Investigation of an antenna array configuration and feeding technique for portable satellite communication applications.

摘要

The satellite communications industry, following the trends seen in personal communications systems, is pursuing the development of smaller and more capable communication terminals. Several antenna technologies and architectures have been studied for a fixed-beam portable communications terminal operating at high frequencies, e.g. 20GHz (receive) and 30GHz (transmit), and capable of providing multiple data links (data, voice, video). However, additional work is required to develop a modular "brick" type of architecture for this application.; This thesis investigates two aspects of the problem: a modular antenna array configuration, and a suitable feeding scheme involving perpendicular interconnection that is essential to the design of the brick architecture.; An antenna array patterns program was developed within the Matlab environment. This versatile tool can be used to predict planar array radiation patterns for design and general illustration purposes. The program can evaluate, display and analyze two- and three-dimensional radiation patterns, and it can easily be modified to suit specific user requirements. An array configuration suitable for fixed-beam portable satellite applications at 30GHz was developed using this program.; To acquire experience with the design of microstrip patch antennas, and to validate the simulation software that would be used throughout this thesis, a critical coupling analysis was then conducted for conventional aperture-fed microstrip patch antennas. Simulation results were analyzed to determine the behavior of various parameters for critically coupled antennas, and charts providing a helpful guide for the design of microstrip patch antennas were produced.; The development of the perpendicular interconnection was then initiated with the simulation, fabrication and successful testing of a perpendicular substrate microstrip line-to-line coupler using the proximity feeding technique. A microstrip patch antenna fed from a perpendicular substrate was then designed to operate in the 2GHz range, with excellent results. Following this, a 30GHz perpendicularly fed microstrip patch antenna was developed, generating promising results.