Down-Conversion Mixer And QVCO Design For 2.4 GHz IoT Application

With the rapid development of IoT technology,as the key module of IoT sensor nodes,RF transceiver design has received extensive attention from both academic and industry.The main work of this paper is to design and optimize two key modules in the low-IF RF receiver:down-conversion mixer and QVCO.These two modules are based on the IEEE 802.15.4 communication protocol for the IoT ISM band.The down-conversion mixer in this paper works in the 2.4 GHz band.With the struc-ture of self-differential topology and complementary current reuse technology.No additional components are needed to generate differential RF signals.And at the same time guarantees superior performance.The QVCO in this paper uses bulk coupling technique to form quadra-ture differential signals.Since the design is to provide LO signals for the down-conversion mixer,the tuning range needs to cover the whole 2.4 GHz band.Both modules in this paper use TSMC 0.18 ?m CMOS technology and Cadence simulation.The chip area of the self-differential I/Q down-conversion is 0.3 mm2,and the core area costs only 0.03 mm2.The current reused QVCO occupies a layout area of 0.96 mm2.Test results show that,the down-conversion mixer achieves design goals.The power consumption of the mixer is 2.88 mW,the conversion gain is above 12 dB,the noise figure is 10.49 dB,the third-order intercept point is 1.795 dBm at I branch and 1.88 dBm at Q branch.The post simulation results shows that the power consumption of the quadrature output voltage-controlled oscillator is 5.2 mW,f0 is 2.4 GHz,the frequency adjustment range is 12.1%,the phase noise is-116.81 dBc/Hz at 1 MHz,and the phase error is 1.03°.