Domenico Zito

SoC CMOS UWB Pulse Radar Sensor for Contactless Respiratory Rate Monitoring

An ultra wideband (UWB) system-on-chip radar sensor for respiratory rate monitoring has been realized in 90 nm CMOS technology and characterized experimentally. The radar testchip has been applied to the contactless detection of the respiration activity of adult and baby. The field operational tests demonstrate that the UWB radar sensor detects the respiratory rate of person under test (adult and baby) associated with sub-centimeter chest movements, allowing the continuous-time non-invasive monitoring of hospital patients and other people at risk of obstructive apneas such as babies in cot beds, or other respiratory diseases.

A 90nm CMOS SoC UWB pulse radar for respiratory rate monitoring

UWB technology (3.1 to 10.6GHz) allows new applications for both data communication and sensing (FCC, reference in [1]). Due to their potential in terms of resolution and extremely low level of EIRP spectral density (< −41.3dBm/MHz, see mask in Fig. 2.4.1) [1], UWB radars are very attractive for a large set of civil and military sensing applications, as ground penetrating, surveillance, localization, intra-wall and through-wall detections and biomedical imaging. Moreover, with respect to continuous-wave (CW) radars [2], UWB radar transceivers present a lower circuit complexity since no frequency conversions are required, leading to lower power consumption (PC) for longer battery autonomy.

UWB CMOS Monocycle Pulse Generator

A low-complexity fully integrated ultrawideband (UWB) monocycle pulse generator realized in 90-nm CMOS technology by ST-Microelectronics is presented. The circuit provides a monocycle pulse when activated by a negative edge of an external trigger signal provided by a microcontroller by exploiting the operating principle of nonlinear waveform shapers. This pulse generator represents a building block of an innovative wearable system-on-chip UWB radar on silicon for cardiopulmonary monitoring. On-chip measurements show that the pulse generator provides monocycle pulses with a duration time equal to 380 ps and a peak-to-peak amplitude of 660 mV (including the losses of the microprobes, cables, and electrostatic-discharge-protected pads), which are in very good agreement with the postlayout simulations. The power consumption is 19.8 mW from a 1.2-V power supply.

13 GHz CMOS Active Inductor LC VCO

A 13 GHz active inductor LC voltage controlled oscillator (VCO) has been realized in 90 nm CMOS technology by ST-Microelectronics. The VCO consists of two complementary cross-coupled pairs, an active LC tank implemented by means of a differential high-Q low-noise active inductor and two p-MOSFET varicaps, and an output buffer stage. The measurements show a phase noise of -105.25 dBc/Hz at 1 MHz frequency offset. The current consumption of the VCO core and differential boot-strapped inductor amount to 0.7 and 1.8 mA, respectively, from a 1.2 V supply voltage.

Wearable system-on-a-chip UWB radar for contact-less cardiopulmonary monitoring: Present status

The present status of the project aimed at the realization of an innovative wearable system-on-chip UWB radar for the cardiopulmonary monitoring is presented. The overall system consists of a wearable wireless interface including a fully integrated UWB radar for the detection of the heart beat and breath rates, and a IEEE 802.15.4 ZigBee low-power radio interface. The principle of operation of the UWB radar for the monitoring of the heart wall is summarized. With respect to the prior art, this paper reports the results of the experimental characterization of the intra-body channel loss, which has been carried out successfully in order to validate the theoretical model employed for the radar system analysis. Moreover, the main building blocks of the radar have been manufactured in 90 nm CMOS technology by ST-Microelectronics and the relevant performance are resulted in excellent agreement with those expected by post-layout simulations.

Feasibility study and design of a wearable system-on-a-chip pulse radar for contactless cardiopulmonary monitoring

A new system-on-a-chip radar sensor for next-generation wearable wireless interface applied to the human health care and safeguard is presented. The system overview is provided and the feasibility study of the radar sensor is presented. In detail, the overall system consists of a radar sensor for detecting the heart and breath rates and a low-power IEEE 802.15.4 ZigBee radio interface, which provides a wireless data link with remote data acquisition and control units. In particular, the pulse radar exploits 3.1–10.6 GHz ultra-wideband signals which allow a significant reduction of the transceiver complexity and then of its power consumption. The operating principle of the radar for the cardiopulmonary monitoring is highlighted and the results of the system analysis are reported. Moreover, the results obtained from the building-blocks design, the channel measurement, and the ultra-wideband antenna realization are reported.

A novel fully integrated antenna switch for wireless systems

A novel RF switch for single antenna time division multiplexing systems, based on the boot-strapped inductor approach is presented. It allows one to wire on-chip the output of the power amplifier and the input of the low noise amplifier directly to the antenna. The approach does not require any external components, it gives better performance and lower cost with respect to the front-end RF switches which commonly use PIN diodes as switching elements and it allows one to step towards fully integrated transceiver solutions. The operating principle is demonstrated, the most representative performances are summarized and a preliminary estimation of the yield has been obtained by means of Monte Carlo simulations.

Wearable System-on-a-Chip UWB Radar for Health Care and its Application to the Safety Improvement of Emergency Operators

A new wearable system-on-a-chip UWB radar for health care systems is presented. The idea and its applications to the safety improvement of emergency operators are discussed. The system consists of a wearable wireless interface including a fully integrated UWB radar for the detection of the heart beat and breath rates, and a IEEE 802.15.4 ZigBee radio interface. The principle of operation of the UWB radar for the monitoring of the heart wall is explained hereinafter. The results obtained by the feasibility study regarding its implementation on a modern standard silicon technology (CMOS 90 nm) are reported, demonstrating (at simulation level) the effectiveness of such an approach and enabling the standard silicon technology for new generations of wireless sensors for heath care and safeguard wearable systems.

Microwave Active Inductors

In this letter, the experimental proofs of two microwave active inductors with very high quality factor, namely Differential Boot-Strapped Inductor (D-BSI) and Cross-Coupled Differential Boot-Strapped Inductor (CCD-BSI), are presented. These circuits can be effectively implemented in modern RF-CMOS processes for high-Q equivalent integrated inductors at high frequency. The cases of study at 13 GHz have been designed and implemented in a modern standard 90 nm bulk CMOS process. The measurements on the test-chips show an equivalent inductance close to 3.2 nH with an associated quality factor up to 400 and a wide linearity range.

22.7-dB Gain

A fully differential CMOS ultrawideband low-noise amplifier (LNA) is presented. The LNA has been realized in a standard 90-nm CMOS technology and consists of a common-gate stage and two subsequent common-source stages. The common-gate input stage realizes a wideband input impedance matching to the source impedance of the receiver (i.e., the antenna), whereas the two subsequent common-source stages provide a wideband gain by exploiting RLC tanks. The measurements have exhibited a transducer gain of 22.7 dB at 5.2 GHz, a 4.9-GHz-wide B 3dB, an input reflection coefficient lower than -10.5 dB, and an input-referred 1-dB compression point of -19.7 dBm, which are in excellent agreement with the postlayout simulation results, confirming the approach validity and the design robustness.