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Modem electronic circuit requires compact, multifunctional technology in communication systems. However, it is verydifficult due to the limitations in passive component miniaturization and the complication of fabrication process. The bandpass filter isone of the most important passive components in millimeter(mm)-wave communication system, attracting significant interest inthree-dimension (3D) miniaturized design, which is few reported. In this paper, a bandpass filter structure using low-temperatureco-fired ceramic (LTCC) technology, which is fully integrated in a system-in package (SIP) communication module, is presented forminiaturized and high reliable mm-wave application. The bandpass filter with 3D end-coupled microstrip resonators is implemented inorder to achieve a high performance bandwidth characteristic. Specifically, all of the resonators are embedded into different ceramiclayers to decrease the insertion loss and enhance the out-of-band rejection performance by optimizing the coupling coefficient and thecoupling strength. A fence structure, which is formed by metal-filled via array with the gap less than quarter wavelength, is placedaround the embedded bandpass filter to avoid electromagnetic (EM) interference problem in multilayer structure. This structural modelis validated through actual LTCC process. The bandpass filter is successfully manufactured by modifying the co-fireablitycharacteristics, adjusting the sintering profile, releasing the interfacial stress, and reducing the shrinkage mismatch with differentmaterials. Measured results show good performance and agree well with the high fiequency EM full wave simulation. The influence of layer thickness and dielectric constant on the frequency response in fabricated process is analyzed, where thicker ceramic sheets let the filter response shift to higher frequency. Moreover, measured S-parameters denote the center frequency is also strongly influenced by the variation of ceramic material’s dielectric constants. By analyzing the relationship between the characteristics of the ceramic tape and the center frequency of the filter, both theoretical and experimental data are accumulated for broadening application filed. With the coupling resonators embedded into the ceramic layers, the bandpass filter exhibits advantages of small size and high reliability compared to conventional planar filter structure, which makes the bandpass filter suitable for SIP communicational application.