Integration of RF Circuits with High Speed GaN Switching on Silicon Substrates

未来一代(5G)移动电话和其他便携式设备将需要以比目前高得多的速率传输数据，以适应用户数量的增加、多频段和多通道操作的使用、预计无线信息交换的急剧增加(如高清晰度视频)以及许多设备将连接到其他设备的连接性的大幅增加(称为物联网)。这对基站在信号保真度和提高能源效率方面的性能提出了巨大挑战，因为能源使用量可能会随着数据传输量的增加而增加。为了满足预计的大规模容量增长，对大型覆盖基站的依赖将会减少，小型基站(在较低功率水平下运行)将变得更加普遍。除了上述挑战之外，小型蜂窝将需要更多的低成本系统。为了应对这些挑战，本提案旨在使用由氮化镓(GaN)制成的电子器件，这种电子器件具有能够在非常高的频率(高数据传输率)下以非常有效的方式工作的理想特性，以减少预计的能量消耗。为了保持这些器件的高频能力，电路将被集成到单个电路中，以减少杂散电感和电容的减速效应。此外，这些集成电路将在大面积硅衬底上制造，这将显著降低系统单位成本。拟议的高水平集成使用GaN器件作为基本构建块，并结合微波和开关技术，以前从未尝试过，需要一个具有互补专业知识的多学科团队。拟议的财团汇集了在GaN晶体生长(剑桥)、器件设计和制造(谢菲尔德)、高频电路设计和制造(格拉斯哥)、可变电源设计(曼彻斯特)和高频特性和功率放大器设计(加的夫)方面拥有专业知识的英国领先集团。在设计和开发制造集成系统的技术以证明所提出的解决方案的可行性之前，需要对硅衬底上GaN晶体的质量如何影响器件的运行有深入的科学理解。总而言之，该项目中强大的团队将汇聚设计和生产新型集成电路和系统的专业知识，以满足本研究提案的苛刻目标。

Future generation (5G) mobile phones and other portable devices will need to transfer data at a much higher rate than at present in order to accommodate an increase in the number of users, the employment of multi-band and multi-channel operation, the projected dramatic increase in wireless information exchange such as with high definition video and the large increase in connectivity where many devices will be connected to other devices (called "The Internet of Things"). This places big challenges on the performance of base stations in terms of fidelity of the signal and improved energy efficiency since energy usage could increase in line with the amount of data transfer. To meet the predicted massive increase in capacity there will be a reduced reliance on large coverage base-stations, with small-cell base-stations (operating at lower power levels) becoming much more common. In addition to the challenges mentioned above, small cells will demand a larger number of low cost systems.To meet these challenges this proposal aims to use electronic devices made from gallium nitride (GaN) which has the desirable property of being able to operate at very high frequencies (for high data transfer rates) and in a very efficient manner to reduce the projected energy usage. To maintain the high frequency capability of these devices, circuits will be integrated into a single circuit to reduce the slowing effects of stray inductances and capacitances. Additionally these integrated circuits will be manufactured on large area silicon substrates which will reduce the system unit cost significantly.The proposed high levels of integration using GaN devices as the basic building block and combining microwave and switching technologies have never been attempted before and requires a multi-disciplinary team with complementary specialist expertise. The proposed consortium brings together the leading UK groups with expertise in GaN crystal growth (Cambridge), device design and fabrication (Sheffield), high frequency circuit design and fabrication (Glasgow), variable power supply design (Manchester) and high frequency characterisation and power amplifier design (Cardiff). Before designing and developing the technology for fabricating the integrated systems to demonstrate the viability of the proposed solutions, a deep scientific understanding is required into how the quality of the GaN crystals on silicon substrates affect the operation of the devices. In summary, the powerful grouping within the project will bring together the expertise to design and produce the novel integrated circuits and systems to meet the demanding objectives of this research proposal.