A miniaturized 2.4 GHz band multi-layer bandpass filter using capacitively loaded /spl lambda//4 slow-wave resonator

In this paper, we proposed new multi-layer /spl lambda//4 slow-wave resonator, which is composed of a strip-line and loading capacitance. Due to the slow-wave effect of the proposed resonator, it is possible to design and fabricate a compact bandpass filter with a wide upper stopband. Using LTCC multi-layer technology, we designed and fabricated a 2.4 GHz ISM-band bandpass filter with a wide upper stopband and a size of 2.0 mm/spl times/1.2mm/spl times/0.8mm.