scholarly journals A rectifier structure for UHF RFID transponder with high efficiency

2010 ◽  
Vol 7 (14) ◽  
pp. 1086-1090 ◽  
Author(s):  
Ji Cui ◽  
Junichi Akita ◽  
Akio Kitagawa
Keyword(s):  
2015 ◽  
Vol 1 (1) ◽  
pp. 318-321
Author(s):  
Mohamed Bourouah ◽  
Vadim Goridko ◽  
Dietmar Schumacher ◽  
Hermann Scheithauer ◽  
Stephan Knappmann ◽  
...  

AbstractThe paper presents research, development and advantage of Radio Frequency IDentification (RFID) technology based system for medical instrument management and safe usage. The system is developed for two scenarios. In the first scenario, a Ultra High Frequency (UHF) is used and the UHF–interrogator system with UHF-antennas is constructed to work as conveyor-belt and instruments are placed between two antennas. Second scenario, suitable for the operating rooms, includes four antennas, placed under the table with instruments, system’s phase shifter, inserted between the antenna and reader in order to reduce the effect of dead spots, caused by the electromagnetic reflections. High reliable identification rate is achieved by synchronizing phase shifters with particular interrogator. The system is software calibrated and can be re-calibrated at run-time to achieve high efficiency of power transmission to the antenna and in order to enable the receiver to decode the tag signals. With currently on the market available RFID tags and previously mentioned technology approaches, detection rate of 87.5% can be achieved.


2015 ◽  
Vol 12 (10) ◽  
pp. 20150194-20150194 ◽  
Author(s):  
Yong Chen ◽  
Xi Tan ◽  
Na Yan ◽  
Yibo Fan ◽  
Hao Min

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Milan Svanda ◽  
Milan Polivka

This paper introduces a small-size, low-profile wearable radiator based on the coupled patches and vertically folded patches techniques for application as a tag antenna for identification of people in the European UHF RFID band. The electric field distribution comes out dominantly from the central coupling slot, and thus the electric properties of the radiator are almost unaffected by the human body to which the antenna is intended to be attached. Accordingly, with the relative size0.14×0.12×0.009 λ0at 866 MHz(50×40×3.04 mm3), the antenna exhibits total efficiency better than 50%, even if it is attached directly to a person.


1988 ◽  
Vol 102 ◽  
pp. 41
Author(s):  
E. Silver ◽  
C. Hailey ◽  
S. Labov ◽  
N. Madden ◽  
D. Landis ◽  
...  

The merits of microcalorimetry below 1°K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.1°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.


Author(s):  
J. M. Cowley ◽  
R. Glaisher ◽  
J. A. Lin ◽  
H.-J. Ou

Some of the most important applications of STEM depend on the variety of imaging and diffraction made possible by the versatility of the detector system and the serial nature, of the image acquisition. A special detector system, previously described, has been added to our STEM instrument to allow us to take full advantage of this versatility. In this, the diffraction pattern in the detector plane may be formed on either of two phosphor screens, one with P47 (very fast) phosphor and the other with P20 (high efficiency) phosphor. The light from the phosphor is conveyed through a fiber-optic rod to an image intensifier and TV system and may be photographed, recorded on videotape, or stored digitally on a frame store. The P47 screen has a hole through it to allow electrons to enter a Gatan EELS spectrometer. Recently a modified SEM detector has been added so that high resolution (10Å) imaging with secondary electrons may be used in conjunction with other modes.


Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.


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