The Novel Design And EM Analysis Of Microwave Planar Circuits

Microwave planar circuits are a major realization form of radio frequency and microwave transmitter and receivers. The structures and characteristics of some important modules including filters and amplifiers are directly related to the performance of the whole transceiver. The electromagnetic analysis and novel design of microwave planar circuits is a constant and important subject in the realm of microwave engineering.In this dissertation, novel microwave bandpass filters are investigated. An optimized multi-step design method of parallel-coupled microstrip bandpass filters is proposed. Several new topologies of microstrip filters are presented, using stacked stepped impedance resonators, folded tapered-line resonators, and center-stubbed half-wavelength resonators. In addition, primitive results of realizing microwave filters using left-handed materials are also given All these results provide new approaches and rich information for understanding and designing microwave filters with more compact size and higher qualities.Wideband amplifiers are also investigated. An optimized mismatching design method of balanced amplifiers is proposed. A deeper analysis is then given to the circuit configuration of cascaded single-stage distributed amplifiers. The design considerations are discussed in detail. All these efforts have brought the knowledge about wideband amplifier design to a higher level.Furthermore, a hybrid FDTD method for the analysis of microstrip circuits is proposed. The transition algorithm between the traditional FDTD and a new online FDTD is investigated. By achieving this, these two methods can be applied in a computation simultaneously, thus greatly reducing the time and storage consumption.The research summarized above is of significant importance for the analysis and design of modern microwave planar circuits.