A High-Resolution 220-GHz Ultra-Wideband Fully Integrated ISAR Imaging System
| Autor: | Sreekiran Samala, Ehsan Afshari, Ali Mostajeran, Brian P. Ginsburg, Mohammed Aseeri, S. M. H. Naghavi, Mohammad Javad Emadi |
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| Rok vydání: | 2019 |
| Předmět: |
Synthetic aperture radar
Physics Radiation business.industry Harmonic mixer 020206 networking & telecommunications 02 engineering and technology Condensed Matter Physics Continuous-wave radar Inverse synthetic aperture radar Optics Intermediate frequency Radar imaging 0202 electrical engineering electronic engineering information engineering Chirp Electrical and Electronic Engineering business Image resolution |
| Zdroj: | IEEE Transactions on Microwave Theory and Techniques. 67:429-442 |
| ISSN: | 1557-9670 0018-9480 |
| Popis: | In this paper, an ultra-wideband fully integrated imaging radar at sub-terahertz (sub-THz) frequencies is presented, which demonstrates a fine lateral resolution without using any focal lens/mirror. We have achieved a lateral resolution of 2 mm for an object at 23-cm distance as well as a range resolution of 2.7 mm. To achieve the decent range resolution, in a frequency modulation continuous wave radar configuration, a state-of-the-art chirp bandwidth (BW) of 62.4 GHz at a center frequency of 221.1 GHz is generated and efficiently radiated. We have presented a design technique for the optimal design of the passive embedding around the core transistor to maximize the tuning BW of the voltage controlled oscillator. At the receiver side, to maximize the intermediate frequency level, a subharmonic mixer is utilized, which is designed for the lowest conversion loss. Finally, to obtain the fine lateral resolution, we have implemented near-field beamforming algorithm based on the inverse synthetic aperture radar (ISAR) systems. The synthesized beamwidth is less than 0.5°; hence, high-resolution images are reconstructed. The system is fabricated in a 55-nm BiCMOS process. To the best of our knowledge, this is the first imaging radar at THz/sub-THz frequencies, which utilizes ISAR to achieve a high lateral resolution while the radar system is fully integrated. |
| Databáze: | OpenAIRE |
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