发明名称 |
AM TRANSMITTER AND MODULATION METHOD USING SAME |
摘要 |
An AM (Amplitude-Modulated) transmitter capable of improving modulation distortion is provided. An adder adds a modulation signal to a pre-set power reference signal. An APC (Automatic Power Control) amplifier compares a level of a detecting signal outputted by the LPF (Low Pass Filter) with a level of an adder signal. The APC amplifier, based on the comparison result, generates a gain controlling signal that makes a difference between a level of the detecting signal and level of the signal approach zero and feeds the gain controlling signal to a power amplifier. The power amplifier modulates the signal outputted from the amplifier by the gain controlling signal and power-amplifies the modulated signal according to a level of the gain controlling signal. Since the APC amplifier feeds the gain controlling signal to the power amplifier, a modulation degree does not depend on a nonlinear distortion characteristic of the power amplifier. |
申请公布号 |
CA2636481(C) |
申请公布日期 |
2014.06.03 |
申请号 |
CA20082636481 |
申请日期 |
2008.06.27 |
申请人 |
ICOM INCORPORATED |
发明人 |
MATSUO, SHIN-ICHI;IWATA, HIROKAZU;KINUGAWA, FUMINORI |
分类号 |
H04B1/04;H03C1/02;H03C1/06;H03F3/68;H03G3/20 |
主分类号 |
H04B1/04 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|