RD-301A测试仪在气象雷达高频参数测试中的应用

RD-301A气象雷达测试仪是由美国爱尔法特公司研制生产,主要用于测量各种航空气象雷达及新一代非相参雷达的高频信号参数,具有测试精度高,测试数据显示直观等优点。在我国民航及气象雷达维修部门均配备有该仪器。本文将对RD-301A气象雷达测试仪检测雷达发射机发射功率、脉冲宽度、接收机灵敏度等高频参数时的使用方法加以论述。

Small-Signal Equivalent Circuit Modeling of a Photodetector Chip

A small-signal equivalent circuit model and the ted. The equivalent lumped circuit, which takes the main extraction techniques for photodetector chips are presen- factors that limit a photodetector＇s RF performance into consideration,is first determined based on the device＇s physical structure. The photodetector＇s S parameters are then on-wafer measured, and the measured raw data are processed with further calibration. A genetic algorithm is used to fit the measured data, thereby allowing us to calculate each parameter value of the model. Experimental resuits show that the modeled parameters are well matched to the measurements in a frequency range from 130MHz to 20GHz, and the proposed method is proved feasible. This model can give an exact description of the photodetector chip＇s high frequency performance,which enables an effective circuit-level prediction for photodetector and optoelectronic integrated circuits.

对电力线载波通道组织与加工的几点意见

本文叙述了国内几大电网内，使用ＧＴＣ—１型电力线高频参数测试仪对电网进行测试时发现的由于通道在组织与加工上存在的弊病，致使通道不能正常工作的情况。为此，根据各系统的实际状况，本文提出了一些行之有效的改进措施。这些措施也适用于通讯与继电保护复用通道。