A Photonic Crystal High-frequency System

Photonic Crystals is an artificial periodic structure with the characteristic of band suppression, which is composed of one kind of material in which another kind of material is periodically distributed. This kind of material has more application value than that of the semiconductor, it is well known that the semiconductor play an important role important in the world in 1950s, the semiconductor control electron movement, which lead to information reform. This reform has great contribution to world. Photonic band gap control photon movement, its potential application can be very interesting. Thereby photonic crystals has been paid great attention by many fields in the world since the introducing of its concept in 1980s. The dielectric's refractive index Periodic change in photonic crystal can affect propagation of light, thus very like periodic field in semiconductor affects electrons. In photonic crystals, due to dielectric constant variety, there is a Periodic field like semiconductor, when dielectric constant change with a large range, and the period of change is assimilate to wavelength of light, the scatter of bragg leads a band gap. That is a PBG(Photonic Band GaP), exist of band gap is difficult in light wave range, but it is easy to realize in microwave range. Photonic crystals are named EBG(Electronmagnetic Band GaP) in microwave range. Because the conditions of realize are easy, so many EBG structure are proposed.The theme of this dissertation is to research the electromagnetic characteristics and application of photonic crystals. The photonic band gap structures have the capability of choosing the frequency of microwaves that transmit in the structure. In this dissertation, the characteristics of this structure are analyzed theoretically with the help of simulation software and other tools. On the basis of this analysis, in the purpose of further study on the current microwave tubes, structure of this kind is applied into the practical applications. In chapter one, the concept and the background of the research of photonic crystals are introduced. The current application and development prospects are also presented. In chapter two, The dispersion of a type of slow-wave structure and the photonic crystal band gap structures are discussed in this chapter. In chapter three, a new metal slow-wave structure which was proposed recently is introduced. The metal slow-wave structure with the PBG structure is also analyzed and the characteristics and advantages are also got. In chapter four the microwave-device development is anticipated, and the later work are also emphasized.