scholarly journals Resonant-frequency discharge in a multi-cell radio frequency cavity

2014 ◽  
Vol 116 (17) ◽  
pp. 173301
Author(s):  
S. Popović ◽  
J. Upadhyay ◽  
J. Mammosser ◽  
M. Nikolić ◽  
L. Vušković
Keyword(s):  
Resonant Frequency ◽  
Radio Frequency

An Estimation of Resonant Frequency of a Curving RFID Tag

2011 ◽  
Vol 314-316 ◽  
pp. 1325-1329
Author(s):  
Lei Xu ◽  
Hui Ming Huang
Keyword(s):  
Resonant Frequency ◽  
Radio Frequency ◽  
Radio Frequency Identification ◽  
Rfid Technology ◽  
Rfid Tag ◽  
Coil Inductance ◽  
Rfid System ◽  
Frequency Identification ◽  
Working Frequency

Radio frequency identification (RFID) technology may be applied to cylindrical objects, but the curving of an RFID tag brings on an increase in resonant frequency of the tag antenna. The tag can not function in an excessively curving case, since the deviation of the antenna resonant frequency from working frequency makes a reduction in inductive energy supplied by a transmitter. The variation in antenna resonant frequency is dependant upon column radius of the cylinder and curving angle of the tag. Analytically, it is found that a reduction in central distance, which is determined by column radius and curving angle, between compound straight tracks leads to the decreasing of overall antenna-coil inductance after the curving of the tag. By introducing a curving turn exponent, the overall antenna-coil inductance is calculated. After neglecting the less variation in overall tag capacitance, the antenna resonant frequency may be estimated. The result provides an instruction for designing a curving tag antenna to fit the tag antenna resonant frequency for working frequency of an RFID system.

scholarly journals VII. A self-contained standard harmonic wave-meter

1924 ◽  
Vol 224 (616-625) ◽  
pp. 259-301 ◽  
Keyword(s):  
Resonant Frequency ◽  
Radio Frequency ◽  
Harmonic Wave ◽  
Wave Form ◽  
Integral Multiple ◽  
Discontinuous Wave ◽  
A Current ◽  
Oscillatory Current

Following a brief introductory survey of the various methods of measuring radio-frequency, the principles of a highly accurate standard harmonic wave-meter are developed. The essential principle is an arrangement of three-electrode valves, known as a multi-vibrator, the invention of H. Abraham and E. Bloch. The arrangement produces a discontinuous wave, the frequency of which may be adjusted to have any value within very wide limits. When a current of such wave form acts by induction on another circuit, this circuit receives what may be considered as a series of electrical blows at equal intervals of time. If the circuit operated upon is highly resonant, then when its resonant frequency is set so as to be an integral multiple of the frequency of the blows, a large oscillatory current is built up, of a persistent kind and of a frequency whose ratio to that of the blows is quite exact.

scholarly journals Design a Compact Coplanar Wideband Antenna Used in Radio Frequency Identification Systems

2020 ◽  
Vol sceeer (3d) ◽  
pp. 134-138
Author(s):  
Sufyan Ali ◽  
Ahmed Reja ◽  
Yousif Hachim
Keyword(s):  
Resonant Frequency ◽  
Radio Frequency ◽  
Radio Frequency Identification ◽  
Return Loss ◽  
Ground Plane ◽  
Substrate Material ◽  
Tangent Loss ◽  
Frequency Interval ◽  
Dielectric Thickness ◽  
Frequency Identification

In this paper, a new compact coplanar antenna used for Radio frequency identification (FID) applications is presented. This antenna is operated at the resonant frequency of 2.45 GHz. The proposed antenna is designed on an epoxy substrate material type (FR-4) with small size of (40 × 28) mm2 in which the dielectric thickness (ℎ) of 1.6 mm, relative permittivity (er) of 4.3 and tangent loss of 0.025. In this design the return loss is less than −10 dB in the frequency interval (2.12 − 2.84) GHz and the minimum value of return loss is -32 dB at resonant frequency. The maximum gain of the proposed antenna is 1.22 dB and the maximum directivity obtained is 2.27 dB. The patch and the ground plane of the proposed antenna are in the same surface. The proposed antenna has a wide bandwidth and omnidirectional radiation pattern with small size. The overall size of the compact antenna is (40 × 28 × 1.635) mm3. The Computer Simulation Technology (CST) microwave studio software is used for simulation and gets layout design.

scholarly journals Miniturize Flexible RFID Antenna Design using Metamaterial Structure

2019 ◽  
Vol 18 (2) ◽  
pp. 55-59
Author(s):  
Nur Rabihah Dulkarim ◽  
Mohd Fairus Mohd Yusoff ◽  
Zaharah Johari
Keyword(s):  
Resonant Frequency ◽  
Radio Frequency ◽  
Radio Frequency Identification ◽  
Rapid Development ◽  
Ground Plane ◽  
Future Application ◽  
Metamaterial Structure ◽  
Microstrip Patch ◽  
Frequency Identification ◽  
Radio Frequency Waves

Radio Frequency Identification (RFID) is the application of electromagnetic fields to identify and track tags that attached on the objects. It transmits or reads the radio frequency waves in the system. However, due to rapid development of technology in telecommunication, a much more smaller and flexible device is needed. Therefore, in this paper, a new design of flexible RFID antenna using metamaterial structure has been proposed. At first, the basic rectangular microstrip patch antenna with resonant frequency of 900MHz is designed. Then, the CSRR metamaterial structure is introduced at the ground plane to reduce the size of the antenna while the polydimethylsiloxane (PDMS) material is being use as the antenna substrate for flexibility. All the simulation designs were done using CST software. The antenna performances such as resonant frequency, return loss, radiation pattern, gain and bandwidth are then be analyzed and presented. The results show good performances and can be applied for future application.

Passive RFID, a new technology for dense and long-term monitoring of unstable structures: review and prospective.

2020 ◽  
Author(s):  
Mathieu Le Breton ◽  
Laurent Baillet ◽  
Éric Larose ◽  
Etienne Rey ◽  
Denis Jongmans ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Radio Frequency ◽  
Radio Frequency Identification ◽  
Earth Science ◽  
Near Field ◽  
Crack Opening ◽  
Rfid Tags ◽  
Far Field ◽  
Displacement Monitoring ◽  
Frequency Identification

<p>            Billions of passive radiofrequency tags are produced by the Radio-Frequency Identification (RFID) industry every year to identify goods remotely. New research and business applications are continuously arising, including recently localization and sensing for earth science. Indeed, the cost of tags is often several orders of magnitudes below conventional outdoor sensors used in earth science, allowing to deploy up to thousands of tags with minimal investment. Furthermore, passive wireless tags require little maintenance, which fits well for years-long monitoring. This study reviews the earth science applications that are being developed today, that use RFID devices available on the market, i.e., 900 MHz far-field tags and 125 kHz near-field tags.</p><p>            Ground displacements of centimeters to hundreds of meters can be monitored using RFID location techniques. Indeed, RFID tags were firstly used in earth science to track the displacement of riverine and coastal sediments due to bedloading. Near-field tags inserted in pebbles can be identified typically up to 0.5 m from the reading device even when buried. The tags are read either by fixed portals or by a mobile device, obtaining either high space or time resolution data, respectively. Very recently, measuring the phase difference of arrival of far-field tags allowed to estimate displacements with centimetric accuracy, with a tag-reader distance up to 50 m. That allowed measuring the ground displacements continuously relatively to a fixed reader, or to estimate tags location placed on the ground by carrying a reader over a drone using the synthetic aperture radar method. Alternatively, RFID tags can also be used for sensing the evolution over time of the temperature, moisture level, vibrations, resonant frequency or crack opening of a geologic object.</p><p>            This review presents multiple applications for monitoring unstable rock/earth structures using RFID. First, slow landslides can be monitored with accurate displacement monitoring and with soil moisture sensors. Then, prone-to-failure rock columns could be monitored by sensing crack opening or resonant frequency, using the same tags as with the concrete structure applications. Finally, sediment loading due to rapid mass movements such as floods, debris flows, tsunami or typhoons, have been studied largely using tags placed into pebbles.</p><p> </p><p>Author’s published work on the topic:</p><ul><li>Le Breton, M., Baillet, L., Larose, E., Rey, E., Benech, P., Jongmans, D., Guyoton, F., 2017. Outdoor UHF RFID: Phase Stabilization for Real-World Applications. IEEE Journal of Radio Frequency Identification 1, 279–290.</li> <li>Le Breton, M., Baillet, L., Larose, E., Rey, E., Benech, P., Jongmans, D., Guyoton, F., Jaboyedoff, M., 2019. Passive radio-frequency identification ranging, a dense and weather-robust technique for landslide displacement monitoring. Engineering Geology 250, 1–10.</li> <li>Le Breton, M., 2019. Suivi temporel d’un glissement de terrain à l’aide d’étiquettes RFID passives, couplé à l’observation de pluviométrie et de bruit sismique ambiant (PhD Thesis). Université Grenoble Alpes, ISTerre, Grenoble, France.</li> </ul>

46: Intermediate Follow-Up Comparison between Partial Nephrectomy and Radio Frequency Ablation in T1A Renal Tumors

2006 ◽  
Vol 175 (4S) ◽  
pp. 16-16 ◽  
Author(s):  
Joshua M. Stern ◽  
Robert S. Svatek ◽  
Sangtae Park ◽  
J. Kyle Anderson ◽  
Yair Lotan ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Partial Nephrectomy ◽  
Radio Frequency Ablation ◽  
Renal Tumors

1913: The Radiographic Evolution of Radio Frequency Ablated Renal Lesions

2004 ◽  
Vol 171 (4S) ◽  
pp. 505-505
Author(s):  
Edward D. Matsumoto ◽  
Lori Watumall ◽  
D. Brooke Johnson ◽  
Kenneth Ogan ◽  
Grant D. Taylor ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Renal Lesions
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