A 40.5GHz-58.5GHz dual-band mixer for FMCW radar synthesizer application

Abstract

With the increasing demand for wireless objects detection, frequency modulated continuous wave (FMCW) radar technology outperforms the other types of sensing technologies in terms of form factors, cost, and robustness against extreme environmental conditions. Highly integrated FMCW radar systems have been demonstrated by both industry and academy in complementary metal-oxide semiconductor (CMOS) processes. However, they all have narrow fractional bandwidth (FBW) (<20%) while large FBW is critical to range resolution and chirp rate improvement. A bandwidth-boosting technique has been proposed for our research group project on FMCW radar synthesizer, which leads to the requirement of a dual-band mixer with high frequency, broadband, low spurs, and small amplitude variations. In this thesis, the design and measurement of the mixer integrated into a 4.25GHz-8.45GHz FMCW synthesizer are briefly introduced. Besides, a dual-band mixer is proposed with a band-switching scheme and output amplitude regulation loop (ARL) for a 40.5GHz-58.5GHz FMCW synthesizer to address the challenges of dual-modes combination, wide output frequency range, low harmonic spur level, and small output amplitude variation. For the first mixer, it’s already been fabricated and measured. The second mixer has been successfully designed and integrated into the FMCW synthesizer, which has already been submitted for fabrication. Post-layout simulation results of the second mixer show that the proposed dual-band mixer achieves -1.3dB conversion gain, less than -51dBc spur level within 40.5GHz to 58.5GHz output frequency range. The output amplitude variation is less than 0.1dB. The total power consumption is only 5 mW at 1.2V supply voltage.

Date of Award	2024
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology
Supervisor	Howard Cam LUONG (Supervisor)