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US 5,235,223 AGranted
Constant Q peaking filter utilizing synthetic inductor and simulated capacitor
AssigneeHarman International Industries, Incorporated
InventorChristopher M. Maple
Life of this patent
Estimating the term…
Abstract
A tunable circuit is disclosed which allows tuning while maintaining a constant Q. The filter uses a synthetic inductor and a capacitance multiplier in place of discrete inductive and capacitive elements. By coupling the synthetic inductor and capacitance through a variable resistor, means are provided for varying the peaking frequency of the circuit while maintaining a constant Q.
Claims8
A tunable filter circuit which maintains a constant Q as the circuit is tuned comprising:
- a synthetic inductor having an inductance dependent on a first resistance;
- a capacitance multiplier having a capacitance dependent on a second resistance;
- and, wherein the first resistance of the synthetic inductor and the second resistance of the capacitance multiplier are coupled together through a first variable resistor so that as the variable resistor is varied, the inductance and capacitance increase or decrease proportionately to thereby tune the filter circuit while maintaining a constant Q.
Dependencies are inferred from the claim text.