Ultra-wide Band (UWB) technology is a new, useful and safe in the field of wireless body networks.This paper focuses on feasibility estimating vital signs -specifically breathing rate heartbeat frequency -from spectrum recorded waveforms, using an impulse-radio (IR) UWB radar.To this end, analytical model developed to perform interpret spectral analysis.Both harmonics intermodulation between respiration heart signals are addressed.Simulations have been performed demonstrate how they affect...

In this paper, an RF identification sensor system is developed. It comprises passive sensors and ultra-wideband (UWB) reader. The are based on time-coded chipless tags. They consist of UWB antenna connected to a delay line that is, in turn, loaded with resistive temperature sensor. This modulates the amplitude backscattered signals as function temperature. tags identified by changing length line. operation principle design presented integration these addressed. addition, two measurement...

Radio frequency identification (RFID) applications are growing rapidly, especially in the UHF band, which is being used inventory management. Passive tags preferred for this application. However, read range often overestimated using free space calculations. This paper presents a method to estimate multipath environments. Other effects with direct impact on as effect of materials tag performance also addressed. Using proposed model and ray trace RFID system simulator presented.

This paper focuses on the feasibility of tracking chest wall movement a human subject during respiration from waveforms recorded using an impulse-radio (IR) ultra-wideband radar. The describes signal processing to estimate sleep apnea detection and breathing rate. Some techniques solve several problems in these types measurements, such as clutter suppression, body orientation are described. Clutter suppression is achieved moving averaging filter dynamically it. artifacts caused by movements...

Obstructive sleep apnoea is one of the most common disorders, which characterized by repetitive cessations respiratory flow during sleep. This paper describes an alternative method to detect parameters measuring a variation in earth's magnetic field. A magnetometer sensor, laid onto body, detects millimeter night-time breathing movements change vectors. soft, non-invasive wearable sensor designed be printed on miniature circuit board, packaged minimal invasive includes wireless Bluetooth...

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Most of single-stage power factor correction (PFC) ac-dc converters usually present a high voltage swing on the storage capacitor. That means, size and cost capacitor is obtained. The Series Inductance Interval (SII) PFC allow reducing since lower than output and, therefore, significantly reduced. In this paper, novel SII-B-2D converter presented. addition, topology provides input current...

The basic theory of operation ultra wideband radio identification systems is explained in this letter. An experimental setup based on an ultrawideband radar working as a reader proposed to measure time-coded tags. A method the Continuous Wavelet Transform developed order overcome detection problems associated low signal-to-noise ratio at receiver. Experimental results obtained with and using antenna connected delay line emulate tag are presented. good improvement achieved processing method.

The integration of dual-band resonators in frequency-coded chipless RFID tags is proposed this letter. It demonstrated that 3 <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</i> words can be coded a tag when using stub-loaded resonators. also shown an operation bandwidth improvement achieved comparison to the use conventional half-wavelength A theoretical analysis resonator provided, and four-resonator designed, manufactured, measured as proof...

This paper studies the detection of chipless frequency-coded tags. The exploits a temporal separation that allows obtaining identification (ID) with only one measurement. In this way, flexibility reading type tags is clearly improved, which highly expected for future real implementation. possible when tag presents long-time signature, longer than backscattering wave corresponding to surrounding objects. A technique based on short-time Fourier transform (STFT) used differentiate useful parts...

A low-cost chipless RFID sensor tag to determine the dielectric properties of materials is presented. The based on a depolarizing dipole resonator loaded with printed capacitors whose capacitance depends permittivity material located contact tag. obtained from shift resonance frequency. tested both individually as well placed periodic arrangement so form frequency selective structure (FSS) increase cross- polar radar cross section, thus facilitating detection. proposed and measurement...

This paper presents a wireless apnoea detector using passive breathing sensor. The device is based on the measurement of airflow temperature changes that are produced during breathing. sensor negative coefficient resistor, which to be placed close nose. functional principle change resistance, since body increases airflow, receives communication performed backscattered field technique, and modulation response from transponder. backscattering technique saves lot energy in comparison its...

Compact-modeling principles and solutions for nanoscale double-gate gate-all-around MOSFETs are explained. The main challenges of compact modeling these devices addressed, different approaches describing the electrostatics, transport mechanisms, high-frequency behavior Several approximations used to derive analytical Poisson's equation doped undoped discussed, need self-consistency with Schrodinger's current continuity resulting from models is addressed. techniques extend regime study RF...

Vital signs detection by means of several topologies based on Doppler radar are proposed in this paper with the aim overcoming problem null detection. They phase and frequency diversity. The an alternative to I/Q demodulation double-sideband transmission. Four proposed, three them diversity one first topology is using two phase-shifted receivers. second a physical antenna displacement between A third system dynamic variation also presented, which permits work only receiver. last within 2.4...

A novel moisture sensor based on near field communication (NFC) is presented. The system consists of a battery-less sensing device that measures temperature, relative humidity, and the volumetric water content, powered from magnetic generated by reader. In order to compute sensed data, includes microcontroller, which has been programmed make calculations send processed data NFC chip through an I <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...

This paper presents a color-based classification system for grading the ripeness of fruit using battery-less Near Field Communication (NFC) tag. The tag consists color sensor connected to low-power microcontroller that is an NFC chip. powered by energy harvested from magnetic field generated commercial smartphone used as reader. raw RGB data measured colorimeter converted HSV (hue, saturation, value) space. hue angle and saturation are features classification. Different algorithms compared...

A novel depolarizing chipless radio-frequency identification tag is employed to estimate the variation of dielectric properties materials. The tag, comprising two 45° tilted dipoles printed on a thin substrate, accommodated top target material, and it interrogated wirelessly at radio frequency with narrowband signal. Once interrogated, radiates back frequency-selective response in cross-polarization. property allows employing materials characterized by arbitrary large size, thus avoiding...

In this paper, we present a low-cost battery-less color sensor based on Near Field Communication (NFC). This system consists of connected to low-power microcontroller an NFC chip. The energy needed power up the chipset is retrieved from magnetic field generated by reader, i.e., commercial smartphone. low cost chips affords opportunity manufacture tags with sensing capability. We have developed mobile application simultaneously data and send them database in cloud. has been tested several pH...

This work presents a seat-occupancy detection system based on PCR (Pulsed Coherent Radar) at the unlicensed 60 GHz ISM band. The radar can measure distances with sub-millimeter resolution. Therefore, detect presence of people occupying seats by measuring small movements body, such as those produced breathing. In consequence, not only measures but also breathing rate, which is estimated from amplitude peaks after filtering measured to remove noise. effect car vibrations and random body...

The fast response double buck (FRDB) dc-dc converter was presented like a low output voltage with transient response, in order to feed devices such as microprocessors and digital signal processors (DSPs). topology of the FRDB is composed two converters connected parallel, each one them different features aims, controlled by means novel linear-non-linear (LnL) control. In this paper, topology, control strategy operation principle are shown. Finally, experimental results prototypes show both,...

Chipless ultra-wideband (UWB) has been proposed as a low-cost alternative for radiofrequency identification (RFID).In this paper, comprehensible theoretical introduction to time-domain operation of UWB RFID tag is described, and circuit model proposed.For commercial applications readers are demanded.To end, paper addresses the measurement time-coded chipless tags in time domain.Two different setups detect presented, one based on impulse radar (IR) other vector network analyzer (VNA).The...

This paper describes a passive harmonic tag for radio frequency identification (RFID) and wireless sensor applications. The uses dual polarized UHF patch antenna as an input antenna. One of the outputs is connected to doubler, which consists Schottky diode with its output tuned at twice frequency. other feeds DC power harvested converter that drives oscillator modulates signal by controlling bias point diode. antenna’s also used humidity sensor. To achieve this, loaded interdigital capacitor...

The COVID-19 pandemic has highlighted a large amount of challenges to address. To combat the spread virus, several safety measures, such as wearing face masks, have been taken. Temperature controls at entrance public places prevent entry virus carriers shown be inefficient and inaccurate. This paper presents smart mask that allows monitor body temperature breathing rate. Body is measured by non-invasive dual-heat-flux system, consisting four sensors separated from each other with an...

This work studies the feasibility of using backscatter-modulated tags to introduce false information into a signal received by frequency-modulated continuous-wave (FMCW) radar. A proof-of-concept spoofing device was designed in 24 GHz ISM band. The based on an amplifier connected between two antennas, and modulation carried out switching bias. use allowed us increase level compared with other modulated backscattering methods. simulated experimental results show that our method has ability...