| 摘要 |
PURPOSE:To simplify a circuit and to reduce the power consumption by detecting a frequency difference signal of 1st and 2nd local oscillation sections and giving the frequency difference signal to a frequency divider. CONSTITUTION:A frequency difference signal generating means C in the local oscillation circuit of the double conversion system having a 1st local oscillation section A and a 2nd local oscillation section B detects the frequency difference signal of the oscillation sections A and B. The means C gives the frequency difference signal to a frequency dividing means D, which frequency-divides the frequency difference signal. A control means E controls an oscillating frequency of the oscillation section B. Thus, even when a frequency synthesizer itself is formed to have a high frequency, the frequency input in the operationable range is given to the means D. Since the oscillating frequency multiplication degree is minimized, the circuit constitution is simplified and the power consumption is reduced. |
