To provide a broadband high-frequency oscillation circuit which is appropriate as a local signal generation source for a terrestrial digital broadcast relay device.
A DDS circuit 16 of a first PLL loop 10 generates a signal Fc1 of the same frequency as a reference signal using, as a system clock, the output signal of a voltage controlled crystal oscillation circuit 13 which is oscillated at a frequency higher than that of the reference signal. A phase comparator 11 compares the phases of the signal Fc1 and the reference signal, controls the voltage-controlled crystal oscillation circuit 13 and generates a reference signal Fref. Each of voltage-controlled oscillation circuits 23a-23c of a second PLL loop 20 is selected by a switching circuit 24, to generate a local signal in accordance with the reference signal Fref. A DDS circuit 26 divides the frequency of the local signal into two stages and generates, as a system clock, a signal Fc2 of the same frequency as that of the reference signal Fref. A phase comparator 21 compares the phases of the signal Fc2 and the reference signal Fref, and performs frequency control on the selected voltage-controlled oscillation circuit.
COPYRIGHT: (C)2007,JPO&INPIT
TAKASHIMA HISAMITSU
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| JPH09270706A | 1997-10-14 | |||
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Satoshi Kono
Makoto Nakamura
Kurata Masatoshi
Takashi Mine
Yoshihiro Fukuhara
Sadao Muramatsu
Ryo Hashimoto
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