Design Of The Lower Voltage Mixer

With fast development of COMS technology, integrate circuit has beendeveloped fast. Radio frequency, intermediate frequency and basebandcircuits goes to the same chip. It is a key part for mixer during radiofrequency front circuit in wireless LAP.The paper describes that new type of mixer is designed under the lowervoltage based on Gilbert Cell Mixer Modified. The new lower voltagestructure is introduced based on the traditional Gilbert Cell Mixer inorder to have lower voltage and high performance. The lower voltagestructure contains resonant circuit with capacitance and inductance andcoupling capacity. For this structure, supply voltage can be decreasedeffectively. On the other hand, three differences are used to replaceone difference dual in the original circuit. Meanwhile, transconductanceof Gilbert Cell Mixer is adjusted to introduce a new transconductance cellin order to improve the transeonductance of the mixer. Then the Circuitplus and linearity are improved and power consumption is lower. That isto say, using this batters in mobile devices can work longer.The new mixer designed with 0.35um CMOS technology is simulated undersimulation environment of Mentor Eldo. The results are: 2.4GHz radiofrequency, 2.2GHz local oscillation, 200MHz intermediate frequency, 7.48dBtransfer plus, -3.4dBm compressed point, 8.2dBm point of cut-off for inputthird-order on, 2.5V supply voltage, 12.4dB noise factor, 11.8Mwconsumption power. That shows the performance is improved greatly,especially for the plus and linearity under the lower supply voltage.