Study On The Technique For Transmission-zeros Of LC Filters Constructed On Multilayer Substrates

Filters, which are widely used in communication system, reduce interference and increase the system performance. There are filters in the communication subsystem, such as radio access subsystem and modulation subsystem. With the improvement of the integration in communication system, the size of the filter propose new requirement. The filter with multilayer dielectric, which could crate Three-dimension capacitor and inductance to conductive coupling between capacitor and inductance, thus introduce transmission zero on each side of the pass-band so as to greatly inhibit the interference from band-stop, can effectively reduce the size and suitable for different system. The design of the filter is completed on HFSS in the article, which is simulation software from Ansoft. The thesis's contribution as below:(1) Design a new structure of feedback capacitor and a new inductor structure.(2) Design two new filters with multilayer dielectric structure, and there is one transmission zero on each side of the pass-band. The transmission zero reduces the interference and improves the filter performance.(3) Base on the work above, design filter horizontal cascade. There are two transmissions zero on each side of the pass-band so as to the performance internal and external is improved.The thesis designs two filter unites with multilayer dielectric structure, analysis horizontal cascade and vertical cascade. The conclusion included in the thesis has reference value to design multilayer dielectric structure filter and the cascade of the filter.