Single chip RF tag oscillator circuit synchronized by base station modulation frequency
DC CAFCFirst Claim
Patent Images
1. A passive radio frequency (RF) transponder (tag) for receiving an RF signal from a base station, comprising;
- a tag antenna for receiving the RF signal fron the base station the RF signal having a carrier frequency;
a tag rectification power supply connected to the tag antenna;
a tag logic section and a tag memory section the tag logic section and the tag memory section receiving power only from the tag antenna through the tag rectification power supply;
a receiver section connected to the tag antenna; and
a tag oscillator connected to the receiver section, the tag oscillator having a plurality of possible discrete frequencies of oscillation, the tag oscillator having a tag oscillation frequency much less than the carrier frequency, the tag oscillator frequency used to determine a tag modulation frequency of an RF signal backscattered from the tag antenna, the tag oscillation frequency determined by the RF signal sent from the base station.
9 Assignments
Litigations
0 Petitions
Accused Products
Abstract
A Radio Frequency (RF) transponder (tag), method, and system, whereby the tag has a low current tag oscillator, the oscillation frequency of the tag oscillator set by RF signal from a base station.
-
Citations
28 Claims
-
1. A passive radio frequency (RF) transponder (tag) for receiving an RF signal from a base station, comprising;
-
a tag antenna for receiving the RF signal fron the base station the RF signal having a carrier frequency; a tag rectification power supply connected to the tag antenna; a tag logic section and a tag memory section the tag logic section and the tag memory section receiving power only from the tag antenna through the tag rectification power supply; a receiver section connected to the tag antenna; and a tag oscillator connected to the receiver section, the tag oscillator having a plurality of possible discrete frequencies of oscillation, the tag oscillator having a tag oscillation frequency much less than the carrier frequency, the tag oscillator frequency used to determine a tag modulation frequency of an RF signal backscattered from the tag antenna, the tag oscillation frequency determined by the RF signal sent from the base station. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. A method of setting a tag oscillation frequency of a tag oscillator of a passive RF tag comprising;
-
a) receiving an RF signal from a base station, and; b) adjusting the tag oscillation frequency in response to the RF signal from the base station, wherein the tag oscillation frequency is much less than a carrier frequency of the RF signal, and wherein the tag oscillation frequency is used to determine a tag modulation frequency of an RF signal backscattered from the tag. - View Dependent Claims (14, 15, 16, 17, 18)
-
-
19. A method of setting an oscillation frequency of a tag oscillator of a passive RF tag, where the tag adjusts the oscillator frequency according to the following steps;
-
a) setting the tag oscillator so that the tag oscillation frequency is the lowest possible frequency by setting all control bits equal to one; b) resetting the most significant bit equal to zero; c) resetting a local counter of tag oscillator pulses on a rising edge of the steadily modulated RF field sent out by the base station; d) counting pulses of the tag oscillator until the next rising edge of the steadily modulated RE field sent out from the base station; e) if the count value is greater than a preset number, resetting the local counter, setting the last bit reset to one, resetting the next significant bit to zero, and returning to step (c); f) if the count value is less than the preset number, resetting the local counter, resetting the next significant bit to zero, and returning to step (c); and g) continuing until all control bits have been set or reset and the count value is approximately equal to the preset number. - View Dependent Claims (20, 21)
-
-
22. A system for sending and receiving modulated RF signals, comprising;
-
a base station for sending modulated RF signals, the RF signals having a carrier frequency; and at least one passive RF tag for receiving the RF signals, the RF tag comprising a tag antenna for receiving the RF signal from the base station, a tag receiver section connected to the tag antenna; and
a tag oscillator connected to the tag receiver section, the tag oscillator having a tag oscillation frequency much less than the carrier frequency, the tag oscillation frequency used to determine the a modulation frequency of an RF signal backscattered from the tag antenna, the tag oscillator frequency determined by the Rf signals sent by the base station. - View Dependent Claims (23, 24, 25, 26, 27)
-
-
28. A passive radio frequency (RF) transponder (tag) for receiving an RF signal from a base station, comprising;
-
a tag antenna for receiving the RF signal from the base station, the RF signal having a carrier frequency; a receiver section connected to the tag antenna; a tag rectification power supply connected to the tag antenna; a tag logic section and a tag memory section, the tag logic section and the tag memory section receiving power only from the tag antenna through the tag rectification power supply; and a tag oscillator connected to the receiver section, the tag oscillator having a tag oscillation frequency much less than the carrier frequency, the tag oscillation frequency used to determine a tag modulation frequency of an RF signal backscattered from the tag antenna, the tag oscillation frequency determined by the RF signal sent from the base station.
-
Specification