EP3076139B1 - Protection device for a wave guide - Google Patents

Description

Field of the invention

The invention relates to the measurement technology. In particular, the invention relates to a housing device and a field device.

Technical background

Field devices, in particular field devices, which are used with sensors for measuring fill levels or limit levels are often based on runtime measurements. In the transit time measurements, the signal propagation times of radar signals or of guided microwave pulses are determined. Generally, the transit time of an electromagnetic wave is measured. The desired measured variable is then determined from these signal propagation times, for example a fill level or limit level.

The signals have a specific frequency. The radar signals and the microwave signals can be assigned to the field of high-frequency technology (HF technology). As signals that are in the field of high frequency technology, are in Normally signals in the frequency range up to 2 GHz are used as guided microwave signals and signals in the range from 5 GHz to 79 GHz and beyond are used as radar signals.

For safety reasons, it may be necessary for the electronics of the field device to be separated from the measuring environment, that is to say for example an interior of a container filled with a filling medium, in terms of explosion protection. The separation consists for example of a gas-tight seal. In this way it can be avoided that explosive substances or gas mixtures pass from the container interior to the electronics of the field device and ignite there. The IEC (International Electrotechnical Commission) standard IEC 60079-1: 2007, is identical to the standard for potentially explosive atmospheres ÖVE-ÖNORM EN 60079-1 and concerns the equipment protection by flameproof enclosure "d" (Equipment protection by flameproof explosures "d") , Devices that comply with explosion protection class "d", so-called Exd devices, meet the special requirements for the design and testing of electrical equipment in the type of protection Flameproof Enclosure "d", which are intended for use in gas explosive atmospheres.

EP 2 093 846 A1 describes a gas-tight conductor bushing for a field device, which can provide explosion protection. The conductor feedthrough is implemented in coaxial technology and is used for example in a frequency range between 5 and 28 GHz.

The publication EP 2 683 022 A1 describes a gas-tight waveguide coupling for coupling an electromagnetic transmission signal from a high-frequency module in a waveguide. The waveguide coupling may comprise a round disc of a printed circuit board substrate having a metallized edge for soldering to the waveguide.

The publication EP 2 683 023 A1 describes a waveguide coupling with a waveguide whose inner diameter widens in the direction of a planar radiating element.

The publication DE 10 2012 103 493 A1 discloses a first process separation and a second gas-tight ceramic process separation configured to pass the measurement signals and withstand higher mechanical stress than the first process separation.

Antennas can be protected by means of a process separation and / or by means of a filling, which obscures the antenna opening and protects against invading foreign substances. Despite encapsulated or partially filled antenna, it may happen that moisture forms in the waveguide.

Summary of the invention

It may be desirable to provide effective sealing of a waveguide and / or an RF module (high frequency module) for a waveguide. Accordingly, according to one aspect of the present invention, a housing device and a field device may be described.

The invention is indicated by the features of the independent claims. Embodiments and other aspects of the invention are indicated by the dependent claims and the description which follows.

According to one aspect of the invention, a housing device is described, which has a waveguide, which is designed to guide an electromagnetic wave having a predeterminable wavelength. The waveguide has a to the direction of propagation of a guided by the waveguide electromagnetic wave substantially perpendicular edge surface.

In addition, the housing device has a wall device and a protective device. In one example, the waveguide is in the wall device incorporated. This may mean that the edge surface is arranged substantially perpendicular to a longitudinal axis of the waveguide and / or the protective device. On the protective device, a bearing surface is formed, which can come into contact with the edge surface of the waveguide. The wall device is set up to receive a force acting essentially perpendicular to the propagation direction of the electromagnetic wave and / or to exert such a directed force. This means that the wall device is set up to receive a force acting essentially parallel to the bearing surface of the protective device and / or to exert such a directed force. In other words, the wall device is adapted to receive a force acting substantially perpendicular to a longitudinal axis of the waveguide and / or to the longitudinal axis of the protective device and / or to exert such a directed force.

The wall device is at least partially designed as an antenna device and the antenna device has at one end a process separation and / or a filling. In particular, the antenna device may have a partial and / or complete filling. The process separation, encapsulation, and / or filling may substantially prevent intrusion of unwanted matter into the interior of the antenna device.

The protective device is arranged at one end of the waveguide such that it receives and / or exerts a force that is directed substantially perpendicular to the propagation direction of the electromagnetic wave and / or that is directed perpendicular to the longitudinal axis of the protective device or the waveguide, so that the bearing surface of the protective device with the edge surface of the waveguide keeps in contact. In other words, the protection device is arranged at one end of the waveguide such that it has a force substantially parallel to the edge surface receives the waveguide and / or exerts, so that the bearing surface of the protective device with the edge surface of the waveguide keeps in contact.

In other words, this may mean that the protection device, in addition to the process separation and / or in addition to the filling, provides for a separation of the waveguide from the process. The process may refer to a process that takes place in an area intended for the process and in which arise products of a chemical reaction and / or in which a product is.

The process separation may prevent ingress of atmosphere within the hollow body of the antenna, i. H. For example, the penetration of the filling material or a gas. However, for example, it can not be prevented that minimum amounts of atmosphere or even condensate penetrate into the interior of the antenna / penetrates. These penetrating portions may be prevented from interfering with the process separation by preventing penetration of a waveguide and causing damage when the waveguide is connected to the antenna device.

According to another aspect of the present invention, a protective device for a waveguide is described. The waveguide is designed to guide an electromagnetic wave having a predeterminable longitudinal wave and has an electromagnetic wave guided to the waveguide, in particular to a longitudinal axis of the waveguide, substantially perpendicular edge surface. The electromagnetic wave may correspond to a mode dictated by the geometry of the waveguide.

The protective device has a fastening device which is designed to fasten the protective device at one end of the waveguide. Furthermore, the protection device has a locking device, wherein the locking device has a predeterminable sealing effect. The locking device likes prevent by the sealing effect diffusing the filling material and / or moisture in the interior of the waveguide substantially. The propagation direction of the electromagnetic wave may coincide with a longitudinal axis of the waveguide and / or with a longitudinal axis of the protective device.

Furthermore, the blocking device is designed for substantially undamped transmission of the electromagnetic wave guided by the waveguide. In one example, the barrier device may be low-attenuation for an electromagnetic wave. In other words, the barrier device may be configured to block matter in a predeterminable direction and to transmit electromagnetic waves in the opposite or both directions. In one example, the barrier device may transmit an electromagnetic wave in two directions, whereas it may block propagation of matter in the direction of the waveguide.

The locking device has a bearing surface, which is arranged substantially perpendicular to a longitudinal axis of the protective device. The bearing surface is held by the fastening device with the edge surface of the waveguide in a substantially direct contact. The attachment device is designed to receive a force acting essentially perpendicular to the longitudinal axis and / or a force parallel to the support surface and / or to exert a force acting essentially perpendicular to the longitudinal axis and / or a force acting parallel to the support surface, around the support surface with the edge surface of the waveguide in contact. The fastening device may absorb the fastening forces and thus leave the locking device substantially unloaded.

By applying pressure in a direction parallel to the support surface, a gap that may exist between the protection device and a wall device of a waveguide can be reduced so that a passage of unwanted matter, such as moisture, condensate or a filling can be prevented. The gap to be sealed may be formed substantially parallel to the propagation direction of an electromagnetic wave. In the direction substantially perpendicular to the propagation direction of the electromagnetic wave, by the pressure on the fastening means, the contact between the bearing surface and the peripheral surface can be adjusted so as to inhibit the propagation of matter also in this direction. The pressure keeps the protective device inside the wall device. The protective device may be pressed into the interior of the wall device, so that an interference fit between the wall device and the protective device is formed, which holds the protective device in its position. In particular, the protective device may form a press fit with the inner wall of the waveguide and / or the antenna device. Due to the interference fit, the density standard Exd and / or IP67 can be fulfilled.

In accordance with yet another aspect of the present invention, there is provided a field device having the housing device. The field device may be a level measuring device, in particular a measuring device which uses the free propagation of electromagnetic waves and / or the propagation of guided microwaves.

The following describes aspects which are not necessarily part of the claimed invention.

In another aspect, a method of manufacturing a protection device is described. The method comprises providing a stainless steel ring having a predeterminable outer diameter. Furthermore, the method has the provision of a film which has a predeterminable sealing effect and is substantially permeable to an electromagnetic wave. In one example, the film is made of PTFE or PFA and has a thin cross-section. In one example, the cross-section of the film may be so thin that the film within the stainless steel ring is free to move and not rigid.

The film is laminated to the stainless steel ring such that at least one of the two openings of the stainless steel ring is sealed by the film. There is a cutting of the film so that it is aligned with the outer diameter of the stainless steel ring. The lamination substantially seals a gap between the film and the stainless steel ring or press-fit ring. The press-fit ring or stainless steel ring is set up to absorb a pressure that arises when pressed into the wall device.

The locking device may be made of a material which has only a low pressure-absorbing capacity. By providing a fastening device which can take a higher pressure than the locking device, the locking device can be designed for installation in a housing with a certain pressure, wherein the pressure is in an area which ensures the fulfillment of the Exd norm to a Gap according to the Exd standard. Also, a waveguide wall located behind the barrier device can receive a correspondingly high pressure in cooperation with the fastening device.

A protection device for a waveguide may also be referred to as a diffusion barrier or waveguide diffusion barrier. A waveguide diffusion barrier can prevent, for example, condensate from rising into the waveguide system in an antenna system for a high-frequency radar level sensor. For encapsulated or partially filled antennas or antenna devices, the filling may be in contact with the medium to be measured. However, behind the filling of the antenna, ie in the direction of the waveguide or in the direction of an RF module, there may be a cavity, which is filled, for example, with air. Should liquid pass through the filling of the antenna by diffusion into this cavity, the moisture could be present directly underneath a microwave waveguide and / or directly on the RF module, in particular on an electronic system. The moisture would then be very close to the area of the RF module and could be at the Electronics of the HF module cause damage. In other words, despite the fulfillment of the Exd requirements of a process isolation encapsulated or filled antenna, moisture may form on the RF module when no protection device is used. The protection device may prevent moisture from occurring between the protection device and the RF module. The effect of the protective device may be enhanced by the use of an Exd separator, a zone-separating element or a glass window within the waveguide so that substantially no moisture occurs after the wafer or after the Exd separator.

In order to prevent rising of the liquid, which can pass through the encapsulation or filling of the antenna from a lower end of the waveguide through the waveguide, towards waveguides or even up to the electronics of the RF module, the protective device within the waveguide at a be installed appropriate place. The protective device or the waveguide diffusion barrier can be provided as a sole measure and / or as a supplementary measure to the encapsulation or filling of the antenna. In particular, the interaction of encapsulation, process separation and / or filling with the diffusion barrier can protect the RF module.

With the protection device, an additional diffusion brake is provided in the waveguide in an antenna system or waveguide system in addition to the process separation. With the protection device or diffusion brake, the RF module or the electronics may not only be protected against penetrating filling material, fluid or gas or against penetrating, solid substances or dust, but also against penetrating moisture. By the embodiment as a clamping part, pressing part or by providing a snap closure, a simple mounting of the protective device can be effected within the waveguide. The protection device may interact with the process separation and / or filling to provide double or multiple protection. The further the respective protective measure is removed from the contents of the more effective may be the protective effect. For example, the process separation may offer a rough protection against matter penetrating into the interior of the waveguide and the protection device a fine protection.

A shaping of the protective device can lead to beam shaping of the electromagnetic wave passing through the protective device and contribute to beam shaping. For beam shaping, the protective device, in particular the blocking device, can be designed to be conical, spherical or lenticular.

The diffusion barrier in a location that is further away from a pending contents, gas or fluid and located closer to the electronics, can protect the electronics and the waveguide itself from moisture penetration. In other words, the protection device may provide for encapsulation of the waveguide within the waveguide itself. The protection device can supplement the coarse protection at an antenna end, in particular at an antenna opening and / or at a waveguide opening. The protection device may provide protection essentially in the interior of an antenna device and / or in the interior of a waveguide. The coarse protection may be formed, for example, by a process separation and / or a filling.

In addition to the simple assembly by clamping, clamping, press-fitting or sealing presses can be created by these types of connection, a tight connection between the protection device and the waveguide wall and / or the antenna wall. Additional workload by soldering may be omitted. In particular, the protective effect may be given in the formation of the protective device as a rotating part, which is clamped, clamped, pressed or densely pressed. The production as a turned part allows in particular the formation of the protective device in a gap-free, one-piece or monolithic construction, which reduces the presence of gaps compared to a modular construction.

Furthermore, a tight connection can be made by laminating films of material, for example a PTFE (polytetrafluoroethylene), a PTFA (Teflon, polytetrafluoroethylene) or a PFA (perfluoroalkoxy polymers) film on stainless steel.

The protective device or waveguide diffusion barrier can be arranged, for example, in a high-frequency radar level sensor system between the process separation and the electronics or between the process separation and the Exd separator. The Exd separating element is a separating element which has explosion-proofing properties that comply with the Exd standard IEC 60079-1: 2007

The fastening device is designed to receive a force acting essentially parallel to the bearing surface of the protective device and / or to exert a force acting essentially parallel to the bearing surface in order to hold the bearing surface in contact with the edge surface of the waveguide.

According to another aspect, the protection device is formed in one piece or monolithic. For example, the protective device or condensate barrier is designed as a rotating part. Due to the one-piece manufacturing essentially the entire protection device is designed as a locking device and thus has the locking device substantially no gaps, gaps or slots through which moisture could pass through the locking device. The pores of the barrier material used may be so narrow that they are substantially impermeable to moisture, water or other matter, such as the matter used for a filling.

According to another aspect, the fastening device of the locking device is designed as a snap closure.

The locking device may be formed, for example, as a cap, capsule or cover for a housing device or for a housing adapter. The snap closure may make it possible that the edge surface of a waveguide, in particular the edge surface of a waveguide opening and the bearing surface of the protective device are close to each other.

According to another aspect, the fastening device has a press-fit ring. The press-in ring may be made in contrast to the locking device of a very pressure-resistant material, such as stainless steel. This press-fit ring may receive the compressive forces acting in parallel with the bearing surface and position the barrier means in front of an opening of the waveguide by squeezing so that substantially no moisture or other material can diffuse between the existing gaps. In other words, gaps resulting from the modular construction of a multi-component antenna waveguide system may be minimized by the applied pressure such that they can be said to be sealed to IP67.

In yet another aspect, the barrier means is made of a material selected from the group of materials, the group of materials being a dielectric material, PFA, PTFE, PEEK (polyether ether ketone), FKM (fluororubber), FFKM ( Perfluor rubber) or silicone.

Fabrication of a dielectric material may cause an electrical resistance or an impedance of the high-frequency electromagnetic wave protection device to be small, so that these Protective device of an electromagnetic wave substantially no resistance. The dielectric material is distinguished on the basis of the dielectric constant (DK). In other words, the material of the blocking device and / or the material for a one-piece protective device may be selected so that substantially no reflections occur in an opposite direction to the direction of propagation of the electromagnetic wave upon impact of an electromagnetic wave.

According to another aspect, the protective device has a stainless steel ring as a fastening device. Furthermore, the protective device has a film as a barrier device. The film may have a predetermined sealing effect for matter or for a gas and be substantially permeable to an electromagnetic wave.

The stainless steel ring may have substantially two openings, which are covered by the film so that it seals or covers at least one of the openings of the stainless steel ring. The film may be laminated to the stainless steel ring, whereby a high sealing effect can be achieved. The technique of lamination allows a thin film to be applied to the ring.

According to another aspect, the locking device is disc-shaped, conical, lenticular and / or spherical. Due to the shape of the barrier means, a beam shaping of the electromagnetic wave can be achieved.

According to another aspect, a housing device is described. The housing device has a waveguide which is designed to guide an electromagnetic wave having a predeterminable wavelength and which at one end has an electromagnetic waveguide guided to the waveguide Has wave substantially perpendicular edge surface. The edge surface of the waveguide may form from the housing device, in which the waveguide is embedded. In particular, the wall device of the housing device may have the edge surface at the edge of a waveguide opening, so that the surface of a waveguide opening lies in the same plane in which the edge surface lies. In other words, a normal vector which is perpendicular to the waveguide opening may be parallel to a normal vector which is perpendicular to the edge surface.

Furthermore, the housing device has a protective device, wherein the protective device is arranged at one end of the waveguide such that it applies a force perpendicular to the edge surface of the waveguide, so that the bearing surface holds contact with the edge surface of the waveguide.

Such a housing device, which is covered by a protective device or condensate barrier, may be referred to as encapsulated housing adapter. By attaching the protective device, for example by means of a snap closure, the housing adapter, in particular the interior of a housing adapter, may be sealed against penetrating moisture or matter.

According to yet another aspect, a housing device may be provided which comprises a waveguide adapted to guide an electromagnetic wave having a presettable wavelength and having at one end an electromagnetic wave guided by the waveguide or a longitudinal axis of the waveguide having substantially perpendicular edge surface. The housing device may further comprise a wall device and a protective device. The wall device is set up in such a way that a force acting essentially parallel to the support surface of the protective device is applied by the wall device, and wherein the protective device is arranged in the wall device such that the bearing surface of the locking device is held in contact with the edge surface of the waveguide. A force acting parallel to the bearing surface of the protective device may act perpendicular to a normal vector which is perpendicular to the bearing surface. Consequently, the parallel force, which is applied for example by a housing wall, may also act perpendicular to a normal vector, which is perpendicular to the edge surface of a waveguide.

By keeping the contact a gap between the support surface of the locking device and the edge surface of the waveguide can be substantially closed and by the solid holding means, for example, by pressing into the wall device, a gap between wall device and protective device can be reduced so that substantially no matter in the direction the waveguide opening can pass. However, the sealing effect is essentially determined by the close juxtaposition of the bearing surface on the edge surface. In other words, the wall means may force the guard so firmly against the opening of a waveguide that the opening of the waveguide is substantially sealed and substantially sealed against the ingress of matter and a gap between the attachment means and the wall means is substantially closed.

According to yet another aspect, a part of the wall means of the housing device is formed as an antenna means. The antenna device is designed to guide and beamform an electromagnetic wave received by the waveguide, wherein the protective device is arranged between the waveguide and the antenna device. In other words, the protection device may cover a passage or transition from the interior of the waveguide to the interior of the antenna device. A combination of waveguide and antenna device may be referred to as a waveguide antenna system or antenna waveguide system. The Protection device can divide a waveguide antenna system into two different areas. Although an electromagnetic waves and / or electromagnetic energy can be exchanged between the two regions of the waveguide, a matter flow between the separated regions is essentially prevented. An antenna device can also be understood as a part of a waveguide. Thus, the combination between waveguide and antenna device can be considered as a single waveguide, within which a protective device is arranged, which divides the waveguide into different areas.

An antenna device may differ from a waveguide in that an antenna device is provided for beam shaping. The beam shaping may lead to an antenna device specifically assignable antenna characteristic and be represented as an antenna characteristic of the antenna device. The waveguide can have a further section in order to adapt an impedance or a characteristic impedance of the waveguide to the characteristic impedance of the antenna device in order to ensure the most possible reflection-free guiding of an electromagnetic wave. This transition region of the waveguide and / or the antenna device may be formed conical.

The waveguide may have a tube or a trumpet-shaped tube with a longitudinal axis, wherein the waveguide is an axisymmetric structure. The waveguide may be designed substantially cylindrical. The antenna device may be conical in one example and also have a longitudinal axis. The longitudinal axis of the waveguide may coincide in a state connected to the antenna device with the longitudinal axis of the waveguide. The antenna device may provide for adapting the characteristic impedance of the antenna device to a surrounding atmosphere, such as air, gas or other contents. The walls of the Waveguide and the antenna device may have different angles to each other. The angles may be measured relative to the longitudinal axis.

In yet another aspect, the antenna device is detachable from the housing device. The protective device can be introduced, for example, at the separation point between the antenna device and the housing device and the antenna waveguide system or waveguide antenna system can be modularly assembled. In other words, the housing device may have a partial housing, which has the waveguide, and the antenna device may have a housing part, which has the antenna device. The antenna part containing the waveguide may be referred to as a housing adapter, while the antenna device having the part may be referred to as an antenna housing. The separable design or modular design may allow the housing adapter and the antenna housing to be assembled to form the waveguide antenna system

In yet another aspect, a field device is described that includes a sensor and the housing device. The sensor, for example an RF module, is designed to generate and / or to receive an electromagnetic wave. The sensor can be designed in one example as a two-wire system, in which a power supply takes place exclusively via the measuring lines.

The sensor may impress an electromagnetic wave in a waveguide housing device. The protective device of the housing device may protect the sensor from penetrating moisture or condensate. In particular, the protection device may protect the sensor from moisture entering from the direction of the waveguide.

In yet another aspect, the guard includes a stainless steel ring and a foil.

The stainless steel ring may be able to absorb a high pressing force, which may occur, for example, when the protective device is pressed into a housing device. By the pressing force and the assembly in a corresponding position, the film can be held by the stainless steel ring in position in front of the waveguide that the film substantially prevents moisture penetrating into the opening of the waveguide, but allows electromagnetic radiation to pass. Press-fitting may lead to the fulfillment of tightness according to the IP67 standard.

The sealing effect of the locking device may for example be specified by a leak rate, which is given in the unit mbar 1 / sec. The unit mbar denotes the pressure in millibars, 1 denotes a volume in liters and sec denotes the time measured in seconds.

Brief description of the figures

• Fig. 1 zeigt einen Querschnitt einer Gehäusevorrichtung mit Schutzvorrichtung gemäß einem Beispiel.
• Fig. 2 zeigt einen Querschnitt einer Schutzvorrichtung gemäß einem exemplarischen Beispiel.
• Fig. 3 zeigt eine kegelförmige Schutzvorrichtung gemäß einem exemplarischen Beispiel.
• Fig. 4 zeigt eine kugelförmige Schutzvorrichtung gemäß einem exemplarischen Beispiel.
• Fig. 5 zeigt eine modulare Gehäusevorrichtung mit Schutzvorrichtung gemäß einem exemplarischen Ausführungsbeispiel der vorliegenden Erfindung.
• Fig. 5a zeigt eine einstückige Schutzvorrichtung gemäß einem exemplarischen Ausfuhrungsbeispiel der vorliegenden Erfindung.
• Fig. 6 zeigt einen Ausschnitt des Koppelbereichs der Fig. 5 gemäß einem exemplarischen Ausführungsbeispiel der vorliegenden Erfindung.
• Fig. 7 zeigt einen Gehäuseadapter in einer Seitenansicht gemäß einem exemplarischen Ausführungsbeispiel der vorliegenden Erfindung.
• Fig. 8 zeigt ein Diagramm des Anpassungsparameter S11 über der Frequenz gemäß einem exemplarischen Ausführungsbeispiel der vorliegenden Erfindung.
• Fig. 9 zeigt ein Fernfeld einer Antennencharakteristik gemäß einem exemplarischen Ausführungsbeispiel der vorliegenden Erfindung,

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

• Fig. 1 shows a cross section of a housing device with protective device according to an example.
• Fig. 2 shows a cross section of a protective device according to an exemplary example.
• Fig. 3 shows a conical protective device according to an exemplary example.
• Fig. 4 shows a spherical protective device according to an exemplary example.
• Fig. 5 shows a modular housing device with protective device according to an exemplary embodiment of the present invention.
• Fig. 5a shows a one-piece protection device according to an exemplary embodiment of the present invention.
• Fig. 6 shows a section of the coupling region of Fig. 5 according to an exemplary embodiment of the present invention.
• Fig. 7 shows a housing adapter in a side view according to an exemplary embodiment of the present invention.
• Fig. 8 FIG. 12 shows a plot of the fit parameter S11 versus frequency according to an exemplary embodiment of the present invention. FIG.
• Fig. 9 shows a far field of an antenna characteristic according to an exemplary embodiment of the present invention,

Detailed description of examples and embodiments

The illustrations in the figures are schematic and not to scale.

In the following description of the Fig. 1 to Fig. 9 the same reference numerals are used for the same or corresponding elements. However, identical or similar elements can also be designated by different reference symbols.

Fig. 1 shows the housing device 120 in a cross-section, which is made of a single piece, according to an exemplary example. The housing device 120 has the wall device 101, in which the waveguide 102 is embedded. In one example, the waveguide is made inside the wall device. In another example, the waveguide is a metal tube machined into the wall means. The waveguide 102 is incorporated in the wall device 101, for example by a bore. The housing adapter is made of plastic, for example, which is coated in the interior, ie on the waveguide wall 130, with an electrically conductive material in order to guide an electromagnetic wave along the waveguide 102. The waveguide 102 has a tubular portion 102a and a tapered portion 102b.

The waveguide is a rotationally symmetrical structure, which is made symmetrical to the longitudinal axis 103. The outer contours of the housing 120 are made rotationally symmetrical with respect to the longitudinal axis 103. The longitudinal axis 103 may extend parallel to a propagation direction of an electromagnetic wave in the waveguide.

In an in Fig. 1 In the upper area illustrated cavity 104 or RF cavity 104, an RF cup (high-frequency cup), a sensor or the RF module including electronics can be integrated. In Fig. 1 is the RF module and the RF cup not shown. The RF module or sensor may be placed in the RF module cavity 105. The RF module cavity 105 is cylindrically shaped, as is the RF cavity 104. However, the RF module cavity 105 is smaller than the RF cavity 104. The RF module can generate in the RF module cavity 105 an electromagnetic wave which moves as a transmission signal along the longitudinal axis 103 in the direction of the waveguide opening 106. The waveguide opening 106 is predetermined by the conical section 102b. The diameter of the waveguide opening 106 corresponds to a diameter that depends on the guided wavelength and the subsequent antenna device 107. In other words, the diameter of the opening 106 ensures a reflection that is as free from reflection as possible in the conical region 107 designated by the reference numeral 107, which forms the antenna device 107 or the antenna 107 of the waveguide antenna system 120. The antenna device 107 itself may be regarded as a waveguide section that is separated from the cylindrical waveguide section 102a and / or the conical waveguide section 102b by the protection device 100. The interface at which the protection device 100 is disposed is configured such that a reflection value resulting from the protection device and the transition is minimal. The minimum can be determined by experiments by minimizing the S11 parameter. In particular, the waveguide 102 and the antenna device 107 are electrically matched to one another.

The conical antenna region 107 is likewise incorporated rotationally symmetrically into the wall device 101 and coated with an electromagnetically conductive material. Between the antenna opening 1 08 in an input region of the antenna 107, which forms the antenna input 108, and the opening 106 of the waveguide 102, which forms an output of the waveguide 102, the protective device 100 is integrated. The protective device 100 is designed as a closed with a foil 110 stainless steel ring 114 or press-fit 114. At the press-fit point 133, which likewise corresponds to an annular area within the wall device 101, the protective device 100 is pressed in, so that the bearing surface 10 09 of the locking device 100 rests on a shoulder 131 of the wall device 101 running perpendicular to the longitudinal axis 103. Since the shoulder is part of the wall device 101 and thus also of an edge region of the waveguide 102, the blocking device 110 rests with the bearing surface 109 on the edge surface 131 of the waveguide 102.

The press-fit 133 of the wall device 101 exerts a pressing force on the lateral surface 132 of the press-fit ring 114. By pressing at the points 133, 132 and / or resting on the edge surface 131 of the waveguide, the inner region 112 of the waveguide 102 can be sealed off from the inner region 113 of the antenna device 107. Both the squeeze 133, 132 and the foil 110 prevent matter from diffusing between the cavity 113 of the antenna 107 and the cavity 112 of the waveguide 102. Thus, moisture still penetrating the lower region 113 of the antenna device 107 can be prevented , substantially does not rise further in the direction of the RF module cavity 105. The pressing forces are substantially absorbed by the stainless steel ring 114 of the protective device 100, whereby the locking device 110 is substantially free of high pressure forces. The locking device 110 holds with its bearing surface 109 contact with the edge surface, wherein the pressure with the bearing surface 109 and the edge surface 131 together can be pressed arbitrarily. The waveguide opening 106 is thus sealed.

By the locking device 100 can be substantially prevented that of a in Fig. 1 With the letter "A" designated container area or process area matter by the antenna device 107 in the direction of the RF module cavity 105 rises, although both the antenna device 107 and the waveguide 102 are substantially unfilled or hollow. In the Fig. 1 "A" denotes a region below the RF module cavity 105. In the region "A" may be the contents. In one example, the interior region 113 of the antenna device 107 may be potted with material or the antenna opening 134 may be closed with a capsule. Despite such a process separation (not shown in Fig. 1 However, condensate could still penetrate into the waveguide 102. Further penetration of the condensate into the waveguide 102, in particular into the inner region 112 of the waveguide 102, may prevent the protective device 100.

Fig. 2 shows the protection device 100 from Fig. 1 as a cross section according to an exemplary example. In Fig. 2 a disc-shaped protective device 100 is shown. The disk-shaped protective device has a disk 110 as a locking device. This disk 110 or disk-shaped locking device 110 is arranged on a stainless steel press ring 114, which is made of stainless steel and has the two openings 200a and 200b. If the disk-shaped locking device 110 is made very thin, the locking device 110 may be referred to as a disk-shaped film 110 or film 110. The film 110 is laminated as a barrier means 110 on one of the openings 200b. The film 110 is made of PFA or PTFE material and covers one of the two openings 200a, 200b so that substantially no flow of material through the openings 200a, 200b can be made. In Fig. 2 Like the hidden opening 200b as the upper opening of the Edelstahleinpressrings 114 are designated. The opening 200a may be referred to as the lower opening. The lower opening may be facing a medium when used in a waveguide. The protective device 100 is shown as an axisymmetric element with respect to the longitudinal axis 103. The protective device 100 has the bearing surface 109, which can come into contact with the edge surface 131 of a waveguide. In particular, the bearing surface 109 is the part of the protective device which is in contact with the fastening device 114. The film 110 is laminated in a membrane-shaped manner on the stainless steel ring 114. The bearing surface 109 corresponds in one example essentially to an edge surface of the stainless steel ring 114.

Fig. 3 shows a conical protective device according to an exemplary example. In the realization of the protective device 100a as a cone, the film 110a, which may be made of PFA or PTFE, is laminated onto the stainless steel press ring 114. The bearing surface 109a is formed on the locking device 110a along the stainless steel ring 114, in particular along an edge surface of the stainless steel ring 114. The locking device 110a covers the upper opening 200b, but is tapered along the axis of symmetry 103 towards the lower opening 200a. This conical design can serve the beam shaping.

Fig. 4 shows a ball-shaped protective device 100b, which has the stainless steel ring 114 and the foil 110b. The bearing surface 1 09b is formed on the locking 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 as a locking device 110b on the stainless steel press ring 114 and covers the opening 200b of the stainless steel ring. In the direction of the lower opening 200a, the film, which may be made of PFA or PTFE, formed spherical. The blocking device 100b is made rotationally symmetrical to the longitudinal axis 103.

Due to the spherical or lenticular design beam shaping can be effected.

Like in the Fig. 2 As shown, a protective device can be made as a PFA disc 110 or PTFE disc 110 laminated to a stainless steel ring 114. By a laminated connection between a metal ring 114 and a disk 110, a condensate-tight connection can be realized. A condensate-tight connection may mean that the press-fit ring 114 can be pressed so strongly against a housing wall 101 of the housing 120 at the point 133 that substantially no condensate can pass through this pressure. The pressure is designed so that the density according to the IP67 standard is met. The pressing points 132, 133 are designed as a press fit or interference fit so that an assembly is made possible by pressing. That is, the protection device 100 is held substantially only by the pressing force of the wall device 101 within the waveguide antenna system 120.

Like the figures FIG. 3 and FIG. 4 In the case of auto lamination of the disk 110, 110a, 110b, a shaping of the locking device 110, 110a, 110b can be carried out. For shaping, the disc is pressed into a corresponding shape. By forming, a conical protective device 100a or a spherical protective device 100b can be produced as well as a lenticular protective device (not shown). By means of these shapes, for example the conical, spherical or lens shape, microwaves in a waveguide 102 can pass the waveguide through the protective device with little damping.

Despite an existing process separation (in Fig. 1 not shown) and in spite of other protective measures which are intended to prevent a material or condensate penetrating from the region A into the antenna device 107 or into the interior 113 of the antenna device 107, small amounts of the condensate within the waveguide antenna system 120 may arise, ie within the combination of the Waveguide 102 and antenna device 107. This condensate can both affect a measurement signal and create a damaging effect in an RF module located in RF module cavity 105 as it advances to the module. In particular, condensate which is behind one (in Fig. 1 not shown) process coverage at the antenna opening 134 in the antenna region 107 or in the antenna device 107 is formed, lead to measurement errors. In contrast, condensate that arises in the waveguide 102, in particular in the interior of the waveguide 112 and possibly even penetrates to the RF module in the RF module cavity 105, lead to failure of a measurement. The diffusion barrier 100 or protective device 100, which in addition to a in Fig. 1 not shown process separation or process coverage is installed, can prevent further increase of liquid, material, condensate or gas in the direction of the RF module cavity 105 from the area "A" as far as possible and thus support a reliable measurement. The protective device 100 is arranged parallel to the antenna opening 134 and / or parallel to the waveguide opening 106. In particular, the longitudinal axes 103 of the protective device 100 are arranged parallel to the longitudinal axis of the antenna opening 134 and / or parallel to the longitudinal axis of the waveguide opening 106. In other words, the surface of the protective device 100 is arranged parallel to the surface of the antenna opening 134 and / or parallel to the surface of the waveguide opening 106.

Fig. 5 shows a cross section of a modular housing device with protective device according to an exemplary embodiment of the present invention. The housing device 500 is constructed of two separable elements 502, 503. The housing device 502 including the waveguide 501 or the housing adapter 502 is mounted on the housing device 503 including the antenna device 507. The waveguide housing device 502 or the housing adapter 502 can be separated from the antenna housing device 503 with the antenna device 507. The housing adapter 502 includes the RF module cavity 504 and the waveguide 501 is composed of two waveguides 501a and 501b. The RF module cavity 504 may receive an RF module (the RF module is in FIG Fig. 5 not shown). The waveguide 501a and the waveguide 501b are separated by the Exd separator 505. This Exd separating element is designed as a glass window. The Exd separator is a zone separating element and divides the waveguide 501 into two separate regions 501a, 501b.

In the coupling region 506, the housing adapter 502 and the housing 503 of the antenna come into contact. Between the waveguide housing device 502 and the antenna housing device 503, the protection device 508 is arranged. The protective device 508 is designed as a condensate lock and made of one piece as a rotating part.

Fig. 5a FIG. 10 shows a one-piece protection device 508 according to an exemplary embodiment of the present invention. It is the one-piece and gap-free structure to recognize, with the functional areas fastening device 604, guard 609 and support surface can be distinguished.

Fig. 6 shows a section of the transition region or coupling region 506 of Fig. 5 according to an exemplary embodiment of the present invention. The Fig. 6 shows the trumpet-shaped end 501c of the waveguide 501. Further, the housing wall or wall means 601 of the housing means 502 is shown, in which the waveguide is incorporated. In the housing wall device 601, the waveguide 501b, 501c is incorporated as a tubular portion. The waveguide 501c has the edge surface 602. This edge surface 602 can come into contact with the bearing surface 603 of the locking device 508.

By means of the snap fastener 604, which is the fastening device 604 of the protective device 508, the protective device 508 is attached to the waveguide 501c attached, in particular to the wall device 502 or wall 502 of the waveguide. The wall means 502 of the waveguide 501c thus has in the region of the trumpet-shaped portion 501c of the waveguide corresponding receptacles into which the snap-action devices 604 designed as brackets can engage. The brackets 604 or fastener 604 exert a force directed toward the wall 502 of the waveguide, thus maintaining the protector 508 on the waveguide 501b, 501c. The pressure on the wall 502 may be enhanced by the winder 503. In other words, the protection device 508 encapsulates the waveguide with respect to an outside area. The snap device can ensure that the protective device 508 cooperates with the housing wall 503 of the antenna device. By juxtaposing corresponding surfaces, a sealing effect can be achieved. The wall device 502 has a further cavity 530.

The diameter of the waveguide 501 is determined by the useful frequency with which the RF module operates. Thus, a different antenna waveguide system 120, 500 may be provided for different RF modules.

The protection device 508 is designed as a conical protective device, so that a conical cavity 605 results as a continuation of the trumpet-shaped cavity 501c of the waveguide. The conical cavity 605 is designed so that the protective device 508 has a uniform or homogeneous wall thickness from the bearing surface 603.

The Fig. 6 also shows wall portion 606 which abuts fastener 604. This wall region 606 is located near the coupling region 506 of the antenna device 503. The wall region 606 exerts pressure on the fastening device 604 parallel to the waveguide opening 630, parallel to the bearing surface 603 and / or parallel to the edge surface 602. The pressure can be strong, since the pressure of the wall means 531 of the housing means 502 of the waveguide 501c is received. The round shape of the waveguide 501c promotes a high power consumption. By pressing forces, the sealing effect can be adjusted.

In the wall portion 606 of the antenna housing device 503, the antenna 507 or the antenna waveguide 507 is incorporated. The antenna 507 or the antenna waveguide 507 may be a recess of the housing wall 606 of the antenna housing device 503, which is coated with conductive material. The conical locking device 609 of the conical protective device 508 projects into the antenna tube 507.

The wall portion 607 of the waveguide end 501c is spaced from a wall portion 608 of the antenna wall. The spacing is created by the waveguide housing device 502 or its wall 531, 631 and the protective device 508, in particular their fastening device 604.

In the coupling region 506, the housing wall 531 of the housing adapter 502 or the waveguide 501 and the wall 606 of the housing device 503 of the antenna region 507 overlap. Thus, it is possible that the antenna wall 606 exerts a force on the fastening device 604 in the direction of the waveguide 501c and the Transition from the antenna portion 507 in the waveguide 501c substantially sealed.

At a lower end, which is directed towards a medium, which in the Fig. 5 represented by the letter "B", the antenna device 507, the process separation 509 on. The process separation 509 is lens-shaped and covers the antenna opening 510, so that essentially no direct transition from the filling region "B" or the process region "B" into the interior of the antenna device 507 can take place. In Fig. 5 is thus one Level radar antenna system 500 with process separation 509, condensate barrier 508 and Exd separator 505 shown.

Fig. 7 shows the waveguide housing device 502 or the housing adapter 502 in a side view. On the housing adapter 502, an integrally manufactured protective device 508 is arranged, which has the fastening device 604 and the locking device 609. The locking device 609 and the fastening device 604 are made of the same material.

As material for the barrier device 100, 100a, 100b, 100c, 110a, 110b, 609, dielectrically conductive material, for example PTFE, PEEK, PFA or also elastomers, as in O-rings, can be used. Also FKM, FFKM and silicone can be used. PFA can be well suited for manufacturing as an injection molded part, ie for one-piece or monolithic production. The arrangement of the locking device in the waveguide easy mounting of the locking devices in the waveguide is possible. In particular, the one-piece design allows a simple Monatge.

The housing adapter 502 is a cylinder body with a tapered end portion 701. This end portion 701 is located in the region of an in Fig. 7 The diameter of the end portion 701 or housing neck 701 is less than the diameter of the housing adapter, so that there is a Haschenförmige shape of the housing adapter 502. The housing adapter 502 may, as in Fig. 5 and Fig. 6 is shown releasably connected to an antenna housing device 503. Thus, from the conical locking device 609, an electromagnetic wave in the direction of the apex of the cone can be emitted out of the housing adapter. It is also possible to receive an electromagnetic wave through the blocking device 508 in the opposite direction to the apex of the cone-shaped blocking device 609 and inside the Housing adapters in the existing waveguide system 501 continue to transport. The condensate barrier 508 or barrier 508 prevents moisture and / or other matter from entering the interior of the housing adapter 502. The waveguide 501 and the antenna device 507 are substantially hollow.

Fig. 8 FIG. 12 is a plot of S-parameters vs. frequency according to an exemplary embodiment of the present invention. FIG. In particular, in Fig. 8 representing the reflection behavior describing fitting parameter S11. The presentation in the Fig. 8 refers to the waveguide antenna system 500 of Fig. 5 ,

The curve 801 shown in the coordinate system 800 is a reflection curve representing the portion of an electromagnetic wave reflected at a protective device 100, 508. The ordinate 802 shows a fitting curve S11 in the unit dB, which has the negative values of -50 dB to 0 dB. The abscissa 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.

Fig. 9 shows a far field of an antenna characteristic of a waveguide antenna system 120, 505, which can be achieved with an antenna device 107, 507. The presentation in the Fig. 9 refers to the waveguide antenna system 500 of Fig. 5 , In the polar coordinate system 900, the field strength is shown in the radial direction and the emission angle in the polar direction. In other words, in Fig. 9 the longitudinal axis 103, 103 a of the waveguide antenna system with the polar axis 901 shown at +90 degrees. A transmission wave radiated by the RF module in the RF module cavity 105 would propagate in Fig. 9 move in the direction to the left side. It can be seen that in the emission direction, ie to the left, a main lobe of the field diagram 902 trains. This is rotated from an origin axis 902 in one direction by 90 degrees.

In addition, it should be noted that "comprising" and "having" does not exclude other elements or steps, and "a" or "an" does not exclude a multitude. It should also be appreciated that features or steps described with reference to any of the above embodiments may also be used in combination with other features or steps of other embodiments described above. Reference signs in the claims are not to be considered as limiting.

Claims (9)

1. A casing apparatus (500), comprising:

   a waveguide (501) having a wall (502) which is designed for guiding an electromagnetic wave of a predefinable wavelength and which comprises an edge face (602) extending substantially perpendicularly to the direction of propagation of an electromagnetic wave guided by the waveguide;

   a wall device (606);

   a protection device (508) having a bearing surface (603);

   wherein the wall device (606) is designed to absorb and/or exert a force which acts substantially perpendicularly to the direction of propagation of the electromagnetic wave;

   wherein the wall device (606) is formed as an antenna device (503, 507) at least in part, such that the waveguide transitions into the antenna device, wherein the antenna device is separated from the waveguide by the protection device;

   wherein the antenna device has a process cut-off (509) and/or a filling at one end;

   wherein the protection device protects against the penetration of particles from an antenna device into the waveguide;

   characterized in that the protection device is arranged at one end (501c) of the waveguide in a way that the said protection device absorbs and/or exerts a force oriented substantially perpendicularly to the direction of propagation of the electromagnetic wave, such that the bearing surface (603) of the protection device (508) keeps in contact with the edge face (602) of the waveguide;

   wherein the protection device is arranged between the waveguide and the antenna device (507) and comprises a snap lock (604) for fixing the protection device to the end of the waveguide; wherein a wall area of the wall device (606) bears against the snap lock;

   wherein the wall (502) of the waveguide (501c) comprises corresponding sockets in which snap lock devices (604) formed as bracket can engage.
2. Casing apparatus (500) according to claim 1, the protection device (100, 508) further comprising:

   a locking device (609);

   wherein the locking device (609) has a predefinable sealing effect in order to prevent a diffusion of filling materials and/or of moisture into the interior of the waveguide; and

   wherein the locking device (609) is designed to allow the electromagnetic wave guided by the waveguide to pass through substantially undamped;

   wherein the locking device (609) comprises the said bearing surface (603) which is kept in substantially direct contact with the edge face (602) of the waveguide by the snap lock (604);

   wherein the protection device (508) comprises a longitudinal axis (103) that extends perpendicularly to the bearing surface (603);

   wherein the snap lock (604) is designed for absorbing a force which acts substantially perpendicularly to the longitudinal axis (103) and/or for exerting a force which acts substantially perpendicularly to the longitudinal axis (103) in order to keep the bearing surface (603) in contact with the edge face (602) of the waveguide.
3. Casing apparatus (500) according to claims 1 or 2, wherein the protection device is formed in one piece.
4. Casing apparatus (500) according to any of claims 1 to 3, wherein the protection device (100, 508) is made of a material selected from the group of materials consisting of a dielectric material, PFA, PTFE, PEEK, PFA, FKM, FFKM and silicone.
5. Casing apparatus (500) according to claim 2, wherein the locking device (609) is configured to be conical.
6. Casing apparatus (500) according to any of claims 1 to 5, wherein the antenna device (507) is designed for guiding and beam-forming the electromagnetic wave received by the waveguide.
7. Casing apparatus (500) according to any of claims 1 to 6, wherein the antenna device (507) is separable from the casing apparatus.
8. Casing apparatus (500) according to any of claims 1 to 7, wherein the process cut-off (509) and/or the filling is arranged behind the protection device (508) when viewed in a transmission direction of the electromagnetic wave.
9. A field device comprising:

   a sensor;

   a casing apparatus (500) according to any of claims 1 to 8;

   wherein the sensor is designed to generate and/or receive an electromagnetic wave.

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