| 摘要 |
<P>PROBLEM TO BE SOLVED: To realize high-speed sweep speed which cannot be conventionally obtained, and to supply a correct frequency sweep signal. <P>SOLUTION: A switch 4 is switched to an (a) side, and phase locking is applied to each of ten frequency points in total ranging from a sweep start frequency fmin to a sweep finish frequency fmax. Ten VCO control input voltages V<SB>CNT</SB>acquired for each of the frequency points are stored in a memory 12. Next, the switch 4 is to a (b) side, thereby separating a VCO 5 from a PLL. Then, adjacent two voltages are sequentially read from among the ten VCO control voltages V<SB>CNT</SB>stored in the memory 12, and linear interpolation operation is performed so that the predetermined number of points may come within between these two voltages. These interpolation point voltages are sequentially read from the memory 12 in an order of frequency, and the read voltages are supplied to the (b) terminal of the switch 4. A frequency signal corresponding to this voltage is outputted from the VCO 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
