Optically Controlled Microwave Switch And Its Applications In Reconfigurable Antennas

Optically controlled microwave switch (OCMS) and its applications inreconfigurable antenna have been investigated in this thesis. First，the design process ofsilicon-OCMS is introduced. Then, an improving scheme for the switch is presented andthe insertion loss of the switch is obviously decreased while the switch keeps highisolation. In addition, an optically controlled reconfigurable band-notched UWBantenna is presented and it has powerful functions in blocking interferences and makingfull use of spectrum.In Chapter1, the background, advantages, and advancement of OCMS, and themain work of this thesis are outlined. Compared to the traditional electronic switches,OCMS has the advantages of free from DC bias, allowing perfect isolation between thecontrolling signal and the RF signal, avoiding the effect of DC bias lines and it has agood application prospect in reconfigurable antenna.In Chapter2, the principle of OCMS and its related theories are introduced. Then,an effective electromagnetic simulation model for OCMS is established so that we cananalyze OCMS via the model.In Chapter3, an analysis about the influence factors of the performance of OCMSis made. Then, the choice of semiconductor, the output power and center-wavelength ofthe laser source and the dimensions of the gap for the design of the switch are decidedbased on the previous analysis. At last, a defected ground structure is presented forperformance improvement of OCMS.In Chapter4, the applications of OCMS in reconfigurable antenna aredemonstrated. An optically controlled reconfigurable band-notched UWB antenna ispresented for cognitive radio systems.In Chapter5, the summary about the research of the project and the expectationabout the future work are presented.