公开(公告)号：EP0519489B1

公开(公告)日：1997-09-10

申请号：EP92110360.2

申请日：1992-06-19

申请人： FUJITSU LIMITED

发明人： Kumagai, Yoshiaki, c/o Fujitsu Limited ,  Itaya, Eiji, c/o Fujitsu Limited ,  Endo, Yoichi, c/o Fujitsu Limited

IPC分类号： H03J7/06

CPC分类号： H03J7/047 ,  H03J7/065

公开(公告)号：EP0519489A1

公开(公告)日：1992-12-23

申请号：EP92110360.2

申请日：1992-06-19

申请人： FUJITSU LIMITED

发明人： Kumagai, Yoshiaki, c/o Fujitsu Limited ,  Itaya, Eiji, c/o Fujitsu Limited ,  Endo, Yoichi, c/o Fujitsu Limited

IPC分类号： H03J7/06

CPC分类号： H03J7/047 ,  H03J7/065

摘要： In a first embodiment of the present invention, an AFC circuit comprises a frequency divider (24) for dividing a frequency of a local oscillation signal output from a voltage controlled oscillator, and a switch (15) for selecting an output signal of the frequency divider (24) or a pilot signal extracted from converted signals. While the pilot signal is not obtained, the switch selects the output signal of the frequency divider (24), to thereby construct a PLL to stabilize the frequency of the local oscillation signal.
In a second embodiment of the present invention, an AFC circuit comprises a frequency divider for selectively dividing a frequency of a pilot signal included in the converted signal. Various frequencies of the pilot signal can be dealt with by altering a division number in the frequency divider.

摘要翻译： 在本发明的第一实施例中，AFC电路包括用于分压从压控振荡器输出的本地振荡信号的频率的分频器（24）和用于选择分频器的输出信号的开关（15） （24）或从转换的信号中提取的导频信号。 在没有获得导频信号的情况下，开关选择分频器（24）的输出信号，构成PLL以使本地振荡信号的频率稳定。 在本发明的第二实施例中，AFC电路包括用于选择性地分频转换信号中包括的导频信号的频率的分频器。 可以通过改变分频器中的分频数来处理导频信号的各种频率。