Mikrovagsegenskaper hos Styrda Kiselskivor vid Pulsad Optisk belysning (Microwave Performance of Optically Steerable Silicon Wafers During Pulses Illumination).

摘要

If a silicon wafer, in a simple way, can be shifted from being electrically non-conducting (insulating) to be electrically conducting when its surface is illuminated, a number of applications can be realized. If a radar is equipped with an optically steerable silicon surface in front of the antenna, the radar cross section can be reduced and the system can also withstand high power microwave (HPM) pulses. In this work the authors have studied theoretically and experimentally the microwave performance of optically steerable silicon wafers, where the silicon surface was illuminated with pulsed light. The theory developed in chapter 2 has been implemented in a simulation program called Tectum II. Tectum II derives the excess carrier densities and the microwave performance for the case when the silicon surface is illuminated with pulsed light. To experimentally investigate different pulsed illumination intensities, microwave measurements have been performed on silicon wafers. As the pulsed light source a high power laserdiode and a flashlamp from EG&G has been used. During the experiment with the flashlamp, an 18 dB increase in microwave transmission loss was obtained at 9 GHz.