| 摘要 |
In a polar modulation system, there is disclosed a polar-modulation transmission device, which can be dispensed with an isolator thereby to suppress a circuit scale and the heat loss of a power amplifier. In this device, a current detecting unit (130) detects a current value (Icc) to flow from a power source voltage transforming unit (120) to a power amplifier (180), and a power control unit (140) inputs a power control signal (S30) and outputs a control signal (S31) to a power applying unit (150) on the basis of the current value (Icc). The power applying unit (150) multiplies a baseband amplitude modulation signal (S11) by the control signal (S31) thereby to produce an amplitude modulation signal (S13). A regulator (160) feeds a power source voltage (S22), which is changed from a power source voltage (S21) by the amplitude modulation signal (S13), to a power amplifier (180). This power amplifier (180) amplifies the power of a phase modulation high-frequency signal (S14) by using the power source voltage (S22) as a power source, thereby to acquire an RF transmission signal (S15). |
