Patent ID: 7234234

Claim:
A method of manufacturing a bandpass filter for GHz bands having the structure that an input signal line ( 2 ) and an output signal line ( 3 ) made of conductive strips run in the series direction with a small gap between them on a surface of a sheet ( 1 ), which is made by dispersing soft magnetic metal powder in a sheet-formed polymer matrix; that an internal line ( 6 ) made of a conductive strip is piled on both the opposite ends of the input signal line and the output signal line to bridge them with intermediation of an insulating film ( 5 ) so that electrostatic capacitance may occur between the internal line and the input signal line, and the internal line and the output signal line; and that a GND line ( 4 ) run on the reverse surface of the above-sheet ( 1 ); the method comprises the steps of inserting an intermediate product, which is made by disposing on both the sides of an insulating film ( 5 ) the above-mentioned input signal line ( 2 ), output signal line ( 3 ) and internal line ( 6 ), on one side of the cavity of a mold for injection; inserting a metal piece for the GND line ( 4 ) on the other side of the cavity of the mold; and injecting a polymer compound prepared by dispersing soft magnetic metal powder in the polymer into the mold so as to obtain a molded article in which the above components are consolidated.