Digital microwave power amplifiers for energy-efficient and wireless sub-THz communication

在移动通信(例如5G和物联网)的最新发展过程中，需要确保更高的数据速率和吞吐量。因此，由于其更高的带宽(10倍)，亚太赫兹频段越来越受到关注。这推动了对亚太赫兹(100 GHz+)能效射频微波功率放大器(RF PA)的需求。由于射频功率放大器是基站中最耗电的部分，所以当聚焦绿色信息技术时，它们是一个重要的部分。在所提出的项目中，将首次实现W波段和G波段的混合放大模块，并遵循数字方法。此外，两个射频功率放大器模块的重点都是将(降低的)信号输入功率之上的效率下降降至最低。这在具有高信号带宽的应用中是必要的，因为放大器必须在大多数时间远低于最大输入功率范围工作。有了这个项目，5G标准的进一步开发基础已经通过新的放大器架构产生，这种架构可以用非常宽带的输入信号提供相对较高的效率，而且紧凑和灵活。特别是，倍频驱动器的使用允许与传统发生器兼容的正弦输入信号。对于数字功率放大器方法，技术目标(这里指的是InP DHBT传输衬底)和建模紧密相连：除了在W频段(100 GHz)实现总效率超过50%、最大输出功率至少为100 mW的数字放大器MMIC(包括驱动器和滤波器)外，所提出的概念还显示在G频段(200 GHz)。关于在亚太赫兹范围内评估数字电路概念的重要见解值得期待。此外，应回答现有InP技术是否适合拟议的电路概念的问题。在晶体管建模中，对非周期性开关功率晶体管进行建模，以便在最高频率对宽带数字调制信号进行线性放大。为此，描述了HBT的外围(电源线、触点)，并将其优化至最高频率。阐明了连接方式对开关行为的影响和优化。同时，对参考水平的有意义的定义问题进行了研究。建模的另一个目标是建立用于开关操作的数值稳健、高效和准确的模型。为此，研究了表征的类型和建模测量工作量的任何减少。

In the course of the newest developments in mobile communications (e.g. 5G and IoT) much higher data rates and throughput need to be ensured. Thus, due to its much higher bandwidth (10x), the sub-THz frequency region is targeted more and more. This drives the need for energy-efficient RF microwave power amplifiers (RF PA) at sub-THz (100 GHz+). As the RF PA is the most power hungry part in a base station they represent an important part when focusing Green-IT. In the proposed project, for the first time hybrid amplifier modules for the W- and G-band will be realized, which follow the digital approach. In addition, the focus of both RF PA modules is on minimizing the efficiency drop above the (reduced) signal input power. This is necessary in applications with high signal bandwidths because the amplifiers must work well below the maximum input power range for most of the time. With this project, the basis for the further development of the 5G standard is already being generated with novel amplifier architectures that can potentially deliver comparatively high efficiencies with very broadband input signals and are also compact and flexible. In particular, the use of frequency multiplier drivers allows a sinusoidal input signal that is compatible with conventional generators. With the digital PA approach, the goals in technology (here: InP DHBT transfer substrate) and modeling are closely linked:In addition to the implementation of digital amplifier MMICs (including driver and filter) for the W-band (100 GHz) with a total efficiency of over 50% and a maximum output power of at least 100 mW, the proposed concept is shown at G-band (200 GHz) as well. Important insights regarding the evaluation of the digital circuit concept in the sub-THz range are expected. In addition, the question should be answered as to whether the existing InP technology is suitable for the proposed circuit concept. In transistor modeling, aperiodically switched power transistors are modeled for the linear amplification of broadband digitally modulated signals at highest frequencies. For this purpose, the periphery (supply line, contacts) of the HBT is described and optimized up to the highest frequencies. The influence and the optimization of the connections on the switching behavior are clarified. At the same time, the question of the meaningful definition of reference levels is examined. Another goal in modeling is the numerically robust, efficient and accurate model for switching operation. For this, the type of characterization and any reductions in the measurement effort for modeling are examined.