PURPOSE: To miniaturize two conductor transmission line elements by forming any arbitrary part of a part to arrange a transmission line from a material for which the dielectric constant is made different from that of the surrounding part.
CONSTITUTION: When the dielectric substrate with an equal entire dielectric constant is used, the part to form a large electrode pattern (the transmission line) is replaced with the material, for which the dielectric constant is larger than that of the other part, so that the electrode pattern can be miniaturized. Concerning a dielectric substrate 2 to be used for a low-pass filter, for example, the material with dielectric constant r=17.0 and length L1=4.310mm is arranged for a part 2a, the material with dielectric constant r=60.0 and length L1=2.178mm is arranged for a part 2b, and the material with dielectric constant r=17.0 and length L1=10.00mm is used for a part 2c so that this dielectric substrate can be formed. As a result, the characteristic impedance of the electrode part 1a formed at the part 2a with the small dielectric constant is turned to 50.0Ω and that of the part 2b with the large dielectric constant is similarly turned to 25.3Ω. Thus, the area of the electrode pattern is reduced to about 1/4 of concentional area without changing the width of the electrode pattern 1 and desired filtering characteristics can be provided.
AMACHI NOBUMITSU
TAKAGI HIROSHI
