High-Resolution Grid-Independent Imaging for Terahertz 2-D Synthetic Aperture Radar With Spatial Under-Sampling

Abstract

Abstract-For the purpose of two-dimensional (2-D) imaging in the Terahertz (THz) near field through 2-D synthetic aperture radar technology, Fourier transform (FT) is one of the most popular imaging ways. However, FT-based algorithms would encounter performance loss either when spatial sampling is under Nyquist frequency or there are off-grid scatterers in the scene of interest. Therefore, by exploiting the theory of matrix enhancement and continuous parameter estimation, we propose to use matrix enhancement and matrix pencil (MEMP) method and matched filter to deal with arbitrarily located scatterers when spatial under-sampling is adopted. Through constructing a specifically expanded matrix, the information of the scatterers involved in the small data set can be enhanced. Then, highresolution grid-independence 2-D imaging can be achieved by the combination of MP and matched filter. Simulation results verify the effectiveness of the proposed algorithm.

Frequency tunable switching between transmission and absorption modes based on graphene and VO2 layers at the THz range

“…THz region lies between the microwave and far-infrared regions from 0.1 to THz 10 [2]. Benefiting from its low radiation energy, strong penetration, and high resolution [3], terahertz wave has many promising applications such as sensing [4,5], imaging of biological objects, medical imaging [6], astronomy [7], and high-speed wireless communication [8]. For instance, switching between transmission and absorption light is a kind of manipulation that is highly applicable in photonics [4].…”