Boosting Efficiency in Mm-Wave III-V Power Amplifiers

毫米波段的几个大众市场应用正在涌现，包括5G、卫星通信和移动基础设施(回程)。考虑到发射机(有源阵列)的复杂性增加，在这些频率下更能感受到对高效功率放大器的需求；这与在毫米波频率下设计的内在困难形成了鲜明对比。此外，高效的功率放大器设计必须依赖于精确的波形工程，其在毫米波频率下的可行性仍有待开发。与硅基放大器相比，III-V技术具有在性能方面提供提升的潜力。然而，在毫米波频率，更好地了解波形方面的非线性操作是实现更复杂的设计技术以及反馈到晶体管设计以优化操作的关键。卡迪夫大学高频工程中心最近获得了具有110 GHz带宽和波形测量能力的GB 1.4M谐波负载-拉动表征系统。其想法是利用该系统来表征、比较和模拟由Qorvo提供的毫米波晶体管样品(GaN和GaN)。这将使我们能够探索和定义实现高效率的最佳功率放大器设计技术，以及了解如何改进器件以提高性能。开发的技术将在GaAs和GaN上的MMIC设计上进行测试。

Several mass market applications are emerging in mm-wave bands, including 5G, satcom and mobile infrastructure (backhaul). The need for efficient power amplifiers is even more felt at these frequencies given an increased complexity of the transmitters (active arrays); this is in contrast with the intrinsic difficulty of designing at mm-wave frequencies. Moreover, efficient power amplifier design must rely on accurate waveform engineering whose feasibility at mm-wave frequencies is still unexplored.III-V technologies have the potential of offering a boost in terms of performance compared to Si-based amplifiers. However, at mm-wave frequencies, a better understanding of non-linear operation in terms of waveforms is key in enabling more sophisticated design techniques as well as feeding-back to the transistor design o optimise operation.The Centre for High Frequency Engineering at Cardiff University has recently acquired a £1.4m harmonic load-pull characterisation system with 110 GHz bandwidth and waveform measurement capability. The idea is to exploit the system to characterise, compare and model mm-wave transistors samples provided by Qorvo (GaAs and GaN). This will enable to explore and define the best power amplifier design technique to achieve high efficiency, as well as understanding how the devices can be improved to improve the performance. The technique developed will be tested on MMIC designs on GaAs and GaN.