RADAR MODULE

Abstract

A radar module for process automation including process measurement technology and the automation industry is provided, the radar module including: a radar signal source configured to generate and to transmit, and/or to receive, a radar signal; and a dielectric radar signal guide configured to receive the radar signal and then to transmit the radar signal to an antenna, a waveguide, and/or a dielectric lens, the dielectric radar signal guide being arranged at a predetermined distance from the radar signal source, forming an intermediate space, and an end face of the dielectric radar signal guide facing the radar signal source at least partially has a metallic layer.

Claims

1. A radar module for process automation including process measurement technology and the automation industry, comprising: a radar signal source configured to generate and to transmit, and/or to receive, a radar signal; and a dielectric radar signal guide configured to receive the radar signal and then to transmit the radar signal to an antenna, a waveguide, and/or a dielectric lens, wherein the dielectric radar signal guide is arranged at a predetermined distance from the radar signal source, forming an intermediate space, and wherein an end face of the dielectric radar signal guide facing the radar signal source at least partially has a metallic layer.

2. The radar module according to claim 1, wherein at least the intermediate space comprises a gas, a gas mixture, a fluid, or a vacuum.

3. The radar module according to claim 1, wherein the metallic layer has a recess at the end face facing the radar signal source, the recess comprising a non-metallic material.

4. The radar module according to claim 3, wherein the recess is arranged above an antenna structure of the radar signal source.

5. The radar module according to claim 1, further comprising an additional waveguide, which is formed as a metallic waveguide or as a non-metallic waveguide and is arranged between the dielectric radar signal guide and the antenna.

6. The radar module according to claim 5, wherein the additional waveguide formed as the metallic waveguide at least partially surrounds the dielectric radar signal guide and is configured to couple the radar signal from the dielectric radar signal guide into the metallic waveguide, and wherein the metallic waveguide is connected to the antenna.

7. The radar module according to claim 6, where the metallic waveguide is integrally formed with the antenna.

8. The radar module according to claim 1, wherein the radar signal source is mechanically decoupled from a carrier material.

9. The radar module according to claim 1, wherein the radar signal source is mechanically decoupled from a carrier material by means of an adhesive layer.

10. The radar module according to claim 8, wherein the carrier material is further conductively connected to the radar signal source by means of at least one bonding wire, which serves as a low-frequency supply and/or signal line.

11. The radar module according to claim 8, wherein a metallic housing substantially completely surrounds the radar signal source and is attached to and/or is conductively connected to the carrier material.

12. The radar module according to claim 11, wherein the dielectric radar signal guide is mechanically held by a metallic holder.

13. The radar module according to claim 12, wherein the metallic holder is integrally formed in one piece with the metallic housing of the radar signal source.

14. The radar module according to claim 11, wherein the dielectric radar signal guide is mechanically held by a dielectric holder, and wherein a permittivity of the dielectric holder is smaller than a permittivity of the dielectric radar signal guide.

15. The radar module according to claim 14, wherein the dielectric holder is arranged in the metallic housing of the radar signal source.

16. The radar module according to claim 1, wherein an end of the dielectric radar signal guide facing away from the radar signal source is of conical, frustoconical, or hemispherical shape.

17. The radar module according to claim 1, wherein a cross-section of the dielectric radar signal guide is round, square, rectangular, oval, or elliptical.

18. A level radar, comprising a radar module according to claim 1.

19. The radar module according to claim 1, wherein the radar module is configured for process automation or monitoring of a space area as a replacement of a light barrier.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0031] Further embodiments are described below with reference to the figures. The representation in the figures is schematic and not to scale. The same or similar elements are given the same reference signs.

[0032] FIG. 1 shows a schematic sectional view of a section of a radar module according to an exemplary embodiment.

[0033] FIG. 2 shows a schematic sectional view of a radar module according to an exemplary embodiment.

[0034] FIG. 3 shows a schematic sectional view of a radar module according to an exemplary embodiment.

[0035] FIG. 4 shows a schematic sectional view of a radar module according to an exemplary embodiment.

[0036] FIG. 5 shows a schematic diagram of a radar signal guide according to an exemplary embodiment.

[0037] FIG. 6 shows a schematic diagram of a radar signal source according to one embodiment.

[0038] FIG. 7a shows a schematic diagram of a radar signal source according to an embodiment.

[0039] FIG. 7b shows a schematic representation of a positioning of the radar signal guide of FIG. 5 above the radar signal source of FIG. 7a.

DETAILED DESCRIPTION OF EMBODIMENTS

[0040] FIG. 1 shows a sectional view of a radar module 1 according to an exemplary embodiment. The radar module 1 has a radar signal source 2 and a dielectric radar signal guide 3. The radar signal source 2 is adapted to generate and transmit and/or receive a radar signal 100 (see FIG. 4). The radar signal guide 3 is designed to receive the radar signal 100 from the radar signal source 2 and to forward it to an antenna 11 (see FIG. 2) and/or to forward a radar signal from the antenna 11 to the radar signal source 2. The radar signal 100 is in particular a high-frequency radar signal in a frequency range from 100 GHz to 500 GHz, preferably from 150 GHz to 300 GHz, particularly preferably from 180 GHz to 280 GHz.

[0041] The radar signal source 2 has an unhoused part of a semiconductor wafer, a so-called die, and is attached to a carrier material 5 by means of an adhesive layer 4. The carrier material 5 is designed as a printed circuit board substrate and can be based, for example, on paper, glass fiber, glass fleece ceramic, a synthetic fluoropolymer of tetrafluoroethylene such as TEFLON®, etc., whereby printed circuit board substrates for the high frequency range are preferably based on ceramic or TEFLON®. A surface 6 of the radar signal source 2 is conductively connected to the substrate 5 by means of bonding wires 7. The bonding wires 7 serve in particular as low-frequency supply and signal lines, e.g., for a supply voltage, control lines, etc., for the radar signal source 2.

[0042] The dielectric radar signal guide 3 is arranged at a distance “a” from the surface 6 of the radar signal source 2 and is at least partially received in a waveguide 8 by means of pressing, soldering, or bonding, and is mechanically held by the latter. Thus, in this exemplary embodiment, the waveguide 8 serves as a holder 9 for the radar signal guide 3. Furthermore, the waveguide 8 is integrally formed in one piece with a metallic housing 10.

[0043] The metallic housing 10 is supported on the carrier material 5 and conductively connected to it. The metallic housing 10 is attached to the carrier material 5, e.g., by gluing, soldering, or screwing. Due to this arrangement, the waveguide 8 and any further elements connected to it, e.g., an antenna 11 (see FIG. 2), are supported on the carrier material via the metallic housing 10, and possible forces acting on the waveguide 8 and/or the antenna 11 are transmitted directly from the housing 10 to the carrier material 5, and not to the radar signal source 2.

[0044] Furthermore, the metallic housing 10 surrounds the radar signal source 2, protecting it from environmental influences, such as dust, moisture, etc. In addition, the metallic housing 10 can at least reduce or completely avoid unwanted electromagnetic radiation.

[0045] In this exemplary embodiment, the dielectric radar signal guide 3 is substantially cylindrical or pin-like in shape and may also be referred to as a single-coupling pin. The radar signal guide 3 is arranged such that an end surface 12 located at a longitudinal end faces the radar signal source 2. The distance a between the surface 6 of the radar signal source 2 and the end face 12 of the radar signal guide 3 is defined as a function of the frequency range of the radar signal to be transmitted and serves, among other things, to mechanically decouple the radar signal guide 3 from the radar signal source 2. This means that mechanical loads, for example due to forces acting on the radar signal guide 3, are not transmitted to the radar signal source 2. This protects the very fragile and brittle radar signal source 2 from mechanical loads.

[0046] An intermediate space or gap 13 formed by the distance “a” is here exemplarily filled with air. Alternatively, the gap 13 and optionally also the interior space 14 formed by the housing 10 can be filled with another dielectric gas or gas mixture, with a dielectric liquid, or with a vacuum, as long as the mechanical decoupling of the radar signal source 2 and the radar signal guide 3 is substantially maintained.

[0047] With reference to FIG. 5, the radar signal guide 3 is shown in an exemplary embodiment. The end face 12 of the radar signal guide 3 facing the radar signal source 2 has at least partially a metallic layer 15, which is interrupted by a metal-free recess 16. In FIG. 5, the recess 16 is slot-like and essentially rectangular in shape. The metal-free recess 16 defines an area in which the radar signal 100 emitted by the radar signal source 2 is coupled into the radar signal guide 3. The metallic layer 15 serves as a shield, so that the radar signal 100 cannot be coupled into the radar signal guide 3 in the region of the metallic layer 15.

[0048] The radar signal guide 3 preferably has a round cross-section. Alternatively, the radar signal guide 3 may have a square, rectangular, oval, or elliptical cross-section. A round cross-section is particularly easy to manufacture. A radar signal guide 3 with a rectangular cross-section can maintain the polarization of the radar signal 100.

[0049] It should be noted that in the case of a radar signal transmission from the antenna 11 to the radar signal source 2, the directions are reversed. In this case, this means that the radar signal is coupled out of the radar signal guide 3 in the direction of the radar signal source 2 in the area of the recess 16, and the metallic layer 15 prevents the radar signal from being coupled out of the radar signal guide 3 in an area of the end face 12 other than the recess 16.

[0050] A longitudinal end of the radar signal guide 3 facing away from the radar signal source 2 is here exemplarily tapered, i.e., cone-shaped. The cone shape 17 (see FIG. 5) or a truncated cone shape (not shown) is particularly suitable for a transmission of the radar signal 100 between the radar signal guide 3 and the waveguide 8, as exemplarily shown in FIG. 1.

[0051] FIG. 2 shows an exemplary embodiment of the radar module 1, which essentially corresponds to the embodiment shown in FIG. 1, which is why the similarities will not be discussed in more detail again. The exemplary embodiment shown in FIG. 2 differs from FIG. 1 essentially in that an antenna 11 designed as a horn antenna 18 is additionally arranged on the waveguide 8. The waveguide 8 and the horn antenna 18 are integrally formed in one piece. The radar signal can be radiated or received via the horn antenna 18. The horn antenna 18 is further provided with a dielectric lens 19, which serves to emit the radar signal outwardly to the surroundings and enables the horn antenna 18 to be shorter than without the lens 19. The lens 19 has a relative permittivity greater than 1, whereby the electromagnetic waves are deflected so as to form a beam bundle. In addition, FIG. 2 shows a radar module housing 20 which surrounds the entire radar module 1 except for the antenna 18. In the area of the antenna 18, the lens 19 serves to seal the radar module 1 from the outside and thus protect it from external influences, such as dirt, dust, moisture, aggressive media, etc.

[0052] FIG. 3 and FIG. 4 each show a further exemplary embodiment of the radar module 1, wherein the radar signal 100 is transmitted from the radar signal guide 3 into a further dielectric waveguide 21 (see FIG. 3) or is emitted from the radar signal guide 3 to the environment (see FIG. 4).

[0053] In these exemplary embodiments, the radar signal guide 3 is held in position by the metallic housing 10. Alternatively, the radar signal guide 3 may be held in place by a retainer made of a dielectric material (not shown) that is received, for example, within the metallic housing 10. The dielectric retainer preferably has a relative permittivity that is less than the relative permittivity of the radar signal guide 3, in order to maintain the functionality of the radar signal relay. For example, the radar signal guide 3 may comprise substantially polyether ether ketone (PEEK) and thus have a relative permittivity of about 3.2. The dielectric material may comprise, for example, substantially TEFLON® and thus have a relative permittivity of about 2.

[0054] In FIG. 3, the dielectric waveguide 21 may either transmit the radar signal 100 to an antenna 11 or directly radiate and/or receive it to the outside. The dielectric waveguide 21 may have the same or a different cross-section than the radar signal guide 3. In FIG. 4, a dielectric lens 22 is located at a predetermined distance from the radar signal guide 3 and is illuminated by the radar signal 100 emitted to the air by the dielectric waveguide 21. Various lens geometries are conceivable for the dielectric lens 22, with parabolic lens geometries having been shown to be particularly advantageous.

[0055] In FIGS. 3 and 4, the longitudinal end of the radar signal guide 3 facing away from the radar signal source 2 is formed as a hemisphere 23. The hemispherical shape has proven to be particularly advantageous for coupling the radar signal 100 into the dielectric waveguide 21 as well as for radiation in air.

[0056] FIGS. 6, 7a, and 7b show various exemplary embodiments of the radar signal source 2. The radar signal source 2 has a high-frequency circuit 24, an antenna structure 25, and a plurality of bond pads 26. In particular, for the transmission of radar signals in a high frequency range, for example in a frequency range from about 120 GHz, it is useful to arrange or integrate the antenna structure 25 on the surface 6 of the radar signal source 2 in addition to the high frequency circuit 24, since in this frequency range the losses are considerably large in a transmission via a bonding wire or bonding pads and the carrier material. Since the antenna structure 25 is small in this frequency range due to its dependence on the wavelength of the radar signal 100, the antenna structure 25 can be well-integrated on the surface 6 of the radar signal source 2 without significantly enlarging the radar signal source 2.

[0057] The antenna structure 25 is coupled to the radio frequency circuit 24 and may be formed in various ways. For example, as shown in FIG. 6, the antenna structure 25 may be formed as a bow-tie antenna having an hourglass-like contour. Bow-tie antennas are preferably excited via symmetrical signals. Alternatively, the antenna structure 25 may be rectangular and/or may be formed, for example, as a patch element. Rectangular antennas are preferably excited via unbalanced signals. The size of the patch element is defined by the wavelength of the signal. The size of the patch element is selected in such a way that the patch element is set into resonance by the, in particular high-frequency, radar signal and its wavelength, i.e., is excited. This is mainly due to the long edge of the rectangular patch element. In FIG. 7b, the position of the radar signal guide 3 relative to the radar signal source 2 is shown by means of dashed contours. Here it can be seen that the end face 12 of the radar signal guide 3 is arranged above the antenna structure 25. Here, the position of the recess 16 relative to the antenna structure 25 is precisely determined to ensure coupling of the radar signal 100 emitted by the radar signal source 2 into the radar signal guide 3.

[0058] A rectangular recess 16, as shown in FIG. 7b, is particularly suitable because the field image of such a rectangular slot-like recess 16 resembles the field image of a mode propagating in a dielectric radar signal guide 3. The orientation of the rectangular recess 16 relative to the antenna structure 25 can be used to specify the polarization of the mode in the dielectric radar signal guide 3.

[0059] According to an exemplary embodiment, an electrical signal, preferably of high frequency, is applied to the antenna structure 25 via the high frequency circuit 24 to generate an electromagnetic field in the form of the radar signal 100. The radar signal 100 is transmitted through the gap 13, which may contain a dielectric medium, preferably air, or a vacuum, to the radar signal guide 3, where it excites a propagating waveguide mode at the end face 12 via the recess 16. The waveguide mode then passes through the radar signal guide 13 until it separates at the other end of the radar signal guide 3 via the geometry appropriately formed there. This means that in the embodiment shown in FIG. 1, the waveguide mode detaches from the radar signal guide 3 via the cone 17, into the waveguide 8, and is capable of propagation as a waveguide mode from there on. In the embodiments shown in FIG. 3 and FIG. 4, respectively, the waveguide mode detaches via the hemisphere 23 and propagates into the dielectric waveguide 21 and into the air, respectively.

[0060] It should be noted that with reference to the figures, the radar signal forwarding from the radar signal source 2 to the antenna 11, or outward to the surroundings, has been described. However, the radar module 1 is also designed to forward a radar signal received from the outside, for example through the antenna 11, to the radar signal source 2.

[0061] Supplementally, it should be noted that “comprising” and “having” do not exclude other elements or steps, and the indefinite articles “an” or “a” do not exclude a plurality. It should further be noted that features or steps that have been 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 regarded as limitations.