is then fabricated on the FR-4 substrate, and its matching performance and the far-field characteristics are measured. Later, the designed antenna along with the associated microwave components is used to image the glacier-like situation in the laboratory environment. The glacier terrain in the present situation is emulated using the hard-plastic plates denoting the ice, buried inside fine sand particles representing the snow. It is found that the designed antenna, along with the simple imaging methodology proposed in this work, can conveniently be used to locate hidden crevasse in the glacier terrain.