| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem that it is difficult for a transmitter which performs signal amplification using a class D switching amplifier used for communication fields to perform the amplification by the class D switching amplifier with high efficiency since a signal to be amplified by the class D switching amplifier is a very-high-speed signal whose sampling frequency is four times as high as a carrier frequency. <P>SOLUTION: A signal generated by multiplying an I signal or a sign-inverted Q signal by a carrier is processed at a sampling rate which is twice as high as the carrier frequency. An I component signal and a Q component signal are shifted in phase by a half of a clock, amplified by the class D switching amplifier, and supplied to one terminal and the other terminal of a two-terminal load respectively. Consequently, although the operating frequency of the class D switching amplifier is twice as high as the carrier frequency, a signal supplied to a load is a ternary signal of a sampling rate four times as high as the carrier frequency, thereby facilitating high-efficiency amplification. <P>COPYRIGHT: (C)2011,JPO&INPIT |
