摘要 |
An inexpensive variable inductor has inductance value continuously changeable without reducing a Q value. When a control voltage is applied to a control terminal of a MOS transistor from a power supply, a continuity region is formed in a channel, and a region between main terminals becomes conductive. When the control voltage is changed, length of the continuity region in the channel is changed. This changes length of a path area of an induced current, flowing in an induced current film. Thus, the amount of induced current is increased or decreased. Therefore, when the control voltage of the MOS transistor is changed, the inductance value of the coil is continuously changed. |