Research And Design Of Multi-Band Microstrip Antennas For Handsets

In the wireless communication systems, antennas are very important components. Their performances determine the quality of communication. Nowadays, microstrip antennas are widely studied and used due to their low profile, ease of fabrication and integration.This thesis focused on researching and summarizing of compact microstrip antennas, multi-band microstrip antennas,and also proposed two kinds of novel triple-band planar inverted-F antennas. By etching UU-shaped slots or LU-shaped slots in a rectangular patch, the triple-band characters can be obtained easily. The triple resonant frequencies can be tuned independently by changing corresponding parameters. Antennas for GSM/DCS/ISM were presented separately for these two kinds of structures. The designed antennas were simulated by IE3D software and agreed quite well with the experimental results. Additionally, the proposed PIFA only used one single feed, and had a compact profile and simple structure, hence was easy to design, manufacture and adjust.In the chapter 2, the principles and design methods of microstrip antennas were introduced. The chapter 3 focused on the compact methods and multi-band methods of microstrip antennas. Using special material substrates, shorted-loaded, slot-loaded, adding active networks were effective compact methods. Orthogonal-mode method, multi-patch method, lumped element-loaded method and slot-loaded method were used to realize multi bands. The chapter 4 was the innovation of this thesis. In this chapter, the two novel triple-band antennas were described in detail. The chapter 5 gave a summary and a view of the future research.