In this work, 3D terahertz (THz) tomography was demonstrated with a signal source and imagers based on transistor circuits fabricated with standard semiconductor technologies. For the signal source, a 300 GHz oscillator based on InP HBT technology was employed. For detection, two types of imagers operating near 300 GHz were employed, one direct and the other heterodyne, both realized with SiGe HBT technology. With a set of 2D images taken from different angles, sinograms and tomograms were obtained, which led to a successful reconstruction of 3D images of the target object based on the filtered back-projection (FBP) algorithm. A systematic comparison was made for the direct imager and the heterodyne imager, for which the signal input power and the video bandwidth were varied for both imagers. The results revealed that the heterodyne imager shows a better sensitivity than the direct imager. However, a similar dynamic range of around 30 dB was achieved for both imagers because of a saturation observed for the heterodyne imager when the input power exceeds the threshold. The video bandwidth did not affect the image quality significantly for the bandwidth variation over four orders of magnitude for both imagers.
|Journal||IEEE Transactions on Terahertz Science and Technology|
|Publication status||Accepted/In press - 2018 Jun 27|
ASJC Scopus subject areas
- Electrical and Electronic Engineering