| 摘要 |
PROBLEM TO BE SOLVED: To attain phase modulation at an arbitrary angle. SOLUTION: A selecting circuit 6 alternately selects an I signal and a Q signal obtained from an input carrier wave in each semicycle(1/fs) of a first switching signal. A selecting circuit 5 outputs a signal whose phase is different only by 1/fs from the output signal of the selecting circuit 6. A CPU 10 generates coefficients C1 and C2 according to the phase variation of input phase change data. The coefficient C2 is generated so as to be alternately inverted in each 1/fs, the coefficient C1 is supplied to a multiplier 7, and the coefficient C2 is supplied to a multiplier 8. The output signals of the multipliers 7 and 8 are added and synthesized by an adder 11, and a signal processed by a matrix operation for phase change is extracted. Afterwards, an analog phase modulated signal is obtained by a Pythagoras converter 15, LUT 16, multiplier 17, and D/A converter 18. |
