C波段大动态小步进数控衰减器设计

Design of a Wide-range and Small-step Digital Control Attenuator in C-band

为了实现C波段大动态小步进数控衰减器的设计目的,提出了一种设计方法,详细介绍了利用I2C总线来控制一个数控衰减器单片和一个数控开关,数控衰减器单片来实现小步进控制,数控开关配合实现大动态的功率控制的原理.基于大量的仿真设计和多次实际试验结果,分析了采用共面波导射频电路来改善驻波,减少插损,采用隔离器来改善2级数控衰减器阻抗匹配的设计步骤。最后给出一个设计实例,测试结果表明,这种设计方法思路简单,设计效率高。

In order to design a wide-range and small-step digital control attenuator in C-band, a design method is proposed. The principle of this attenuator is introduced in detail, which uses I2C bus to control the digital control attenuator chip to realize small-step control and digital control switch to realize wide attenuator range. Based on a great number of simulations and test results, the design step of using coplanar waveguide （CPW） to decrease standing wave and lessen the wastage and using isolator to improve the impedance matching of the n-order digital control attenuator. At last a practical example is presented. The testing results show this design method is easier and has higher efficiency.