skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • Home
  • Search Results
  • Page 1 of 1

Search for: All records

Award ID contains: 1660253

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. ; ; ; (, 2019 IEEE 20th Wireless and Microwave Technology Conference (WAMICON))
    One of the challenges in direct conversion Doppler radar lies in the dc offset resulted from antenna coupling. The dc offset may saturate the baseband amplifiers, preventing sufficient amplification of the received signal. In this work, a Coupling-Cancellation-Antenna (CCA) was implemented in the radar front end to enhance radar detection accuracy by minimizing the TX-RX antenna coupling. The idea is to have two transmitting antennas fed by signals with 180° phase difference such that the two signals cancel at the RX antenna. As a result, a larger receiver gain can be used to improve the signal to noise ratio without saturating the baseband output. Experimental validations of the CCA concept demonstrate 37-dB reduction in the TX-RX coupling. Furthermore, the CCA method reduces the detection error from 15.8% to 2.4%. 
    more » « less
    Full Text Available 
  2. ; ; ; ; ; (, 2019 IEEE 20th Wireless and Microwave Technology Conference (WAMICON))
    Contact-based cardiac motion detection using Quadrature Doppler radar faces a challenge of the I/Q-formed non-arc constellation. In this work, a hypothesis is brought forward that such complicated constellation originates from not one, but two moving targets. The dual-motion model may very well explain that contact-based Doppler radar detects both atrium and ventricle motions during cardiac cycles. In this work, dual-motion simulation and phantom measurements are presented, verifying that the atrial-ventricular motions are the reason that I/Q baseband signals transcribe a complex non-arc constellation. It offers the first evidence that contact-based Doppler radar measures actual heart motion. 
    more » « less
    Full Text Available 
  3. ; ; ; ; ; (, 2018 IEEE/MTT-S International Microwave Symposium - IMS)
    In this paper a phase shifter based multi-arc circle fitting method was proposed to improve accuracy of Doppler radar remote motion sensing. Experiments were conducted to validate the approach by measuring displacement of 3 mm using 2.4 GHz quadrature continuous wave (CW) Doppler radar. It was demonstrated that mean error drops from 4.529% to 1.073% when multiple shifting arcs are utilized to enhance detection accuracy. A greater improvement in accuracy is observed when more arcs are applied. 
    more » « less
    Full Text Available