| 摘要 |
<p>PROBLEM TO BE SOLVED: To suppress with inexpensive and simple configuration the deterioration of reception characteristics due to the leakage of a transmission carrier at reception by miniaturized radio equipment. SOLUTION: An oscillator 1 oscillates an oscillation signal having a 2/3-times oscillation frequency as high as the local frequency of a local signal to be inputted to a quadrature modulator 6. A 1/2 frequency divider 3 divides the oscillation frequency of the oscillation signal into two stages and outputs the signal of a frequency divided into two stages. A 3-multiplier 4 multiplies the frequency of the signal, having the frequency divided into two stages by 3 and outputs a 3-multiplied signal. The 3-multiplied signal is supplied to the quadrature modulator 6 as the local signal. At reception, the frequency dividing operation of the 1/2 frequency divider 3 is stopped but at the time of transmission, the required local signal is provided by performing the frequency dividing operation at the 1/2 frequency divider 3. In addition, a 1/5 frequency divider 10 divides the oscillation frequency of the oscillation signal output from the oscillator 1 into 5 stages and supplies the signal of the frequency divided into 5 stages to a second mixer 25 at a reception part as a second local signal.</p> |
