A Modeling And Study Of RF Passive Components Based On LTCC Technology

Low Temperature Co-fired Ceramic (LTCC, Low Temperature Co-fired Ceramic)technology, as a new packaging technology, can be used to bury a variety of passivecircuit components in the medium, such as capacitors, inductors, resistors, filters,couplers, diplexers etc. It can achieve the miniaturization of chip products by formingthree-dimensional multi-layer circuit, and can be used to develop the RF andmicrowave modules of highly integrated, low-cost and low-power by combining withsome active devices. Different from the conventional passive devices, the filters,couplers, diplexers and other three-dimensional RF passive components berried in themedium, need to make full use of three-dimensional space, which gives us a newresearch direction for the development of RF passive components. Taking into accountof research projects, the low-pass filters, band-pass filters, power dividers anddirectional couplers are studied in this paper. The main work and results of the authorcan be summarized as follows:1. Based on the processing line of modeling method for LTCC passivecomponents are studied in this paper. Specifically, this paper models and simulates thesingle-layer capacitors, multi-layer capacitors, stub inductors, planar spiral inductorsand does some process validation to them. Then it analysis of the use methods andnotes to the single-layer capacitors, multi-layer capacitors, planar spiral inductors andother passive components of variable structures, and after that it establishes a HFSSmodel library of some key components through setting up some variables, whichcontain transmission lines, inductors, capacitors, DC bias circuits of millimeter-wave.2. Some high/low pass filters are introduced in this paper. It first researches thethree-dimensional electromagnetic device models of LTCC low pass filters withfive-order parallel resonant, seven-order parallel resonant or nine-order series resonant.In the case of the inhibition of high-order elliptic function LTCC filter is not enough,this paper proposes a new LTCC low pass filter model of parallel resonant withadditional zeros. What’s more, it deals with some LTCC high pass filter models withdifferent medium of different dielectric constant.3. The design and modeling methods of SIR and LC band pass filter are presentedin this paper. It not only puts forward an improved SIR band pass filter and a T-typeLC filer with transmission zeros, but also gives an detail design method of designingthe SIR band pass filter based on the LTCC technology. At the same time, it does process validation to some of the band pass filters in the previous design examples,and the text results are consistent with the simulation results, so that these band passfilters can be applied to modern communications systems.4. The implementation methods of the miniaturized LTCC power dividers anddirectional couplers are described in this paper. In details, it designs thethree-dimensional electromagnetic models of the Wilkinson power divider,90°bridge,90°series-bridge,180°balun,180°broad band balun, and implements theminiaturization of them. Some devices, such as power divider,90°series-bridge,180°balun use a standard of3216package, so that they can be applied to the Beidounavigation system of1.616GHz and can be used for the wireless communicationsystem of2.45GHz. Mainly used in the mobile TV (CMMB) dipole antenna, the180°broad band balun solves the problem of built-in antenna in mobile TV (CMMB).