| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inexpensive solution having an improved performance in spectrum purity, ease of implementation and stability of control of an interme diate frequency (IF) signal. <P>SOLUTION: In the tuner for converting a radio frequency signal to the IF signal and having a voltage converter for supplying a control signal and a mixer related with an oscillator voltage-controlled by the control signal, the voltage converter is provided with an auto-oscillating circuit for generating an ac voltage signal of a variable level, a rectifying means for supplying a dc voltage signal of a variable level based on the ac voltage signal of a variable level and an additional circuit for reducing the variations of the attenuation coefficient of the auto-oscillating circuit, and this additional circuit receives the dc voltage signal of the variable level and supplies the control signal. <P>COPYRIGHT: (C)2003,JPO |
