Mushroom Structure The Crlh The Microwave Filter

In this century, an artificial composite material which called "left-handed materials" becomes more and more popular in fields such as solid state physics, materials science, optics and electromagnetic field. The unusual electrical and magnetic properties of the material obtain more and more attention and research.In this dissertation, the composite transmission line which composed by mushroom structure that proposed by Sievenpiper is been deeply studied. The nature of this mushroom transmission line and the applications in filters has been investigated through experiments and simulation. The main results in the paper are as follows:1. The left-handed electromagnetic characteristics of mushroom structure is analyzed, the left-handed characteristic which effected by the various parameters is studied by changing the parameter values. The transmission characteristic of the CLRH-TL which has good coupling characteristics is analyzed by detailed simulation.2. The good coupling characteristics between CRLH-TL and general microstrip transmission is studied, the stop filter is realized by using the coupling and the transmission characteristics of the filter is analyzed by simulations and experiments.3. The negative resonance characteristics of mushroom CRLH TL is studied. The capacitive gap coupled transmission line filters is realized by negative resonance characteristics, and the transmission characteristics of the filter is fully analyzed by simulations and experiments, and the advantages and disadvantages are compared between this filter and the general capacitive gap coupled filters.4. The new parallel-coupled filter is realized by using the mushroom CRLH TL in classes of parallel-coupled filter, the filter functionality is optimized and the characteristic is fully analyzed through simulation and experiments.