A Novel 10 Ghz Super-heterodyne Bio-radar System Based on a Frequency Multiplier and Phase-locked Loop

This paper presents a novel 10 GHz bio-radar system based on a frequency multiplier and phase-locked loop (PLL) for non-contact measurement of heartbeat and respiration rates. In this paper, a 2.5GHz voltage controlled oscillator (VCO) with PLL is employed as a frequency synthesizer, and 10 GHz continuous wave (CW) signal is generated by using frequency multiplier from 2.5 GHz signal. This paper also presents the noise characteristics of the proposed system, and the analysis result shows that the same signal-to-noise-ratio (SNR) performance can be achieved with the proposed system based on the frequency multiplier compared with the conventional system with identical carrier frequency. The experimental results shows excellent vital-signal measurement up to 100 cm without any additional digital signal processing (DSP), thus proving the validity of the proposed system. Received 13 November 2010, Accepted 12 January 2011, Scheduled 27 January 2011 Corresponding author: Seong-Sik Myoung ([email protected]).