Design And Optimization Of CMOS Mixer

These mixers have been presented in this paper:a 5.8 GHz CMOS mixer with a low voltage,high conversion gain and high linearity;Ultra wideband uniform distributed drain-pμmped mixer and Ultra wideband non-uniform distributed drain-pμmped mixer;passive doubled-balanced mixer.A folded configuration is adoped in 5.8GHz CMOS mixer on the basis of Gilbert Cell.By using folded configuration it is eleminated that we trade off between conversion gain,noise and linearity.The RF frequency is from 5.725-8.825 GHz, the IF frequency is set to 480 MHz.The operation voltage is only 1Ⅴ.This mixer achieves a high conversion gain of 17 dB,a highⅡP3 of 1.29 dBm.The proposed folded mixer has demonstrated a better FOM than conventioanl Gilbert Cell.The dc power is only 8 mW.Distributed Topology is the best candidate for UWB systems.The parasitic capacitances of the transistors are absorbed into the transmission lines so that broad bandwidth is achieved.A drain-pμmped mixer is demonstrated that LO signal inputs into the drain of the MOS transistor so that push the transistor into triode region without dc power.That means that drain-pμmped mixer is very suitable for low power system.A closed-form analytical model for the conversion loss of distributed drain-pμmped mixer is presented for the first time to verify the broadband theory.We propose an optimization method of V_GS to minimize conversion loss of a CMOS drain-pμmped mixer.The designed three-stage uniform distribted drain-pμmped mixer consμmes zero dc power and exhibits a low and flat conversion loss of 5±1dB from 2 to 40 GHz.The single side-band(SSB) noise figure(NF) is below 12.6 dB for the entire range of frequencies and the minimal SSB NF of 10.7 dB achieves at 33GHz.An input third-order intercept point of is from 7-17dBm.A non-uniform distributed drain-pμmped mixer is designed for the first time. Decreasingly scaling of the transistor and transmission line sizes will contributed to a better gain-bandwidth-product and more flat frequency response. Simulations confirm the superiority of the proposed non-uniform distributed mixer. The designed three-stage non-uniform distributed mixer consμmes zero dc power and exhibits a low and flat conversion loss of 5.35±0.65dB from 4 to 50 GHz.An input third-order intercept point of 14 dBm achieves at 26.9 GHz.This mixer is well suitable for low power-consμming,wideband monolithic microwave integrated circuit(MMIC) implementation.A passive double balanced 2.4 GHz mixer is designed consμming no dc power so it fulfill the demand of low power.The RF frequency is from 2.4-2.4835 GHz, the IF frequency is set to 2 MHz.The conversion loss is tolerable as 5.6 dB andⅡP3 is as high as 7.7 dBm.