高精度、低附加相移数控衰减器设计

A Digital Attenuator with High Accuracy and Low Phase Variation

采用0.13μm双极的互补金属氧化物半导体(Bipolar Complementary Metal Oxide Semiconductor,BiCMOS)工艺,设计了一款高精度、低附加相移的6位数控衰减器。电路采用6个基本衰减单元级联组合的方式,通过控制各衰减单元的工作状态,实现64个衰减状态。衰减器衰减步进为0.5 dB,最大衰减量为31.5 dB。仿真结果表明,衰减误差均方根小于0.22 dB,附加相移小于±3°,插入损耗小于8.2 dB,回波损耗小于-20 dB,芯片尺寸为750μm×500μm。

This letter presents a 6 bits digital attenuator with high accuracy and low phase variation in 0.13μm Bipolar Complementary Metal Oxide Semiconductor(BiCOMS)technology.Circuit,composed of 6 cascaded units,gets 64 states by controlling the state of attenuation units.Proposed attenuator exhibits 31.5 dB tuning range with 0.5 dB tuning step.The simulation result of proposed circuit shows root mean square attenuator error better than 0.22 dB and phase error less than±3°.Besides,the insert loss is less than 8.2 dB,and return loss is less than-20 dB.Die dimension of attenuator is 750μm×500μm.