Communications: electrical – Selective – Interrogation response
Reexamination Certificate
2002-12-09
2004-08-24
Zimmerman, Brian (Department: 2635)
Communications: electrical
Selective
Interrogation response
C345S572000, C343S795000
Reexamination Certificate
active
06781508
ABSTRACT:
TECHNICAL FIELD
This invention relates to radio frequency communication devices, and more particularly to an adjustable radio frequency interrogator tag and method of adjusting transponder sensitivity.
BACKGROUND OF THE INVENTION
As large numbers of objects are moved in inventory, product manufacturing, and merchandising operations, there is a continuous challenge to accurately monitor the location and flow of objects. Additionally, there is a continuing goal to interrogate the location of objects in an inexpensive and streamlined manner. Furthermore, there is a need for tag devices suitably configured to mount to a variety of objects including goods, items, persons, or animals, as well as any moving or stationary and animate or inanimate object. One way of tracking objects is with an electronic identification system.
One presently available electronic identification system utilizes a magnetic field modulation system to monitor tag devices. A controller or interrogator unit creates a magnetic field that becomes detuned when the tag device is passed through the magnetic field. In some cases, the tag device may be alternatively tuned and detuned in a sequence unique to the tag device in order to distinguish between a number of different tags, each having a distinct identify sequence. Typically, the tag devices are entirely passive, eliminating the need for a portable power supply which results in a small and portable package. However, this identification system is only capable of distinguishing a limited number of tag devices, over a relatively short range, limited by the size of the resulting magnetic field. Detuning is the means of encoding the identification number of the tag device or its data.
Another electronic identification system utilizes an RF transponder device affixed to an object to be monitored, in which a controller or interrogator unit transmits an interrogation signal to the device. The device receives the signal, then generates and transmits a responsive signal. The interrogation signal and the responsive signal are typically radio-frequency (RF) signals produced by an RF transmitter circuit. Since RF signals can be transmitted over greater distances than magnetic fields, RF-based transponder devices tend to be more suitable for applications requiring tracking of a tagged device that may not be in close proximity to an interrogator unit. However, when a large number of devices are utilized, the interrogator unit triggers frequent wake-up of each device. As a result, responsive signals are frequently generated. For the case of a battery powered device, the life of the battery is severely diminished due to frequent unintentional wake-ups of the device. Therefore, there is a need to produce tags having different receiver sensitivities, and to produce tags having either factory or user adjustable sensitivity. Such constructions are the subject of this invention.
REFERENCES:
patent: 3155954 (1964-11-01), Larrick et al.
patent: 3967202 (1976-06-01), Batz
patent: 4075632 (1978-02-01), Baldwin et al.
patent: 4167010 (1979-09-01), Kerr
patent: 4215341 (1980-07-01), Cole
patent: 4470047 (1984-09-01), Vogt et al.
patent: 4572976 (1986-02-01), Fockens
patent: 4724427 (1988-02-01), Carroll
patent: 4822990 (1989-04-01), Tamada et al.
patent: 4825220 (1989-04-01), Edward
patent: 4854328 (1989-08-01), Pollack
patent: 4856082 (1989-08-01), Kasa
patent: 4857893 (1989-08-01), Carroll
patent: 4862160 (1989-08-01), Ekchian et al.
patent: 4870419 (1989-09-01), Baldwin et al.
patent: 4888591 (1989-12-01), Landt et al.
patent: 4890072 (1989-12-01), Espe et al.
patent: 4912471 (1990-03-01), Tyburski et al.
patent: 4926182 (1990-05-01), Ohta et al.
patent: 4999636 (1991-03-01), Landt et al.
patent: 5030807 (1991-07-01), Landt et al.
patent: 5086290 (1992-02-01), Murray
patent: 5086389 (1992-02-01), Hassett et al.
patent: 5119070 (1992-06-01), Matsumoto
patent: 5134085 (1992-07-01), Gilgen et al.
patent: 5144314 (1992-09-01), Malmberg et al.
patent: 5164985 (1992-11-01), Nysen et al.
patent: 5175774 (1992-12-01), Truax et al.
patent: 5272367 (1993-12-01), Dennison et al.
patent: 5280643 (1994-01-01), Ishii
patent: 5287112 (1994-02-01), Schuermann
patent: 5300875 (1994-04-01), Tuttle
patent: 5323150 (1994-06-01), Tuttle
patent: 5365551 (1994-11-01), Snodgrass et al.
patent: 5374930 (1994-12-01), Schuermann
patent: 5406263 (1995-04-01), Tuttle
patent: 5420757 (1995-05-01), Eberhardt et al.
patent: 5432027 (1995-07-01), Tuttle et al.
patent: 5448242 (1995-09-01), Sharpe et al.
patent: 5461385 (1995-10-01), Armstrong
patent: 5471212 (1995-11-01), Sharpe et al.
patent: 5479172 (1995-12-01), Smith et al.
patent: 5480834 (1996-01-01), Lake et al.
patent: 5489546 (1996-02-01), Ahmad et al.
patent: 5494495 (1996-02-01), Tuttle
patent: 5495260 (1996-02-01), Couture
patent: 5500650 (1996-03-01), Snodgrass et al.
patent: 5521600 (1996-05-01), McEwan
patent: 5525993 (1996-06-01), Pobanz et al.
patent: 5532707 (1996-07-01), Klinger
patent: 5621412 (1997-04-01), Sharpe et al.
patent: 5626630 (1997-05-01), Markowitz
patent: 5649296 (1997-07-01), MacLellan et al.
patent: 5668560 (1997-09-01), Evans et al.
patent: 5970398 (1999-10-01), Tuttle
patent: 6122494 (2000-09-01), Tuttle
patent: 6574454 (2003-06-01), Tuttle
“CMOS Analog Integrated Circuits Based on Weak Inversion Operation”, by Eric Vittoz and Jean Fellrath, IEEE Journal of Solid State Circuits, vol. SC-12, No. 3, Jun. 1977.
Mitsubishi Motors Corporation Web Page, 1995.
“Digital RF/ID Enhances GPS”, by John R. Tuttle, Proceedings of the Second Annual Wireless Symposium, pp. 406-411, Feb. 15-18, 1994, Santa Clara, CA.
“Micron Morning Report”, The Idaho Statesman, Jul. 16, 1993.
“A Low-Power Spread Spectrum CMOS RFIC for Radio Identification Applications”, by John R. Tuttle, Conference Proceedings from RF Expo West, pp. 216-222, Mar. 22-24, 1994, San Jose, CA.
Electronics Engineer's Handbook—3rdEd., Fink et al.,Distributed Circuits, §100, p. 8-104, ©1989.
U.S. patent application Ser. No. 60/017,900, Provisional Patent Application, filed May 13, 1996.
U.S. patent application Ser. No. 60/023,318, Provisional Patent Application, filed Jul. 30, 1996.
Tuttle John R.
Tuttle Mark E.
Wells St. John P.S.
Zimmerman Brian
LandOfFree
Radio frequency data communications device with adjustable... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Radio frequency data communications device with adjustable..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Radio frequency data communications device with adjustable... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3359472