用于无线体域/个人网的低功耗低成本超宽带调频收发机设计研究

Frequency modulated ultra-wideband (FM-UWB) technology has shown promising features for short-range and low-data-rate wireless communications, and has been considered as a good candidate for medical electronics, wireless personal area network (WPAN) and wireless body area network (WBAN) applications, due to high penetration capability, low radiated power, low hardware complexity, and low power dissipation, etc. This project focuses on the design implementation and efficiency optimization of FM-UWB transceivers, with the following innovations...With switched-capacitor based V-to-I converter and slew-rate controlled relaxation oscillator, the subcarrier generation employs high-robust open-loop architecture to accomplish traditional closed-loop FSK modulation. The low-power dual-path RF ring oscillator achieves, not only current-controlled RF frequency modulation via the differential V-to-I module of analogue path, but voltage-controlled carrier-frequency correction by the binary-weighted digital path, together with the successive approximation register logic based automatic frequency calibration (AFC) loop. Regenerative architecture based on differential slope frequency detectors, employs two symmetric detuning band-passed filters (BPFs) to recover the subcarrier frequency components with high linearity. The subsequent FSK demodulator based on low-complexity energy discrimination, digitally reconstructs the baseband data. To improve the FM-UWB transceiver efficiency, both the dynamic power control method enabling the transceiver with low-duty-cycled intermittent mode, and the M-FSK rather than traditional 2-FSK modulation/demodulation scheme, are proposed.

超宽带调频(FM-UWB)具有穿透性强、辐射小、设计简单、功耗低等适合人体通信环境的特点，成为医疗电子、无线体域/个人网青睐的短距离、低速率无线通信技术。本项目在FM-UWB收发机的实现和能效优化上提出了以下创新。.子载波生成基于开关电容型电压-电流转换器(V-to-I)和摆率受控型弛豫振荡器，以高鲁棒、开环的方式实现了传通的、闭环FSK调制功能。低功耗的双通路环型振荡器，使用差分模拟通路的V-to-I实现流控型射频调频；借助二进制权值数字通路，伙同逐次逼近型自动频率校准实现压控型载频校正。基于差分型斜率鉴频的可再生结构，利用中心频率对称失谐的双带通滤波器高线性恢复子载波频率。FSK解调器基于低成本的能量检测技术，数字化地重建基带数据。系统级采用双能效优化方案：动态功耗优化方法 + M-FSK调制/解调机理；收发机工作在低占空比的间歇工作模式下，且运用M-FSK而非传统的2-FSK机理。

超宽带调频(FM-UWB)具有穿透性强、辐射小、设计简单、功耗低、定位精度高等适合人体环境的特点，成为医疗电子、无线体域网、单兵作战系统青睐的短距离无线通信与测距技术。本项目在通信收发机与调频连续波(FMCW)雷达的共架构低成本设计及低功耗高性能优化上提出了若干创新。. 借助超宽带调频及可再生鉴频，并基于中频时差而非射频频差的测距机理，实现FM-UWB通信与FMCW雷达的共架构设计；射频大电流及中低频模拟模块完全复用，只有数字化的FSK解调及时延-数字转换器(TDC)需要并行切换，系统复用率高达90%。系统级引入动态功耗优化方案，收发机的射频大电流模块工作在低占空比的间歇模式下，功耗优化41%。. 使用过零点时延判决技术和低功耗TDC，消除传统FMCW雷达受限于射频带宽的缺陷，将测距分辨率倍增。在差分型鉴频器中引入两个单端放大器，降低内置减法器的增益，克服传统鉴频器的解调性能受制于放大器失调电压的不足。引入多样化的子模块性能优化方案，确保收发机低功耗低成本实现，包括射频前端电流堆叠共享、差分鉴频失调电压抑制、多模块数字式频率校正、射频FM双通路/噪声优化、推挽型宽带功放鲁棒性加固、FSK解调阈值判别鲁棒性加固等。. 研制的收发机瞄准10米通信距离，-90dBm灵敏度，功耗低于3mW，芯片面积小于1mm2，测距分辨率可优化到mm级，射频带宽500MHz，发射效率高于21%，数据率为100kbps，噪声系数低于4dB，射频相位噪声为-75dBc/Hz @ 1MHz offset；满足体域/个人网、单兵系统所需的短距离无线通信及非接触式心率/呼吸等测量需求。所研制的芯片，可应用在远程医疗监控及战场感知系统中；其非接触式测量感知特性，对于疫情防控亦尤为重要。