The design and fabrication of RF band pass filter by LTCC technology

LTCC (Low Temperature Co-fired Ceramics) has been become the key technology of packaging for the integrated of RF passive components due to its higher performance of thermal sink, reliability and plays an important role in increasing higher frequency, decreasing the loss, minimize the volume, etc. This paper mainly focuses on the design and fabrication of RF band pass filter by LTCC technology. The filter model was established according to the capacitor coupled resonate band-pass filter’s circuit structure and the connect type of embedded coupling capacitor was neatly designed to make it be linked between in port an out port, for two translations zeros using two stage resonator can be produced. After tuning up the distances between the strip line inductor and ground to adjust the inductance and quality Q, the circuit’s whole performance could be improved. The band-pass filters with center frequency separated at 1.8GHz and 1.3GHz were fabricated using ULF140 material as the dielectrics to further validate the model and the samples were tested with high consistence with the simulated data.