Research On Miniature Handset GPS Antennas

In the last few years, the Global Position System (GPS) shifted from military to civilian use gradually. In particular, as carriers actively promoted the location-based services of GPS, portable navigation devices and mobile phones with built-in GPS functionality will become increasingly popular. Higher and higher performance on GPS antennas has been put forward, not only in size, but also their appearance and system integration. In addition, low cost is the key whether it can be applied widely. Microstrip antenna is one of the research objects of miniature antenna, and its size can be further reduced by taking advantage of LTCC(Low temperature Co-fired Ceramic) technology.LTCC is very suitable to be used in miniature antenna due to its high performance in microwave such as low medium loss, high Q, etc. LTCC techniques employ multi-layer technique which allows configurations of antenna to expand form one dimension to 3D.In this thesis, some new designs and researches have been done towards these demands in the basic of original design. The detailed processes of designs and experimental results are presented. The thesis mainly consists of following parts.Firstly, there is a survey of the pervious progress in GPS antenna (helix antenna and microstrip antenna); circular polarization and miniaturization apply in these antennas. In addition, there are describes of the development and current status of LTCC technology, and a brief introduction of the LTCC technology processes and commonly used materials.Secondly, based on LTCC technology and surface mount technology, two kinds of linearly polarized ceramic chip antenna are proposed. It reduces the volume of GPS antenna significantly. By using 3D electromagnetic field simulation software, the VSWR, gain, radiation patterns and other features of antennas was studied. The antenna was manufactured using LTCC technology, and measured results agree well with simulated ones.Thirdly, a stacked dual-band equilateral-triangular GPS microstrip antenna has been designed and researched, working in 1227MHz and 1575MHz band. By stacking two patches, a dual-band can be achieved. The feed position is determined experimentally. After simulated, we found it can achieve characters such as dual-band and circular polarization.