Patent ID: 6911880

Claim:
A transmission line type noise filter connectable between an electrical load component and a power supply for attenuating an alternating current while passing a direct current, said transmission line noise filter comprising: a first electrode terminal connected to the electrical load component; a second electrode terminal connected to the power supply; a third electrode terminal connected to a fixed potential; and first, second, and third distributed constant transmission line type filter segments, each of which includes a first metal conductor comprising a plate, a second metal conductor opposed to the first metal conductor, and a dielectric layer which is made of an oxide of the first metal conductor and which is sandwiched between the first metal conductor and the second metal conductor; wherein the second filter segment and third filter segment each have a greater impedance than the first filter segment; and wherein the first, the second, and the third filter segments are cascaded such that: the first metal conductor of the first filter segment is electrically connected to the first metal conductor of the second filter segment and to the first metal conductor of the third filter segment; the first metal conductor of the second filter segment is electrically connected to the first electrode terminal; the first metal conductor of the third filter segment is electrically connected to the second electrode terminal; and the second metal conductor of each of the first, the second, and the third filter segments is electrically connected to the third electrode terminal.