A 2.4GHz CMOS Low Power Zero-IF Receiver For Wireless Sensor Network

Recently,Wireless Sensor Networks(WSNs) has got a great range of applications, market prospects and research boom.This article designed a chip of 2.4GHz fully integrated low-power zero-IF receiver front-end circuit chip with independent intellectual property using TSMC 0.18um CMOS RF/Mixed Signal process.In this paper, top-down chip design method has been used.First, based on low-power, low-cost design requirements of WSNs nodes, we choose the zero-IF architecture as the structure of the 2.4GHz RF receiver, and propose solutions of DC-offset and flicker noise problem. Secondly, based on the physical layer protocol defined in IEEE802.15.4 standard of 2.4GHz WSNs, we get 2.4GHz zero-IF receiver's system performance indicators,such as system noise figure, system linearity, sensitivity, spurious-free dynamic range, system gain, channel selection and power consumption performance. Thirdly, according to the nature of the cascade network, we calculate the performance requirements for each module, then using reasonable and optimization of circuit parameters to design their circuit schematic and layout,and get their simulation results. At last, we design the 2.4GHz zero-IF receiver system circuit and layout schematic as a whole, and get system-level simulation results, then compare with the same type of design results.This design of 2.4GHz zero-IF receiver front-end chip has a gain variation range of 19.4dB-75.3dB, the system noise figure of 20.1dB-24.4dB,5MHz from the carrier at the adjacent channel rejection ratio of 33dB,10MHz offset from the carrier at the adjacent adjacent channel rejection ratio of 53dB, 1dB gain compression point of -19.7dBm, the input third order intercept point of -10dBm, the overall power consumption as low as 1.8Vx8.2mA, the overall layout area small 1.6mmx1.0mm, which means the indicators meet the 2.4GHz wireless sensor network applications. Using AC coupling to eliminate the zero-IF receiver DC offset problems and at the same time successfully solve the problem of flicker noise through making the flicker noise corner down to 57KHz.