System and method for dynamically biasing oscillators for optimum phase noise
First Claim
1. A frequency oscillator comprising:
- a tank circuit having an inductor, a first coupling capacitor, and a second coupling capacitor;
a varactor circuit electrically coupled to the first coupling capacitor and the second coupling capacitor;
a first MOS device having a first gate, a first drain, and a first source, the first source being electrically coupled to the varactor circuit, and the first gate being electrically coupled to the first drain;
a second MOS device having a second gate, a second drain, and a second source, the second source being electrically coupled to the varactor circuit opposite the first source and the second gate being electrically coupled to the second drain;
a first input electrically coupled to the first drain and the second drain operable to receive a first bias voltage; and
a second input electrically coupled to the first gate and the second gate to receive a first gate bias voltage.
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Accused Products
Abstract
Systems and methods for biasing frequency oscillators to minimize phase noise are disclosed. The system may comprise a tank circuit having an inductor, at least a first coupling capacitor and a second coupling capacitor. The system may further comprise a varactor circuit electrically connected to the first coupling capacitor and the second coupling capacitor. The system may further comprise at least one first metal oxide semiconductor (MOS) device electrically connected in shunt with the tank circuit and a bias voltage. The at least one first MOS device may be electrically connected to a first gate bias voltage configured to bias the at least one first MOS device such that a first gate-to-source voltage of the at least one first MOS device remains below the first threshold voltage.
20 Citations
23 Claims
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1. A frequency oscillator comprising:
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a tank circuit having an inductor, a first coupling capacitor, and a second coupling capacitor; a varactor circuit electrically coupled to the first coupling capacitor and the second coupling capacitor; a first MOS device having a first gate, a first drain, and a first source, the first source being electrically coupled to the varactor circuit, and the first gate being electrically coupled to the first drain; a second MOS device having a second gate, a second drain, and a second source, the second source being electrically coupled to the varactor circuit opposite the first source and the second gate being electrically coupled to the second drain; a first input electrically coupled to the first drain and the second drain operable to receive a first bias voltage; and a second input electrically coupled to the first gate and the second gate to receive a first gate bias voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A frequency oscillator comprising:
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a variable capacitance circuit; a tank circuit having at least one inductor and at least one capacitor, the tank circuit being electrically coupled in parallel to the variable capacitance circuit; a first MOS device having a first gate, a first source, and a first drain, the first source electrically coupled to the tank circuit and the variable capacitance circuit, and the first gate being electrically coupled to the first drain; a second MOS device having a second gate, a second source, and a second drain, the second source electrically coupled to the tank circuit and the variable capacitance circuit, and the second gate being electrically coupled to the second drain; a first input electrically coupled to the first drain and the second drain, and configured to receive a first bias voltage; and a second input electrically coupled to the first gate and the second gate, the second input configured to receive a first gate bias voltage, the first gate bias voltage operable to bias the first MOS device such that a first gate-to-source voltage of the first MOS device remains below a first threshold voltage, and to bias the second MOS device such that a second gate-to-source voltage of the second MOS device remains below a second threshold voltage, when the frequency oscillator is in operation. - View Dependent Claims (10, 11, 12, 13)
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14. A method for biasing an oscillator circuit, comprising:
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generating an oscillating output using a tank circuit electrically coupled to a varactor circuit; biasing the varactor circuit using a first MOS device having a first threshold voltage and a second MOS device having a second threshold voltage, the varactor circuit being electrically coupled to a first source of the first MOS device and to a second source of the second MOS device; biasing the first MOS device and the second MOS device with a first gate bias voltage at a first gate of the first MOS device and at a second gate of the second MOS device; electrically coupling the first gate of the first MOS device to a first drain of the first MOS device; electrically coupling the second gate of the second MOS device to a second drain of the second MOS device; and controlling a first transconductance of the first MOS device and a second transconductance of the second MOS device with a first bias voltage and the first gate bias voltage. - View Dependent Claims (15, 16, 17, 18)
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19. An apparatus for producing an oscillating frequency comprising:
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a resonating means for storing energy at a resonant frequency, the resonating means having and at least one inductor and at least one capacitor; a variable capacitance means having a first end and a second end, the first end and the second end being electrically coupled to the resonating means; a first transistor means having a first gate, a first drain, and a first source, the first source being electrically coupled to the first end, and the first gate being electrically coupled to the first drain; a second transistor means having a second gate, a second drain, and a second source, the second source being electrically coupled to the second end, and the second gate being electrically coupled to the second drain; a first biasing means electrically coupled to the first drain and the second drain; and a second biasing means electrically coupled to the first gate and the second gate. - View Dependent Claims (20, 21, 22, 23)
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Specification