A Broadband MFCW Agile Radar Concept for Vital-Sign Detection under Various Thoracic Movements

Yi Hsien Lin, Jen Hao Cheng, Li Chi Chang, Wen Jie Lin, Jeng Han Tsai, Tian Wei Huang*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


A multiple-frequency continuous-wave (MFCW) agile radar system has the ability to cope with various physiological conditions of a human subject. Following the mathematic model, a favorable carrier frequency for detection is pursued by analyzing the amplitude and composition of the baseband signal. In Experiment-1, a CMOS dual-band transceiver prototype emulate searching a subject from a distance. The frequencies of the dual-band system are 4.26-4.95 GHz and 17.06-19.79 GHz. During the experiment, the respiratory signal could be detected up to 12 m, and the heartbeat signal up to 6 m. Even with a wooden or a brick barrier in the path, the vital-sign detection remained satisfactory. Later, a concurrent MFCW detection is performed in Experiment-2 for more precise analyses. From the concurrent results, the breathing status can be inferred, and by cross-correlating the results after the ensemble empirical mode decomposition (EEMD) and principal component analysis (PCA), the nonlinear effects of respiratory harmonics or intermodulation tones are reduced, resulting in an accurate heart rate extraction. The receiver front-end and the signal source are manufactured using a 180-nm CMOS process, both packaged on an RO4003C printed-circuit board (PCB).

Original languageEnglish
Pages (from-to)4056-4070
Number of pages15
JournalIEEE Transactions on Microwave Theory and Techniques
Issue number8
Publication statusPublished - 2022 Aug 1
Externally publishedYes


  • Cross correlation
  • Doppler radar
  • dual-band transceiver
  • ensemble empirical mode decomposition (EEMD)
  • frequency agility
  • multiple-frequency continuous-wave (MFCW) radar
  • principal component analysis (PCA)
  • resolution
  • vital-sign detection

ASJC Scopus subject areas

  • Radiation
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


Dive into the research topics of 'A Broadband MFCW Agile Radar Concept for Vital-Sign Detection under Various Thoracic Movements'. Together they form a unique fingerprint.

Cite this