A multiband concentric annular slot array for mobile communication

This dissertation investigates the use of a multi-band concentric annular slot array for mobile communications. The research reported in this dissertation will consist of two parts:;1. The analytical development of the annular slot and the various configurations of the annular slot with a delta gap feed. The particular configurations include: (i) annular slot in free space -- input impedance and far-field radiation; (ii) mutual coupling between two annular slots of different mean radii; (iii) annular slot above an infinite ground plane -- input impedance and far-field radiation pattern.;2. The second part of the dissertation will investigate practical issues involved in the application of the annular slot in the mobile environment. Specific issues which need to be addressed numerically due to their complexity and lack of an exact solution include: (i) finite ground plane; (ii) microstrip feed networks; (iii) non-optimal height of the annular slot above a ground plane; (iv) effect of concentric annular slots on far-field radiation.;The examination of the above affects will be accomplished through the use of a 3D full wave MOM (method of moments) code that is capable of solving both EFIE's (electric field integral equations) and MFIE's (magnetic field integral equations).;3. The final part of the dissertation will examine a novel dual fed annular slot that can be used to improve the directional characteristics of the annular slot and change the polarization response of the annular slot. Two antenna applications are proposed for application of the annular slot in the automotive environment, which make use of the dual feed.