| 摘要 |
A voltage controlled oscillator of the present invention includes power supply terminal ( 101 ), control terminal ( 2 ) for controlling an output frequency, output terminals ( 3 a, 3 b), cross-coupled transistors ( 5 a, 5 b), capacitances ( 6 a, 6 b, 7 a, 7 b), LC tanks ( 10 a, 10 b), resistor ( 117 ), grounding capacitance ( 18 ) and center frequency control circuit ( 16 ). Center frequency control circuit ( 16 ) includes resistors ( 11 a, 11 b), grounding capacitance ( 12 ), center frequency control terminal ( 4 ) for controlling a center frequency of the output frequency, and voltage-divider circuit ( 15 ). Resistors ( 11 a, 11 b) are connected to the base terminals of cross-coupled transistors ( 5 a, 5 b), the other ends of resistors ( 11 a, 11 b) are connected to each other, and, to this connecting point, one end of grounding capacitance ( 12 ) and one end of voltage-divider circuit ( 15 ) are connected. The other end of voltage-divider circuit ( 15 ) is connected to center frequency control terminal ( 4 ). |
