scholarly journals A Passive Harmonic Tag for Humidity Sensing

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Antonio Lazaro ◽  
Ramon Villarino ◽  
David Girbau
Keyword(s):  
Schottky Diode ◽  
Radio Frequency Identification ◽  
Humidity Sensor ◽  
Second Harmonic ◽  
Interdigital Capacitor ◽  
Sensor Applications ◽  
Dc Power ◽  
Frequency Identification ◽  
Bias Point ◽  
Harmonic Power

This paper describes a passive harmonic tag for radio frequency identification (RFID) and wireless sensor applications. The tag uses a dual polarized UHF patch antenna as an input antenna. One of the outputs is connected to a frequency doubler, which consists of a Schottky diode with its output connected to a patch tuned at twice the input frequency. The other output of the input antenna feeds a DC power harvested converter that drives an oscillator which modulates its output signal by controlling the bias point of the Schottky diode. The antenna’s output is also used as a humidity sensor. To achieve this, the antenna is loaded with an interdigital capacitor with humidity-dependent capacitance. The antenna is consequently detuned when humidity varies, and therefore the second harmonic power is received. The tag is manufactured using standard fiberglass substrate. The basic theory of harmonic tag operation is described and compared with the standard backscattering approach. Experimental results with a proof of concept using commercial components are presented.

Research on Improved Range of Passive Radio Frequency Identification Tag by Taking Advantage of Energy-Harvesting and Efficient E-Class Oscillator

2013 ◽  
Vol 340 ◽  
pp. 493-496
Author(s):  
Gang Ye
Keyword(s):  
Solar Cell ◽  
Energy Harvesting ◽  
Radio Frequency ◽  
Radio Frequency Identification ◽  
Power Source ◽  
Electromagnetic Simulation ◽  
Dc Power ◽  
Electromagnetic Power ◽  
Back Scattering ◽  
Frequency Identification

Using energy-harvesting technology can make the work scope of passive radio frequency identification tag to achieve the maximum .The study put forward to collecting light from the solar cell share tag antenna area, that provides the power source except from the reader receive to electromagnetic power ,which to activate the label circuit. In order to make solar cell to the influence of the tag antenna to minimum ,so optimize it with electromagnetic simulation on its position .The collected dc power could convert into the radio frequency with the efficient E-class oscillator , as well as it could flow into the radio frequency identification tag terminal with the aid of the proper designed coupled circuit .The oscillation frequency is selected on the principle of not affecting the operation of label back scattering .The presented oscillator is showed in the simulations .The E-class oscillator is used together with other forms of collection technology ,such as thermoelectric collect machine.

scholarly journals Integration of Blockchain Technology in IoT for High Level Security

2019 ◽  
Vol 8 (10) ◽  
pp. 491-497
Keyword(s):  
Radio Frequency Identification ◽  
Humidity Sensor ◽  
Raspberry Pi ◽  
Distributed Network ◽  
Peer Communication ◽  
Blockchain Technology ◽  
Frequency Identification ◽  
A Chain ◽  
High Level ◽  
Machine Communication

IoT (Internet of Things) made headway from Machine to Machine communication without human intrusion for number of machines to connect with the aid of network. There is esteem; by 2020 there will be 26 times more connected things than people. Hence, the concern of security rises along with the high installments. The BlockChain Technology takes place of all central entities, which is peer to peer communication with the distributed network. In this paper, two Arduino boards as nodes and a Raspberry Pi as server are to be configured to connect to the Wi-Fi using ESP8266(node mc). To make data transmission from the two nodes to server, integration of temperature and humidity sensor in one node and RFID (Radio Frequency Identification) reader in other node is to be done. Data should be in the form of blocks and integration of data is in the form of a chain, forming it a Blockchain. All the blocks are linked in the chain manner of which the current hash of the previous block must match with the previous hash of the next block. Then only the blocks of data are secured. While receiving data every time from nodes to server, the previous hash is to be checked such that the arrival of the information is being verified to know if it’s really genuine. If the cryptographic hash does not match then data manipulation is happened. So, in this paper, we will see, along with how practically the security is highly offered by the blockchain technology and how can we easily identify if the data has been tampered along the way it reaches to us. Henceforth, we will found a way of application to secure our IoT data without any regrets in this paper.

scholarly journals Interdigital Capacitor-Based Passive LC Resonant Sensor for Improved Moisture Sensing

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6306
Author(s):  
Kristian Chavdarov Dimitrov ◽  
Sanghun Song ◽  
Hyungjun Chang ◽  
Taejun Lim ◽  
Yongshik Lee ◽  
...  
Keyword(s):  
Radio Frequency Identification ◽  
Frequency Offset ◽  
Detection Distance ◽  
Moisture Sensor ◽  
Interdigital Capacitor ◽  
Enhanced Sensitivity ◽  
Low Profile ◽  
Frequency Identification ◽  
Fringing Capacitance ◽  
Moisture Sensing

Herein, a passive low-profile moisture sensor design based on radio frequency identification (RFID) technology is proposed. The sensor consists of an LC resonant loop, and the sensing mechanism is based on the fringing electric field generated by the capacitor in the circuit. A standard planar inductor and a two-layer interdigital capacitor (IDC) with a significantly higher fringing capacitance compared to that of a conventional parallel plate capacitor (PPC) are used, resulting in improved frequency offset and sensitivity of the sensor. Furthermore, a sensor tag was designed to operate at an 8.2 MHz electronic article surveillance (EAS) frequency range and the corresponding simulation results were experimentally verified. The IDC- and PPC-based capacitor designs were comprehensively compared. The proposed IDC sensor exhibits enhanced sensitivity of 10% in terms of frequency offset that is maintained over time, increased detection distance of 5%, and more than 20% increase in the quality factor compared to sensors based on PPC. The sensor’s performance as a urine detector was experimentally qualified. Additionally, it was shown experimentally that the proposed sensor shows a faster response to moisture. Both simulation and experimental data are presented and elucidated herein.

POLAR-OPTICAL PHONON ENHANCEMENT OF HARMONIC GENERATION IN SCHOTTKY DIODES

2002 ◽  
Vol 12 (02) ◽  
pp. 469-478
Author(s):  
B. GELMONT ◽  
D. WOOLARD ◽  
S. CHEN
Keyword(s):  
Schottky Diode ◽  
Optical Phonon ◽  
Power Efficiency ◽  
Semiconductor Device ◽  
Second Harmonic ◽  
Schottky Diodes ◽  
Frequency Multiplier ◽  
Optical Frequency ◽  
Polar Optical Phonon ◽  
Harmonic Power

Polar-optical phonons have an important influence on polar semiconductor device behavior, in polar crystals at very high frequency, because they directly perturb the effective material permittivity in the vicinity of the transverse polar-optical vibration frequency. This phenomenon leads to dramatic nonlinear effects on the resistive and the reactive physics at the Schottky barrier interface. Hence this physical effect provides a mechanism with the potential for producing significant levels of power at higher harmonics. We have established a simulator that combines the modified harmonic-balance circuit analysis technique with a polar-optical phonon hydrodynamic transport model to determine the maximum power generation and/or power efficiency in the second harmonic. An abrupt junction model that includes the polar-optical phonon dynamics in a depletion layer was developed and utilized in this study. Simulation results have revealed a dramatic influence on the second harmonic power of the Schottky diode at the transverse polar-optical frequency and in the vicinity of one-half of the transverse polar-optical frequency. The transverse polar-optical frequency in GaAs is 7.78 THz and this is a rather high for practical applications. Bismuth trisulfide ( Bi 2 S 3) has been identified as a polar material that has the transverse polar-optical frequency on the order of 300 GHz, which is in a range more suited to THz-frequency multiplier applications. The dependence of the second harmonic power of the Schottky diode on the frequency demonstrates two enhanced peaks in the vicinity of the transverse polar-optical frequency. These preliminary results suggest that Bi 2 S 3 Schottky diode based multipliers have potential as enhanced sources within the terahertz regime.

scholarly journals Flexible Radio-Frequency Identification (RFID) Tag Antenna for Sensor Applications

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4212 ◽  
Author(s):  
Mohammad Islam ◽  
Touhidul Alam ◽  
Iskandar Yahya ◽  
Mengu Cho
Keyword(s):  
Radio Frequency ◽  
Radio Frequency Identification ◽  
Low Cost ◽  
System Level ◽  
Uhf Rfid ◽  
Rfid Tag ◽  
Sensor Applications ◽  
Frequency Identification ◽  
Flexible Radio ◽  
Read Range

In this paper, an inkjet-printed flexible Radio-Frequency Identification (RFID) tag antenna is proposed for an ultra-high frequency (UHF) sensor application. The proposed tag antenna facilitates a system-level solution for low-cost and faster mass production of RFID passive tag antenna. The tag antenna consists of a modified meander line radiator with a semi-circular shaped feed network. The structure is printed on photo paper using silver nanoparticle conductive ink. The generic design outline, as well as tag antenna performances for several practical application aspects are investigated. The simulated and measured results verify the coverage of universal UHF RFID band with an omnidirectional radiation pattern and a long-read range of 15 ft. In addition, the read range for different bending angles and lifetimes of the tag antenna are also demonstrated.

scholarly journals Improving the Sensitivity of Chipless RFID Sensors: The Case of a Low-Humidity Sensor

Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2861
Author(s):  
Giada Marchi ◽  
Viviana Mulloni ◽  
Omar Hammad Ali ◽  
Leandro Lorenzelli ◽  
Massimo Donelli
Keyword(s):  
Frequency Shift ◽  
Radio Frequency Identification ◽  
Humidity Sensor ◽  
Experimental Tests ◽  
Dielectric Substrate ◽  
Resonance Peak ◽  
Sensitive Layer ◽  
Chipless Rfid ◽  
Frequency Identification ◽  
Low Humidity

This study is supposed to introduce a valid strategy for increasing the sensitivity of chipless radio frequency identification (RFID) encoders. The idea is to properly select the dielectric substrate in order to enhance the contribution of the sensitive layer and to maximize the frequency shift of the resonance peak. The specific case of a chipless sensor suitable for the detection of humidity in low-humidity regimes will be investigated both with numerical and experimental tests.

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