PURPOSE: To pull-in stably a frequency in a wide frequency range by setting a required offset voltage corresponding to a desired frequency to a loop filter in a phase locked loop.
CONSTITUTION: The output of a synthesizer 10 which generates a reference signal to give a frequency and a phase in a rough step is supplied to a high frequency mixer 4, and the output of a synthesizer 60 which transmits a reference signal to give a frequency and a phase in a fine step is supplied to a phase comparator 7. The phase locked loop is formed with a voltage control microwave oscillator 2, the mixer 4, an intermediate frequency amplifier 5, the phase comparator 7, and a loop filter 15. A frequency is designated in a rough step by an operation controller of the filter 15, and a control voltage of the oscillator 2 which is required for generation of this frequency is calculated and is preset as the offset voltage to the filter 15. Frequencies for synthesizers 10 and 60 are calculated, and control voltages are transmitted individual synthesizers.
| JP2848156 | VARIABLE FREQUENCY TYPE HIGH FREQUENCY OSCILLATOR CIRCUIT |
| WO/2002/089405 | FIBRE CHANNEL TRANSCEIVER |
| JPH03114318 | MICROWAVE SYNTHESIZER |
YAMAZAKI TOYOE
IGARASHI TAKAHARU
