Dual-mode voltage controlled oscillator using integrated variable inductors
First Claim
1. A dual-mode voltage controlled oscillator including a dual-mode variable inductor comprising a transformer having a primary coil and a secondary coil, wherein a variable capacitance is provided in parallel to said secondary coil and a fixed capacitor or a variable capacitor is provided in parallel with the primary coil;
- and a negative gm cell connected to said primary coil for cancellation of a loss in the variable inductor, wherein, by changing the variable capacitance in parallel with the secondary coil of the transformer, a resonant frequency of the dual-mode voltage controlled oscillator changes from a from a first frequency mode to a second frequency mode.
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Accused Products
Abstract
A novel form of an integrated variable inductor uses an on-chip transformer together with a variable capacitor. The variable capacitor can either be a varactor or a switched capacitor array and is connected to the secondary coil of the transformer. By changing the capacitance at the secondary coil of a transformer, the equivalent inductance looking into the primary coil of the transformer can be adjusted. With another capacitor in parallel to the primary coil, two different modes of resonance inherently exist, and a very wide frequency tuning range can be achieved by combining the two modes.
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Citations
8 Claims
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1. A dual-mode voltage controlled oscillator including a dual-mode variable inductor comprising a transformer having a primary coil and a secondary coil, wherein a variable capacitance is provided in parallel to said secondary coil and a fixed capacitor or a variable capacitor is provided in parallel with the primary coil;
- and a negative gm cell connected to said primary coil for cancellation of a loss in the variable inductor, wherein, by changing the variable capacitance in parallel with the secondary coil of the transformer, a resonant frequency of the dual-mode voltage controlled oscillator changes from a from a first frequency mode to a second frequency mode.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
Specification