Patent ID: 8717112
Filing Date: 2014-05-06
Classification: H03B

Abstract:
1. An inductance-capacitance (LC) oscillator, comprising: a first varactor cell, providing a first variable capacitance to tune a frequency of a first differential oscillation signal generated by the LC oscillator, and outputting the first differential oscillation signal; a first transistor, coupled between a core dc supply voltage and a first terminal of the first varactor cell; a second transistor, coupled between a ground potential and a second terminal of the first varactor cell; and a first pair of differential transformers, connected in cascade with the first transistor and the second transistor between the core dc supply voltage and the ground potential, for increasing an output swing of the first differential oscillation signal, and making a current flowing through the first transistor to be reused by the second transistor, wherein the first pair of differential transformers provides a feedback action, such that under the feedback action provided by the first pair of differential transformers, voltages on a drain and a source of each of the first and the second transistors have the same phase.