Transformer Based Filter for Complementary Oscillator Circuitry
AssigneeApple Inc.
InventorOmar E Elaasar
Life of this patent
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Abstract
An electronic device may include wireless circuitry having an oscillator. The oscillator can include a pair of n-type transistors coupled to a first tail node, a pair of p-type transistors coupled to a second tail node, a load inductor coupled between the pair of n-type transistors and the pair of p-type transistors, a load capacitor coupled between the pair of n-type transistors and the pair of p-type transistors, a tunable capacitor, and a first transformer coupled between the first tail node and the tunable capacitor. The oscillator can further include a second transformer coupled between the second tail node and the tunable capacitor. The tunable capacitor can include multiple differential switchable capacitor circuits.
Claims20
Circuitry comprising:
- a first n-type transistor coupled to a first tail node;
- a first p-type transistor coupled between the first n-type transistor and a second tail node;
- a first transformer coupled to the first tail node;
- a second transformer coupled to the second tail node;
- and
- a tunable capacitor having a first terminal coupled to the first transformer and a second terminal coupled to the second transformer.
Oscillatory circuitry comprising:
- a first pair of cross-coupled transistors coupled to a first tail node;
- and
- a first transformer having a first tail coil coupled to the first tail node and a first filter coil inductively coupled to the first tail coil;
- and
- a tunable capacitor directly coupled to the first filter coil.
Oscillator circuitry comprising:
- a first pair of cross-coupled transistors coupled to a first tail node;
- a first transformer coupled between the first tail node and a first power supply line;
- and
- a second transformer coupled to the first transformer and to a second power supply line different than the first power supply line.
Dependencies are inferred from the claim text.