RFID system with multiple reader transmit frequencies
First Claim
1. An RFID system, comprising:
- a) an RF-blocking enclosure having a port with a selected shortest dimension;
b) an active RFID tag including a controller and an interior antenna coupled to the controller and located in the enclosure, the tag responsive to a selected RF downlink frequency range; and
c) an RFID reader located outside the enclosure, the RFID reader adapted to simultaneously transmit directional RF signals on a plurality of frequencies corresponding to respective wavelengths smaller than the selected shortest dimension, the plurality of frequencies including a carrier frequency and an interference frequency, so that a beat frequency is defined between the carrier frequency and the interference frequency and the beat frequency is within the selected RF downlink frequency range,so that the transmitted signals pass through the port and the tag responds to the beat frequency.
13 Assignments
0 Petitions
Accused Products
Abstract
An RFID system includes an RF-blocking enclosure having a port with a selected shortest dimension. An active RFID tag including a controller and an interior antenna coupled to the controller is located in the enclosure. The tag responds to a selected RF downlink frequency range. An RFID reader located outside the enclosure simultaneously transmits directional RF signals on a plurality of frequencies corresponding to respective wavelengths smaller than the selected shortest dimension, the plurality including a carrier frequency and an interference frequency. A beat frequency is thus defined between the carrier frequency and the interference frequency and the beat frequency is within the selected RF downlink frequency range, so that the transmitted signals pass through the port and the tag responds to the beat frequency.
-
Citations
4 Claims
-
1. An RFID system, comprising:
-
a) an RF-blocking enclosure having a port with a selected shortest dimension; b) an active RFID tag including a controller and an interior antenna coupled to the controller and located in the enclosure, the tag responsive to a selected RF downlink frequency range; and c) an RFID reader located outside the enclosure, the RFID reader adapted to simultaneously transmit directional RF signals on a plurality of frequencies corresponding to respective wavelengths smaller than the selected shortest dimension, the plurality of frequencies including a carrier frequency and an interference frequency, so that a beat frequency is defined between the carrier frequency and the interference frequency and the beat frequency is within the selected RF downlink frequency range, so that the transmitted signals pass through the port and the tag responds to the beat frequency. - View Dependent Claims (2, 3, 4)
-
Specification
-
- Resources
-
Current AssigneeEastman Kodak Company
-
Original AssigneeEastman Kodak Company
-
InventorsRimai, Donald Saul, Hinman, Mark P.
-
Primary Examiner(s)Zimmerman, Brian
-
Assistant Examiner(s)Lau, Kevin
-
Application NumberUS13/532,831Publication NumberTime in Patent Office651 DaysField of SearchNoneUS Class Current340/10.1CPC Class CodesG06K 19/07327 Passive means, e.g. Faraday...
