Research And Design Of Small LTCC Antennas Applied To GPS And WLAN

With the rapid development of wireless communication technology, wireless communi- cation products gradually to became small, integration, high-performance. Antenna, as a very important and indispensable component of wireless communication system, is developing towards light,thin,short,small direction, small antenna is an inevitable development trend in the future. Microstrip antenna is one of the research objects of miniature antenna, and its size can be further reduced by taking advantage of LTCC technology.LTCC (Low Temperature Co-fired Ceramic) is a multilayer ceramic technology. All layers are first printed, punched and dried in parallel. These layers are then aligned, stacked and co-fired into a highly compact structure at temperature between 800oC and 900oC . According to the design, the conductor lines of antenna can print on different layers to realize the antenna miniature and integration. Due to its high performance in microwave such as low medium loss, high Q, etc, LTCC is very suitable to be used in miniature antenna.Firstly, this paper introduces the LTCC technology including LTCC technological process and research progress of LTCC antenna. Secondly, makes a concrete exposition on the basic theory of antenna including antenna radiation mechanism and the main electrical performance parameters, HFSS high frequency simulation software and the Finite Element Method which the software based on are also introduced. Thirdly, the miniaturization methods of LTCC antenna are studied, theory analyses the mutual relationship between the dielectric constant of the material, the size, bandwidth, gain of the antenna. Puts forward two small LTCC antenna structures, helical type and meander line type, the radiation characteristics of the two structures are analyzed , research status of the two structures are also summarized. Lastly, use for reference on the theory above, designs and simulations of two small antennas, one is a helical LTCC chip antenna applied to GPS , the size of the antenna is 8mm×3mm×0.77mm, its resonate frequency is 1.575GHz,-10dB bandwidth is 60MHz(1.54GHz-1.60GHz),the other is a stacked meander line LTCC chip antenna with their current flow on the same direction which applied to WLAN, the size of the antenna is 6mm×2mm×0.7mm, its resonate frequency is 2.45GHz, -10dB bandwidth is 250MHz(2.325GHz-2.575GHz), both of the antennas have obvious characteristic of omni-direction, good gain and field patterns, the simulation results show all the performance parameters can meet the needs of practical application.