| 摘要 |
A UWB bandpass filter using an LTCC(Low Temperature Cofired Ceramic) multilayer substrate is provided to enhance operation reliability of the bandpass filter by using a coupling pad. A UWB(Ultra-Wide Band) bandpass filter includes an LTCC multilayer substrate, a filter sheet layer, resonators(11,12,13,14a,14b,15), a via(21), and coupling pads(60,61). An uppermost layer and a lowermost layer of the filter sheet layer are grounded. The resonators are arranged to be apart from each other on at least one of the filter sheet layers. The via couples the resonators with each other. The coupling pad electrically couples the resonators, which are formed on the same filter sheet layer. The via short-circuits a vertical coupling portion of the resonator to the grounded uppermost and lowermost layers. The resonators are formed in a 1/4 lambda structure. The filter sheet layer includes a notch coupling pad, which increases frequency selectivity of the bandpass filter.
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