EP0166809A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Pluricavities microwave filters
Assignee: Telettra Laboratori di Telefonia Elettronica e Radio SpA
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Filing: 1984-10-10
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Granted: —
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Expires: 2004-10-10
Abstract
Abstract The filter according to the present invention has minimum dimensions, because the centers of cavities are foreseen in the apexes of a broken line, whose sides form among themselves angles greater than 90°. The filter body is preferably realized by pressure die-casting of an aluminium alloy having an high flowability in the dies: the dilatation coefficient of the cavities is compensated using, in the resonators and syntony screws, some materials different from the one of the filter body. The electric losses are minimized by differential ratios among the diameters of cavities (Dc) and of the relevant resonators. The weight is optimized by lightenings got by cavities realized in the body.
Inventors
- 👤 Enrico Cesani
- 👤 Adriano Forti
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 09:26
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/20; H01P1/201; H01P1/205; H01P1/30
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
56 words
1) Microwave filter consisting in a generally parallelepiped-shaped metallic body, in which the resonant cavities are practiced, supplied in the centre with rod-shaped resonators and syntony and connection screws, characterized in that the centres of the "n" cavities are placed in the vertexes of a broken line, whose sides form among themselves angles greater than 90°.
Claim 2
Dependent Claim
56 words
1) Microwave filter consisting in a generally parallelepiped-shaped metallic body, in which the resonant cavities are practiced, supplied in the centre with rod-shaped resonators and syntony and connection screws, characterized in that the centres of the "n" cavities are placed in the vertexes of a broken line, whose sides form among themselves angles greater than 90°.
Claim 3
Dependent Claim
63 words
2) Filter according to claim 1, characterized in that the connection of each cavity with the following one occurs by a slit located in the trasversal central axis of the relevant section of the broken line, has a depth substantially - equal to the one of the cavity and realizes the seat for a threaded hole for the adjustment screw of the connection.
Claim 4
Dependent Claim
36 words
3) Filter according to claim 2, characterized in that at least one of the two longitudinal faces presents two holes (preferably spot-faced in the external side) that communicate with the first and respectively the last cavity.
Claim 5
Dependent Claim
25 words
4) Filter according to claim 3, characterized in that the face opposite and parallel to the bottom presents threaded dead holes for the closing cover.
Claim 6
Dependent Claim
42 words
5) Filter according to the previous claims, characterized in that the filter body with relevant cavities, resonators . and screws, is realized using a full estruded rod that, after its cutting and squaring, is milled, spot-faced, threaded, burred and stabilized by heat-treating.
Claim 7
Dependent Claim
53 words
6) Filter according to the claim 1, characterized in that the filter body with relevant cavities, resonators and holes, manufactured by pressure die-casting of an aluminium alloy, preferably followed by a light flattering of the parallelepiped faces, by a spot-facing of the holes on the vertical longitudinal and transversal faces and by tumbling.
Claim 8
Dependent Claim
37 words
7) Filter according to claim 6, characterized in that during the pressure die-casting, the resonant cavities are obtained with a light draft taper and all the filter body is further lightened obtaining shaped empty recesses in it.
Claim 9
Dependent Claim
23 words
8) Filler according to claim 7, characterized in that the initially dead holes are advantageously transformed into through holes owing to lightening recesses.
Claim 10
Dependent Claim
53 words
9) Filter according to claims 5 and 6, characterized in that - the ratios among the diameters Dc of the various cavities and dr of the relevant resonators that are variable, preferably decreasing in the passage from the central cavities, that are hierachically more important, as to electric losses, than the peripheric ones.
Claim 11
Dependent Claim
19 words
10) Filter according to claim 9, characterized in that the ratios Dc/dr decrease from ab. 3.5 to ab. 2.5.
Claim 12
Dependent Claim
24 words
11) Filter according to claims 9 and 10, characterized in that the diameter of the cavity is variable and the resonators diameter is constant.
Claim 13
Dependent Claim
62 words
12) Filter according to claim 6, characterized in that it is used the pressure die-casting alloys having an high flowability in the dies and the relavant dilatation coefficient is compensated using syntony rods and screws, made of materials different from the said pressure die-casting alloy and having different coefficients for getting the range of frequency variation versus temperature within very restricted limits.
Claim 14
Dependent Claim
35 words
13) Filter according to claim 12, characterized in that the cavities are made of aluminium-silicium alloy (more than copper and traces of iron) and the rods and the screws are of iron-lead or copper-zinc alloys.
Claim 15
Dependent Claim
36 words
14) Filter according to claim 7, characterized in that the taper of the cavities is ab. 2% and the lightenings of the full walls are got making the wall thicknesses within the limits od 2÷4 mm..
Claim 16
Dependent Claim
32 words
15) Filter according to the previous claims, characterized in that the cavity diameters and the broken line segments are equal for couples of cavities placed simmetrically with respect to the central cavity.
Claim 17
Dependent Claim
56 words
16) Filter according to the previous claims, characterized in that, having the holes of input and output connectors placed on two different longitudinal axes, when one of the two holes is fixed in obliged position, it is allowed to the other hole to assume different positions turning the filter around the axis of the fixed hole.
Claim 18
Dependent Claim
11 words
17) Pluricavities microwave filter, substantially according to what described and represented.
Claim 19
Dependent Claim
11 words
17) Pluricavities microwave filter, substantially according to what described and represented.
References Cited (Backward Citations)
No citation records indexed.
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