Patent ID: 7982557
Filing Date: 2011-07-19
Classification: H03H

Abstract:
1. A layered low-pass filter comprising: a layered substrate including a plurality of dielectric layers stacked; an input terminal and an output terminal each disposed on a periphery of the layered substrate; a first inductor and a second inductor each formed using at least one conductor layer provided within the layered substrate, the first and second inductors being connected in series to each other and, in terms of circuit configuration, located between the input terminal and the output terminal; first to fifth capacitors and third to fifth inductors provided within the layered substrate; and first to third grounding terminals each disposed on the periphery of the layered substrate and connected to a ground, wherein: in terms of circuit configuration, the first inductor is located closer to the input terminal than is the second inductor; each of the first and second inductors has an input for receiving signals and an output for outputting signals; the output of the first inductor is connected to the input of the second inductor; the first capacitor is connected in parallel to the first inductor; the second capacitor is connected in parallel to the second inductor; the third capacitor has a first end connected to the output of the first inductor and to the input of the second inductor; the fourth capacitor has a first end connected to the input of the first inductor; the fifth capacitor has a first end connected to the output of the second inductor; the third inductor connects a second end of the third capacitor to the ground; the fourth inductor connects a second end of the fourth capacitor to the ground; the fifth inductor connects a second end of the fifth capacitor to the ground; each of the third to fifth capacitors includes a capacitor-forming conductor layer and a ground-side conductor layer that are opposed to each other; the third inductor connects the ground-side conductor layer of the third capacitor to the first grounding terminal; the fourth inductor connects the ground-side conductor layer of the fourth capacitor to the second grounding terminal; the fifth inductor connects the ground-side conductor layer of the fifth capacitor to the third grounding terminal; the ground-side conductor layers of the third to fifth capacitors are disposed on a surface of one of the dielectric layers; and the third to fifth inductors are disposed on a surface of another one of the dielectric layers.