| 摘要 |
A voltage controlled oscillator 100 comprises an inductor circuit including inductors 101, 102; a variable capacitance circuit 110 which includes variable capacitance elements 111, 112 for changing a capacitance value in accordance with a voltage difference between both of two terminals thereof and capacitive elements 113, 114 for cutting a DC component, and which is connected in parallel to the inductor circuit; a negative resistance circuit including cross-coupled oscillating transistors 103, 104; and a time-switched level shift circuit 108 for shifting a reference voltage to be output to two or more levels in accordance with time. A connection point A of the variable capacitance elements is supplied with a control voltage Vt for controlling an oscillation frequency, and connection points B, C of the variable capacitance elements and the capacitive elements are supplied with a reference voltage Vref output from the time-switched level shift circuit 108 via resistors 115, 116. |
