Patent ID: 6486776
Filing Date: 2002-11-26
Classification: B60C

Abstract:
A passive RF transponder, including:an antenna; a rectifier circuit connected to the antenna to provide electrical power from a RF signal received by the antenna to the other components of the transponder; a modulator circuit, operatively connected to the antenna to form a RF signal output for the transponder by modulation of the RF signal received by the antenna; a first parameter sensor for sensing a first parameter; a second parameter sensor for sensing a second parameter; a timing generator for generating a first timing window during which the first parameter is measured and a second timing window during which the second parameter is measured; a first register for capturing first data indicative of the first parameter; a second register for capturing second data indicative of the second parameter; and the modulator circuit impressing the first data as a first portion of a data stream on a signal output by the transponder, and impressing the second data as a second portion of the data stream on the signal output by the transponder; characterized by: an oscillator outputting a signal having a first frequency which is indicative of the first parameter during the first timing window, and having a second frequency which is indicative of the second parameter during the second timing window; and a register/counter circuit which counts the oscillations of the oscillator signal during the first timing window to capture the first data in the first register, and which counts the oscillations of the oscillator signal during the second timing window to capture the second data in the second register.