Filter circuit and electronic device using the same
AssigneeMurata Manufacturing Co., Ltd.
InventorHiroshi Nishikawa
Life of this patent
Estimating the term…
Abstract
A filter circuit includes a first distributed parameter RC circuit having a first distributed parameter resistor and a first distributed parameter capacitance and a second distributed parameter RC circuit having a second distributed parameter resistor and a second distributed parameter capacitance, wherein one end of each of the first and second distributed parameter resistors connected in parallel is connected to an input terminal of a buffer circuit and the second distributed parameter capacitance is connected to an output terminal of the buffer circuit, and when the number of distributed parameter RC circuits connected in parallel is n, which can be two or more, the number of distributed parameter capacitances connected to the output terminal of the buffer circuit is one to n−1.
Claims20
A filter circuit comprising:
- n (n≧2) distributed parameter RC circuits each having a distributed parameter resistor and a distributed parameter capacitance arranged along the distributed parameter resistor;
- and
- a buffer circuit;
- wherein
- the distributed parameter resistors are connected in parallel at a first node and a second node, and the second node is connected to an input terminal of the buffer circuit, and one to n−1 distributed parameter capacitances of the n distributed parameter RC circuits are connected to an output terminal of the buffer circuit.
A filter circuit comprising:
- a dielectric layer;
- distributed parameter resistors including n (n≧2) resistor layers disposed on one surface of the dielectric layer;
- distributed parameter capacitances distributed along the distributed parameter resistors including n electrode layers arranged on the other surface of the dielectric layer so that the n electrode layers oppose the respective distributed parameter resistors;
- and
- a buffer circuit;
- wherein
- first ends of the n resistor layers are electrically connected to each other and second ends of the n resistor layers are electrically connected to each other so that the distributed parameter resistors are connected in parallel, the second ends of the n connected resistor layers are connected to an input terminal of the buffer circuit, and one to n−1 electrode layers are connected to an output terminal of the buffer circuit.
A filter comprising:
- an alumina substrate having two main surfaces;
- a plurality of electrode layers and a plurality of resistor layers provided on one of said main surfaces of said alumina substrate;
- and
- a buffer circuit provided on the other main surface of the alumina substrate;
- wherein
- said plurality of electrode layers and said plurality of resistor layers are disposed so as to oppose each other, such that the plurality of resistor layers define a plurality of distributed parameter resistors, and a plurality of distributed parameter capacitances are defined between the plurality of electrode layers and the plurality of resistor layers;
- and
- first ends of the plurality of resistor layers are electrically connected to each other and second ends of the plurality of resistor layers are electrically connected to each other such that the plurality of distributed parameter resistors are connected in parallel, the second ends of the plurality of connected resistor layers are connected to an input terminal of the buffer circuit, and at least one of the plurality of electrode layers are connected to an output terminal of the buffer circuit.
Dependencies are inferred from the claim text.