Analogue predistorter (APD) has gained a new significance due to the need for high bandwidth in the fifth generation (5G) communication. As predistorted signal is generated in the analogue domain, it is free from data converter bandwidth limitation and presents an attractive linearisation solution for power amplifier (PA) in the 5G base station. Furthermore, it also finds its application in the multicarrier repeater system for long-distance communication, where the baseband information is not readily available. However, the performance of the conventional APD is dependent on the appropriate control of gain and phase of the predistorted signal. The state-of-the-art work in analogue linearisation solutions mostly utilises vector multiplier for such a control. This work points out the limitations of such a scheme and proposes a novel control scheme (CS) that is capable of extracting better benefits of the APD. An experimental validation is carried out by linearising 10 W HMC8500 broadband GaN PA, excited by a eight-component carrier 160 MHz ultra-broadband long-term evolution signal. The proposed Type-II CS delivers an adjacent channel power ratio of −45.05 dBc with an improvement of 18 dB, which is 4 dB better than Type-I CS.

中文翻译：

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用于5G发射机中超宽带信号传输的模拟预失真线性化器控制方案

由于第五代（5G）通信中需要高带宽，因此模拟预失真器（APD）有了新的意义。由于在模拟域中生成了预失真信号，因此它不受数据转换器带宽的限制，并为5G基站中的功率放大器（PA）提供了一种有吸引力的线性化解决方案。此外，它还发现其在长距离通信的多载波转发器系统中的应用，在该系统中基带信息不易获得。然而，常规APD的性能取决于对预失真信号的增益和相位的适当控制。模拟线性化解决方案中的最新技术主要是将矢量乘法器用于这种控制。这项工作指出了这种方案的局限性，并提出了一种新颖的控制方案（CS），该方案能够从APD中获得更好的收益。通过线性化10 W HMC8500宽带GaN PA（由八分量载波160 MHz超宽带长期演进信号激发）进行实验验证。拟议的II型CS提供的邻信道功率比为-45.05 dBc，改善了18 dB，比I型CS高4 dB。