基于数字辅助技术的可重构射频接收技术

CMOS Radio frequency integrated circuits (RFIC) have entered into a nano-scale era, accompanied by continuous reduction of the power supply that brings harsh design challenges. The deep development of software-defined radio requires the front-ends with tolerance to blockers and harmonic interferences. By presenting several innovative technologies, significant technical contributions are expected in the following points: (1) several novel circuit building blockers are presented. Optimization strategies for noise, linearity, and bandwidth of the nano-scale circuits are to be established. And we then utilize the proposed strategies to optimize our designs with excellent performance.② aiming at the harmonic interference issue in wideband receiving, we explore a new type of harmonic rejection technology, using the current mode method to handle the linearity degradation by reduced supply voltage. Noise cancellation after frequency conversion guarantees the receiver’s superiority in noise figure.③ the reconfigurable receiving front-end is digitally controlled/corrected/tuned. For example, dual band switching in low-noise amplifier and mixer module is digitally controlled; the current recombination factor in the harmonic rejection channel is digitally tuned; IP2/flicker noise of the receiving chain is digitally corrected, etc. Ultimately, the receiver features low noise, high linearity, anti-interference, reconfiguration, etc. The project is of innovativeness and practical value.

CMOS射频集成电路已进入纳米尺度时代，与之相伴的是电源电压不断降低带来设计上严峻挑战；软件无线电技术向纵深发展又对射频接收前端提出了抗阻塞干扰，谐波抑制等苛刻要求。通过若干创新性技术，课题有望在以下方面取得突破性成果：①在单元电路层面，尝试建立新型的单元电路结构，并探索纳米尺度下电路噪声、线性度、带宽设计优化策略。进而应用优化设计获得高性能优值。②在射频技术层面，针对宽带接收的谐波干扰症结，探索新型谐波抑制接收技术。使用电流模式理念，以应对电源电压减小带来的线性度退化挑战；变频后噪声消除保证了优越的噪声指数；③在数字辅助技术层面，对可重构性接收前端进行数字控制/校正/调谐。包括：低噪放、混频器模块频带之间的控制切换等，谐波抑制通道中的电流比例系数控制调谐，接收链路的IP2/闪烁噪声校正等。最终实现整个接收通道的低噪声、高线性、抗干扰、可重构等技术特征。项目具有创新性和实用价值。

CMOS射频集成电路已进入纳米尺度时代，晶体管特征截止频率得以不断提高，同时伴随着电源电压不断降低带来设计上的挑战；软件无线电技术向纵深发展又对射频接收前端提出了抗阻塞干扰，谐波抑制等苛刻要求。本项目通过长期研究探索，在相关技术领域获得了如下进展突破：①在模块电路层面，设计提出了高线性低噪声的宽频带低噪声跨导放大器，并对噪声、线性度、带宽性能做了完整的理论分析，和仿真验证。分析了开关跨导混频器电路的闪烁噪声机理，对各个噪声源做了相关的传递函数分析模拟建模。最后给出一个半解析的噪声预测模型，来指导混频器的低噪声设计。进一步地，还实现了一款B类模式工作的低噪声开关跨导混频器电路设计。结合时域的充放电效应，深入研究了噪声，工作频率的折中约束关系。并给出了如何缓解该性能约束的电路解决方法。在此基础上又论证了本振激励下，正弦波形和脉冲波形的优劣。②在射频接收技术层面，在重点关注接收通道的低噪声、高线性、抗干扰、可重构技术特征基础上，针对不同的无线通信场景，陆续提出了若干不同技术特征的射频接收机前端电路，具体包括：1-6 GHz内嵌巴伦结构的接收机前端；大基带带宽，抗阻塞干扰的混频器前置接收机前端；数字辅助可重构的双通道射频接收机前端；低中频极低功耗蓝牙接收机前端电路。项目发表SCI期刊论文11篇（含IEEE TCAS1），会议论文9篇(含IEEE RFIC Symp. )，申请发明专利10项。培养硕士研究生8名，对于当前的无线移动通信网、物联网、低功耗蓝牙通信等领域，项目取得的成果具有较高的科学指导意义和工程实用价值。