LTCC MLC bandpass filter using /spl lambda//4 hairpin resonators for K-PCS

In this paper, a novel /spl lambda//4 hairpin resonator is proposed to reduce the size of resonators. A LTCC MLC bandpass filter is designed using the /spl lambda//4 hairpin resonators. The electromagnetic coupling structure between two planar resonators is analyzed. The equivalent circuit is derived to explain the behavior of the LTCC MLC bandpass filter using /spl lambda//4 hairpin resonators. A design procedure is also described. The simulated and measured results of 1.8 GHz band 2-pole bandpass filter are presented.