Research And Design On Filtering Antenna Base On Coplanar Waveguide

Integration of antenna and RF front end has great influence on the miniaturization and integration of wireless communication equipment, especially portable devices. Currently, the studies on filtering antennas, or on the integration of antenna and filter, have become important focal points in the field of microwave systems. The defects of current filtering antenna are large in sizes, narrow in bandwidth. Based on this background and extensive studies of achievements of filtering antennas in published literatures, a new structure of combination of coplanar waveguide(CPW) and filtering antenna is proposed and studied in this dissertation. The purpose of this new structure is to achieve integration design and reduction of overall size of the filtering antenna, while holding the characteristics of filter and antenna. To conduct the research work, methods of EDA simulation modeling and experimental validation are used. Two new filtering antenna structures and an UWB filter, all based on the CPW structure, are implemented. These two filtering antennas are small in size, and have good sideband selectivity. For purpose of design UWB filtering antenna, an ultra-wideband filter is also designed and analyzed.The main contents of this dissertation are:1. With reference of design method of coupled bandpass filter, the equivalent RLC circuit model of the filtering antenna is set up. The design methods and procedures of filtering antenna are summarized; 2. A new structure of CPW feed filtering antenna is proposed and extensively studied. Through the study of CPW transmission line characteristics, CPW transmission lines are used to build 1/4 wavelength open stubs resonator, rectangular ring loaded stub resonator, CPW diamond resonator. And these resonators are employed in filtering antenna design. Finally, a single-frequency filtering antenna, a dual-band filtering antenna, and an ultra-wideband filter are successfully designed; 3. All the filtering antennas are simulated, designed, fabricated, and tested. And the results of measurement have good agreement with the simulated ones;4. For the purpose of study on the UWB filtering antenna, a UWB filter with CPW feed structure is also designed.Through the works of simulation and experiment validation, it shows that the filtering antennas with CPW feed structures have good characteristics, and that the design approach is feasible. All the works conducted in this dissertation have reference value for filtering antenna engineering design.