Modeling Research For LTCC Microwave Equalizer And Filter

LTCC(Low Temperature Co-fired Ceramic) technology is the hot research field and mainstream of microwave miniaturization, has been widely used with its unique three-dimensional multi-layer structure in multi-layer high-density packaging, built-in passive components, the conductor wiring,interconnects and other aspects of the interlayer. Currently LTCC technology in China is more mature, but has not established model library design systematically. Modeling work just meets in the project needs, and is lack of efficient design platform, affects the project development cycle and design costs, which is not beneficial to the promotion and application of LTCC technology in the field of military electronics. Microwave LTCC technology provides a new way of thinking in the compact design of equalizer and filter. How to improve the efficiency and accuracy of LTCC design of passive microwave devices, and establish a complete model library and a practical LTCC design platform, now becomes the focus of research.In this paper, the writer analyzes the integrated microwave and equalizer filters theory, and then establishes model-building based on the characteristics of high density integration of LTCC. Based on the characteristics of processes and structures of LTCC technology, the writer develops 2-6GHz lumped LC gain equalizer structure and carry out testing after modeling the circular spiral inductors and capacitors multilayer respectively. The writer establishes a gain equalizer model library by using microstrip circuit and substrate integrated waveguide theory, including minor micro strip equalizer and LTCC SIW model. And complete the automatic equalizer design wizard by using the model in microwave equalizer design platform software, which improves the equalizer design efficiency greatly. In addition, this paper designs four LTCC filters including two low-pass filters(stepped-impedance type low pass filter and open-circuited stubs type low pass filter) and two band pass filters(parallel coupled lines, interdigital type) by insertion loss method and odd mode analysis. The writer programs and tests these four models by using the filter electrical parameters as input and external physical dimensions as output, tests results verify the accuracy of the four models. This paper uses the four filter models in designing LTCC microwave filter design software platform, which enriches model library of LTCC passive components. The software design platform could do the model parameters calculation according to the indicator and gives electromagnetic simulation and optimization results.