A distinctive method of eliminating out-band instability in cascaded active device system based on narrow-band attenuation

作者：Zhu, Xiaowei^*; Geng, Junping; Liang, Xianling; Jin, Ronghong; Huang, Yangzhen

来源：Progress in Electromagnetics Research Letters, 2014, 48: 59-65.

DOI：10.2528/PIERL14062504

• Active devices
• Cascaded system
• Connection method
• In-band signals
• Input impedance
• Low gains
• Narrow bands

A distinctive connection method in cascaded RF/MW active device system achieving both stability and low gain loss is presented. Unlike traditional methods (isolator and attenuator), the proposed solution introduces an appropriate length of transmission line to change the input impedance at the out-band instable frequency point and uses a narrow-band termination to absorb the instable power without deteriorating in-band signal. Moreover, the reason that instability often occurs in the cascaded system is analysed with S-parameters, and it turns out to be a kind of out-band instability. The solution is verified by an adjustable circuit example whose insertion loss is below 0.3 dB.

• 出版日期2014
• 单位上海交通大学