Patent ID: 6741478
Filing Date: 2004-05-25
Classification: H01P,H05K

Abstract:
An electronic circuit unit having a circulator, comprising:a circuit board which is obtained by laminating a plurality of dielectric substrates and in which an electric component is provided to form a desired electronic circuit; first, second, and third central conductors provided for the circuit board and partially intersecting with each other in the upper and lower directions; a magnet and a ferrite member disposed above and below the intersection of the central conductors; a first yoke for covering the outside of the magnet; and a second yoke for covering the outside of the ferrite member, wherein the first, second, and third central conductors are provided on the plurality of dielectric substrates and are formed by laminating the plurality of dielectric substrates; a cavity for accommodating the ferrite member is provided at a lower section of the circuit board in which the central conductors are disposed; a plurality of through holes vertically passing through the circuit board are filled with a magnetic material; and a magnetic path is formed by the magnetic material between the first and second yokes disposed above and below the circuit board so as to cover the magnet and the ferrite member, to make a closed magnetic circuit.