一款集成驱动放大器的低变频损耗混频器设计

采用0.5μm GaAs工艺设计并制造了一款单片集成驱动放大器的低变频损耗混频器.电路主要包括混频部分、巴伦和驱动放大器3个模块.混频器的射频(RF)、本振(LO)频率为4～7 GHz,中频(IF)带宽为DC～2.5 GHz,芯片变频损耗小于7 dB,本振到射频隔离度大于35 dB,本振到中频隔离度大于27 dB.1 dB压缩点输入功率大于11 dBm,输入三阶交调点大于20 dBm.该混频器单片集成一款驱动放大器,解决了无源混频器要求大本振功率的问题,变频功能由串联二极管环实现,巴伦采用螺旋式结构,在实现超低变频损耗和良好隔离度的同时,保持了较小的芯片面积.整体芯片面积为1.1 mm×1.2 mm.

Design of a Low Conversion Loss Mixer with Integrated Driving Amplifier

A low conversion loss mixer with monolithic integrated driving amplifier was designed and fabricated with the 0.5 μm GaAs process.The circuit mainly consisted of three modules:mixing section,balun and driving amplifier.The radio frequency (RF) and local oscillator (LO) frequency of the mixer are 4-7 GHz,the intermediate frequency (IF) bandwidth is DC-2.5 GHz,and the conversion loss of the chip is less than 7 dB.The isolations from LO to RF and LO to IF are greater than 35 dB and 27 dB,respectively.The input power at 1 dB compression point is better than 11 dBm and the input third-order intercept point is better than 20 dBm.The mixer was integrated with a drive amplifier to solve the problem that the passive mixer requires large LO power.The frequency conversion function of the mixer was realized by a series ring-diode,and the balun employed a spiral structure,maintaining a small chip area while achieving ultra-low conversion loss and good isolation.The overall area of the chip is 1.1 mm× 1.2 mm.