Develop a Spatial Decision Support System Based on Service-Oriented Architecture

Abstract

Although an analytical approach can sometimes provide a fast approximation of helix radiation properties (Maclean & Kouyoumjian, 1959), generally it is a very complicated procedure for an engineer to apply efficiently and promptly to the specified helical antenna design.Therefore, we combine the analytical with the numerical approach, i. e. the thorough understanding of the wave propagation on helix structure with an efficient calculation tool, in order to obtain the best method for analyzing the helical antenna.In this chapter, a theoretical analysis of monofilar helical antenna is given based on the tape helix model and the antenna array theory.Some methods of changing and improving the monofilar helical radiation characteristics are presented as well as the impact of dielectric materials on helical antenna radiation pattern.Additionally, backfire radiation mode formed by different sizes of a ground reflector is presented.The next part is dealing with theoretical description of bifilar and quadrifilar helices which is followed by some practical examples of these antennas and matching solutions.The chapter is concluded with the comparison of these antennas and their application in satellite communications.