Q波段高速宽带无线通信发信机的关键技术研究

Q band is one of the key frequency spectrum for the evolution of high-speed wideband wireless communication systems in China. Due to the limitation of semiconductor process, power amplifiers (PAs) normally exhibit low efficiency and output power, which cannot satisfy the requirements of Q-band wireless communication transmitters excited by high Peak-to-average power ratio signals. Meantime, envelope tracking (ET) PA receives more and more attention, since it can significantly improve the PA’s efficiency at backed-off power. However, very few studies have explored the high-efficiency wideband PA with high linearity in the scenario of millimeter wave frequency band. Hence, the research on Q-band ET PA will have important theoretical and practical values.. This project will focus on the development of Q-band ET PA technique. The novel envelope bandwidth reduction method and multi-envelope generation technique will be proposed to satisfy the requirements for the wideband transmitters. The nonlinear behavioral model for Q-band ET PA will be constructed. Moreover, considering the memory effects, the model will build the relationships between the gain, efficiency, output power and the drain voltage, gate bias, input signal, in order to enhance PA’s efficiency and thus optimize the overall performance of the transmitter. Also, the digital predistortion model and linearization architecture will be investigated to improve the linearity of the ET PA, mainly based on envelope bandwidth reduction and multi-envelope generation technique. Finally, a prototype of the Q-band high-efficiency wideband ET PA with high linearity will be built to validate the proposed techniques.

Q波段是我国高速宽带无线通信系统的重点发展频段之一.但受半导体工艺的限制，功率放大器的效率和输出功率低，无法满足采用高峰均比信号的Q波段无线通信发信机的需求。而包络跟踪（ET）功率放大器因其能提高功率回退时的效率而倍受关注.目前对毫米波段宽带、高效、线性功放技术的研究尚处于起步阶段，因此研究Q波段ET技术具有重要的理论意义和实用价值。.本项目将专注于研究Q波段ET功放新的包络带宽削减技术，多包络合成技术，以满足发信机的超大带宽要求；研究ET功放的非线性行为模型，考虑记忆效应的影响，提出漏极电压，偏置状态和输入信号与ET功放整体增益，效率和输出功率的关系，提高功放效率，优化发信机的整体性能；研究针对于包络带宽削减和多包络合成技术的数字预失真模型和预失真器结构，用于提升ET功放线性度。最终将完成Q波段高效、宽带、线性化ET功率放大器的研制。

Q波段是我国高速宽带无线通信系统的重点发展频段之一，也是5G毫米波通信系统，以及未来6G通信系统的候选频段，由于波长短、尺寸小、受半导体工艺限制等因数，系统和电路设计难度大、工艺要求高。线性输出功率小、效率低，无法满足当今宽带高峰均比信号传输的需求。因此，本项目的研究对毫米波段宽带、高效无线通信发展具有重要的理论意义和技术支撑作用。.本项目的研究重点集中在Q波段包络跟踪（ET）功率放大器，包括高效率电源调制器、宽带功率放大器和功率合成放大器；Q波段高速宽带无线通信发信机及关键电路模块，包含多种SIW平面集成滤波器、功分器等；低相位噪声振荡器和锁相源；多波束天线阵列及单元，包括渐变长度梳状齿加载和二阶感性窗加载的TSA天线阵列、超表面加载的4×4圆极化贴片天线阵列；ET功放的非线性行为建模及其数字预失真技术（DPD），研究了包络带宽削减技术、基于DVR技术的改进SVR模型，并提出了有效的DPD模型和算法；还研究了受天线串扰影响大规模阵列的空口测试DPD技术。.在研究过程中，发表学术论文35篇，申请发明专利9项；重要的研究成果主要体现在Q波段高速宽带无线通信发信机实现500Mbps宽带调制信号的传高速输，功率合成放大器的合成效率达到88%，输出功率大于28dBm，ET功率放大器整体效率为 41.7%（9-dB回退），包络信号带宽削减到信号调制带宽的1.2倍，DPD后ACPR低于-45dBc；高次模耦合的SIW滤波器插入损耗小于1.9dB、带外抑制大于40dB，空气腔SIW振荡器的相位噪声达到-118 dBc/Hz@1MHz；TSA阵列天线的带宽为38.9~44.5GHz，增益达到13.4dBi；超表面加载的4×4圆极化贴片天线阵列的带宽37.4~52.2 GHz，增益为18.2 dBi；用于ET功放DPD的SVR模型，相比DVR模型精度提升2dB。