Method for optimizing the design and implementation of RFID tags

• US 20050030201A1
• Filed: 04/21/2004
• Published: 02/10/2005
• Est. Priority Date: 04/21/2003
• Status: Active Grant

• Current Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Bridgelall, Raj
• Granted Patent: US 7,516,057 B2
• Time in Patent Office: Days
• US Class Current: 340/870.110
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer

Abstract

A method is provided for optimizing the design parameters of a RFID tag for use with a RFID reader in a RFID system. In the method, a desired frequency band that the RFID tag will operate in is chosen. Additionally, a maximum acceptable cost for the RFID tag, a minimum acceptable data range for the RFID tag and a minimum operating voltage for the RFID tag are chosen. For a given cost, an optimal data rate is calculated by varying a carrier modulation period of an interrogation signal generated by the RFID reader and antenna capacitance of the RFID tag. Next, an optimal range for a given operating voltage is calculated using the optimal data rate.

Claims

1. A method for optimizing the design parameters of an RFID tag for use with a RFID reader in a RFID system, the method comprising the steps of:

selecting a desired frequency band that the RFID tag will operate in;

selecting an acceptable minimum range between the RFID tag and the RFID reader;

selecting a maximum acceptable cost for the RFID tag and a minimum acceptable data rate for the RFID tag.

selecting a minimum operating voltage for the RFID tag;

calculating an optimal data rate by varying a carrier modulation period of an interrogation signal generated by the RFID reader and an antenna capacitance of the RFID tag; and

calculating an optimal range for a given operating voltage and the calculated optimal data rate.

2. The method of claim 1 further comprising repeating the steps of calculating an optimal data rate and calculating an optimal range for different cost for the RFID tag to determine a set of optimal range, data range, and cost.

3. The method of claim 2 further comprising the steps of determining the most optimal combination of data rate, range and cost.

4. The method of claim 3 wherein the step of determining the most optimal combination further comprises:

calculating a vector distance between each of the set of optimal range and data rate for each cost; and

determining which of the set of optimal range and data rate for each cost is at a minimum total vector distance from the acceptable minimum range, acceptable data rate and acceptable cost.

5. The method of claim 1 wherein the desired frequency is in the ultra-high frequency band.

6. The method of claim 1, wherein the step of selecting a desired frequency band further comprises applying regulatory constraints associated with the desired frequency band to the design of the RFID tag.

7. The method of claim 1 further comprising comparing the optimal data range, data rate and cost versus practical values to determine a practical optimized value close to the optimal values.