Microwave stripline filter formed from a pair of dielectric subs

Details Microwave stripline filter formed from a pair of dielectric subs Microwave stripline filter formed from a pair of dielectric subs

1992-12-07

1994-11-15

Ham, Seungsook

Wave transmission lines and networks

Coupling networks

Wave filters including long line elements

333246, H01P 1203

Patent

active

053652088

DESCRIPTION:

BRIEF SUMMARY
TECHNICAL FIELD

The present invention relates to a microwave stripline filter that which may be used as a band-pass filter.


BACKGROUND ART

There is known a variety of microwave stripline filters can be used as bandpass filters for a microwave range.
FIG. 1 of the accompanying drawings illustrates an example of such microwave stripline filters of a known type in which it comprises two superimposed dielectric substrates 1a and 1b made of a BaO-TiO.sub.2 or BaO-TiO.sub.2 -rare type dielectric ceramic material having a high dielectric constant and a low loss factor. The dielectric substrates 1a and 1b are provided with ground conductors 2a and 2b on the outer surface and peripheral portion thereof, respectively. On the inner surface of one 1a of the dielectric substrates 1a and 1b are disposed a plurality of strip-shaped resonator conductors 3a which operate as a filter element. Each resonator conductor has one end connected to the ground conductor 2a to form a short-circuit terminal, while the other end of each resonator conductor is not connected to any ground conductor to form an open-circuit terminal. The open-circuit terminals of the strip-shaped resonator conductors 3a are alternately arranged to form an interdigitated-type arrangement. A stripline filter of the above described type is disclosed in Japanese Patent Kokai No. 54-87480.
With such an arrangement in which the resonator conducors 3a having a desired pattern are formed on the inner surface of one of two dielectric substrates 1a and 1b, and sandwiched between said inner surface and the inner surface of the other dielectric substrate, a gap may often be formed partially between the resonator conductors 3a and the inner surface of the other dielectric substrate 1b when the latter is stacked on the former. Therefore, there is disadvantage that electric characteristics between the respective resonator conductors 3a are varied so that the response frequency of the filter may deviated.
In order to improve such disadvantage, there has been proposed another microwave stripline filter in which as illustrated in FIG. 2 two dielectric substrates 4a and 4b are provided with respective resonator conductors 5a and 5b having a substantially same pattern and same dimensions on the respective inner surfaces. The resonator conductors 5a and 5b are bonded together as the dielectric substrates 4a and 4b are stacked to each other (see Japanese Patent Kokai 3-41802).
In the conventional microwave stripline filter in which two dielectric substrates are provided with respective resonator conductors on the respective inner surfaces, and are stacked and bonded to each other, since respective resonator conductors on the respective inner surfaces have same pattern and same dimensions, the stacking of the dielectric substrates should be performed so that the resonator conductors on one dielectric substrate and the resonator conductors on the other dielectric substrate are overlapped without getting out of position. Consequently, the fact is that this assembling process depends upon the manual procedure of person skilled in the art, and thus there are problems in the manufacturing cost and productivity. Further, it is necessary to provide the resonator conductors on the inner surface of each substrate with very restricted tolerance because the resonator conductors should be formed on the inner surface of each dielectric substrate without involving any positional deviation. Even if the resonator conductors are accurately formed on the inner surface of each dielectric substrate with a predetermined position and dimension, and the dielectric substrates are stacked to each other by those skilled in the art, it is substantially difficult to ascertain whether or not the resonator conductors on the both substrates are deviated from each other at stacking them. As a result, the stacked and bonded resonator conductors on the both substrates may be deviated from each other. As shown in FIG. 3, for example, if any deviation occurs in the axial direction of the resonator conductors,

REFERENCES:
patent: 4266206 (1981-05-01), Bedard et al.
patent: 4609892 (1986-09-01), Higgins, Jr.
patent: 4785271 (1988-11-01), Higgins, Jr.
patent: 4940955 (1990-07-01), Higgins, Jr.

Affiliated with

Also associated with

Rating

Microwave stripline filter formed from a pair of dielectric subs does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Microwave stripline filter formed from a pair of dielectric subs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microwave stripline filter formed from a pair of dielectric subs will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1100441