Study Of Wide-Band Antenna Miniaturized Design Theory And Circular Polarization Microstrip Antenna Techniques

After 300 years development of the modern electromagnetic theory, it is being perfected. As key equipments for achieving wireless applications, antennas are now developing continually. Nowadays, great changes have taken place in the function, design and manufacturing process of antennas. However, the fast development of microelectronics and large scale IC techniques makes the antenna to be a huge and heavy part of the electronic equipment. As a miniaturized antenna, the microstrip antenna has several advantages such as low-profile, conformal and easy to integrate. High performance circular polarization microstrip antennas are being used widely nowadays. Thus, the research on miniaturized wide-band and dual-band circular polarization antenna techniques has become the hot research point of the academic area, and this is the main content of this thesis.In this thesis, firstly, we composite the research results of the relative area, and use electromagnetic field and antenna theory and computational electromagnetic numerical methods to do research in miniaturized antenna theory and design key techniques, the simulation and test of the miniaturized planar spiral antenna and the achievement of the single-fed dual-band polarization. The research content contains theory and measurements.Following are the contribution of these work:(1) We proposed a new method to miniaturize the size of the planar spiral antennas for the first time, and it can achieve a 84% reduction in the antenna size;(2) We proposed a miniaturized wide-band planar spiral antenna. When it is compared to a conventional wide-band planar spiral antenna, it can have a 56% size reduction, and the bandwidth is wider. (3) We analysis the reason of cross-polarization and proposed a rectangle ground plane to reduced the large cross-polarization of the proposed antennas with vias.(4) We proposed a novel single-fed dual-band circular polarization antenna which has two operation frequences 2.45GHz and 5.2GHz, respectively. It can produce right hand circular polarization. And it can be used in ISM applications. Meanwhile, if changes the feeding point, it can produce left hand circular polarization. It has a simple structure and easy to fabricate, and avoiding complex feeding network of the conventional dual-fed circular. And it is satisfied the requirement of the antenna miniaturization.