Patent ID: 6734760
Filing Date: 2004-05-11
Classification: H03H

Abstract:
A lumped filter comprising:a substrate including a plurality of inductors having spiral electrodes, a plurality of capacitors, an input terminal, an output terminal, and a ground electrode, which are arranged to define a circuit on said substrate; a plurality of parallel elements connected between the input terminal and the ground electrode, and between the output terminal and the around electrode, the plurality of parallel elements include parallel LC resonators each being defined by an inductance generated by one of the spiral electrodes and a capacitance produced between adjacent turns of the spiral electrodes; and a plurality of series elements inserted between the plurality of parallel elements, the plurality of series elements include a parallel LC resonators being defined by an inductance generated by one of the spiral electrodes and a capacitance produced between adjacent turns of the spiral electrodes; wherein the number of turns in the spiral electrodes of the plurality of the series elements is greater than the number of turns in the spiral electrodes of the parallel elements adjacent to the series element.