Wireless sensor reader

Abstract

A wireless sensor reader is provided to interface with a wireless sensor. The wireless sensor reader transmits an excitation pulse to cause the wireless sensor to generate a ring signal. The wireless sensor reader receives and amplifies the ring signal and sends the signal to a phase-locked loop. A voltage-controlled oscillator in the phase-locked loop locks onto the ring signal frequency and generates a count signal at a frequency related to the ring signal frequency. The voltage-controlled oscillator is placed into a hold mode where the control voltage is maintained constant to allow the count signal frequency to be determined. The reader uses an ambient reading or other information to select a subset of the possible ring signal frequencies, and tunes or adjusts its circuits and algorithms to focus on that subset.

Description

[0001] Cross References to Related Applications [0002] This patent application is a continuation-in-part of U.S. Patent Application No. 13 / 423,693, filed March 19, 2012, entitled "Wireless Sensor Reader," and claims the April 25, 2011 titled " Priority to U.S. Provisional Application No. 61 / 478,647, "Wireless Sensor Reader Tuning Based on Environmental Conditions," each of which is incorporated herein by reference in its entirety. technical field [0003] The present invention generally relates to an apparatus and apparatus for measuring wireless signals from sensors. Background technique [0004] Wireless sensor and reader systems can be designed to wirelessly monitor the status of remote sensors. Some such wireless systems include sensors that convert physical parameters into signal frequencies. In turn, the reader is configured to receive and measure the frequency of the sensor signal. [0005] figure 1 The operating frequency bandwidth and corresponding parameter...

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Problems solved by technology

However, this often requires significant additional circuitry and processing

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