宽带pin二极管单刀双掷开关的设计与实现

Design and Implementation on the Broadband pin Diode SPDT Switch

采用两个pin二极管设计、仿真,制作了一个8～20 GHz并联结构的高功率容量的单刀双掷开关。首先通过采用一个新的电路结构,该电路结构除了传统的并联pin单刀双掷开关结构外,还有微带线匹配电路部分,克服了并联结构单刀双掷开关难以实现大的带宽的缺点。然后选择合适的二极管,根据其参数,建立开路、短路等效电路模型;利用Ansoft Designer软件对电路进行了仿真和优化。最后根据优化结果制作并测试了单刀双掷开关。该单刀双掷开关插入损耗在频率8～20 GHz内小于1.7 dB,在频率8～15 GHz内小于1.5 dB;开关隔离度在整个频带内大于21 dB;在14 GHz耐功率容量大于10 W(CW)。

Using two pin diodes,the 8-20 G Hz high power capacit y SPDT（single pole double throw） switch with a parallel structure was designed,simulated and fabricated.First of all,the shortcoming that parallel structure SPDT switch is difficult to achieve large bandwidth was overcame with a new circuit structure.Besides traditional parallel circuit SPDT pin switch structures,the microstrip matching circuits also are a part of the new circuit structure.Then the open and short equiva lent circuit models were established through selecting the appropriate diode and according to its parameters.The circuit was simulated and optimized by Ansoft Designer.Finally according to the optimized result,a SPDT switch was fabricated and tested.The insertion loss of the SPDT switch is less than 1.7 dB from 8 GHz to 20 GHz and less than 1.5 dB from 8 GHz to 15 GHz.The isolation of the switch is more than 21 dB across the band.The power capacity is more than 10 W（CW） at 1 4 GHz.