Search

This paper presents the design of a V-band logarithmic power detector (PD) and the integration with a 60-GHz CMOS vital-signs Doppler radar sensor to be incorporated with a microprocessor control unit (MCU) for fast automatic clutter cancellation. The PD adopts the successive detection logarithmic amplifier (SDLA) topology and achieves a high dynamic range by replacing the limited amplifiers with millimeter-wave (MMW) linear amplifiers. From the measurement results, the PD exhibits a dynamic range and logarithmic errors higher than 35 dB and within ±2 dB from 50 to 62 GHz. The whole integrated radar sensor chip is fabricated by a 90-nm CMOS process with a chip size of 2 mm $\times2.34$ mm and a dc power consuming of 243 mW. The radar chip and a 60-GHz 17-dBi patch-array antenna are integrated by bondwire interconnection on a compact single carrier board for experimental test. By incorporating the MCU to the radar chip board, the fast automatic clutter canceling can achieve more than 25-dB clutter cancellation. Moreover, it shows a successful vital-signs detection for a distance more than 1.2 m. [ABSTRACT FROM PUBLISHER]

This paper presents a compact integration design of a low-cost bondwire-interconnection scheme between a 60-GHz CMOS vital-signs Doppler radar sensor chip and a millimeter-wave patch-array planar antenna (17-dBi gain). The interconnection has the form of an inductance-capacitance-inductance structure configured as a T-matching network. It consists of a short microstrip line as a small capacitance and parallel bondwires as inductance. Open-ended stubs are additionally applied in the design to improve the ground connection at 60 GHz. To enhance the robustness of the impedance-matching bandwidth to withstand possible bonding length variations, additional series and shunt transmission lines are also deployed. The proposed low-cost integrated circuit-to-board interconnection design requires no additional processing (e.g., cavity etching of the carrier board). In the experimental measurement, compared with the radar sensor connected with a 7-dB-loss V -band cable to the planar antenna in a previous report, the implemented compact bondwire-interconnected CMOS radar antenna module can enhance the detection range from 75 to at least 105 cm [and potentially up to 120–150 cm if the radar chip output power (0 dBm) is the same as 3 dBm]. This shows the potential facilitation for the incorporation of the 60-GHz radar sensor chip into portable devices for wireless remote physiological monitoring healthcare applications. [ABSTRACT FROM AUTHOR]

This paper presents a 60-GHz CMOS direct-conversion Doppler radar RF sensor with a clutter canceller for single-antenna noncontact human vital-signs detection. A high isolation quasi-circulator (QC) is designed to reduce the transmitting (Tx) power leakage (to the receiver). The clutter canceller performs cancellation for the Tx leakage power (from the QC) and the stationary background reflection clutter to enhance the detection sensitivity of weak vital signals. The integration of the 60-GHz RF sensor consists of the voltage-controlled oscillator, divided-by-2 frequency divider, power amplifier, QC, clutter canceller (consisting of variable-gain amplifier and 360^\circ phase shifter), low-noise amplifier, in-phase/quadrature-phase sub-harmonic mixer, and three couplers. In the human vital-signs detection experimental measurement, at a distance of 75 cm, the detected heartbeat (1–1.3 Hz) and respiratory (0.35–0.45 Hz) signals can be clearly observed with a 60-GHz 17-dBi patch-array antenna. The RF sensor is fabricated in 90-nm CMOS technology with a chip size of \2 mm\times \2 mm and a consuming power of 217 mW. [ABSTRACT FROM PUBLISHER]