| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a frequency synthesizer which has a high reference frequency, easily suppresses a phase noise, and has a small circuit scale and consumption power in a broadcast system which has an assigned bandwidth equivalent to a bandwidth such as terrestrial digital television broadcast. <P>SOLUTION: A signal of 16MHz generated by a quartz oscillator 1 is divided into 1/224 by a fixed frequency divider 2 and a reference frequency of 1/14MHz is obtained. The reference frequency becomes 1/n times(n:integer)(1/9) of 9/14 MHz being a value obtained by subtracting an offset of 1/126 MHz from 1/7 + 32/63 = 41/63 MHz. By a phase synchronization loop comprising the fixed frequency divider 2, a phase comparator 3, a loop filter 4, a voltage control oscillator 5, and a phase comparator 6, an output frequency to be 6N + 473 + 1/7 + 1/2 MHz in which the offset is set to a predetermined oscillation frequency 6N + 473 + 1/7 + 32/63 MHz is obtained. Thus, it is possible to set a high reference frequency 1/14 MHz. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
