| 摘要 |
Disclosed is an oscillator circuit (1A) for use in a local oscillator of an RF communications device (100) that communicates over an RF channel. The oscillator circuit includes an oscillator circuit portion (2) and a bias circuit portion (3) coupled to the oscillator circuit portion for setting the operating point of the oscillator transistors. The oscillator circuit further includes a switch (6) for selectively one of connecting or disconnecting the bias circuit portion from the oscillator circuit portion, and a capacitance (5) for storing an output of the bias circuit portion during a time that the switch disconnects the bias circuit portion from the oscillator circuit portion, thereby maintaining control of the operating point of the oscillator transistors of the oscillator circuit portion. When the switch is open any noise generated by the biasing circuit portion is prevented from reaching the oscillator circuit portion, thereby reducing the overall noise floor of the oscillator circuit. The capacitance may have a value that is measured in tens of picofarads, and the oscillator circuit, including the capacitance, is formed within an integrated circuit.
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