Capacitive-degeneration double cross-coupled voltage-controlled oscillator
First Claim
1. A voltage-controlled oscillator comprising:
- a main cross-coupled oscillating unit including first and second transistors cross-coupled to first and second output nodes of a resonating unit to perform an oscillation operation; and
an auxiliary cross-coupled oscillating unit including third and fourth transistors cross-coupled to the first and second output nodes and the first and second transistors and a degeneration capacitor connected between emitters of the first and second transistors so as to form a positive-feedback loop capable of increasing a negative resistance and decreasing an input capacitance by the positive-feedback loop,wherein the positive-feedback loop is contributed to by the first transistor, the fourth transistor, the degeneration capacitor, the third transistor and the second transistor,wherein the auxiliary cross-coupled oscillating unit comprises;
the third transistor having a collector connected to the base of the first transistor and a base connected to the emitter of the second transistor;
the fourth transistor having a collector connected to the base of the second transistor and a base connected to the emitter of the first transistor;
the degeneration capacitor connected between emitters of the third and fourth transistors; and
a first current source connected to emitters of the third and fourth transistors.
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Accused Products
Abstract
A capacitive-degeneration double cross-coupled voltage-controlled oscillator is provided. The capacitive-degeneration double cross-coupled voltage-controlled oscillator includes a main cross-coupled oscillating unit including an oscillation transistor pair cross-coupled to first and second output nodes of a resonating unit to perform an oscillation operation; and an auxiliary cross-coupled oscillating unit including a positive-feedback transistor pair cross-coupled to the first and second output nodes and the transistor pair of the main cross-coupled oscillating unit and a degeneration capacitance connected between emitters of the positive-feedback transistor pair so as to increase a negative resistance of the main cross-coupled oscillating unit. Accordingly, it is possible to increase a maximum attainable oscillation frequency and to decrease an input capacitance.
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Citations
13 Claims
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1. A voltage-controlled oscillator comprising:
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a main cross-coupled oscillating unit including first and second transistors cross-coupled to first and second output nodes of a resonating unit to perform an oscillation operation; and an auxiliary cross-coupled oscillating unit including third and fourth transistors cross-coupled to the first and second output nodes and the first and second transistors and a degeneration capacitor connected between emitters of the first and second transistors so as to form a positive-feedback loop capable of increasing a negative resistance and decreasing an input capacitance by the positive-feedback loop, wherein the positive-feedback loop is contributed to by the first transistor, the fourth transistor, the degeneration capacitor, the third transistor and the second transistor, wherein the auxiliary cross-coupled oscillating unit comprises; the third transistor having a collector connected to the base of the first transistor and a base connected to the emitter of the second transistor; the fourth transistor having a collector connected to the base of the second transistor and a base connected to the emitter of the first transistor; the degeneration capacitor connected between emitters of the third and fourth transistors; and a first current source connected to emitters of the third and fourth transistors. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A voltage-controlled oscillator comprising:
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a main cross-coupled oscillating unit including first and second transistors cross-coupled to first and second output nodes of a resonating unit to perform an oscillation operation; and an auxiliary cross-coupled oscillating unit including third and fourth transistors cross-coupled to the first and second output nodes and the first and second transistors and a degeneration capacitor connected between emitters of the first and second transistors so as to form a positive-feedback loop capable of increasing a negative resistance and decreasing an input capacitance by the positive-feedback loop, wherein the positive-feedback loop is contributed to by the first transistor, the fourth transistor, the degeneration capacitor, the third transistor and the second transistor, and wherein the auxiliary cross-coupled oscillating unit comprises; the third transistor having a collector commonly connected to the base of the first transistor and the second output node and a base connected to the emitter of the second transistor; the fourth transistor having a collector commonly connected to the base of the second transistor and the first output node and a base connected to the emitter of the first transistor; a first current source connected to emitters of the third and fourth transistors; and wherein the degeneration capacitor is connected between emitters of the third and fourth transistors.
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8. A voltage-controlled oscillator comprising:
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a resonating unit having first and second output nodes; a main cross-coupled oscillating unit configured to cooperate with the resonating unit and perform an oscillation operation, the main cross-coupled oscillating unit including; a first transistor having a first base coupled to the first output node and a first collector coupled to the second output node, and a second transistor having a second base coupled to the second output node and a second collector coupled to the first output node; and an auxiliary cross-coupled oscillating unit configured to form a positive-feedback loop with the main cross-coupled oscillating unit in order to increase a negative resistance of the main cross-coupled oscillating unit, the auxiliary cross-coupled oscillating unit including; a third transistor having a third collector coupled to the first base of the first transistor and a third base coupled to a second emitter of the second transistor, wherein the third base is configured to receive a signal from the second emitter, and a fourth transistor having a fourth collector coupled to the second base of the second transistor and a fourth base coupled to a first emitter of the first transistor, wherein the fourth base is configured to receive a signal from the first emitter. - View Dependent Claims (9, 10, 11, 12, 13)
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Specification