Ltcc Filters Based On Space Mapping Method

It is difficult to be simulated the LTCC multilayer microwave circuits with electromagnetic simulation software , and its equivalent circuits can not be extracted from itself because of the complex electromagnetic coupling. The space mapping arithmetic has been proposed, which reduce the simulation workload and improve the design efficiency by applying the rapid coarse model and accurate fine model.In this thesis, A special LTCC filters have been designed with space mapping algorithms, which is a contribution in the application field of designing the LTCC passive elements with space mapping algorithm. Firstly, three frameworks of LTCC capacitances including Mental Insulator Mental,Vertically Interdigitated Capacitor and Interdigital Capacitors have been analyzed, and the volume of Vertically Interdigitated Capacitor is smallest. Making use of the miniaturization of LTCC, the multilayer capacitance and inductance are modeled. Their optimization parameters have been optimized with aggressive space mapping (ASM). The kind of transition modes between microstrip and stripline have been simulated and optimized with neural space mapping (NSM), after analyzing the transmission and reflection characteristic.Based on LTCC capacitance and inductance, a LTCC multilayer filter with two transmission zeros has been proposed. Its electric performances require that the center frequency is 2.45 GHz, and the bandwidth is 300 MHz. And its three-dimensional structure requires transition modes between microstrip and stripline,multilayer capacitance and spire inductance. Making use of neural space mapping,bulid the relation between fine model and coarse model. Optimization parameters of 2.3-2.6GHz LTCC filter have been obtained in the iterative optimization process. It is avoided to optimize directly in the electromagnetic software, but it is not suitable for establishing the complex filter framework in coarse model.The correctness and validity of optimization theory about space mapping algorithms have been validated by the electromagnetic simulation responses of LTCC filter.