Design Of The Key RF Passive Components Based On LTCC Technology

With the rapid development of wireless communication, the demand of RF components with miniaturization, high performance and high integration is increasing. To meet the requirements of miniaturization and high reliability of communication system, the LTCC technology which has the characteristics of high reliability, high-temperature, high- humidity and high performance of high-frequency has been applied to the design of RF components.Based on the LTCC technology, the common passive components including filters, splitters, diplexers, baluns, directional couplers and etc. used in RF system are analysed and designed in this paper. The analysis of miniaturization methods of dipole antenna and patch antenna is focused on. Two kinds of meander line antennas are achieved. The performances of these antennas are as follow: the center frequency is 2.45GHz, the peak gain is more than 2.0dBi, the bandwidth is more than 200MHz, the pattern is omni-directional and the polarization is linear.Two filter design methods (insertion loss methods and coupled matrix methods) are analysed. According to the traditional SIR filter and combline filter two new structures of bandpass filters are proposed and these two new structures are designed based on the coupled matrix method. Several filters have been completed with different packages and different performances. In these filters, cross-coupling according to the CT and CQ structure is introduced to achieve the miniaturization and high performance of bandpass filters. The simulation results show that the center frequency, bandwidth, VSWR, insertion loss and other parameters meet the design requirements.