Patent ID: 6985701

Claim:
A frequency synthesizer comprising: a first synthesizer which outputs signal of which frequency is within one of a plurality of frequency bands; a second synthesizer which outputs a fixed frequency signal; a first mixer which mixes the signal output from the first synthesizer with the fixed frequency signal output from the second synthesizer; a first divider which divides a signal output from the first mixer by a first division ratio; a second divider which divides the fixed frequency signal output from the second synthesizer by a second division ratio; a second mixer which mixes the signal output from the first synthesizer with a signal output from the second divider; a third divider which divides a signal output from the second mixer by a third division ratio to output a signal to be used as a first local signal; and a switch which outputs either a signal output from the first divider or a signal output from the third divider as a second local signal.