测三级管特性的改进电路

指出了电子线路基础实施教材中所给出的测三级管特性的电路所存在的问题，提出了合理的.     

Pulse-Width Increase of Reflex Triode Vircator Using the Carbon Fibre Cathode

We present the investigation on the reflex triode virtual cathode oscillator in which performances of carbonfibre and stainless-steel cathodes are compared with each other. The experimental results and analyses show that surface tracking induces the electron emission of the carbon fibre cathode. There are electron emission phenomena observed not only from the top of the carbon fibre but also from its side surface. Compared with the case of the stainless steel cathode, the plasma expansion velocity for the carbon fibre cathode is slower, and using the carbon fibre cathode can widen the pulse width of output microwave. The output microwave pulse width reaches an increase of about 20%. This mechanism ＆ different from the conventional explosive emission of metal cathodes.