Multi-passband bandpass filters with low-temperature co-fired ceramic technology

The bandpass filters with multiple passbands have been proposed. To achieve multiple passbands, transmission lines shunted with short-circuit transmission lines are adopted. Moreover, the bandwidth of each passband can be controlled by properly choosing impedances and electrical lengths of the transmission lines and short-circuit transmission lines shunted. The design procedures of the proposed multi-passband filter are also described here. Finally, the agreement between the measured results and theoretical predictions sufficiently validates the proposed design and filter configuration.