A Fully Integrated Doppler-Assisted FMCW Radar With Low Hertz-Range Noise Figure and High Chirp Linearity for Vital Signs Sensing and Indoor Localization

Yuqin Zhang; Yuri Lu; Zitong Zhang; Kangjie Zhao; Zhiluo Zhang; Zhenyu Zhang; Yue Zhu; Ruilai Xu; Ying Liu; Shixiang Ding; Jikun Wang; Kaige Wang; Dalin Li; Peng Wang; Hao Deng; Guangsheng Chen; Leilei Huang; Chunqi Shi; Jinghong Chen; Runxi Zhang

doi:10.1109/TMTT.2026.3662756

A Fully Integrated Doppler-Assisted FMCW Radar With Low Hertz-Range Noise Figure and High Chirp Linearity for Vital Signs Sensing and Indoor Localization

Yuqin Zhang
, Yuri Lu
, Zitong Zhang
, Kangjie Zhao
, Zhiluo Zhang
, Zhenyu Zhang
, Yue Zhu
, Ruilai Xu
, Ying Liu
, Shixiang Ding
, Jikun Wang
, Kaige Wang
, Dalin Li
, Peng Wang
, Hao Deng
, Guangsheng Chen
, Leilei Huang^*
, Chunqi Shi^*
, Jinghong Chen
, Runxi Zhang^*

^*Corresponding author for this work

School of Communication and Electronic Engineering

East China Normal University
University of Houston

Research output: Contribution to journal › Article › peer-review

Abstract

This article presents a Doppler-assisted frequency-modulated continuous-wave (FMCW) radar that combines precise range resolution capability of FMCW with high sensitivity of Doppler radar, enabling versatile performance for indoor applications. A comprehensive analysis of low-frequency noise contributions from key receiver (RX) blocks including low-noise amplifier (LNA), mixer, local oscillator (LO) buffer, and analog baseband (ABB) circuits is conducted. An “RF+LO+BB” joint noise figure (NF) improvement method is proposed to effectively suppress the low-frequency noise. To minimize frequency modulation (FM) error in charge-pump-based fractional-N phase-locked loops (PLLs), a nested-PLL architecture with an optimized loop parameter selection method is employed, significantly enhancing chirp linearity. Fabricated in a 55-nm CMOS technology, the proposed Doppler-assisted FMCW radar achieves NFs of 32.13 and 12.94 dB at 10 Hz and 1 kHz, respectively, and a chirp linearity of 0.0039% over a 3.52 GHz chirp bandwidth (BW), resulting in a maximum detection range of 19.41 m and a range resolution of 4.7 cm. The radar occupies a die area of 12.7 mm² and consumes 594 mW in FMCW mode and 432 mW in Doppler mode under a 3.3 V supply.

Original language	English
Pages (from-to)	3353-3365
Number of pages	13
Journal	IEEE Transactions on Microwave Theory and Techniques
Volume	74
Issue number	4
DOIs	https://doi.org/10.1109/TMTT.2026.3662756
State	Published - 1 Apr 2026

Keywords

CMOS
DC offset
Doppler
flicker noise
frequency-modulated continuous-wave (FMCW)
indoor localization
radar
sensor
vital signs sensing

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10.1109/TMTT.2026.3662756

Cite this

Zhang, Y., Lu, Y., Zhang, Z., Zhao, K., Zhang, Z., Zhang, Z., Zhu, Y., Xu, R., Liu, Y., Ding, S., Wang, J., Wang, K., Li, D., Wang, P., Deng, H., Chen, G., Huang, L., Shi, C., Chen, J., & Zhang, R. (2026). A Fully Integrated Doppler-Assisted FMCW Radar With Low Hertz-Range Noise Figure and High Chirp Linearity for Vital Signs Sensing and Indoor Localization. IEEE Transactions on Microwave Theory and Techniques, 74(4), 3353-3365. https://doi.org/10.1109/TMTT.2026.3662756

@article{b34a3aa398cb4b428c61337ef562166a,

title = "A Fully Integrated Doppler-Assisted FMCW Radar With Low Hertz-Range Noise Figure and High Chirp Linearity for Vital Signs Sensing and Indoor Localization",

abstract = "This article presents a Doppler-assisted frequency-modulated continuous-wave (FMCW) radar that combines precise range resolution capability of FMCW with high sensitivity of Doppler radar, enabling versatile performance for indoor applications. A comprehensive analysis of low-frequency noise contributions from key receiver (RX) blocks including low-noise amplifier (LNA), mixer, local oscillator (LO) buffer, and analog baseband (ABB) circuits is conducted. An “RF+LO+BB” joint noise figure (NF) improvement method is proposed to effectively suppress the low-frequency noise. To minimize frequency modulation (FM) error in charge-pump-based fractional-N phase-locked loops (PLLs), a nested-PLL architecture with an optimized loop parameter selection method is employed, significantly enhancing chirp linearity. Fabricated in a 55-nm CMOS technology, the proposed Doppler-assisted FMCW radar achieves NFs of 32.13 and 12.94 dB at 10 Hz and 1 kHz, respectively, and a chirp linearity of 0.0039\% over a 3.52 GHz chirp bandwidth (BW), resulting in a maximum detection range of 19.41 m and a range resolution of 4.7 cm. The radar occupies a die area of 12.7 mm2 and consumes 594 mW in FMCW mode and 432 mW in Doppler mode under a 3.3 V supply.",

keywords = "CMOS, DC offset, Doppler, flicker noise, frequency-modulated continuous-wave (FMCW), indoor localization, radar, sensor, vital signs sensing",

author = "Yuqin Zhang and Yuri Lu and Zitong Zhang and Kangjie Zhao and Zhiluo Zhang and Zhenyu Zhang and Yue Zhu and Ruilai Xu and Ying Liu and Shixiang Ding and Jikun Wang and Kaige Wang and Dalin Li and Peng Wang and Hao Deng and Guangsheng Chen and Leilei Huang and Chunqi Shi and Jinghong Chen and Runxi Zhang",

year = "2026",

month = apr,

day = "1",

doi = "10.1109/TMTT.2026.3662756",

language = "英语",

volume = "74",

pages = "3353--3365",

journal = "IEEE Transactions on Microwave Theory and Techniques",

issn = "0018-9480",

publisher = "Institute of Electrical and Electronics Engineers Inc.",

number = "4",

}

Zhang, Y, Lu, Y, Zhang, Z, Zhao, K, Zhang, Z, Zhang, Z, Zhu, Y, Xu, R, Liu, Y, Ding, S, Wang, J, Wang, K, Li, D, Wang, P, Deng, H, Chen, G, Huang, L, Shi, C, Chen, J & Zhang, R 2026, 'A Fully Integrated Doppler-Assisted FMCW Radar With Low Hertz-Range Noise Figure and High Chirp Linearity for Vital Signs Sensing and Indoor Localization', IEEE Transactions on Microwave Theory and Techniques, vol. 74, no. 4, pp. 3353-3365. https://doi.org/10.1109/TMTT.2026.3662756

TY - JOUR

T1 - A Fully Integrated Doppler-Assisted FMCW Radar With Low Hertz-Range Noise Figure and High Chirp Linearity for Vital Signs Sensing and Indoor Localization

AU - Zhang, Yuqin

AU - Lu, Yuri

AU - Zhang, Zitong

AU - Zhao, Kangjie

AU - Zhang, Zhiluo

AU - Zhang, Zhenyu

AU - Zhu, Yue

AU - Xu, Ruilai

AU - Liu, Ying

AU - Ding, Shixiang

AU - Wang, Jikun

AU - Wang, Kaige

AU - Li, Dalin

AU - Wang, Peng

AU - Deng, Hao

AU - Chen, Guangsheng

AU - Huang, Leilei

AU - Shi, Chunqi

AU - Chen, Jinghong

AU - Zhang, Runxi

PY - 2026/4/1

Y1 - 2026/4/1

N2 - This article presents a Doppler-assisted frequency-modulated continuous-wave (FMCW) radar that combines precise range resolution capability of FMCW with high sensitivity of Doppler radar, enabling versatile performance for indoor applications. A comprehensive analysis of low-frequency noise contributions from key receiver (RX) blocks including low-noise amplifier (LNA), mixer, local oscillator (LO) buffer, and analog baseband (ABB) circuits is conducted. An “RF+LO+BB” joint noise figure (NF) improvement method is proposed to effectively suppress the low-frequency noise. To minimize frequency modulation (FM) error in charge-pump-based fractional-N phase-locked loops (PLLs), a nested-PLL architecture with an optimized loop parameter selection method is employed, significantly enhancing chirp linearity. Fabricated in a 55-nm CMOS technology, the proposed Doppler-assisted FMCW radar achieves NFs of 32.13 and 12.94 dB at 10 Hz and 1 kHz, respectively, and a chirp linearity of 0.0039% over a 3.52 GHz chirp bandwidth (BW), resulting in a maximum detection range of 19.41 m and a range resolution of 4.7 cm. The radar occupies a die area of 12.7 mm2 and consumes 594 mW in FMCW mode and 432 mW in Doppler mode under a 3.3 V supply.

AB - This article presents a Doppler-assisted frequency-modulated continuous-wave (FMCW) radar that combines precise range resolution capability of FMCW with high sensitivity of Doppler radar, enabling versatile performance for indoor applications. A comprehensive analysis of low-frequency noise contributions from key receiver (RX) blocks including low-noise amplifier (LNA), mixer, local oscillator (LO) buffer, and analog baseband (ABB) circuits is conducted. An “RF+LO+BB” joint noise figure (NF) improvement method is proposed to effectively suppress the low-frequency noise. To minimize frequency modulation (FM) error in charge-pump-based fractional-N phase-locked loops (PLLs), a nested-PLL architecture with an optimized loop parameter selection method is employed, significantly enhancing chirp linearity. Fabricated in a 55-nm CMOS technology, the proposed Doppler-assisted FMCW radar achieves NFs of 32.13 and 12.94 dB at 10 Hz and 1 kHz, respectively, and a chirp linearity of 0.0039% over a 3.52 GHz chirp bandwidth (BW), resulting in a maximum detection range of 19.41 m and a range resolution of 4.7 cm. The radar occupies a die area of 12.7 mm2 and consumes 594 mW in FMCW mode and 432 mW in Doppler mode under a 3.3 V supply.

KW - CMOS

KW - DC offset

KW - Doppler

KW - flicker noise

KW - frequency-modulated continuous-wave (FMCW)

KW - indoor localization

KW - radar

KW - sensor

KW - vital signs sensing

UR - https://www.scopus.com/pages/publications/105030714732

U2 - 10.1109/TMTT.2026.3662756

DO - 10.1109/TMTT.2026.3662756

M3 - 文章

AN - SCOPUS:105030714732

SN - 0018-9480

VL - 74

SP - 3353

EP - 3365

JO - IEEE Transactions on Microwave Theory and Techniques

JF - IEEE Transactions on Microwave Theory and Techniques

IS - 4

ER -

A Fully Integrated Doppler-Assisted FMCW Radar With Low Hertz-Range Noise Figure and High Chirp Linearity for Vital Signs Sensing and Indoor Localization

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Keywords

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