一种基于 HTCC 的高隔离度开关电路设计

A High Isolation Switch Circuit Design Based on HTCC

中文关键词:  隔离腔体  高温共烧陶瓷  级联开关电路

英文关键词:isolation cavity  high-temperature co-fired ceramics  cascade switch circuit

中文摘要:

      基于开关芯片实现的开关电路是射频前端的基本单元之一,其功能是实现射频信号的导通和关断,在小功率射频信号传输中应用广泛。 本文以6 GHz~15 GHz 超宽带、60 dB 隔离度为设计目标,采用高温共烧陶瓷基板工艺和级联腔体隔离技术,以级联开关芯片为基本电路结构,设计了高隔离度开关电路。 该电路包含一只限幅器和两只吸收式砷化镓单刀单掷开关,装配于两个相邻的隔离腔体结构中,通过类同轴垂直传输过渡到基板内对称带状线传输结构,再辅以两侧地孔,实现电磁屏蔽。 对开关电路进行电磁场建模仿真,结果表明该结构具有良好的传输特性和隔离特性;在射频前端电路制造完成后对开关电路进行装配和测试,测试结果与建模仿真结果一致性高,验证了本文设计的开关电路具有高隔离度特性。

英文摘要:

      Switch circuit based on the switch chip is the basic unit of radio frequency front-end circuits, which can achieve radio frequency signal on and off and is widely used in low-power radio frequency signal transmission. In this paper, a high isolation switch circuit based on the high-temperature co-fired ceramics substrate and the cascaded isolation cavity, formed by cascaded switch chips as the basic circuit is designed. The frequency is 6 GHz~ 15 GHz and the isolation index is 60 dB. The switch circuit consists of a limiter chip and two absorption type gallium arsenide single-pole single throw switches, which are assembled in two adjacent isolation cavity structures, and transitioned to a symmetrical stripline transmission structure inside the substrate through the coaxial-like vertical transmission, supplemented by ground holes on both sides to achieve electromagnetic shielding. The electromagnetic field modeling and simulation of the switch circuit show that it has good transmission and isolation characteristics. After the radio frequency front-end circuit is manufactured, the switch circuit is assembled and tested. The test results are consistent with the modeling and simulation results, verifying the high isolation switch circuit design in this paper.