The preparation of alumina ceramics by casting method was studied, and the effects of powder characteristics and casting parameters on the structure and performance of ceramics were discussed.
The impurity content of alumina ceramic raw materials, crystallization tracing, α·phase conversion rate, particle size distribution, etc. have influence on the casting process and the quality of ceramic plates, and the performance index of alumina raw materials for ceramic plates by combined casting method is proposed.
It can be seen from the comparison of the heavy ceramic heat dissipation substrate that although the thermal conductivity of the al2o3 material is about 20~51 (w/mk), ltcc adds 30%~50% glass to reduce the sintering temperature. The thermal conductivity of htcc is lower than the sintering temperature of pure al2o3 substrate due to its common co-firing temperature, which makes its thermal conductivity lower than that of al2o3 due to its low material density. The substrate is about 16~17(w/mk).
Microstrip line filters are widely used in microwave and millimeter wave frequency bands because of the advantages of convenient drawing, easy machining through photolithography, and easy integration with other active circuits.
The half-wavelength parallel-coupled microstrip line band-pass filter is a form of band-pass filter widely used in microwave integrated circuits. Its structure is compact, and the center frequency of the second parasitic passband is located in the main passband. At 3 times the center frequency, the applicable frequency range is relatively large, and the relative bandwidth can reach 20% when used in a wideband filter.
In order to facilitate the transformation of various transmission line structures, kuroda proposed the following four identities, as shown in the figure. Compared with the pbg structure, the primary benefit of the dgs structure microstrip line is that it can operate at certain frequencies without establishing a periodic structure. The dots resonate with brilliant stop-band characteristics.