Electricity: electrical systems and devices – Housing or mounting assemblies with diverse electrical... – For electronic systems and devices
Reexamination Certificate
2000-02-02
2002-04-09
Gandhi, Jayprakash N. (Department: 2841)
Electricity: electrical systems and devices
Housing or mounting assemblies with diverse electrical...
For electronic systems and devices
C361S782000, C361S814000, C361S816000, C174S034000, C333S185000, C336S200000
Reexamination Certificate
active
06370033
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electronic device for use at high frequencies comprising a printed circuit board joined to a cavity resonance filter, and having the functions of a filter used in a miniaturized radio communications device.
2. Description of the Related Art
In recent years, there has been remarkable development of radio communications devices, such as cordless telephones and mobile telephones. The miniaturized shape and moderate cost of such radio communications devices have been the primary factors behind their proliferation.
As is well known, various types of functional circuits and devices, such as an antenna, a filter, and an amplifier, are required to form a radio communications device. The functional circuits are provided on a printed circuit board, and various other devices are mounted on the printed circuit board to form a radio communications device.
Several filters, such as an antenna filter, an intermediate-frequency filter, and the like, are required to form a communications device, though their number, function (LP, HP, etc.) or position and the like differ according to the communications method used. For example, in the case of an antenna bandpass filter connected to an antenna, in recent communications devices, an individual component which fulfils a predetermined function, such as a surface acoustic wave filter or a ceramic filter, are used as the bandpass filter. This is because a surface acoustic wave filter, a ceramic filter, and the like, have frequency characteristics which are superior to conventional LC filters, and also have a miniaturized component shape. Consequently, when a surface acoustic wave filter or a ceramic filter is used, the communications device can be miniaturized.
By using surface acoustic wave filter, a ceramic filter, or the like, it is possible to miniturize the communications device more than when a conventional LC filter is used. However, a surface acoustic wave filter, a ceramic filter, or the like, usually comprises an independent electronic component (termed a discrete component) functioning as a filter, which is mounted on the printed circuit board and electrically connected to a wiring pattern thereon.
Since each discrete component must be purchased separately, and since filter-type discrete components are especially expensive, the manufacturing cost of the communications device is high. Furthermore, when discrete components are used, the size of the discrete components, and spaces and the like provided for mounting or soldering them on the printed circuit board, increase the size of the communications device, and make it difficult for the communications device to be miniaturized and made thin.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an electronic device having the function of a filter which enables a communications device to be miniaturized and made thin at low cost.
The electronic device of the present invention comprises a printed circuit board having multiple electronic elements mounted thereon; a ground pattern provided on the printed circuit board; a pair of spiral conductive patterns provided adjacent to each other on the printed circuit board, one end of each pattern connecting to the ground pattern; and a cavity case electrically connected to the ground pattern, and covering the top faces of the pair of spiral conductive patterns.
REFERENCES:
patent: 3718874 (1973-02-01), Cooper, Jr.
patent: 5036301 (1991-07-01), Takao et al.
patent: 5497137 (1996-03-01), Fujiki
patent: 5618777 (1997-04-01), Hey-Shipton et al.
patent: 5696471 (1997-12-01), Fugiwara
patent: 5752182 (1998-05-01), Nakatsuka et al.
patent: 6097273 (2000-08-01), Frye et al.
patent: 6175727 (2001-01-01), Mostov
patent: 6222427 (2001-04-01), Kato et al.
Nakamura Naoshi
Saegusa Seiichiro
Gandhi Jayprakash N.
Pillsbury & Winthrop LLP
Toko Kabushiki Kaisha
Vigushin John B.
LandOfFree
Electronic device having printed circuit board joined to... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electronic device having printed circuit board joined to..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electronic device having printed circuit board joined to... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2834179