Near field RFID system with multiple reader coils

Abstract

A near field RFID system includes an RFID reader and an RFID tag. The RFID reader includes a transmit path and a receive path, wherein the transmit path includes: an encoding section coupled to convert data into encoded data; a digital to analog conversion module coupled to convert the encoded data into an analog encoded signal; a power amplifier coupled to amplify the analog encoded signal; and a plurality of coils coupled to generate a plurality of electromagnetic fields from the analog encoded signal. The RFID tag that includes: a coil coupled to generate a current and a recovered signal from at least one of the plurality of electromagnetic fields; a power recovery circuit coupled to generate a voltage from the current; and a data processing section coupled to process the recovered signal, wherein the data processing section is powered via the voltage.

Description

[0001] This patent application is claiming priority under 35 USC §119 to a provisionally filed patent application entitled NEAR FIELD RFID SYSTEM WITH MULTIPLE READER COILS, having a provisional filing date of Jan. 16, 2007, and a provisional Ser. No. of 60 / 880,592 and is further claiming priority under 35 USC §120 as a continuation-in-part patent application of co-pending patent application entitled DECODING OF BI-PHASE ENCODED DATA, having a filing date of Jan. 26, 2006, and a Ser. No. of 11 / 340,243; of co-pending patent application entitled POWER GENERATING CIRCUIT, having a filing date of Mar. 31, 2006, and a Ser. No. of 11 / 394,808; and of co-pending patent application entitled HYBRID ON-CHIP-OFF-CHIP TRANSFORMER, having a filing date of Sep. 28, 2006, and a Ser. No. of 11 / 529,055.CROSS REFERENCE TO RELATED PATENTS [0002] NOT APPLICABLE STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0003] NOT APPLICABLE INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMP...

AI Technical Summary

Benefits of technology

"The present invention is about a device and methods for using it. The technical effects of the invention will be explained in detail in the following description with reference to the accompanying drawings."

Problems solved by technology

While an on-chip transformer provides the convenience of not requiring an external transformer, the on-chip transformer's power capabilities are limited due to its size.

As such, a margin type transformer consumes a significant amount of PCB real estate, but does provide significant power in comparison to the on-chip transformer.

In RFID systems, the cost and the size of the tag and the ability to provide secure communication between the reader and the tag are critical design challenges.

The reduction of the cost and the size of the tag in existing RFID systems, however are primarily limited to the design and implementation of passive components, i.e. bulky antenna or coupling coil that can not be integrated on-chip.

In addition, the use of complex data encryption algorithms, for security, requires a lot of power consumption and therefore, is not practical for extremely low-power passive tags.

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