| 摘要 |
PROBLEM TO BE SOLVED: To produce and send AM stereo modulated waves, without using a limiter. SOLUTION: This AM stereo broadcasting transmitter 1 converts left and right sound signals which are outputted from a sound signal source 2 into a sum signal and a difference signal by a matrix circuit 3, adds direct current offset to the sum signal by an offset adder circuit 4 and performs orthogonal modulation by an orthogonal modulator circuit, which receives an output signal of the circuit 4, the difference signal and a carrier. On the other hand, it calculates the cosine value of a phase angleθbetween a vector sum signal of the output signal of the circuit 4 and the difference signal and the output signal of the circuit 4 by a cosθextraction arithmetic circuit 12, multiplies an output signal of the orthogonal modulator circuit by the cosine value of the phase angleθwith multiplier 13 and sends them as AM stereo modulated waves.
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