一种双路矢量合成式毫米波预失真线性化器

针对目前行波管放大器模拟预失真技术中存在的幅度和相位特性关联性强的问题,提出一种双路矢量合成式预失真器。该预失真器由90°电桥、模拟电调衰减器和反射式二极管预失真电路构成。根据理论分析和ADS软件仿真结果加工了实际电路并进行测试。实测结果表明:在工作频率29~31GHz和额定输入功率区间内,该电路可实现与行波管特性相反的预失真性能;合理调整两支路偏置电压,可实现相位扩张改变30°,而增益扩张变化量小于1dB的性能,有效减小了模拟预失真器幅度和相位特性的关联性。

A dual-branch vector synthesis millimeter-wave predistortion linearizer

In view of the strong correlation between amplitude and phase characteristics of Traveling Wave Tube Amplifier (TWTA) analog predistortion technology, a dual-branch vector synthesis predistortion linearizer is proposed, which consists of branch line hybrid couplers, an adjustable attenuator and a reflective diode-based predistortion circuit. This linearizer is fabricated and measured according to the theoretical analysis and simulation results. The measurement results show that the linearizer can compensate the nonlinearity of the TWTAs. Once the two branches bias voltages are rationalized, the phase expansion can change 30 degrees, while the change of the amplitude expansion is less than 1 dB, which effectively reduces the correlation between the amplitude and the phase characteristics of the analog predistortion linearizer.