Programmable selective wake-up for radio frequency transponder

Abstract

A remote keyless entry (RKE) transponder has a programmable selective wake-up filter for determining whether the RKE transponder should wake-up to process a received signal. The wake-up filter correlates the timing of an input signal's carrier amplitude on and off time periods to a predefined programmable time period profile for a desired signal which has a certain carrier on time (time period on) and a certain carrier off time (time period off) arranged into a coded “header.” When a received signal matches the predefined time period profile, then the RKE transponder will wake-up to process the incoming signal data. The predefined time period profile may be programmable and may be stored in a header configuration register. Each RKE transponder has unique predefined time period on and time period off profiles.

Description

RELATED PATENT APPLICATION [0001] This application claims priority to commonly owned U.S. Provisional Patent Application Ser. No. 60 / 564,829; filed Apr. 23, 2004; entitled “Programmable Wake-Up Filter for Radio Frequency Transponder,” by Thomas Youbok Lee, James B. Nolan, Steve Vernier, Randy Yach and Alan Lamphier, which is hereby incorporated by reference herein for all purposes. [0002] This application is related to commonly owned U.S. patent application Ser. No. ______; filed ______; entitled “Reducing False Wake-Up in a Low Frequency Transponder,” by James B. Nolan, Thomas Youbok Lee, Alan Lamphier, Ruan Lourens and Steve Vernier; U.S. patent application Ser. No. ______; filed ______; entitled “Noise Alarm Timer Function for Three-Axis Low Frequency Transponder,” by James B. Nolan, Thomas Youbok Lee, Steve Vernier and Alan Lamphier; and U.S. patent application Ser. No. ______; filed ______; entitled “Dynamic Configuration of a Radio Frequency Transponder,” by Thomas Youbok Lee,...

AI Technical Summary

Benefits of technology

[0020] A technical advantage of the present invention is substantially eliminating false wake-up from unwanted signals and noise that unnecessarily uses power and thus reduces battery life. Another technical advantage is using a unique input signal pulse time period header for each transponder so as to avoid response collisions from multiple transponders. Still another technical advantage is reprogramming the wake-up filter parameters via a simple SPI command. Yet another technical advantage is the wake-up filter may be disabled for testing and calibration purposes. Other technical advantages should be apparent to one of ordinary skill in the art in view of what has been disclosed herein.

is substantially eliminating false wake-up from unwanted signals and noise that unnecessarily uses power and thus reduces battery life. Another technical advantage is using a unique input signal pulse time period header for each transponder so as to avoid response collisions from multiple transponders. Still another technical advantage is reprogramming the wake-up filter parameters via a simple SPI command. Yet another technical advantage is the wake-up filter may be disabled for testing and calibration purposes. Other technical advantages should be apparent to one of ordinary skill in the art in view of what has been disclosed herein.

Problems solved by technology

This type of RKE system is prone to false wake-up, short battery life, unreliable operating range that is too dependant upon orientation of the key fob (not shown).

In a closely coupled or near field noisy environment, however, a noise source, e.g., magnetic or electromagnetic, could cause the analog front-end and associated external control device to “wake-up” or remain “awake” and thus cause increased power consumption and thereby reduce battery life.

A problem exists, however, when the transponder receiver is exposed to noise sources such as electromagnetic radiation (EMR) emanating from, for example, televisions and computer monitors having substantially the same frequency as the interrogation signal, the RKE device will wake-up unnecessarily.

If the RKE transponder receiver is exposed to a continuous noise source, the battery may be depleted within a few days.

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