实现了一个基于不定中频结构的唤醒接收机,其中本振信号由环形振荡器产生,高Q值滤波匹配网络由外接电容和电感组成.本接收机采用工作于亚阈值区的MOS器件大幅降低电路总功耗,实现超低功耗;采用不定中频技术降低对本振信号的精度要求,从而降低振荡器的设计复杂度和功耗;采用双栅结构合并射频放大器和混频器,简化射频前端的设计并降低功耗.4级差分放大器电路作为中频放大器,在34μA低电流下实现了50 dB以上的增益和60MHz以上的-3 dB带宽,实现了对中频信号的滤波和放大.本接收机采用SMIC0.13μm工艺,开关键控调制,采用0.9V电源供电,功耗不到130μW,在100 kbps传输速率和10-3差错率下,灵敏度达到-60 dBm,核心芯片面积小,仅160×232μm2,满足通信频繁的无线体域网应用中对超低功耗及短延时、快速响应的要求.
The dedicated wake-up receiver in body area networks is realized based on an "uncertain-IF" architecture,in which the LO(Local Oscillator) signal is generated by a free-running CMOS ring oscillator and the high-Q filtering match network is consisted by the external inductors and capacitors.Ultra-low power is achieved by MOS transistors operating in sub-threshold region.In addition,"uncertain-IF" architecture is adopted to reduce the requirements on high accuracy of the LO signal,therefore the design complexity and power of the oscillator are largely decreased.A dual-gate topology which combines the low noise amplifier with the mixer is chosen for low power dissipation and the simplified radio frequency front-end circuit design.A four-stages differential intermediate amplifier is adopted to filter and amplify the intermediate signal,which has high gain above 50 dB over-3 dB bandwidth of 60 MHz with 34 μA low current.The prototype receiver is implemented in 130 nm CMOS technology and OOK modulation.The simulation results show that a sensitivity of-60 dBm at 100 kbps and 10-3 bit error rate is achieved,while only with the power consumption of 130 μW in a global 0.9 V supply,and with small core chip size of 160×232 μm2.It is available for applications where frequent interaction,short delay and fast response are required.