Cloaking circuit for use in a radiofrequency identification and

Details Cloaking circuit for use in a radiofrequency identification and Cloaking circuit for use in a radiofrequency identification and

1997-05-30

1999-10-05

Zimmerman, Brian

Communications: electrical

Continuously variable indicating

With meter reading

3405727, H04Q 100

Patent

active

059631449

ABSTRACT:
The antenna of an RFID tag or label is disconnected from the balance of the RFID chip by means of a series switch activated in response to a logic command, CLOAK, generated by the RFID chip. Activation of the switch disconnects the antenna of the RFID tag for the remainder of the RFID chip and effects a high impedance resistance across the antenna terminals. An RC circuit is charged by activation of the CLOAK signal and thereafter discharges during a predetermined RC time period as determined by a high impedance series antifuse leakage transistor. The antenna is thus disconnected for a time sufficient to allow the remaining RFID tags in an RF interrogation field to be identified. Meanwhile, during the disconnection of the antenna from the RFID chip and its loading causes its effective absorption and scattering aperture to be reduced near zero so as to electromagnetically remove the RFID tag from the zone of interrogation during the predetermined time period. Hence, the interrogated tag remains disconnected and noninterferring with the RF field used to interrogate the remaining tags.

REFERENCES:
patent: 3694754 (1972-09-01), Baltzer
patent: 4414690 (1983-11-01), Norboldt
patent: 5074947 (1991-12-01), Estes et al.
patent: 5196371 (1993-03-01), Kulesza et al.
patent: 5237130 (1993-08-01), Kulesza et al.
patent: 5418358 (1995-05-01), Bruhnke
patent: 5471196 (1995-11-01), Pilsted
patent: 5611140 (1997-03-01), Kulesza et al.
patent: 5701121 (1997-12-01), Murdoch
patent: 5701595 (1997-12-01), Green

Affiliated with

Also associated with

Rating

Cloaking circuit for use in a radiofrequency identification and does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Cloaking circuit for use in a radiofrequency identification and , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cloaking circuit for use in a radiofrequency identification and will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1176411