Design Of Filters Based On LTCC

The methods and procedures of designing LTCC filters has been presented, and microwave filter theory has been analyzed in this thesis. Based on the above work, two lowpass filters has been designed, the simulation and test results show they are all meet the demand of miniature and high performance.The main works in this thesis are as follow:Firstly, introduced the structures of conductors and inductors which used frequently in LTCC condition and their models has been made to analyze and summarize their transmission characteristics.Secondly, the methods of filter designing has been analyzed systematically and the performance index, lowpass filter prototypes, frequency transformation and transmission zeros has been introduced.Thirdly, based on the specific index of microwave filter designing and requirements of LTCC technology, two lowpass filters and one highpass filter were designed, one of them was made into product and its simulation results was similar to its test results Its miniature size and high performance made it has some practical value.Finally, to design a bandpass filter with bandwidth more than 50% is very difficult by traditional methods of bandpass filter design. Some simple methods are needed to fulfill this target. Based on this consideration a new way of bandpass filter design has been proposed in this thesis Through tested and verified ,the results show that this way is feasible.