Experimental Validation of Uniformly Undersampled Imaging in 6G D-Band with Interpolation Techniques

This article presents an experimental setup and validation of interpolation techniques for uniformly undersampled D-band planar imaging. Interpolation techniques, including our previously proposed rational thin-plate spline (RTPS) and the bicubic methods, are implemented on the scattered echoes, to mitigate spatial aliasing in reconstructed images. The reconstructed 2-D images are evaluated in both simulations and practical imaging scenarios to verify the achievable cross-range resolution. Both RTPS and bicubic interpolation demonstrated effectiveness for a uniform receiver array with sub-Nyquist spatial sampling interval of 1λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</inf>. Imaging results show that the developed system can achieve millimeter-scale localization of targets with 1λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</inf> length at 150 GHz and resolve targets separated 2λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</inf> apart.