Research On Miniaturized Power Divider And Filter Based On LTCC Technology

In recent years,with the increasing demand for information,microwave wireless transmission technology has developed rapidly.Now low temperature co-fired ceramic（LTCC）technology has become an important leading technology for integrating various passive components（including inductance,capacitance,resistance,etc.）in RF electronic devices.Because of its three-dimensional laminated structure,so it has great flexibility in designing multi-layer circuits.With LTCC technology,many passive electronic components with novel structure that could not be realized by traditional integration methods have been widely used in various wireless communication devices（especially RF front-end）,filters and power dividers are very widely used in RF front-end.The threedimensional multilayer microwave filter and power divider constructed with the help of LTCC technology are advanced transceiver components of RF system.Because LTCC technology has many incomparable advantages,it can well meet the development requirements of modern RF system with high frequency band,small size and low cost.This thesis mainly studies the design,simulation and processing test of LTCC multilayer passive filter and power divider.Microwave passive components are widely used in RF transceiver system.They occupy a large space in the entire circuit network,and there is a strong parasitic effect in the interconnection due to the close distance between components.Therefore,in order to improve the integration and reliability of the whole system,the importance of improving the integration of passive components is self-evident.Firstly,aiming at this problem,this thesis extracts the equivalent circuit of inductance and capacitance,and then studies the design of inductance and capacitance,which are the basic passive components of filter and power divider designed by LTCC embedded technology,by using software simulation and other methods.Through the simulation modeling and optimization of the embedded inductance and capacitance in LTCC in the simulation software HFSS,and then the equivalent circuit method is used to extract the inductance value,capacitance value and other parameters to realize the inductance and capacitance we need.In the simulation,it can be found that the threedimensional multi-layer structure using LTCC technology can effectively reduce the size of components and improve the performance of components.However,the multi-layer structure makes the design and processing more difficult,so it needs to be considered globally in the actual design.After the research on the embedded inductor and capacitor,combined with the design theory of filter and power divider,the design of LTCC filter and power divider is completed.The low-pass filter and power divider are fabricated and processed into real objects by using the above capacitors and inductors,and the test comparison is completed.The overall size of the final designed filter is 3.2mm × 1.6mm × 0.9mm,the center frequency is 3GHz,the insertion loss in passband is less than 0.6d B,the stopband suppression is less than 24 d B at 3.55-5GHz,the insertion loss at 5-9GHz is less than 38 d B,and the voltage standing wave ratio is less than 1.2.The overall size of the power divider is 3.2mm× 1.6mm × 0.9mm,the center frequency is 3GHz,within the passband of 2.6-3.4GHz,the return loss is lower than-15 d B,the insertion loss is greater than-3.3db,and the isolation of the output port is lower than-15dB.