The Design And Simulation Of LTCC Microwave Filters

After coming into the twenty-first century, microwave passive devices are moving towards the direction of miniaturization and high performance. In the traditional design process of microwave passive devices, such as high temperature co-fired ceramic technology, PCB technology, etc., they all can not meet the requirements of the miniaturization and high performance of microwave passive devices. While the low dielectric loss, multilayer layout, superior electric and thermal conductivity, high frequency and high Q value of LTCC technology make it possible for the microwave passive devices to be miniaturized and high performance.In this paper, microwave filters and duplexers based on the low temperature co-fired ceramic technology are mainly studied. Firstly, the different structures of the capacitors and inductors are analyzed, and the influences of all kind of parameters to the performance of the capacitors and inductors are discussed. Secondly, based on the principle of microwave filters, the low pass filters and high pass filters are studied. The chebyshev low pass filters and elliptic function low pass filters with the cut-off frequency of 1GHz, and the chebyshev high pass filters and elliptic function high pass filters with the cut-off frequency of 2GHz,are successfully been designed in this paper. In addition, the design and simulation of LTCC duplexer is studied in this paper based on the design theory of microwave filter and duplexer. Then a low high pass complementary duplexer is designed based on the complementary principle of the full complementary filter. The duplexer saves the matching network of the common end, which makes the structure simpler and realizes the miniaturization of the duplexer. A low high pass complementary duplexer based on Low Temperature Co-fired Ceramic technology is been designed in this paper,which is successfully meet the design requirements and the size is just 3.3mm×2.7mm×0.8mm.