三阶交调

最后借助ADS软件对所设计功放的三阶交调系数及效率等指标进行仿真分析，并完成了射频功放电路参数及性能的总体优化设计。

Finally , the third-order intermodulation coefficient and efficiency of the RF PA are simulated by use of ADS and the circuit parameters and performance of the RF PA are optimal designed .

应用CAD软件对电路进行仿真和优化，最后完成电路制作并给出了结果.测试结果为增益12dB，输出功率30dBm，三阶交调45dBc。

Simulation and optimization of the circuit by means of a microwave CAD software are presented , giving a circuit with a 12 dB gain , 30 dBm output power , and the third-order inter-modulation of 45 dBc .

谐波插入方法对中频三阶交调产物抑制作用明显。

The third intermodulation products be decreased obviously .

采用了功率回退法和前馈法，使本功率放大器的三阶交调优于51dBc。

Using power back and feedforward methods , the IM_3 of this power amplifier is better than 51 dBc .

此外，由于电光调制器的传输曲线为非线性的正弦函数，所以在输出信号中会产生高阶谐波项和三阶交调分量，这将严重影响系统的无杂散动态范围。

In addition , due to the sinusoidal transfer function of the intensity modulator , the higher-order harmonics and intermodulation components are generated , which reduces the spur-free dynamic range ( SFDR ) of the APLs .