Research And Design Of Multi-band And Low Profile Antenna Based On LTCC Technology

The demand of antennas capable to operate at multi-band and wide-band isincreasing. Size reduction, low profile and light weight have become a popular topic inrecent antenna researches with the development of modern communications. The LTCC(Low Temperature Co-fired Ceramic) technology meets the demand. First the green sheetsare printed, punched, and dried in parallel, then the layers are stacked and co-firedbetween850and900centigrade. Due to the performance of high Q, low loss and so on,LTCC technology has become an effective method in the miniature antenna researches.Firstly, this paper presents a compact LTCC antenna using the electromagneticcoupling effect concept for WLAN and WiMAX applications. The overall dimension ofthe antenna is9×15.5×0.8mm3. It consists of three meander lines and a coupled line.The top meander line with a coupled line operates at2.55GHz, the middle patch is tunedto3.50GHz, and the bottom radiating patch is designed for5.22GHz. The coupled line isemployed to match the input impedance of the antenna at WLAN/WiMAX bands. Withthe2.5:1VSWR impedance bandwidth definition, the lower, middle, and upper bandshave the bandwidth of270,530, and180MHz, respectively. The proposed antenna hasbeen successfully designed, simulated, and analyzed by a high frequency structuresimulator (HFSS). The results show that the antenna is compact, efficient, and of nearomnidirectional radiation pattern.Secondly, a novel dual-band helix-meander line LTCC antenna which can be used inboth UMTS and Bluetooth, are proposed and designed. The size of the antenna is10×2.8×1mm3.The simulation results show that the-10dB bandwidth are220,90MHz, and thegain are2.82,3.24dB for UMTS and Bluetooth. With different geometrical parameters,the performance of the proposed antenna is different.In order to verify the antenna for WLAN/WiMAX application design is correct, weused DuPont951C2(r=7.80.2, tan δ=0.014) green tapes for the manufacture.Through experiments to optimize the antenna parameters, the LTCC antennas were cofiredat850centigrade. The return loss of the manufactured antenna was tested by the vectornetwork analyzer. The measured return loss are about-16.5，-26.3，-25.9dB at the resonant frequency.