| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a voltage controlled oscillation circuit capable of adjusting the suppression of nonuniformity in output characteristics regardless of manufacturing nonuniformity in the characteristics of a configuration element through the use of a simple circuit constitution, and to provide its adjustment method. <P>SOLUTION: A low-pass filter 15 and a high-pass filter 16 are constituted of an element with a structure being the same as that of the element which constitutes a voltage control oscillation circuit 11, so as to obtain prescribed correlation. A correction element 14 is connected in parallel with a main element, to which an oscillation frequency control signal VT is input, in the voltage control oscillation circuit 11. Frequency-gain characteristics of the low-pass filter 15 and the high-pass filter 16 are intersected, having mutually opposite inclinations at a target gain value TG. In the case of the nonuniformity of low capacity values, an output signal SL2 is larger in output level than an output signal SH2 in a reference frequency fREF. Thus, an output level difference LD2 is generated, so as to output an adjustment signal VCNT 2 corresponding to the LD2. Then, an oscillation frequency fVCO is made to be lower. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
