Microwave and mm-meter wave devices using GaAs Gunn emitters

砷化镓显示了耿氏效应，在这里产生了一个电场域并周期性地移动。我们研究了一种利用Gunn效应直接产生聚束光束的砷化镓基场发射体。制作了常规体效应二极管，研究了二极管结构与振荡特性的关系。实验结果表明，要在发射极结构中获得耿氏效应，需要一个长宽比大于10的发射极。然后，我们用干法和湿法两种方法成功地制备出了长宽比大于10的GaAs场发射极。我们观察到了发射极电流-电压特性中的饱和行为。这一结果有力地表明，由Gunn效应产生的聚束光束是从阴极发射的。为了获得聚束光束的直接证据，我们设计并制作了一套聚束光束频率测量系统。利用聚束光束和光栅设计并制作了用于产生毫米波和亚毫米波的真空室。

GaAs shows the Gunn effect, where an electric field domain is created and periodically traveled. We have studied a GaAs-based field emitter for the generation of bunched beam directly from the emitter using the Gunn effect.l. We fabricated conventional Gunn diodes and studied the relation between the diode structures and the oscillation characteristics. The experimental results reveal that a GaAs emitter with an aspect ratio larger than 10 is necessary to get the Gunn effect in the emitter structure. Then, we have successfully fabricated the GaAs field emitter with an aspect ratio larger than 10 using both dry- and wet-etching.2. We observed saturation behavior in the current-voltage characteristic of the GaAs emitter. This result strong suggests that the bunched beam generated by the Gunn effect is emitted from the cathode.3. To get a direct evidence of the bunched beam, we designed and fabricated a measurement system of the bunched beam frequency.4. We designed and fabricated the vacuum chamber that is used for the generation of mm- and sub mm-meter wave using the bunched beam and a grating.