| 摘要 |
<p>There is provided a voltage control oscillator constituting a resistance division circuit by a switch element for modifying a control voltage gain and a reference value so as to reduce the IC chip area, reduce the AFC voltage noise, and improve C/N. The voltage control oscillator (100) includes: reference bias voltage generation means (20) for generating a reference bias voltage by adjusting the reference voltage; a gain adjusting circuit (21) for adjusting the gain of the control voltage; and an oscillation circuit (22). It should be noted that the reference bias voltage generation means (20) includes resistors Rd, Re, Rf, Rg connected in series between VREF and the ground, and switches SW_AR1, SW_AR2 connected in parallel to the resistors Rd and Re, respectively. The gain adjusting circuit (21) includes three resistors Ra, Rb, Rc, switches SW1 to SW6, and inverters INV1, INV2. The oscillation circuit (22) includes a varactor (23) assuming an oscillation circuit of Kolpitz type.</p> |
