US 9,438,249 B1 · Resonant circuit temperature compensation

Abstract

Certain aspects of the present disclosure provide methods and apparatus for temperature-dependent adjustment of a resonant circuit, such as that found in a voltage-controlled oscillator (VCO). Such adjustment may be performed in an effort to compensate for the frequency drift of the resonant circuit due to temperature changes. One example adjustment circuit for temperature-dependent adjustment of a resonant circuit generally includes at least one varactor and two sets of semiconductor devices configured to apply, across the at least one varactor, a differential adjustment voltage based on an ambient temperature of the semiconductor devices to adjust a capacitance of the at least one varactor, wherein each device in the sets of semiconductor devices has a temperature-dependent junction and wherein the two sets of semiconductor devices are configured such that voltage changes of the temperature-dependent junctions in the two sets of semiconductor devices are added in the differential adjustment voltage.

Claims30

Dependent claims

An adjustment circuit for temperature-dependent adjustment of a resonant circuit, comprising:

at least one varactor having a first terminal and a second terminal;
a first set of one or more semiconductor devices connected with the first terminal and configured to generate a first adjustment voltage;
and
a second set of one or more semiconductor devices connected with the second terminal and configured to generate a second adjustment voltage, wherein:
each device in the first and second sets of semiconductor devices has a temperature-dependent junction;
the first and second adjustment voltages are based on an ambient temperature affecting the temperature-dependent junction of each device in the first and second sets of semiconductor devices, respectively;
a differential adjustment voltage based on a difference between the first and second adjustment voltages is applied to the first and second terminals to adjust a capacitance of the at least one varactor;
and
voltage changes due to changes in the ambient temperature affecting the temperature-dependent junctions in the first and second sets of semiconductor devices are added in the differential adjustment voltage.

6 more elements

Dependencies are inferred from the claim text.

Resonant circuit temperature compensation

Life of this patent

Resonant circuit temperature compensation

Life of this patent

Abstract

Claims30