Protection apparatus for a hollow conductor and method for producing a protection apparatus

Abstract

A housing apparatus is described which comprises a hollow conductor which is adapted for guiding an electromagnetic wave having a predeterminable wavelength and which comprises an edge surface which extends substantially perpendicularly to the propagation direction of an electromagnetic wave guided by the hollow conductor, wherein the housing apparatus comprises both a wall element and a protection apparatus having a bearing surface. The wall element holds the protection apparatus on an end of the hollow conductor by means of a pressing force.

Claims

1. A housing apparatus, comprising: a hollow conductor adapted for guiding an electromagnetic wave having a predetermined wavelength comprising an edge surface extending substantially perpendicularly to a propagation direction of an electromagnetic wave guided by the hollow conductor; a wall element configured to at least one of absorb and exert a force acting substantially perpendicularly to the propagation direction of the electromagnetic wave, the wall element being formed at least in part as an antenna device, the antenna device comprising at least one of a process separation and a filling at a first end, the antenna device adapted to guide and beam form the electromagnetic wave received by the hollow conductor; and a protection apparatus comprising a bearing surface and having a longitudinal axis extending perpendicularly to the bearing surface, the protection apparatus arranged on an end of the hollow conductor to at least one of absorb and exert a force directed substantially perpendicularly to the propagation direction of the electromagnetic wave so that the bearing surface of the protection apparatus maintains contact with the edge surface of the hollow conductor, the protection apparatus arranged between the hollow conductor and the antenna device, the protection apparatus further comprising: a fastening device fastening the protection apparatus to the end of the hollow conductor, the fastening device designed to at least one of absorb a force acting substantially perpendicularly to the longitudinal axis and exert a force acting substantially perpendicularly to the longitudinal axis to maintain the bearing surface in contact with the edge surface of the hollow conductor; and a blocking device having a predetermined sealing effect and adapted to allow the electromagnetic wave guided by the hollow conductor to pass through in a substantially unattenuated manner, the blocking device comprising the bearing surface that is maintained in substantially direct contact with the edge surface of the hollow conductor by the fastening device.

2. The housing apparatus of claim 1, wherein the fastening device comprises a ring.

3. The housing apparatus of claim 2, wherein the ring is a press-in ring.

4. The housing apparatus of claim 2, wherein the ring is made of stainless steel.

5. The housing apparatus of claim 2, wherein the ring is configured to absorb a pressure produced when pressing the ring into the wall element.

6. The housing apparatus of claim 2, wherein the blocking device is formed as a film.

7. The housing apparatus of claim 6, wherein, inside the ring, the film is configured to be freely movable and not rigid.

8. The housing apparatus of claim 6, wherein the ring has at least two openings, and wherein the film is laminated onto the ring to seal one of the two openings of the ring.

9. The housing apparatus of claim 6, wherein the film has a predetermined sealing effect and is substantially permeable to the electromagnetic wave.

10. The housing apparatus of claim 2, wherein the blocking device is formed from a dielectric material.

11. The housing apparatus of claim 2, wherein the blocking device is formed from a material selected from the group of materials consisting of PFA, PTFE, PEEK, PFA, FKM, FFKM, and silicone.

12. The housing apparatus of claim 2, wherein the blocking device is formed in the shape of a disc.

13. The housing apparatus of claim 2, wherein the blocking device is formed in the shape of one of a cone, a lens, and a sphere.

14. The housing apparatus of claim 1, wherein the protection apparatus is configured so that: electromagnetic energy is exchangeable between an interior of the hollow conductor and an interior of the antenna device; and a flow of material is prevented between the interior of the hollow conductor and the interior of the antenna device.

15. The housing apparatus of claim 14, wherein the protection apparatus protects against penetration of atmosphere or condensate from the antenna device into the hollow conductor.

16. The housing apparatus of claim 1, wherein the housing apparatus is configured so that an interior of the hollow conductor transitions into an interior of the antenna device.

17. The housing apparatus of claim 16, wherein the protection apparatus covers the transition of the interior of the hollow conductor into the interior of the antenna device.

18. The housing apparatus of claim 1, wherein the at least one of the process separation and the filling is arranged behind the protection apparatus when viewed in a transmission direction of the electromagnetic wave.

19. A field device, comprising: a sensor configured to at least one of generate and receive an electromagnetic wave; and a housing apparatus, comprising: a hollow conductor adapted for guiding an electromagnetic wave having a predetermined wavelength and comprising an edge surface extending substantially perpendicularly to a propagation direction of the electromagnetic wave guided by the hollow conductor; a wall element configured to at least one of absorb and exert a force acting substantially perpendicularly to the propagation direction of the electromagnetic wave, the wall element being formed at least in part as an antenna device, the antenna device comprising at least one of a process separation and a filling at a first end; and a protection apparatus comprising a bearing surface, the propagation apparatus arranged on an end of the hollow conductor to at least one of absorb and exert a force directed substantially perpendicularly to the propagation direction of the electromagnetic wave so that the bearing surface of the protection apparatus maintains contact with the edge surface of the hollow conductor.

20. A protection apparatus for a hollow conductor adapted for guiding an electromagnetic wave having a predetermined wavelength and comprising an edge surface extending substantially perpendicularly to the electromagnetic wave guided by the hollow conductor, the protection apparatus comprising: a fastening device configured to fasten the protection apparatus to an end of the hollow conductor; and a blocking device having a predetermined sealing effect and adapted to allow the electromagnetic wave guided by the hollow conductor to pass through in a substantially unattenuated manner, the blocking device comprising a bearing surface that is maintained in substantially direct contact with the edge surface of the hollow conductor by the fastening device, wherein the protection apparatus having a longitudinal axis extending perpendicularly to the bearing surface, and wherein the fastening device is designed to at least one of absorb a force acting substantially perpendicularly to the longitudinal axis and exert a force acting substantially perpendicularly to the longitudinal axis to maintain the bearing surface in contact with the edge surface of the hollow conductor.

21. A method for producing a protection apparatus for a hollow conductor, comprising: providing a stainless steel ring having a predetermined external diameter, the stainless steel ring configured so that the protection apparatus is fastenable to an end of the hollow conductor using the stainless steel ring; providing a film having a predetermined sealing effect, wherein the film is substantially permeable to an electromagnetic wave, the hollow conductor configured to guide the electromagnetic wave having a predetermined wavelength; laminating the film onto the stainless steel ring so that at least one of the two openings of the stainless steel ring is sealed by the film; and cutting the film so that the film aligns with the external diameter of the stainless steel ring.

22. The method of claim 21, further comprising: sealing a gap between the film and the stainless steel ring using the lamination to generate a condensate-tight connection between the stainless steel ring and the film.

23. The method of claim 21, further comprising: forming the film from a material selected from a group of materials consisting of dielectric material, PFA, PTFE, PEEK, PFA, FKM, FFKM, and silicone.

24. The method of claim 21, further comprising: shaping the film when laminating so that the film is shaped in a conical, a spherical, or a lens shape.

25. The method of claim 21, wherein the hollow conductor comprises an edge surface extending substantially perpendicularly to the electromagnetic wave; wherein the film has a bearing surface, which is oriented perpendicularly relative to a longitudinal axis of the protection apparatus; and wherein the stainless steel ring is configured to absorb a force acting substantially perpendicularly to the longitudinal axis to maintain the bearing surface in contact with the edge surface of the hollow conductor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, further embodiments of the present invention will be described with reference to the figures:

(2) FIG. 1 shows a cross section of a housing apparatus comprising a protection device according to an exemplary embodiment of the present invention.

(3) FIG. 2 shows a cross section of a protection apparatus according to an exemplary embodiment of the present invention.

(4) FIG. 3 shows a conical protection apparatus according to an exemplary embodiment of the present invention.

(5) FIG. 4 shows a spherical protection apparatus according to an exemplary embodiment of the present invention.

(6) FIG. 5 shows a modular housing apparatus comprising a protection apparatus according to an exemplary embodiment of the present invention.

(7) FIG. 5a shows a protection apparatus formed in one piece according to an exemplary embodiment of the present invention.

(8) FIG. 6 shows a detail of the coupling region of FIG. 5 according to an exemplary embodiment of the present invention.

(9) FIG. 7 shows a side view of a housing adapter according to an exemplary embodiment of the present invention.

(10) FIG. 8 shows a diagram of the adaptation parameter S11 over the frequency according to an exemplary embodiment of the present invention.

(11) FIG. 9 shows a far field region of an antenna characteristic according to an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

(12) The drawings are schematic and not to scale.

(13) In the following description of FIGS. 1 to 9, the same reference numerals are used for the same or corresponding elements. However, like or similar elements may also be denoted by different reference numerals.

(14) FIG. 1 shows a cross section of the housing apparatus 120, which is formed from a single piece, according to an exemplary embodiment of the present invention. The housing apparatus 120 comprises the wall element 101 or wall device 101 in which the hollow conductor 102 is embedded. In one example, the hollow conductor is produced in the interior of the wall element. In another example, the hollow conductor is a metal pipe which is incorporated into the wall element. The hollow conductor 102 is incorporated into the wall element 101, for example by drilling. The housing adapter is produced from plastics material for example, which is coated internally, i.e. on the hollow conductor wall 130, with an electrically conductive material in order to guide an electromagnetic wave along the hollow conductor 102 or wave guide 102. The hollow conductor 102 or wave guide 102 comprises a pipe-shaped portion 102a and a conical portion 102b.

(15) The hollow conductor is an axisymmetric or a rotationally symmetric structure, which is produced symmetrically with respect to the longitudinal axis 103. The external contours of the housing 120 are also produced rotationally symmetrically with respect to the longitudinal axis 103. The longitudinal axis 103 may extend parallel to a propagation direction of an electromagnetic wave in the hollow conductor.

(16) An HF cup (high-frequency cup), a sensor, or the HF module, together with the electronics thereof, can be integrated into a cavity 104 or HF cavity 104 shown in the top region in FIG. 1. The HF module and the HF cup are not shown in FIG. 1. The HF module or the sensor can be positioned in the HF module cavity 105. The HF module cavity 105 and the HF cavity 104 are both designed to be cylindrical. However, the HF module cavity 105 is designed to be smaller than the HF cavity 104. The HF module can generate an electromagnetic wave in the HF module cavity 105, which wave travels along the longitudinal axis 103 towards the hollow conductor opening 106 as a transmission signal. The hollow conductor opening 106 is determined by the conical portion 102b. The diameter of the hollow conductor opening 106 corresponds to a diameter which is dependent on the guided wavelength and the subsequent antenna device 107. In other words, the diameter of the opening 106 ensures a transition which is as free of reflections as possible into the conical region 107 denoted by reference numeral 107 which forms the antenna device 107 or the antenna 107 of the hollow conductor-antenna system 120. The antenna device 107 can itself be interpreted as a hollow conductor portion which is separated from the cylindrical hollow conductor portion 102a and/or the conical hollow conductor portion 102b by the protection apparatus 100. The transition location, on which the protection apparatus 100 is arranged, is designed such that a reflection value produced by the protection apparatus and the transition is minimal. The minimum can be determined by tests, by minimising the S11 parameter. In particular, the hollow conductor 102 and the antenna device 107 are electrically adapted or matched to one another.

(17) The conical antenna region 107 is also incorporated into the wall element 101 in a rotationally symmetrical manner and coated with an electromagnetically conductive material. The protection apparatus 100 is integrated between the antenna opening 108 in an input region of the antenna 107 which forms the antenna input 108, and the opening 106 of the hollow conductor 102 which forms an output of the hollow conductor 102. The protection apparatus 100 is designed as a stainless steel ring 114 or a press-in ring 114 which is sealed by a film 110. The protection device 100 is pressed in at the press-in location 133, which also corresponds to an annular region inside the wall element 101, such that the bearing surface 109 of the blocking device 100 is positioned on a shoulder 131 of the wall element 101 extending perpendicularly to the longitudinal axis 103. Since the shoulder is part of the wall element 101 and thus also part of an edge region of the hollow conductor 102, the blocking device 110 is positioned together on the edge surface 131 of the hollow conductor 102 by using the bearing surface 109.

(18) The press-in location 133 of the wall element 101 exerts a pressing force on the casing surface 132 of the press-in ring 114. The interior region 112 of the hollow conductor 102 can be sealed off from the interior region 113 of the antenna device 107 by means of the pressing on the locations 133, 132 and/or the abutting to the edge surface 131 of the hollow conductor. Both the pressing 133, 132 and the film 110 prevent diffusion of matter or material between the cavity 113 of the antenna 107 and the cavity 112 of the hollow conductor 102. Moisture which is still penetrating into the lower region 113 of the antenna device 107 can thus be substantially prevented from rising further towards the HF module cavity 105. The pressing forces are substantially absorbed by the stainless steel ring 114 of the protection apparatus 100, with the result that the blocking device 110 is substantially free from high compressive forces or pressing forces. The blocking device 110 maintains contact, by means of the bearing surface 109 thereof, with the edge surface, wherein selecting pressure with which the bearing surface 109 and the edge surface 131 are pressed together is possible as desired. The hollow conductor opening 106 is consequently sealed.

(19) The blocking apparatus 100 can substantially prevent material from rising through the antenna device 107 from a container region or process region denoted by the letter A in FIG. 1 towards the HF module cavity 105, although both the antenna device 107 and the hollow conductor 102 are substantially unfilled or hollow. In FIG. 1, A denotes a region below the HF module cavity 105. The filling material may be located in region A. In one example, the interior region 113 of the antenna device 107 may be encapsulated, sealed or casted by material or the antenna opening 134 may be closed by means of an enclosure, a capsule or a casing. However, despite a process separation of this type (not shown in FIG. 1), condensate may still penetrate into the hollow conductor 102. The protection apparatus 100 may prevent additional penetration of the condensate into the hollow conductor 102, in particular into the interior region 112 of the hollow conductor 102.

(20) FIG. 2 shows a cross section of the protection apparatus 100 from FIG. 1 according to an exemplary embodiment of the present invention. FIG. 2 shows a disc-shaped protection apparatus 100. The disc-shaped protection apparatus comprises a disc 110 as a blocking device. Said disc 110 or disc-shaped blocking device 110 is arranged on a stainless steel press-in ring 114 which is produced from stainless steel and comprises the two openings 200a and 200b. If the disc-shaped blocking device 110 is formed to be very thin, the blocking device 110 can be referred to as a disc-shaped film 110 or a film 110. The film 110 is laminated onto one of the openings 200b as a blocking device 110. The film 110 is produced from PFA or PTFE material and covers one of the two openings 200a, 200b so that there can be substantially no flow of material through the openings 200a, 200b. In FIG. 2, the covered opening 200b may be referred to as the upper opening of the stainless steel press-in ring 114. The opening 200a may be referred to as the lower opening. The lower opening may face a filling material when used in a hollow conductor. The protection apparatus 100 is shown as an axisymmetric element with respect to the longitudinal axis 103. The protection apparatus 100 comprises a bearing surface 109 which can come into contact with the edge surface 131 of a hollow conductor. In particular, the bearing surface 109 is the part of the protection apparatus which is in contact with the fastening device 114. The film 110 is laminated onto the stainless steel ring 114 in the form of a membrane. In one example, the bearing surface 109 substantially corresponds to an edge surface of the stainless steel ring 114.

(21) FIG. 3 shows a conical protection device according to an exemplary embodiment of the present invention. When producing the protection apparatus 100a as a cone, the film 110a, which may be produced from PFA or PTFE, is laminated onto the stainless steel press-in ring 114. The bearing surface 109a is formed on the blocking device 110a along the stainless steel ring 114, in particular along an edge surface of the stainless steel ring 114. The blocking device 110a covers the upper opening 200b but is designed to be conical along the axis of symmetry 103 towards the lower opening 200a. Said conical design can be used for beam formation or beam forming.

(22) FIG. 4 shows a spherical protection apparatus 100b which comprises the stainless steel ring 114 and the film 110b. The bearing surface 109b is formed on the blocking device 110b along the stainless steel ring 114, in particular along an edge surface of the stainless steel ring 114. The film 110b is laminated onto the stainless steel press-in ring 114 as a blocking device 110b and covers the opening 200b of the stainless steel ring. The film, which may be produced from PFA or PTFE, is spherical towards the lower opening 200a. The blocking apparatus 100b is produced so as to be rotationally symmetrical with respect to the longitudinal axis 103. Beam forming can be achieved by the spherical or lens-shaped design.

(23) As shown in FIG. 2, a protection apparatus may be produced in the form of a PFA disc 110 or a PTFE disc 110 which is laminated onto a stainless steel ring 114. A condensate-tight connection can be produced between a metal ring 114 and a disc 110 by means of a laminated connection. A condensate-tight connection may mean that the press-in ring 114 can be pressed so firmly against a housing wall 101 of the housing 120 at the location 133 that substantially no condensate can pass through said pressing. The pressing is carried out in such a way that the sealing complies with the standard IP67. The pressing locations 132, 133 take the form of a press fit or an interference fit in such a way as to allow assembly by means of pressing. This means that the protection apparatus 100 is held inside the hollow conductor-antenna system 120 substantially solely by the pressing force of the wall element 101.

(24) As shown in FIGS. 3 and 4, the blocking device or blocking apparatus 110, 110a, 110b can be shaped when laminating the disc 110, 110a, 110b. For the purpose of shaping, the disc is pressed into an appropriate shape. By means of shaping, a conical protection apparatus 100a or a spherical protection apparatus 100b can be produced, as can a lens-shaped protection apparatus (not shown). Due to said shapes, for example the conical, spherical or lens shape, microwaves in a hollow conductor 102 can pass in a low-attenuated manner from the hollow conductor through the protection device.

(25) Despite the presence of a process separation (not shown in FIG. 1) and despite other protection measures which are intended to prevent material or condensate from penetrating from region A into the antenna device 107 or into the interior 113 of the antenna device 107, small amounts of the condensate may develop inside the hollow conductor-antenna system 120, i.e. inside the combination of the hollow conductor 102 and the antenna device 107. Said condensate may both affect the measuring signal and produce a damaging effect in an HF module arranged in the HF module cavity 105 if said condensate penetrates as far as the module. In particular, condensate which develops behind a process cover (not shown in FIG. 1) on the antenna opening 134 in the antenna region 107 or in the antenna device 107 may lead to measuring errors. On the other hand, condensate which develops in the hollow conductor 102, in particular in the interior of the hollow conductor 112, and perhaps even penetrates to the HF module in the HF module cavity 105 may lead to the omission of a measurement. The diffusion barrier 100 or the protection apparatus 100, which is incorporated in addition to a process separation or process cover (not shown in FIG. 1), can as far as possible prevent moisture, material, condensate or a gas from further rising up towards the HF module cavity 105 from region A, and can thus contribute to secure or accurate measuring. The protection apparatus 100 is arranged parallel to the antenna opening 134 and/or parallel to the hollow conductor opening 106. In particular, the longitudinal axes 103 of the protection apparatus 100 are arranged parallel to the longitudinal axis of the antenna opening 134 and/or parallel to the longitudinal axis of the hollow conductor opening 106. Or, in other words, the surface of the protection apparatus 100 is arranged parallel to the surface of the antenna opening 134 and/or parallel to the surface of the hollow conductor opening 106.

(26) FIG. 5 shows a cross section of a modular housing apparatus comprising a protection apparatus according to an exemplary embodiment of the present invention. The housing apparatus 500 is constructed from two elements 502, 503 which can be separated from one another. The housing element 502 or housing device 502 which contains the hollow conductor 501, or the housing adapter 502, is attached to the housing element 503 or housing device 503 which contains the antenna device 507. The hollow conductor housing device 502 or the housing adapter 502 can be separated from the antenna housing device 503 containing the antenna device 507. The housing adapter 502 comprises the HF module cavity 504, and the hollow conductor 501 is constructed from two hollow conductors 501a and 501b. The HF module cavity 504 can receive an HF module (the HF module is not shown in FIG. 5). The hollow conductor 501a and the hollow conductor 501b are separated by means of the Exd separating element 505. Said Exd separating element is formed as a glass window. The Exd separating element is a zone-separating element and divides the hollow conductor 501 into two regions 501a, 501b which are separated from each other.

(27) The housing adapter 502 and the housing device 503 of the antenna come into contact in the coupling region 506. The protection apparatus 508 is arranged between the hollow conductor housing device 502 and the antenna housing device 503. The protection apparatus 508 is designed as a condensation barrier and is formed in one piece as a turned part.

(28) FIG. 5a shows a protection apparatus 508 formed in one piece according to an exemplary embodiment of the present invention. The one-piece and gap-free construction should be noted, in which the functional regions of the fastening device 604, the protection device 609 and the bearing surface can be distinguished.

(29) FIG. 6 shows a detail of the transition region or coupling region 506 of FIG. 5 according to an exemplary embodiment of the present invention. FIG. 6 shows the trumpet-shaped end 501c of the hollow conductor 501. In addition, the housing wall or wall element 601 of the housing device 502 is portrayed, into which wall device the hollow conductor is incorporated. The hollow conductor 501b, 501c is incorporated into the housing wall element 601 as a pipe-shaped portion. The hollow conductor 501e comprises the edge surface 602. Said edge surface 602 can come into contact with the bearing surface 603 of the blocking device 508.

(30) The protection apparatus 508 is fixed to the hollow conductor 501c, in particular to the wall device 502, the wall element 502 or the wall 502 of the hollow conductor, by means of the snap fastener 604 which represents the fastening device 604 of the protection apparatus 508. The wall element 502 of the hollow conductor 501c thus comprises corresponding recesses in the region of the trumpet-shaped portion 501c of the hollow conductor, in which recesses the snap devices 604, formed as brackets, can engage. The brackets 604 or the fastening device 604 exert(s) a force which is directed towards the wall 502 of the hollow conductor and thus holds the protection apparatus 508 on the hollow conductor 501b, 501c. The pressure on the wall 502 can be increased by the wall element 503 or wall device 503. In other words, the protection apparatus 508 encloses or encapsulates the hollow conductor from an external region. The snap device can ensure that the protection apparatus 508 cooperates with the housing wall 503 of the antenna device. A sealing effect can be achieved by corresponding surfaces adjoining one another. The wall device 502 comprises a further cavity 530.

(31) The diameter of the hollow conductor 501 is determined by the signal frequency or used frequency at which the HF module operates. Thus, for different HF modules, a different antenna-hollow conductor system 120, 500 can be provided in each case.

(32) The protection apparatus 508 is designed as a conical protection apparatus, so that a conical cavity 605 is produced as a continuation of the trumpet-shaped cavity 501c of the hollow conductor. The conical cavity 605 is designed such that the protection apparatus 508 has a uniform or homogeneous wall thickness beginning from the bearing surface 603.

(33) FIG. 6 also shows the wall region 606 which is in contact with the fastening device 604. Said wall region 606 is located in the vicinity of the coupling region 506 of the antenna device 503. The wall region 606 exerts a pressure on the fastening device 604 parallel to the hollow conductor opening 630, parallel to the hearing surface 603 and/or parallel to the edge surface 602. The pressure may be high, since the pressure is absorbed by the wall device 531 of the housing device 502 of the hollow conductor 501c. The round shape of the hollow conductor 501c favours high force absorption. The sealing effect can be adjusted by means of the pressing forces.

(34) The antenna 507 or the antenna hollow conductor 507 is incorporated into the wall region 606 of the antenna housing device 503. The antenna 507 or the antenna hollow conductor 507 may be a recess in the housing wall 606 of the antenna housing device 503 which is coated with a conductive material. The conical blocking device 609 of the conical protection apparatus 508 projects into the antenna pipe 507.

(35) The wall region 607 of the hollow conductor end 501c is at a distance from a wall region 608 of the antenna wall. The spacing is produced by the hollow conductor housing device 502 and/or the wall 531, 631 thereof and the protection device 508, in particular the fastening means 604 thereof.

(36) In the coupling region 506, the housing wall 531 of the housing adapter 502 or of the hollow conductor 501 and the wall 606 of the housing device 503 of the antenna region 507 overlap. It is therefore possible for the antenna wall 606 to exert a force on the fastening device 604 in the direction of the hollow conductor 501c and to substantially seal the transition from the antenna region 507 into the hollow conductor 501c.

(37) The antenna device 507 comprises the process separation 509 at a lower end which is directed towards a filling material and is shown by the letter B in FIG. 5. The process separation 509 is designed in a lens shape and covers the antenna opening 510 such that substantially no direct transition can occur from the filling material region B or the process region B into the interior of the antenna device 507. FIG. 5 thus shows a level radar-antenna system 500 comprising a process separation 509, a condensate barrier 508 and an Exd separating element 505.

(38) FIG. 7 shows a side view of the hollow conductor housing element 502 or the housing adapter 502. A protection apparatus 508, formed in one piece, is arranged on the housing adapter 502, which apparatus comprises the fastening device 604 and the blocking device 609. The blocking device 609 and the fastening device 604 are produced from the same material.

(39) Dielectrically conductive material, for example PTFE, PEEK, PFA or elastomers, such as in the case of O-rings, may be used as the material for the blocking device 100, 100a, 100b, 100c, 110a, 110b, 609. FKM, FFKM and silicone may also be used. PFA can be particularly suitable for production as an injection-moulded part, i.e. for production in one piece or in a monolithic manner. Simple assembly of the blocking apparatuses in the hollow conductor is possible on account of the arrangement of the blocking apparatus in the hollow conductor. In particular, the design in one piece permits simple assembly.

(40) The housing adapter 502 is a cylindrical body having a tapering or pointed end region 701. Said end region 701 is located in the region of a hollow conductor end 501c (not shown in FIG. 7) in the interior of the housing adapter 502. The diameter of the neck-like end region 701 or the housing neck 701 is narrower than the diameter of the housing adapter, such that the housing adapter 502 acquires a bottle-like shape. As shown in FIGS. 5 and 6, the housing adapter 502 can be releasably connected to an antenna housing device 503. In this way, the conical blocking device 609 can emit an electromagnetic wave from the housing adapter towards the point of the cone. It is also possible to receive an electromagnetic wave through the blocking device 508 in the opposite direction from the point of the cone of the conical blocking device 609 and to transport said wave onwards in the interior of the housing adapter in the hollow conductor system 501 present therein. The condensate barrier 508 or blocking device 508 prevents moisture and/or other material from penetrating into the interior of the housing adapter 502. The hollow conductor 501 and the antenna device 507 are substantially hollow.

(41) FIG. 8 shows a diagram of the S-parameters over the frequency according to an exemplary embodiment of the present invention. In particular, the adaptation parameter S11 which describes the reflective properties is shown in FIG. 8. The diagram in FIG. 8 relates to the hollow conductor-antenna system 500 of FIG. 5.

(42) The curve 801 shown on the coordinate system 800 is a reflection curve showing the portion of an electromagnetic wave which is reflected on a protection apparatus 100, 508. The ordinate or Y-axis 802 shows an adaptation curve S11 in the unit dB, which curve has the negative values of from 50 dB to 0 dB. The abscissa or X-axis 803 shows the frequency in GHz, which ranges from 74 GHz to 84 GHz. It can be seen that the reflection curve 801 has a substantially constant course.

(43) FIG. 9 shows a far field region of an antenna characteristic of a hollow conductor-antenna system 120, 505 which can be reached using an antenna device 107, 507. The presentation in FIG. 9 relates to the hollow conductor-antenna system 500 of FIG. 5. The polar coordinate system 900 shows the field strength in the radial direction and the radiation angle in the polar direction. In other words, FIG. 9 shows the longitudinal axis 103, 103a of the hollow conductor-antenna system by the polar axis 901 at +90 degrees. A transmission wave emitted from the HF module in the HF module cavity 105 would move towards the left-hand side in FIG. 9. It should be noted that a main lobe of the field diagram 902 is formed in the radiation direction, i.e. towards the left. Said lobe is rotated about 90 degrees proceeding from an axis of origin 902.

(44) In addition, it is pointed out that the terms comprising and having do not exclude any other elements or steps and a or one do not exclude a plurality. It should further be noted that features or steps which have been described with reference to one of the above embodiments may also be used in combination with other features or steps of other above-described embodiments. Reference numerals in the claims should not be interpreted as limiting.