宽带高线性高隔离无源双平衡混频器

Wideband high linearity and high isolation passive double balanced mixer

基于InGap/GaAs HBT工艺设计了一款宽带无源双平衡混频器,针对双平衡混频器射频中频交叠及射频到中频端口隔离度差的问题,采用了双混频环+新型滤波补偿网络的结构,不仅提高了隔离度和线性度,同时扩宽了带宽,改善了混频器整体性能。射频、本振频率为1.5~5.0 GHz,射频功率为-10 dBm,本振功率为13 dBm,中频频率为DC~1.5 GHz。仿真结果表明,变频损耗(Conversion Loss)为7 dB,本振与射频信号隔离度(Iso_LO/RF)为44 dB,本振与中频信号隔离度(Iso_LO/IF)为45 dB,射频与中频信号隔离度(Iso_RF/IF)为35 dB,IIP3为20 dBm,芯片面积为1.6 mm×1.6 mm。

A broadband passive double-balanced mixer was designed based on the InGap/GaAs HBT process.Aiming at the problem of RF to IF ports overlap and poor isolation from the double-balanced mixer,the structure of double mixing loop plus new filter compensation network was adopted,which not only improves the isolation and linearity,but also broadens the bandwidth,leading to the improvement of the overall performance of the mixer.RF and LO frequency is 1.5-5.0 GHz,RF power is-10 dBm,LO power is 13 dBm and IF frequency is DC-1.5 GHz.The simulation results show that the conversion loss is 7 dB,the signal of LO to RF isolation(Iso_LO/RF)is 44 dB,the signal of LO to IF isolation(Iso_LO/IF)is 45 dB,the signal of RF to IF isolation(Iso_RF/IF)is 35 dB,the input third-order intermodulation point is 18 dBm and the chip area is 1.6 mm×1.6 mm.