| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a multiple PLL oscillator for a millimeter frequency band that decreases a lockup time until an oscillated frequency reaches a desired frequency even when the number of frequency divisions is increased. <P>SOLUTION: The multiple PLL oscillator uses a switch 13 to select either of reference frequency sources 11, 12 and uses the signal from the selected source for a reference frequency signal, and a phase comparator 14 compares the phase of the reference frequency signal with a phase of an output of a frequency divider 19 and controls a voltage-controlled oscillator 16 as a result of the comparison. A mixer 17 mixes an output of the voltage-controlled oscillator with an output of another reference frequency source 18, an upper side band output signal of the mixer 17 is used for an output of the multiple PLL oscillator and a lower side band output signal of the mixer 17 is given to the frequency divider 19. <P>COPYRIGHT: (C)2004,JPO |
