An improved uncalibrated metal diaphragm antenna diplexer

Abstract

 An improved uncalibrated metal diaphragm antenna diplexer comprises an outer conductive metal material casing (2), containing a metal thin sheet extending longitudinally of said diplexer and thereon diaphragms (6) defining therebetween resonating cavities (7) are formed, said casing (2) further supporting signal input/output guides (8, 9) and a T joint (5), characterized in that the first/last of said resonating cavities (7A) is formed at said inlet/output guides (8, 9).

Description

BACKGROUND OF THE INVENTION

[0001] The present invention relates to an improved uncalibrated metal diaphragm antenna diplexer.

[0002] The field of the invention is that of the antenna diplexer arrangements, that is those devices allowing to convey microwave signals from a transmitter to an antenna, and respectively from an antenna to the receiver.

[0003] As is known, antenna diplexer arrangements including an uncalibrated metal diaphragm, must fit size tolerances which could affect, mainly at a diaphragm measurement level, the diplexer arrangement performance (in terms of band width, matching properties, central frequency and so on).

[0004] Also known is the fact that at present the number of filter cavities depends on the overall diplexer size, which, in turn, must properly fit the size of the system the diplexer arrangement must be assembled to.

[0005] Thus, for the above reason, in a standard size arrangement, the diplexer performances are fixedly set, and could not be improved without exceeding a preset constructional size.

SUMMARY OF THE INVENTION

[0006] Accordingly, the main object of the invention is to provide a novel and improved uncalibrated metal diaphragm antenna diplexer, which, with respect to prior like devices, has very improved properties, in particular from a selectivity and band width standpoint, without exceeding a standard size provided for such a diplexer arrangement.

[0007] The above aim, as well as yet other objects, which will become more apparent hereinafter, are achieved by the antenna diplexer according to claim 1.

[0008] Further preferred embodiments of the invention are defined in the other claims.

[0009] With respect to prior uncalibrated metal diaphragm antenna diplexers, the inventive diplexer has the advantage that it comprises, the distance between the diplexer inlet/output parts being the same, a great number of resonant cavities.

[0010] Thus, it is possible either to achieve a greater diplexer selectivity or, alternatively, a larger band, the selectivity being the same.

[0011] In particular in this latter case, the inventive diplexer arrangement is adapted to fit or compensate for the effect of its constructional tolerances, without negatively affecting the diplexer performance, the diplexer size being the same (with great advantages allowing the diplexer arrangement to be easily made at a low cost.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above mentioned aim and objects, advantages and features of the invention will become more apparent hereinafter from the following detailed disclosure of a preferred embodiment of the invention, which is illustrated, by way of an indicative, but not limitative, example in the accompanying drawings, where:

Figure 1 shows an exemplary construction of a prior uncalibrated metal diaphragm antenna diplexer;

Figure 2 is a perspective view showing a diagram of the inventive diplexer;

Figure 3 is a top plan view showing the inventive diplexer of Figure 2;

Figure 4 is a further perspective view showing a detail of the bent or curved portion of the antenna diplexer shown in Figure 2; and

Figure 5 is yet another perspective view showing the diplexer according to the present invention in an assembled condition thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Figure 1 shows a prior antenna diplexer, generally indicated by the reference number 1.

[0014] That prior antenna diplexer comprises a metal casing 2, forming the diplexer rectangular wave guide, in which casing are formed the transmitter and receiver bent portions 3 and 4, and the T joint 5 for providing an antenna connection.

[0015] At the bent portions 3 and 4 of said metal casing 2 input/output guides 8 and 9 are provided.

[0016] Said metal material casing 2 also contains a metal thin sheet element, extending longitudinally of said diplexer and made of a conductive metal blade or sheet element, thereon are formed the diaphragms 6 defining therebetween the filter resonating cavities 7.

[0017] As shown in the above prior embodiment, the first resonating cavity 7A of the receiving or transmitting filter, being formed by the first diaphragm 6a, is arranged at an end of the bent portion (that is either downstream or upstream of the latter, depending on the transmitting or receiving filter branch).

[0018] Accordingly, the diplexer spaces occupied by the diplexer bent portions 3 and 4 do not affect the filter performance, that is said spaces are passively operating with respect to the diplexer signal processing.

[0019] Thus, the performance of the above prior diplexer are strictly related to that of the resonating cavities arranged between the bent portion 3 (or 4) and the T joint 5.

[0020] Figure 2 shows the inventive diplexer, generally indicated by the reference number 10.

[0021] The inventive diplexer also comprises a metal conductive material casing 2, having a quadrangular configuration, and including signal input/output guides 8 and 9, and a T joint guide 5.

[0022] Said metal material casing 2 comprises a conductive material sheet element, including a plurality of diaphragms 6, therebetween corresponding resonating cavities 7 are formed.

[0023] According to the present invention, the first (or last) resonating cavity 7A is formed at the signal input/output guides 8, 9.

[0024] Moreover, the first (or last) resonating cavity 7A is interconnected to said inlet/output guides 8 and 9 at an iris 11 thereof, said cavity 7A being arranged on the longitudinal axis 12, or on an axis parallel to said longitudinal axis, of said guides 8, 9 in turn perpendicular to the longitudinal axis 13 of the diplexer casing 2.

[0025] Thus, differently from the prior antenna diplexer shown in Figure 1, in the space between the T joint 5 and guide 8, instead of a conventional bent portion 3 (or 4), the first (or last) resonating cavity 7A is arranged.

[0026] Consequently, in that same operating space of the filters is formed an additional resonating cavity which may be used either for increasing the filter selectivity, or for increasing the antenna diplexer pass band, the diplexer antenna selectivity being the same.

[0027] In this latter case, the diplexer shown in Figure 2 is also adapted to compensate for, the diplexer size being the same, the machining operation dimensional errors.

Claims

1. An antenna diplexer of a type including an uncalibrated metal diaphragm, comprising an outer conductive metal material casing (2), containing a metal thin sheet extending longitudinally of said diplexer and thereon diaphragms (6) defining therebetween resonating cavities (7) are formed, said casing (2) further supporting signal input/output guides (8, 9) and a T joint (5), characterized in that the first/last of said resonating cavities (7A) is formed at said inlet/output guides (8, 9).

2. A diplexer, according to claim 1, characterized in that said first/last resonating cavity (7A) is interconnected to said inlet/output guides (8, 9) at an iris (11) thereof.

3. A diplexer, according to claim 2, characterized in that said iris (11) is arranged on a longitudinal axis (12), or on an axis parallel to said longitudinal axis, of said guides (8, 9), in turn perpendicular to a longitudinal axis (13) of said diplexer casing (2).

Drawing