| 摘要 |
PROBLEM TO BE SOLVED: To provide a local oscillation circuit which can prevent the occurrence of frequency fluctuation by improving the isolation between a plurality of synthesizers and is suitable for TDMA radio equipment. SOLUTION: The synthesizer output S1a from a frequency synthesizer 1A becomes a local oscillation signal S2a through a multiplying circuit 20A which multiplies the output S1a by 3/2. The synthesizer output S1b from another frequency synthesizer 1B becomes another local oscillation signal S2b through a multiplying circuit 20B which multiplies the output S1b by 3/2. An output selection switch 40A alternately selects and outputs the synthesizer outputs S1a and S1b as a local oscillation signal S4a for output at every TDMA time slot upon receiving a switch signal S3a from the control section of radio equipment. The switch signal S3a disconnects the power supply from a local oscillation power source 30A to the multiplying circuits 20 when the circuits 20 generate nonselected local oscillation signals S3. |
