用于蓝牙收发机的低电压CMOS Gilbert混频器

对已报道的Gilbert混频器工作在低电压时存在的问题进行了分析,在此基础上,描述了利用改进的低电压设计技术,用于2.4GHz蓝牙收发机的上混频器/下混频器的设计.利用适用于低电压工作的负反馈与电流镜技术提高上混频器的线性度;而通过采用折叠级联输出,增加了低电压时下混频器的设计自由度,从而降低了噪声,提高了转换增益.基于0.35μm CMOS工艺技术,在2V电源电压下,对电路进行了仿真.结果表明:上混频器消耗的电流为3mA,输入三阶截距点达到20dBm,输出的信号幅度为87mV;下混频器消耗的电流为3.5mA,得到的转换增益是20dB,输入参考噪声电压是6.5nV/ Hz,输入三阶截距点为4.4dBm.

Low Voltage CMOS Gilbert Mixers for Bluetooth Transceiver

Based on the analyses of the reported Gilbert mixers operating at low supply voltage,a down-conversion mixer and an up-conversion mixer for 2.4GHz bluetooth transceiver are presented with the modified low voltage design techniques,respectively.Feedback and current mirror techniques suitable for low voltage operation are used to improve the linearity of the up-conversion mixer,and folded-cascode output stage is adopted to optimize the noise and conversion gain of the down-conversion mixer operating at low voltage.Based on 0.35μm CMOS technology,simulations are performed with 2V supply voltage.The results show that 20dBm third-order intercept point (IIP3),87mV output signal amplitude are achieved for up-conversion mixer with about 3mA current;while 20dB conversion gain (CG),6.5nV/ Hz input-referred noise,4.4dBm IIP3 are obtained for down-conversion mixer with about 3.5mA current.