| 摘要 |
PURPOSE:To expand the transmission/reception frequency band of a radio communication equipment by multiplying the 1st local signal inputted to a mixer to form the 2nd local signal and changing over the input to the mixer to the 2nd local signal. CONSTITUTION:A programmable counter 12 consists of the 1st digit part 12a and the 2nd digit part 12b. The 1st digit part 12a and the 2nd digit part 12b are inputted to a multiplier 22 in an integral number of times in response to the ratio of respective unit numbers and outputs the 2nd local signal fL2 by multiplying the 1st local signal fL1 being an output of a PLL circuit 5. In varying the signal fL1 by a frequency adjusting device 11, the variable range of the multiplied signal fL2 is also multiplied. Then the transmission/reception frequency band is expanded by changing over the input to the mixer 3 from the signal fL1 to the signal fL2. |
