Design Of Low Power Up-conversion Mixer For WSN Applications

Wireless sensor network(WSN)refers to a set of randomly distributed sensors with integrated sensors,data processing units and communication modules in the form of self-organized wireless network.It can collaboratively perceive,collect and process information in the network coverage area and send it to the observer.A variety of technology are used and WSN is applied to multiple fields.It is the key technology to build a wireless Internet of things.RF transceiver module is a key module of WSN node,which is of great significance to build wireless Internet of things.In the transmitter chip,the mixer module can realize the frequency conversion function,the circuit design directly affects the performance of the entire launch module.This paper mainly introduces the design of a low-power up-conversion mixer for WSN.The Mixer is based on CSMC 0.18?m RF CMOS process,It operates at 1.8Vsupply voltage.The Mixer improves 2M base-band signal to 2.4G?2.4835G RF signal in one steps.The up-conversion mixer is improved in consideration of the advantages and disadvantages of the conventional Gilbert mixer,achieving a high overall performance.The load part of the mixer uses LC parallel resonant network to improve the conversion gain.At the same time,it uses the load boost technology in which positive feedback produces negative resistance to improve the mixer's final impedance.The up-conversion mixer takes advantage of the current-reuse structure to improve the equivalent transconductance of the mixer.In addition,it uses the source feedback technology to improve the linearity of the mixer in the transconductance level.Finally,the current bleeding technique reduces the noise figure of the mixer.The paper introduces the design of the circuit,the former simulation,the layout design and the post-simulation.The simulation results show that the conversion gain of the up-conversion mixer is 5.17dB at the 1.8V power supply voltage,the input 1dB compression point is-7.86dBm,the input third order intercept point is 0.94dBm,and the noise figure is about 13.4dB.The design of the up-conversion mixer achieves a high overall performance in the premise of low power consumption,it can be applied to WSN transmitter system.