Design Of LTCC Filters And Synthesis Of Filters With Non-Resonant Nodes

With the development of wireless communication technology, microwave devices are developing towards the direction of miniaturization, high selectivity. It’s easy to realize the former by introducing the stack process and the layout way of three-dimensional technique of LTCC. By the introduction of non-resonant nodes, it’s easy to improve the out-off-band attenuation and frequency selectivity without increasing the order of the filter.This thesis introduces two ways to extract the valid values of inductors and capacitors. One is the data processing on the S-parameters calculated by three-dimensional simulation software(HFSS); The other is direct access to simulation results of software(Q3D). This thesis models and validates the multilayer U-type inductor,single-layer capacitors,double-layer capacitors and three-layer capacitors. Modeling results indicate we should firstly use software method(Q3D) to estimate the valid values of passive components, which can not only save a lot of time for the modeling of passive devices, but also facilitate the adjustment of the circuit.This thesis designs two types of microwave filters: chebyshev lowpass filters with the cut-off frequency of 1.5GHz,chebyshev bandpass filters with center frequency of 1.5GHz and the relative bandwidth of 30%. With optimization simulation, the lowpass filters have slight frequency shift, the bandpass filters meet the design requirements well. This also verify the correctness of using Q3 D to extract passive components.Finally, this thesis introduces the synthesis technique of Generalized Chebyshev bandpass filters with non-resonant nodes, designs a fifth-order bandpass filter with five reflection zeros and builds a equivalent model based on admittance inverters.