π型阵列光电探测器研究与设计

Research and design of type π array photodetector

提出了一种基于高阶π型低通滤波器电路结构的阵列探测器,可实现高输出功率和大工作带宽并存。该探测器根据光电二极管等效电容模型,用电感元件连接各光电二极管构成等效的π型滤波器结构,合成各光电二极管支路输出电流;并在光电二极管支路上串联电容,增加探测器工作带宽。仿真结果表明,在串联电容等于光电二极管结电容时,π型阵列探测器比行波探测器阵列工作带宽提高一倍,再通过增加级联的光电二极管数量,提高探测器输出功率,即可设计出高功率、大带宽的光电探测器。

A novel arrays photodetector based on high order type π low pass filter circuit structure was proposed, which could achieve high output power and large operating bandwidth. According to the equivalent capacitance model of photodiode, the inductors were used to connect each photodiode in order to constitute the circuit structure which was similar to type π filter, this type π array photodetector synthesized the output current of each photodiode branch. And series capacitors were cascaded on the branch of the photodiode to increase the working bandwidth of the detector. Simulation results show that type π arrays detector＇s working bandwidth is doubled compared with that of traveling-wave detector arrays（TWDA） when the capacitance cascaded in the photodiode branch is equal to the photodiode junction capacitance. Then by increasing the number of cascaded photodiode, the output power of the detector is improved, eventually, high power and large bandwidth photodetector can be designed.