Search International and National Patent Collections

1. (WO2001004621) FREQUENCY WARPING FOR IMPROVING RESONATOR SIGNAL-TO-NOISE RATIO

Pub. No.:    WO/2001/004621    International Application No.:    PCT/US2000/018793
Publication Date: Fri Jan 19 00:59:59 CET 2001 International Filing Date: Tue Jul 11 01:59:59 CEST 2000
IPC: G01N 29/02
G01N 29/34
G01N 29/36
G01N 29/42
Applicants: FISHER CONTROLS INTERNATIONAL, INC.
Inventors: DILGER, John, P.
LIU, Guojun
Title: FREQUENCY WARPING FOR IMPROVING RESONATOR SIGNAL-TO-NOISE RATIO
Abstract:
A sensor circuit for use in measuring concentrations of an analyte in a fluid is comprised of a BAW sensor, a voltage variable capacitor connected to the sensor, an input which supplies a bias warping dc voltage to the voltage variable capacitor, and a resonant oscillator circuit. The resonant oscillator circuit detects the fundamental frequency of the sensor and produces a resonant signal frequency. The bias warping dc voltage applied to the voltage variable capacitor warps the resonant frequency of the circuit away from inharmonic noise.