Patent ID: 6759915
Filing Date: 2004-07-06
Classification: H03B

Abstract:
A multi-band, voltage-controlled oscillator comprising:an oscillating transistor; a resonant circuit coupled between a base and a collector of said oscillating transistor, said resonant circuit including an inductor and a capacitor coupled in parallel with each other, wherein said inductor comprises a serial assembly having a first inductor and a second inductor coupled in series with each other, and said capacitor comprises a variable-capacitance diode; a buffer transistor coupled to an output of said oscillating transistor; a first output port coupled to an output of said buffer transistor; a control port adapted to supply a control voltage to said variable-capacitance diode; a first switching device operable to selectively open and short-circuit both ends of said second inductor; a negative source generator coupled to the output of said buffer transistor; a second switching device operable to selectively switch switching between an output of said negative source generator and a positive source; a mode switching circuit adapted to receive an output frequency switching signal from outside said multi-band, voltage-controlled oscillator; and a package including said oscillating transistor, said buffer transistor, said negative source generator circuit, and said mode switching circuit integrated therein, wherein said second switching device issues an output to control an opening and short-circuiting operation of said first switching device to select an oscillation output at a first output frequency and an oscillation output of a second output frequency released from said first output port, the second output frequency being different from the first output frequency.