一款高精度大衰减量单片数控衰减器

High Precise MMIC Digital Attenuator with Large Attenuation

介绍了一款高精度大衰减量单片数控衰减器的主要技术指标和设计方法。电路设计基于Agilent ADS微波软件设计环境,采用GaAs HFET工艺技术实现。对开关器件建模流程和数控衰减器电路设计流程分别作了相应的描述。针对不同衰减值的基本衰减位,选择合适的衰减拓扑。通过采用创新的大衰减量衰减结构,既实现了63.5 dB的大衰减量,又满足其衰减精度的要求,还达到了整个单片数控衰减器低插入损耗和高衰减精度的目标。单片电路测试结果为:在3～100 MHz工作频率范围内,插入损耗≤2.2 dB,驻波比≤1.4∶1,衰减范围为0.5～63.5 dB。测试结果表明设计方法有效、可行。电路尺寸为3.5 mm×1.4 mm×0.1 mm,控制电压为0 V和-5 V。

The design method and the main technical parameters of the MMIC attenuator were described. The circuit was fabricated using GaAs HFET process and designed with Agilent ADS. The flows of switched FET modeling and circuit design were described. The suitable configurations were chosen for different attenuate bits. The high accuracy and large attenuation were realized by using a new configuration of attenuation. And the attenuator is realized low insertion loss and high precision. The measurement results are that the frequency range is from 3 MHz to 100 MHz, the insertion loss is less than 2.2 dB, the VSWR is less than 1.4：1, the attenuate range is from 0.5 dB to 63.5 dB. The design method was demonstrated on the following test results. The die size is 3.5 mm × 1.4 mm × 0. 1 mm, the control voltages are 0 V and -5 V.