Researches On Conformal Radiating Elements And Array Antennas

Conformal antenna and arrays have some particular advantages on the aerocrafts such as airplanes, missiles, rockets and so on, because their configurations are suited for aerodynamics demands. Researches on the analysis and design methods of conformal antenna and arrays have been done in this dissertation.In Chapter 1, the research background and recent developments about conformal antenna and arrays are reviewed, and then the analysis and design methods are summarized.In Chapter 2, general far-field formulations for arrays conformed with arbittary curved surface are developed at first. Then active element pattern technique is applied to the analyzing of conformal arrays with element coupling, which divides a large array analysis problem as a superposition of various simplified small array problems and greatly reduces the computation burden. The proposed new method is effective when the number of array elements is enormous and the other methods become incapable due to computer hardware limitation.In Chapter 3, the wideband traits and reconfigurable characteristics of radiating elements are investigated. A novel wideband double folded-slot antenna, a wideband and dual-band printed antenna with an integrated balun, and a pattern reconfigurable double folded-slot antenna are proposed and designed.In Chapter 4, based on the general far-field formulations and novel radiating elements mentioned above, far-field radiating characteristics of conformal arrays are reseached. And then, novel synthesis methods for low sidelobe arrays are proposed. Finally, a new approach, which is based on reconfigurable elements, for overcoming the influence of structure curvature on the array properties is proposed and researched.In Chapter 5, a summary of the whole dissertation is given, and future research topics are suggested.