DK180435B1 - A radar system holding an antenna module with cavity slotted-waveguide antenna arrays for radiating and receving radar wave signals - Google Patents

A radar system holding an antenna module with cavity slotted-waveguide antenna arrays for radiating and receving radar wave signals Download PDF

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Publication number
DK180435B1
DK180435B1 DKPA201970080A DKPA201970080A DK180435B1 DK 180435 B1 DK180435 B1 DK 180435B1 DK PA201970080 A DKPA201970080 A DK PA201970080A DK PA201970080 A DKPA201970080 A DK PA201970080A DK 180435 B1 DK180435 B1 DK 180435B1
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DK
Denmark
Prior art keywords
antenna
waveguide
array
columns
parallel
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DKPA201970080A
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Danish (da)
Inventor
van der Meer Rob
Hamminga Siete
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Robin Radar Facilities Bv
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Priority to DKPA201970080A priority Critical patent/DK180435B1/en
Priority to PCT/EP2019/060604 priority patent/WO2019211158A1/en
Priority to US17/051,962 priority patent/US11881626B2/en
Priority to EP19719867.4A priority patent/EP3788676B1/en
Priority to CN201980029619.6A priority patent/CN112055916B/en
Priority to EP24152656.5A priority patent/EP4346011A3/en
Publication of DK201970080A1 publication Critical patent/DK201970080A1/en
Application granted granted Critical
Publication of DK180435B1 publication Critical patent/DK180435B1/en
Priority to US18/524,731 priority patent/US20240106133A1/en

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/52—Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
    • H01Q13/20—Non-resonant leaky-waveguide or transmission-line antennas; Equivalent structures causing radiation along the transmission path of a guided wave

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  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

A radar system comprising a first radar antenna module, which radar module comprises a first planar slotted waveguide antenna array configured for radiating electromagnetic wave, and a second planar slotted waveguide antenna array configured for receiving electromagnetic waves. Each of the planar slotted waveguide antenna array comprises several longitudinal extending waveguide columns disposed in a parallel and adjacent position with respect to one another, where the waveguide columns have a front side and a rear side with a plurality of cavity slots on the front side, and where the waveguide columns further have first and second column ends. The waveguide columns of the first and second antenna arrays have equal internal height and equal internal width. The first and second antenna arrays are arranged with the waveguide columns of the first antenna array disposed in a parallel position to the waveguide columns of the second antenna array. The front side of the columns holding the cavity slots of the first planar antenna array are positioned in a first plane and the front side of the columns holding the cavity slots of the second planar antenna array are positioned in a second plane parallel to the first plane. The first antenna and second antenna arrays are positioned at a distance to each other with a longitudinal extending outer sidewall of an outermost waveguide column of the first array arranged closest to a longitudinal extending outer sidewall of an outermost waveguide column of the second array, where the closest outer sidewalls of the outermost columns of the first and second antenna arrays are positioned with a minimum parallel column distance to each other in a direction parallel to the first and second planes, said minimum parallel column distance being at least 10 times the internal width of the waveguide columns.

Description

DK 180435 B1 1 A RADAR SYSTEM HOLDING AN ANTENNA MODULE WITH CAVITY SLOTTED-
WAVEGUIDE ANTENNA ARRAYS FOR RADIATING AND RECEVING RADAR WAVE SIGNALS
TECHNICAL FIELD The disclosure relates to a radar system holding cavity slotted-waveguide antenna arrays for radiating and receiving radar wave signals. In particular, the disclosure relates to antenna modules with radiating and receiving antenna arrays positioned with a distance to each other. The disclosure also relates to a radar system comprising back-to-back positioned radar antenna modules.
BACKGROUND In the prior art, slotted-waveguide antennas, SWA, are well-known, where the waveguides may be arranged in an array of waveguides, such as a planar array of parallel waveguides. As the name suggests, slotted-waveguide antennas consist of lengths of waveguides with a multiple number of slots formed in the conducting walls of the waveguides. These slots introduce discontinuities in the conductor and interrupt the flow of current along the waveguide. Instead, the current must flow around the edges of the slots, causing them to act as dipole antennas. The two basic types of SWAs are standing wave and traveling wave antennas. In a traveling wave SWA, the waveguide is built with matched loads or absorbers at the end, while in a standing wave SWA, the end of the waveguide is short-circuited. Depending on the desired electric field polarization, the slots can be placed on either the narrow or broad wall of the waveguide. At the fundamental TE10 mode, longitudinal slots on the broad wall will produce a field with vertical polarization, while transverse slots on — the narrow wall result in a horizontal field polarization. For antenna systems used to detect small targets, such as birds or Unmanned Aerial Vehicles, UAV's, in a clutter rich environment, a horizontal polarization is preferred, which can be obtained by using an array of waveguides with transverse slots on the narrow wall.
DK 180435 B1 2 Multi-beam radar systems with Frequency Modulated Continuous Wave, FMCW, waveforms is known in the art, and by using an antenna holding cavity slotted-waveguide arrays for transmitting and receiving electromagnetic waves, it is possible to obtain a multi- beam FMCW antenna system, which is very compact in size, and which is suitable for detecting small targets, such as birds or UAV's.
When detecting small objects or targets, it is required to have a high signal to noise ratio.
Noise may be introduced by having false reflections from the radiating antenna reaching the receiving antenna.
US 20170346169 A1 discloses an integrated slot waveguide antenna array for a radar system.
The antenna array includes substrate integrated waveguide (SIW) elements, transmit, receive and processing electronics in a lightweight, low-cost, highly integrated package.
The combination of antenna layout, specific dimensions of SIW features, including vias, terminal edges and slot placement may allow an efficient transmit and receive radar pattern as well as consistent, reliable and low cost manufacturing.
The antenna array includes a radiating array portion and a receiving array portion being in a single plane with an isolation distance between the radiating and receiving portion in order to reduce false reflections from the radiating portion to the receiving portion.
US 20050001757 A1 discloses an automotive radar having a high level of azimuth accuracy and a broad detectable range by virtue of preventing leaks of unnecessary waves to receiving antennas is to be provided.
A transmitting array antenna and receiving array antennas are arranged on an antenna plate (grounding conductor plate) which serves to ground the antennas, and radio wave absorbers are arranged on two sides of the edges of the antenna plate.
The radio wave absorbers may be configured of, for instance, a sponge material containing radio wave absorbing grains.
In an embodiment the transmitting array antenna is stepped ahead of the receiving array antenna in order to reduce false reflections from the transmitting array to the receiving array.
CN 105226397 A discloses an antenna assembly with high isolation.
The antenna assembly comprises a transmitter antenna, a receiver antenna, a reflecting component and a radome.
The transmitter antenna is used for transmitting a radiation wave with a
DK 180435 B1 3 direction of polarization toward the front part, the receiver antenna is used for receiving the radiation wave, and the reflecting component is arranged in front of the transmitter antenna and the receiver antenna for reflecting the radiation wave transmitted from the transmitter antenna. The reflecting component comprises a frame and at least one reflecting grating rod, the frame comprises two cross bars and two vertical bars, each reflecting grating rod is connected to the two cross bars and is parallel to the two vertical bars. The radome provides an accommodating space for accommodating the transmitter antenna, the receiver antenna and the reflecting component. The transmitter antenna and the receiver antenna are positioned within the same plane in a vertical direction in the center of the radome. First and second electromagnetic shield plates are arranged between the transmitter antenna and the receiver antenna, with each of the shield plates being slanted at an obtuse angle with respect to the front side of the transmitting and receiving antennas, respectively.
It would be advantageous to have an improved cavity slotted-waveguide antenna system, which reduces false reflections from the radiating antenna to the receiving antenna, thereby increasing the possibility of a correct classification of detected objects or targets. A higher signal to noise ratio may also be obtained by having an increased radar signal exposure time on the object or target.
It would therefore be advantageous to have an improved cavity slotted-waveguide antenna system, which allows a high radar signal exposure time on an object or target, and which thereby increases the possibility of a correct classification of detected objects — ortargets.
SUMMARY It is an object of the invention to provide a cavity slotted-waveguide antenna array system, which reduces false reflections from the radiating antenna to the receiving antenna. According to a first aspect there is provided a radar system comprising a first radar antenna module comprising:
DK 180435 B1 4 a first planar slotted waveguide antenna array configured for radiating electromagnetic waves, and a second planar slotted waveguide antenna array configured for receiving electromagnetic waves, wherein: each planar slotted waveguide antenna array comprises several longitudinal extending waveguide columns disposed in a parallel and adjacent position with respect to one another, said waveguide columns having a front side and a rear side with a plurality of cavity slots on the front side, and said waveguide columns further having first and second column ends; the waveguide columns of the first and second antenna arrays have equal internal height and equal internal width; the first and second antenna arrays are arranged with the waveguide columns of the first antenna array disposed in a parallel position to the waveguide columns of the second antenna array; the front side of the columns holding the cavity slots of the first planar antenna array are positioned in a first plane and the front side of the columns holding the cavity slots of the second planar antenna array are positioned in a second plane parallel to said first plane; and the first antenna and second antenna arrays are positioned at a distance to each other with a longitudinal extending outer sidewall of an outermost waveguide column of the first array arranged closest to a longitudinal extending outer sidewall of an outermost waveguide column of the second array, said closest outer sidewalls of the outermost columns of the first and second antenna arrays positioned with a minimum parallel column distance to each other in a direction parallel to the first and second planes, said minimum parallel column distance being at least 10 times the internal width of the waveguide columns.
By having the first radiating antenna array and the second receiving antenna array offset to each other in a direction parallel to the first and second planes, the amount of false reflections from the radiating antenna array reaching the receiving antenna array will be reduced, thereby improving the signal to noise ratio.
DK 180435 B1 In a possible implementation form of the first aspect, said minimum parallel column distance is at least 12 times or at least 15 times the internal width of the waveguide columns.
5 In a possible implementation form of the first aspect, the first and second parallel planes are offset with a minimum perpendicular array distance to each other in a direction perpendicular to said planes. In a possible implementation form of the first aspect, said minimum perpendicular array distance is at least 3 times or at least 5 times the internal width of said waveguide columns.
According to a second aspect there is provided a radar system comprising a first radar antenna module comprising: a first planar slotted waveguide antenna array configured for radiating electromagnetic waves, and a second planar slotted waveguide antenna array configured for receiving electromagnetic waves, wherein: each planar slotted waveguide antenna array comprises several longitudinal extending waveguide columns disposed in a parallel and adjacent position with respect to one another, said waveguide columns having a front side and a rear side with a plurality of cavity slots on the front side, and said waveguide columns further having first and second column ends; the waveguide columns of the first and second antenna arrays have equal internal height and equal internal width; the first and second antenna arrays are arranged with the waveguide columns of the first antenna array disposed in a parallel position to the waveguide columns of the second antenna array; the front side of the columns holding the cavity slots of the first planar antenna array are positioned in a first plane and the front side of the columns holding the cavity slots of the second planar antenna array are positioned in a second plane parallel to said first plane; and the first and second parallel planes are offset with a minimum perpendicular array distance to each other in a direction perpendicular to said planes.
DK 180435 B1 6 In a possible implementation form of the second aspect, said minimum perpendicular array distance is at least 3 times or at least 5 times the internal width of said waveguide columns. By having the first radiating antenna array and the second receiving antenna array offset to each other in the direction perpendicular to the first and second planes, the resulting antenna module may take up less space in the horizontal direction, which is useful when the antenna module is used in a rotating antenna system. Furthermore, by having the first radiating antenna array and the second receiving antenna array offset to each other in the direction perpendicular to the first and second planes, the amount of false reflections from the radiating antenna array reaching the receiving antenna array may be reduced, thereby improving the signal to noise ratio.
In a possible implementation form of the second aspect, the first antenna and second antenna arrays are positioned at a distance to each other with a longitudinal extending — outer sidewall of an outermost waveguide column of the first array arranged closest to a longitudinal extending outer sidewall of an outermost waveguide column of the second array, said closest outer sidewalls of the outermost columns of the first and second antenna arrays positioned with a minimum parallel column distance to each other in a direction parallel to the first and second planes, said minimum parallel column distance being at least 2 times the internal width of the waveguide columns. In a possible implementation form of the second aspect, said minimum parallel column distance is at least 3 times, such as at least 5 times, such as at least 10 times, such as at 12 times or at least 15 times the internal width of the waveguide columns.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the front sides of the first and second antenna arrays face the same direction being a front direction of the antenna module.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first plane is offset from the second plane by the perpendicular array distance in a direction opposite to said front direction.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first antenna array has a first longitudinal extending outermost
DK 180435 B1 7 array sidewall closest to a second longitudinal extending outermost array sidewall of the second antenna array, said closest first and second outermost array sidewalls positioned with a minimum parallel array distance to each other in a direction parallel to the first and second planes, said minimum parallel array distance being smaller than or equal to the — minimum parallel column distance.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first outer array sidewall is the outer sidewall of the outermost waveguide column of the first array, and the second outer array sidewall is the outer sidewall of the outermost waveguide column of the second array.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first outer array sidewall is an outer sidewall of a first spacer part connected to said outermost waveguide column of the first antenna array, and the second outer array sidewall is an outer sidewall of a second spacer part connected to said outermost waveguide column of the second antenna array.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, one or more electromagnetic shield(s) is/are arranged between the first radiating antenna array and the second receiving antenna array.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the front sides of the first and second antenna arrays face the same direction being a front direction of the antenna module, and at least a part of the electromagnetic shields extends outwards from the front side of the antenna module.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the one or more electromagnetic shields comprise a first shield plate and a second shield plate with both shield plates having a first direction of extension and a second direction of extension perpendicular to the first direction of extension. In a possible implementation form of the first aspect or in a possible implementation for of the second aspect, the first direction of extension for both shield plates is parallel to the longitudinal extension of the waveguides.
DK 180435 B1 8 In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first shield plate has a first outer edge in contact with said first outermost array sidewall of the first array and the second shield plate has a first outer edge in contact with said second outermost array sidewall of the second array.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the second direction of extension of the first shield plate has a first obtuse angle to the front side of the first array and the second direction of extension of the second shield plate has a second obtuse angle to the front side of the second array.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the second direction of extension of the first shield plate differs from the second direction of extension of the second shield plate, and the second direction of extension of the first shield plate forms a first acute angle to the second direction of extension of the second shield plate. In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first and second shield plates reach a point or line of contact along said second directions of extension.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first shield plate has a first maximum length of extension in its second direction of extension and the second shield plate has a second maximum length of extension in its second direction extension, said first and second maximum lengths of extension being defined by a point or line of contact between the first and second shields plates. In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first antenna array has a second longitudinal extending outer array sidewall opposite to said first outer array sidewall, and a third shield plate is arranged in contact with said second longitudinal extending outer array sidewall of the first array, said third shield plate extending outwards from the front side of the first antenna array.
DK 180435 B1 9 In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the third shield plate has a first and a second direction of extension, and the first direction of extension of the third shield plate is parallel to the longitudinal extension of the waveguides.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the second direction of extension of the third shield plate differs from the second direction of extension of the first shield plate, and the second direction of extension of the third shield plate has a third obtuse angle to the front side of the first array.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first, second and/or third obtuse angles are in the range of 100° to 140°, such as 120°. In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first acute angle is in the range of 40° to 80°, such as 60°. In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first planar antenna array is a narrow sided slotted waveguide antenna array configured for radiating horizontal polarized electromagnetic waves, and the second planar antenna array is a narrow sided slotted waveguide antenna array configured for receiving horizontal polarized electromagnetic waves. In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the waveguide columns of the first and second antenna arrays are of equal length. In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first antenna array holds a number of parallel plate blinds secured to the front side of the first antenna array besides or between the cavity slots and substantially perpendicular to the longitudinal direction of the waveguide columns of the first antenna array.
DK 180435 B1 10 In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the second antenna array holds a number of parallel plate blinds secured to the front side of the second antenna array besides or between the cavity slots and substantially perpendicular to the longitudinal direction of the waveguide columns of the second antenna array. The plate blinds are vertical blinds or baffles for reducing electromagnetic power radiated in the cross-polarization, that is blinds or baffles for cross- polarization suppression. The plate blinds may be substantially U-shaped with two parallel side plates and a bottom plate.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the number of waveguide columns in the second receiving array is larger than the number of waveguide columns in the first radiating array. In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the number of waveguide columns in the second receiving array is twice the number of waveguide columns in the first radiating array. In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first radiating array comprises four waveguide columns, and the second receiving array comprises eight waveguide columns.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the radar system further comprises a rotation system configured for supporting and rotating the first antenna module around a vertical axis.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first radar antenna module is secured to the rotation system with the first and second planar antenna arrays positioned with the first and second planes holding a second acute angle to the vertical axis of rotation.
In a possible implementation form of the first aspect or in a possible implementation form ofthe second aspect, the radar system further comprises a second radar antenna module being configured and dimensioned equal to the first radar antenna module, said second radar antenna module being supported by the rotation system with the first and second antenna modules arranged in a back-to-back position on opposite sides of a plane intersecting the axis of rotation, and with the rear side of the waveguide columns of the
DK 180435 B1 11 antenna arrays of the first antenna module facing the rear side of the waveguide columns of the antenna arrays of the second antenna module. By having a rotating radar system with two back-to-back positioned antenna modules, it is possible to decrease the speed of rotation to half the speed of a rotating radar system, which comprises only a single radar module, while still having the same speed of update of radar tracks obtained from received signals being reflected from detected objects or targets. By lowering the speed of rotation, a higher signal exposure time on target is obtained, resulting in a higher signal to noise ratio, which again results in more information of any detected target or object.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the second radar antenna module is secured to the rotation system with its first and second planar antenna arrays positioned with the first and second planes holding said second acute angle to the vertical axis of rotation.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the second acute angle is in the range of 15° to 25°, such as 20°.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first and second antenna arrays of each radar antenna module are positioned with said first and second longitudinal extending outermost array sidewalls reaching a single axis parallel to said vertical axis of rotation.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the radar system further comprises a protective housing in the form of a radome covering said antenna module(s).
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the radome has a conically shaped wall part surrounding the antenna module(s), said wall part being slightly inclined towards the antenna module(s) forming a small acute inclination angle to said axis of rotation, said small acute angle being no larger than 10°, such as no larger than 5, such as about 3°.
DK 180435 B1 12 In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first and second shield plates of a radar antenna module each have a second outer edge proximate the conically shaped wall part of the radome, said second outer edges being curve shaped to follow the interior of the conically shaped radome. In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the third shield plate of a radar antenna module has a second outer edge proximate the conically shaped wall part of the radome, said second outer edge being curve shaped to follow the interior of the conically shaped radome.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the distance between the second outer edge of one said shield plates and the interior of the conically shaped wall part of the radome is no larger than 15 mm, such as no larger than 10 mm, such as no larger than 8 mm.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first and second antenna modules are arranged in a mirrored position relative to said plane intersecting the vertical axis of rotation.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the radome is made of a material having a high electromagnetic transparency, such as made of a polyethylene (PE) or polypropylene (PP) based ultra heigh molecular weight plastic material.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the radome is made of a material having a thickness in the range of 1-3 mm, such as in the range of 1-2 mm or such as in the range of 1-1,5 mm.
— When having two back-to-back simultaneously operating antenna modules, it is important to minimize reflection of signals transmitted or radiated from the radiating array of one module to the receiving array of the other module. By reducing the material thickness of the radome, the electromagnetic transparency of the radome is increased, thereby minimizing the internal reflection from the radome. By using a PE or PP based material,
DK 180435 B1 13 such as a PE or PP based ultra heigh molecular weight plastic material, the electromagnetic transparency of the radome is increased even further.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the system further comprises a signal generating system holding a single signal generator, and the first antenna module holds first electronic transmit circuitry configured for feeding the first radiating array of the first antenna module to radiate first electromagnetic signals, and the second antenna module holds second electronic transmit circuitry configured for feeding the first radiating array of the second antenna module to radiate second electromagnetic signals, said first and second electromagnetic signals being fully synchronized electromagnetic signals based at least partly on signals provided by said single signal generator.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the first antenna module holds first electronic receive circuitry configured for processing signals received by the second receiving array of the first antenna module, and the second antenna module holds second electronic receive circuitry configured for processing signals received by the second receiving array of the second antenna module, said first and second electronic receive circuitry being configured for processing the received signals in synchronization with the radiated electromagnetic signals, said synchronization being based on signals provided by the single signal generator.
In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the system further comprises: first processing circuitry for processing signals received by the first antenna module, said first processing circuitry being configured to provide first type radar plots of detected objects presented by said signals received by the first antenna module; and second processing circuitry for processing signals received by the second antenna module, said second processing circuitry being configured to provide second type radar plots of detected objects presented by said signals received by the second antenna module.
DK 180435 B1 14 In a possible implementation form of the first aspect or in a possible implementation form of the second aspect, the system further comprises: radar track processing circuitry, said radar track processing circuitry being configured to provide a radar track for a detected object based on both the first and the second type radar plots. The foregoing and other objects are achieved by the features of the independent claims. Further implementation forms are apparent from the dependent claims, the description and the figures. These and other aspects of the invention will be apparent from the embodiments described below.
BRIEF DESCRIPTION OF THE DRAWINGS In the following detailed portion of the present disclosure, the invention will be explained in more detail with reference to the example embodiments shown in the drawings, in which; Fig. 1 is a schematic block diagram illustrating the basic structure of a detection system holding a radar system according to an example embodiment; Figs. 2a and 2b are schematic cross-sectional views illustrating a back-to-back to arrangement of antenna modules for the radar system of Fig. 1 according to an example embodiment; Figs. 3a, b, c illustrates manufacturing of an array of slotted cavity columns for use in a planar cavity slotted-waveguide antenna array according to an example embodiment, with Fig. 3a illustrating manufacturing of a first one-piece metal element, and Figs. 3b and 3c illustrating manufacturing of a second one-piece metal; Fig. 4 is a bottom view illustrating further manufacturing steps of a cavity slotted- waveguide antenna array according to an example embodiment; Fig. 5 shows a cavity slotted-waveguide antenna array holding plate blinds according to an example embodiment;
DK 180435 B1 15 Figs. 6a and 6b show a cut through end view and an enlarged cut out view of a cavity slotted-waveguide antenna array with signal probes inserted according to an example embodiment; Fig. 7 is a side view of a radar antenna module holding a radiating array and a receiving array with electromagnetic shields according to an example embodiment; Fig. 8 is a schematic cut through view of a radar system holding a single antenna module as illustrated in Fig. 7 covered by a protective radome according to an example embodiment; Fig. 9 is a schematic cut through view of a radar system holding two of the antenna modules illustrated in Fig. 7 with both antenna modules covered by a protective radome according to an example embodiment; Fig. 10 is a perspective view illustrating a radar system with a back-to-back arrangement of two antenna modules according to an example embodiment; and Fig. 11 shows the radar antenna module of Fig. 7 with indications of geometrical dimensions according to an example embodiment.
DETAILED DESCRIPTION Fig. 1 is a schematic block diagram illustrating the basic structure of a detection system holding a radar system according to an example embodiment. The detection system comprises a rotating scanning radar system 101, which is configured to operate as a Frequency Modulated Continuous Wave, FMCW, radar system. The scanning radar system 101 is electronically connected to a computer system 102. Generated output data may be communicated to an external command and control system 103, where the data may be communicated by live data streaming, where for example Extensible Markup Language, XML, may be used for streaming.
DK 180435 B1 16 The scanning radar system 101 holds two back-to-back positioned antenna modules, a first antenna module 110a and a second antenna module 110b, where each antenna module 110a, 110b comprises a first planar slotted waveguide antenna array 111a, 111b configured for radiating electromagnetic waves 113a, 113b, and a second planar slotted waveguide antenna array 112a, 112b configured for receiving electromagnetic waves 114b.
The antennas modules 110a, 110b are mounted to a rotation system 116 configured for rotating 117 the antenna modules 110a, 110b around a vertical axis 115 at a rotational speed.
By having the two simultaneously operating antenna modules 110a, 110b, which are both operating as a FMCW radar antenna module, a full 360 degree radar image can be obtained for every half rotation of the radar system 101. The rotational speed may be of 30 rounds per minute, rpm, whereby a full 360 degree radar image can be obtained every second.
The targets or objects being exposed to the radar signals may include one or more Unmanned Aerial Vehicles, UAVs, 105 and one or more birds 106. The antenna modules 110a, 110b are enclosed by a protecting radome 118 having a high electromagnetic transparency in order to minimize reflection of signals transmitted or radiated from the radiating arrays 111a, 111b to the receiving arrays 112b, 112a.
In order to obtain a high electromagnetic transparency, the radome should be relatively thin and may be made of a material having a thickness in the range of 1-3mm, such as in the range of 1-2mm or such as in the range of 1-1,5 mm.
Also in order to obtain a high electromagnetic transparency, the radome may be made of a polyethylene (PE) or polypropylene (PP) based ultra heigh molecular weight plastic material.
When using a relatively thin wall thickness of below 3 mm, such a in the range of 1-1,5 mm, it is preferred that the radome 118 has a dome shaped upper part in order to increase the mechanical strength of the radome 118. The radome 118 may be arranged in a fixed position without following the rotation of the rotation system 116 and the antenna modules 110a, 110b.
However, it is also within an embodiment that the radome 118 is connected to the rotation system 116 for being rotated together with the antenna modules 110a, 110b.
Figs. 2a and 2b are schematic cross-sectional views illustrating a back-to-back arrangement of the two antenna modules 110a, 110b for the radar system 101 of Fig. 1 according to an example embodiment.
DK 180435 B1 17 For each of the antenna modules 110a, 110b, the radiating arrays 111a, 111b are positioned at a distance to the receiving arrays 112b, 112a. The radiating arrays 111a, 111b have a front side positioned in a first plane, and the receiving arrays 112b, 112a have a front side positioned in a second plane, which second plane may be parallel to the first plane. When the first and second planes are parallel to each other, the resulting distance between a radiating array 111a, 111b and a corresponding receiving array 112a, 112b may be composed of a component in a direction parallel to the first and second planes, and a component in a direction perpendicular to the first and second planes.
For each of the modules 110a, 110b of Fig. 2, a first electromagnetic shield plate 120a, 120b and a second electromagnetic shield plate 121a, 121b are positioned between the radiating array 111a, 111b and the receiving array 112a, 112b. A third electromagnetic shield plate 122a, 122b may also be positioned at a lower edge of the radiating array 111a, 111b, opposite the first electromagnetic shield plate 121a, 121b. The radar system 101 may hold on-board circuitry, which may include a signal generating system 125 holding a single signal generator. For the illustrated embodiment of Figs. 2a and 2b, the signal generating system 125 is positioned at the back of the second antenna module 110b. Each of the FMCW radar antenna modules 110a, 110b may hold electronic on-board circuitry, which includes first electronic transmit circuitry 123a configured for feeding the first radiating array 111a of the first antenna module 110a to radiate first FMCW electromagnetic signals 113a and positioned at the back of the first antenna module 110a, and which may include second electronic transmit circuitry 123b configured for feeding the first radiating array 111b of the second antenna module 110b to radiate second FMCW electromagnetic signals 113b and positioned at the back of the second antenna module 110b. The first and second transmit circuitries 123a, 123b may both be fed with signals from the signal generating system 125 in order to control the first and second electromagnetic signals 113a, 113b to be fully synchronized electromagnetic signals based at least partly on signals provided by the single signal generator of the signal generating system 125.
DK 180435 B1 18 As part of the electronic on-board circuitry, the first antenna module 110a may hold first electronic receive circuitry 124a configured for processing signals received by the second receiving array 112a of the first antenna module 110a, and the second antenna module 110b may hold second electronic receive circuitry 124b configured for processing signals received by the second receiving array 112b of the second antenna module 110b. The first electronic receive circuitry 124a may be positioned at the back of the first antenna module 110a, and the second electronic receive circuitry 124b may be positioned at the back of the second antenna module 110b. The first and second electronic receive circuitry 124a, 124b may be configured for processing the received signals in synchronization with the radiated electromagnetic signals 113a, 113b, which synchronization may be based on signals provided by the single signal generator of the signal generating system 125. The on-board circuitry of the radar system 101 may also include a motor controller 119 for controlling the rotation system 116. An azimuth encoder may be provided at the rotation system 116, which encoder may be configured for encoding and communicating the degree of rotation, and thereby the azimuth angle of the antenna modules 110a, 110b, at a very high precision. The on-board circuitry may also include signal processing circuitry 126 for performing first on-board processing of signals received from the first receive circuitry 124a, and for performing second on-board processing of signals received from the second receive circuitry 124b, to thereby obtain first digital scan data representing the electromagnetic signals received by the first antenna module 110a, and to obtain second digital scan data representing the electromagnetic signals 114b received by the second antenna module 110b. The signal processing circuitry 126 may also provide a control signal to the signal generator system 125.
For the illustrated embodiment of Figs. 2a and 2b, the signal processing circuitry 126 is positioned at the back of the first antenna module 110a. The different circuitries of the on-board circuitry, the signal generator system 125, the first and second transmit circuitry123a, 123b, the first and second receive circuitry 124a, 124b and the signal processing circuitry 126 may be enclosed by an aluminium shield, which shields for electronic noise signals. The on-board signal processing circuitry 126 may be electronically connected to back-end circuitry being part of the azimuth encoder for communicating the azimuth angle. The on-board signal processing circuitry 126 and the
DK 180435 B1 19 back-end circuitry may be electronically connected to the computer system 102, for forwarding the first and second digital scan data together with data for the azimuth angle to the computer system 102. The electronic signals may be transferred via a glass fibre cable from the signal processing circuitry 126 to a rotary joint at the rotation system 116, which is further connected to the computer system 102 by cables. The computer system 102 may hold first processing circuitry for processing the received first digital scan data and azimuth data to provide first type radar plots of detected objects presented by the signals received by the first antenna module, and further hold second processing circuitry for processing the received second digital scan data and azimuth data to provide second type radar plots of detected objects presented by the signals received by the second antenna module. The computer system 102 may also hold radar track processing circuitry configured to provide a radar track for a detected object based on both first and second type radar plots. The computer system 102 may also hold classifying circuitry for classifying the objects of the tracks. The scanning radar system 101 of Fig. 1 is based on two antenna modules 110a, 110b, where each antenna module comprises a first planar slotted waveguide antenna array 111a, 111b configured for radiating electromagnetic waves 113a, 113b, and a second planar slotted waveguide antenna array 112a, 112b configured for receiving electromagnetic waves 114b. Figs. 3a, b, c illustrates manufacturing of an array of slotted cavity columns for use in a planar cavity slotted-waveguide antenna array according to an example embodiment, with Fig. 3a illustrating manufacturing of a first one-piece metal element, and Figs. 3b and 3c illustrating manufacturing of a second one-piece metal. Fig. 4 is a bottom view illustrating further manufacturing steps of a cavity slotted- waveguide antenna array according to an example embodiment.
Fig.3a illustrates manufacturing of a first one-piece metal element 201, which is a first single flat piece of metal, where a plurality of longitudinally extending parallel and equidistantly arranged open rear column portions 203a of equal dimensions are formed in
DK 180435 B1 20 the first flat piece of metal 201. In order to save weight of the final array, grooves 204 may be formed in the metal material left between the rear column portions 203a.
Figs. 3b and 3c illustrate manufacturing of a second one-piece metal element 202, which is a second single flat piece of metal, where a plurality of longitudinally extending parallel and equidistantly arranged open front column portions 203b of equal dimensions are formed in the second flat piece of metal 202. The front column portions 203b have a width and a length equal to the width and length of the rear column portions 203a, and the front column portions 203b are arranged with a spacing equal to the spacing of the rear column portions 203a.
After formation of the front column portions 203b, a plurality of longitudinally extending parallel front recesses 205 are formed in the second metal element 202. These front recesses 205 extend into the second metal element 202 from the front surface of the element 202, and the front recesses 205 define first and second sidewalls 206, 207 of a front part of the front column portions 203b.
After the formation of the front recesses 205, — a plurality of slots 208 are formed in the front column portions 203b.
Each slot 208 extends from the bottom of the corresponding front column portion 203b to a front surface 209 of the second metal element 202. A signal probe hole 210 is formed at the bottom of the rear column portions 203a, where each probe hole extends from the bottom of the corresponding rear column portion 203a to a rear surface 211 of the first metal element 201. When the slots 208 and probe holes 210 have been formed, the first and the second metal elements 201 and 202 are connected together with the openings of the rear column portions 203a facing the openings of the front column portions 203b.
The connection of the first and second metal elements 201 and 202 forms a housing, which comprises a number of parallel slotted- waveguide columns 203 having a rectangular cross-section, see Fig. 5, where the parallel slotted-waveguide columns 203 are formed by the rear and front column portions 203a, 203b.
The arrangement of the probe holes 210 at the rear surface 211 of the first metal element 201 is illustrated in Fig. 4, which also shows the first and second metal elements 201 and 202 being connected together.
The diameter of the probe hole 210 may equal the internal width of the columns 203 or rear column portions 203a.
In Fig. 4 is also shown screw holes 220, which are provided at the rear surface 211 of the first metal element 201 in between the rear column portions 203a.
The screw holes 220 may hold screws connecting the first and second metal elements 201 and 202.
DK 180435 B1 21 The material used for the metal elements 201 and 202 may be anodized aluminum. Is it preferred that the formation of the rear column portions 203a and grooves 204 in the first metal element 201, the formation of the front column portions 203b, the front recesses 205, and the slots 208 in the second metal element 202 are performed by use of milling. The probe holes 210 may also be formed in the first metal element 201 by drilling. Fig. 5 shows part of a cavity slotted-waveguide antenna array 200, which has been manufactured and assembled as described above in connection with Figs. 3a,b,c and Fig.
4. According to an example embodiment, the array 200 is further provided with a number of conductive parallel plate blinds 212, which are conductively secured to the front side or surface 209 of the housing holding the waveguide columns 203b, 203, where the front side or surface 209 holds the cavity slots 208. The plate blinds 212 are arranged substantially perpendicular to the longitudinal direction of the waveguide columns 203. — The plate blinds 212 have two parallel outer surfaces being first and second parallel outer surfaces, and the blinds 212 are substantially U-shaped with two parallel side plates and a bottom plate. The plate blinds 212 are secured to the front side or surface 209 of the housing holding the waveguide columns 203b, 203 by a sliding dovetail joint 213. The tail of a dovetail joint is formed at a bottom part of a U-shaped plate blind 212 and the socket of the dovetail joint is formed in the front side or surface 209 of the housing holding the outermost positioned waveguide columns 203b, 203. The waveguide columns 203 with no dovetail socket in the front surface 209 may hold a cut-out corresponding to the width of the bottom of the plate blinds. The use of dovetail joints and cut-outs serves to increase the mechanical stabilization of the arrays, and to keep the waveguide columns in alignment. The use of plate blinds 212 is optional. In order for the slotted-waveguide columns 203 to emit or receive an electromagnetic signal, a signal probe may be inserted in the probe hole 210. This is illustrated in Figs. 6a and 6b, which show a cut through end view and an enlarged cut out view of a cavity slotted- waveguide antenna array 200 with signal probes 214 inserted in each waveguide column 203, according to an example embodiment. The array 200 has eight waveguide columns 203 disposed in a predetermined adjacent position with respect to one another, where each column may be formed by a rear column
DK 180435 B1 22 portion 203a formed in a first one-piece metal element 201 and by a front column portion 203b formed in a second one-piece metal element 202. Each column 203 has a number of slots 208 formed in the front column portion 203b, see Fig. 3c, and each column 203 has an upper and a lower end.
The waveguide columns 203 have a rectangular cross- section, and the waveguide columns 203 are defined by two wide inner surfaces being first and second wide inner surfaces, a narrow inner back surface, and narrow inner front surface.
The narrow inner front surface and the front side 209 of the housing define a narrow front wall holding the cavity slots 208. The slots 208 are narrow walled slots or transverse narrow walled slots 208, which reach from the first inner wide surface to the second wide inner surface.
A signal probe 214 is operably disposed in each column 203 for emitting and/or receiving an electromagnetic signal.
The electromagnetic signal may have a free-space wavelength of o, and the signal propagates within the column 203 holding the signal probe 214 as electromagnetic waves with a corresponding guided signal wavelength 4. For the embodiment illustrated in Fig. 6, the signal probes 214 are open ended loop probes with an open ended loop disposed at the narrow inner back surface opposite and facing the narrow inner front surface of the waveguide column 203 holding the loop probe 214. The open ended loop of the loop probe 214 is arranged in a direction perpendicular to the longitudinal direction of the waveguide column 203, and the open ended loop probe 214 may be disposed proximal to the lower end of the column 203 holding the probe 214. According to an embodiment, each column 203 has an absorbing load at its upper end while the lower end of the waveguide column may be terminated with a short circuiting end geometry (blind end) or an absorbing load, to enable the column 203 to function in a travelling wave mode.
The signal probes 214 are formed of an electrically conductive material, such as copper or silver-plated copper, and are electrically non-conductively secured to the columns 203. The open ended loop of a loop probe 214 forms part of a loop circle, which may have a circumference in the range of 1/3 to 2/3, such as about 1/2 of the guided signal wavelength 9
DK 180435 B1 23 The housing holding the waveguide columns 203 has a rear side surface, and a waveguide bottom wall is defined by the narrow inner back surface of a waveguide column 203 and the rear side surface of the housing, whereby an outer back surface of the waveguide bottom wall is defined by the rear side of the housing. The open ended loop probes 214 have a probe connection part 215 opposite the open ended loop, where the probe connection part 215 extends through probe holes 210 provided at the waveguide bottom wall. An enclosure part 218 is disposed between a printed circuit board, PCB, 217 and the outer back surface of the waveguide bottom wall, and the loop probe connection part 215 extends through a surrounding part 219 formed by the enclosure part 218 to reach the — printed circuit board 217. An end part of the connection part 215 of each of the loop probes 214, which may reach through the PCB 217 by a so-called via, is electrically connected to a corresponding electrical conductive signal trace provided at the front surface of the printed circuit board 217. The surrounding parts 219 of the enclosure part 218 may be formed to fit or fill out the probe holes 210, and the probe holes 210 may have a diameter equal to the internal width of the column 203. An electrically non-conductive material 216 surrounds the probe connection part 215 extending through the enclosure part 218. The electrical non-conductive material may comprise or is made of Polyether Ether Ketone, PEEK, plastic. The enclosure part 218 holds sidewalls 222, and a lid 223 is secured to the sidewalls to close off the enclosure part 218.
The enclosure part 218 is made of an electrical conductive material, such as aluminium. Before securing the enclosure part 218 to the rear side of the array housing holding the waveguide columns, the probes 214 and the PCB 217 may be connected to the enclosure part 218. First, each loop probe 214 is connected to the enclosure part 218 by having the connection part 215 surrounded by the non-conductive material 216 and arranged within the surrounding part 219 of the enclosure part 218. The printed circuit board, PCB, 217 can then be secured to the enclosure part 218 by screws 221 with the end part of the probe connection part 215 reaching through the PCB 217 by the so-called via. The end part of the probe connection part 215 can now be soldered or electrical connected to a corresponding electrical conductive signal trace provided at the front surface of the printed circuit board 217. The PCB 217 has a bottom surface facing the enclosure part 218, where the PCB bottom surface holds electrical conductive ground traces or parts to provide an electrical ground connection to the enclosure part 218. In an embodiment, the enclosure part 218 is silver plated for maintaining an electrical connection between the enclosure
DK 180435 B1 24 part 218 and the PCB bottom ground traces. Each PCB signal trace corresponding to a loop probe 214 may have a first trace end soldered to the end part 215 of the loop probe 214, and each of these PCB signal traces is a copper trace, which preferably is formed to obtain a characteristic impedance of 50 Ohm. The PCB signal traces having one end electrically corresponding to a loop probe 214, may in the other end be electrically connected to radio frequency transmit circuitry, when the array is a transmitting array, or connected to receive circuitry, when the array is a receiving array, where the transmit or receive circuitry may be arranged at the front surface of the PCB 217. The radio frequency transmit circuitry may comprise a radio frequency amplifier, and the receive circuitry may comprise a pseudomorphic high electron mobility transistor, PHEMT. Fig. 7 is a side view of a radar antenna module 310 holding a first radiating array 300a and a second receiving array 300b with electromagnetic shields 320, 321, 322 according to an example embodiment.
The radiating array 300a and the receiving array 300b may be manufactured and assembled as described above in connection with Figs. 3 to 6. Each of the antenna modules 110a and 110b may hold a radiating and a receiving antenna array 300a, 300b equal to the arrays 300a and 300b of the module 310 of Fig. 7.
For the module 310 of Fig. 7, the waveguide columns 303a and 303b within the first radiating array 300a and second receiving array 303b have equal dimensions. The first radiating array 300a comprises four waveguide columns 303a, and the second receiving array 300b comprises eight waveguide columns 303b. Thus, both antenna modules 110a and 110b may have equal dimensioned waveguide columns 303a, 303b, whereby it is possible to operate within the same frequency band for both antenna modules. For the module 310, the radiating array 300a is positioned at a distance to the receiving array 300b. The radiating array 300a has a front side positioned in a first plane, and the receiving array 300b has a front side positioned in a second plane, which second plane is parallel to the first plane. Thus, the front sides of the first radiating array 300a and the second receiving arrays 300b face the same direction being a front direction of the antenna module 310. When the first and second planes are parallel to each other, the resulting distance between the radiating array 300a and the receiving array 300b holds a distance
DK 180435 B1 25 component in a direction parallel to the first and second planes, and a distance component in a direction perpendicular to the first and second planes. The first plane is offset from the second plane by said perpendicular distance component in a direction opposite to the front direction of the module 310. This perpendicular distance component is in the following referred to as perpendicular array distance. By having the radiating array 300a and the receiving array 300b offset to each other in the direction perpendicular to the first and second planes, the resulting module 310 may take up less space in the horizontal direction when the module 310 is used in a rotating antenna system such as the system 101 of Fig. 1. It is preferred that the first and second parallel planes are offset with a minimum perpendicular array distance, where the minimum perpendicular array distance is at least 3 times or at least 5 times the internal width of the waveguide columns 303a, 303b.
The first radiating antenna array 300a and the second receiving antenna array 300b are positioned at a distance to each other with a longitudinal extending outer sidewall of an outermost waveguide column of the first array 300a positioned closest to a longitudinal extending outer sidewall of an outermost waveguide column of the second array 300b. Here, the closest outer sidewalls of these outermost columns of the first and second antenna arrays 300a, 300b may be positioned with a minimum parallel column distance to each other in a direction parallel to the first and second planes. It is preferred that this minimum parallel column distance is at least 5 times the internal width of the waveguide columns 303a, 303b. It is also within embodiments that this minimum parallel column distance is at least 10 times, such as at least 12 times or at least 15 times the internal width of the waveguide columns.
By having the radiating array 300a and the receiving array 300b offset to each other in a direction parallel to the first and second planes, the amount of false reflections from the radiating antenna reaching the receiving antenna will be reduced, thereby improving the signal to noise ratio.
The module 310 may also hold a support 329 in order to hold the first and second antenna arrays 300a and 300b in the desired position.
DK 180435 B1 26 The waveguide columns 303a, 303b of the first and second antenna arrays 300a, 300b are of equal length, and first ends of the waveguide columns 303a, 303b of both the first and second antenna arrays 300a, 300b may reach a single plane in a direction perpendicular to the longitudinal direction of the waveguide columns 303a, 303b, and opposite second ends of the waveguide columns 303a, 303b of both the first and second antenna arrays 300a, 300b may reach another single plane in a direction perpendicular to the longitudinal direction of the waveguide columns 303a, 303b. The first radiating antenna array 300a may hold a number of parallel plate blinds 312a secured to the front side of the first antenna array 300a besides or between the cavity slots and substantially perpendicular to the longitudinal direction of the waveguide columns 303a of the first antenna array, and the second receiving antenna array 300b may hold a number of parallel plate blinds 312b secured to the front side of the second antenna array 300b besides or between the cavity slots and substantially perpendicular to the longitudinal direction of the waveguide columns 303b of the second antenna array. The plate blinds 312a, 312b are vertical blinds or baffles for reducing electromagnetic power radiated in the cross-polarization, that is blinds or baffles for cross-polarization suppression. The plate blinds 312a, 312b may be substantially U-shaped with two parallel side plates and a bottom plate.
A radiating signal probe, not shown in Fig. 7, see the probe 214 of Figs. 6a and 6b, is operably disposed proximal to a first end in each column 303a of the first antenna array 300a, and a receiving signal probe 214 is operably disposed proximal to a first end in each column 303b of the second antenna array 300b. The waveguide columns 303a, 303b of both the first and second antenna arrays 300a, 300b hold an absorbing load within the second column end. By having aligned waveguide columns of equal length provided with absorbing loads, the antenna arrays may function in the travelling wave mode. For the module 310 of Fig. 7, the first antenna array 300a has a first longitudinal extending outermost array sidewall 326 closest to a second longitudinal extending outermost array sidewall 327 of the second antenna array 300b, where these closest array sidewalls 326 and 327 are positioned with a minimum parallel array distance to each other in a direction parallel to the first and second planes. The first antenna array 300a has spacer parts 323 and 324 connected to the outermost waveguide columns 303a, and the second antenna
DK 180435 B1 27 array 300b has a spacer part 325 connected to the outermost waveguide column 303b closest to the first antenna array 300a.
The first array sidewall 326 is the sidewall of spacer part 323, the second array sidewall 327 is the sidewall of the lower spacer part 325 of the second antenna array 300b, while the lower spacer part 324 of the first antenna array has a third outermost array sidewall 328. A spacer part, not shown in Fig. 7, may also be provided at the upper side of the second antenna array 300b opposite the spacer part 325. For the first and second antenna arrays 300a, 300b the spacer parts 323, 324 are positioned next to the outermost waveguide columns 303a, 303b, whereby the minimum parallel array distance is smaller than the minimum parallel column distance.
However, it is also within an embodiment that the spacer parts 323 and 325 are omitted, whereby the outermost array sidewalls 326 and 327 are the outer sidewall of the outermost waveguide columns of the first antenna array 300a and the outer sidewall of the closest outermost waveguide of the second antenna array 300b, whereby the minimum parallel array distance may be equal to the minimum parallel column distance.
The first and second antenna arrays 300a, 300b may be positioned so that the upper edges of the outermost array sidewalls 327 and 328 reach a common vertical axis 330 as illustrated in Fig. 7, to thereby reduce the space used in the horizontal direction for the — module 310. For the module 310, a first electromagnetic shield plate 320 and a second electromagnetic shield plate 321 are positioned between the first radiating array 300a and the second receiving array 300b.
The electromagnetic shield plates 320, 321 are dimensioned and positioned so that at least a part of the electromagnetic shield plates 320 and 321 extends outwards from the front side of the antenna module 310. Both the first shield plate 320 and the second shield plate 321 have a first direction of extension and a second direction of extension perpendicular to the first direction of extension, with the first direction of extension for both shield plates being parallel to the longitudinal extension of the waveguides 303a, 303b.
The second direction of extension of the first shield plate 320 forms a first obtuse angle a1, see Fig. 11, to the front side of the first array 300a, and the second direction of extension of the second shield plate 321 forms a second obtuse angle a2, see Fig. 11, to the front side of the second array 300b.
The first and second shield plates 320, 321 reach a point or line of contact along their second directions of extension,
DK 180435 B1 28 with second direction of extension of the first shield plate 320 forming a first acute angle a4, see Fig. 11, to the second direction of extension of the second shield plate 321. A third electromagnetic shield plate 322 may also be positioned at a lower edge of the first radiating array 300a, opposite the first electromagnetic shield plate 320. The electromagnetic shield plate 322 is dimensioned and positioned so that at least a part of the electromagnetic shield plate 322 extends outwards from the front side of the first radiating array 300a.
The third shield plate 322 also has a first direction of extension and a second direction of extension perpendicular to the first direction of extension, where the first direction of extension of the third shield plate 322 is parallel to the longitudinal extension of the waveguides 303a, and where the second direction of extension of the third shield plate 322 forms a third obtuse angle a3, see Fig. 11, to the front side of the first array 300a.
The use of the third electromagnetic shield plate 322 is optional.
A fourth electromagnetic shield plate, not shown in Fig. 7, may also be positioned at an upper edge — of the first receiving array 300b, opposite the second electromagnetic shield plate 321. The fourth shield plate may also have a first direction of extension of the third shield plate parallel to the longitudinal extension of the waveguides 303b, and a second direction of extension, which second direction of extension is perpendicular to the first direction of extension and forms an obtuse angle to the front side of the second array 300b.
The use of the fourth electromagnetic shield plate is optional.
By having the electromagnetic shield plates 320 and 321 between the radiating array 300a and the receiving array 300b, the amount of false reflections from the radiating antenna 300a reaching the receiving antenna 300b is further reduced, thereby improving the signal to noise ratio.
Fig. 8 is a schematic cut through view of a radar system 400 holding a single antenna module 310 as illustrated in Fig. 7 covered by a protective radome 418 according to an example embodiment.
The radome 418 may be made of the same material as the radome 118 of the antenna system 101 of Fig. 1. The scanning radar system 101 of Fig. 1 holds two back-to-back positioned antenna modules 110a and 110b, but it is also within an embodiment to provide a detection system using a radar system having only a single antenna module 310, such as the radar system 400 of Fig. 8. When using only a single radar module 310, the rotation speed of the radar system 400 may be increased or
DK 180435 B1 29 doubled when compared to the rotation speed of the radar system 101 having two radar modules 110a, 110b. When increasing the rotation speed, the exposure time on the object target is decreased, thereby decreasing the signal to noise ratio.
It may therefore be preferred to use a radar system with two antenna modules as illustrated with the system 101 of Fig. 1. Fig. 9 is a schematic cut through view of an embodiment of a radar system 500 holding two antenna modules 310a and 310b equal to the module 310 as illustrated in Fig. 7, and with both antenna modules 310a, 310b covered by a protective radome 518. The radome 510 may be made of the same material as the radome 118 of the antenna system 101 of Fig. 1. The radome 418, 518 has a conically shaped wall part surrounding the antenna module(s) 310 or 310a and 310a, and the wall part may be slightly inclined towards the antenna module(s) 310 or 310a and 310a forming a small acute inclination angle to a vertical axis of rotation, where this small acute angle should be no larger than 10°, such as no larger than 5, such as about 3°. The radome 518 of Fig. 9 may in an example embodiment be dimensioned with a height h1 of 561 mm, a lower outer diameter Ø1 of 540 mm, and an upper outer diameter of @2 of 494 mm, resulting in a small acute angle of about 3°. In an example embodiment the first and second shield plates 320, 321 of the radar antenna module 310 or modules 310a and 310b each have a second outer edge proximate the conically shaped wall part of the radome 418 or 518, said second outer edges being curve shaped to follow the interior of the conically shaped radome 418 or 518. The third shield plate 322 of a radar antenna module 310 or 310a and 310b also has a second outer edge proximate the conically shaped wall part of the radome 418 or 518, said second outer edge also being curve shaped to follow the interior of the conically shaped radome. The distance d1, see Fig. 9, between the second outer edge of the shield plates 320, 321 and 322 and the interior of the conically shaped wall part of the radome 418, 519 should be no larger than 15 mm, such as no larger than 10 mm, such as no larger than 8 mm. The system 500 of Fig. 9 may in an example embodiment hold a distance d1 of about 8 mm. For the system 500 of Fig. 9, the first and second antenna modules 310a and 310b are arranged in a mirrored position relative to a plane intersecting a vertical center axis of rotation, see axis 115 of Fig. 1.
DK 180435 B1 30 Fig. 10 is a perspective view illustrating a radar system 600 with a back-to-back arrangement of two antenna modules 610a and 610b covered by a radome 618 according to an example embodiment. Each of the modules 610a and 610b are dimensioned similar to the module 310 of Fig. 7 and arranged in a mirrored position relative to a plane intersecting a vertical center axis of rotation, see axis 115 of Fig. 1. Thus, the first antenna module 610a holds a first and lower radiating array 600aa with four waveguide columns, and a second higher receiving array 600ba with eight waveguide columns. Both the first and second arrays 600aa and 600ba hold plate blinds arranged perpendicular to the longitudinal direction of the waveguide columns, see Fig. 7. Similar to the first antenna — module 610a, the second antenna module 610b holds a first and lower radiating array 600ab with four waveguide columns and a second higher receiving array 600bb with eight waveguide columns, and both the first and second arrays 600ab and 600bb hold plate blinds arranged perpendicular to the longitudinal direction of the waveguide columns, see Fig. 7.
For both the first and second antenna modules 610a and 610b, a first electromagnetic shield plate 620a, 620b and a second electromagnetic shield plate 621a, 621b are positioned between the first radiating array 600aa, 600ab and the second receiving array 600ba, 600bb. Both antenna modules 610a and 610b also hold a third electromagnetic shield plate 622a, 622b positioned at a lower edge of the first radiating array 600aa, 600ab. For both antenna modules 610a, 610b the first shield plate 620a, 620b has a first outer edge in contact with an upper outermost array sidewall of the first array 600aa, 600ab, the second shield plate 621a, 621b has a first outer edge in contact with a lower outermost array sidewall of the second array 600ba, 600bb, and the third shield plate 622a, 622b has a first outer edge in contact with a lower outermost array sidewall of the first array 600aa, 600ab. Fig. 10 shows how the first, second and third shield plates 620a, 620b, 621a, 621b and 622a, 622b all have a second outer edge being curve shaped to follow the interior of the conically shaped radome 618. The radome 618 may be made of the same material as the radome 118 of the antenna system 101 of Fig. 1 and have the same outer dimensions as the radome 518 of the system 500 illustrated in Fig. 9. The distance d1, see Fig. 9, between the second outer edge of the shield plates 620a, 620b, 621a, 621b and 622a, 622b and the interior of the conically shaped wall part of the radome 618 may also be equal to the distance d1 for the system 500 of Fig. 9.
DK 180435 B1 31 The first antenna module 610a may also hold on-board circuitry including signal processing circuitry and electronic transmit circuitry and electronic receive circuitry, not shown in Fig. 10. The second antenna module 610b also holds on-board circuitry including signal generating system, not shown in Fig. 10, and electronic transmit circuitry 623b, and electronic receive circuitry 624b. The system 600 may be supported by a rotation system, not shown in Fig. 10, and holds a motor controller 619 for controlling the rotation system. The following describes construction details for an example embodiment of the antenna array 200 of Fig. 3-6, and the first radiating array 300a and the second receiving array 300b of the antenna module 310 of Fig. 7, when designed to operate in a wideband frequency range of 9550 to 9750MHz, corresponding to a free-space wavelength ¢ in the range of 30,77-31,4 mm, or to operate with a free-space wavelength about 30 mm.
In order to operate in the above-mentioned frequency range, the waveguide columns 203, 303a, 303b are dimensioned with an internal height “a” of the wide inner surfaces to be about 2/3 o, and set to 20 mm, and an internal width “b” of the narrow inner back and front surfaces to be about 1/3 o, and set to 10 mm. The waveguide columns 203 are produced by use of milling from the first and second metal elements 201, 202 being of anodized aluminium having a plate thickness of 12 mm, and the thickness of the walls 106, 107 defining the upper parts of the wide inner surfaces of the waveguide columns 103b, 103 is about 2 mm, and the thickness of the narrow front wall is also 2 mm.
The guided wavelength, 4, can be calculated from the values of ( and “a”, where ¢ set to 30,77mm gives a value of 4, which is equal to 48 mm, and where ¢ set to 31,4 mm gives a value of 4, which is equal to 50,64 mm.
From the above values of and , the average values are found as ¢,av equal to 31 mm and g4avequal to 49,3 mm, which gives a value for half the free-space wavelength, / o, to be about 15,5mm, and a value for half the guided wavelength, /2 4, to be about 24,66 mm.
The distance between the centres of neighbouring slots 208 of a waveguide column 203, 303a, 303b is set to 25 mm, equal to about half the guided wavelength, % 4, and the total
DK 180435 B1 32 length of the edge-slots 208 including the penetrations into the sidewalls 206, 207 is set to about 15 mm, equal to about half the free-space wavelength, % o. The width of the edge-slots 208 is set to 3,6 mm, and the slots 208 are arranged with an angular displacement of about 35 degrees to the longitudinal direction to the waveguide column 203, where neighbouring slots 208 are arranged with equal, but opposite angular displacement. For the travelling waveguide columns 203, 303a, 303b the absorbing load at the second end is arranged with a spacing of three quarters of the guided wavelength, 4, which is equal to 37 mm, to the centre of the last slot 208. The signal probe 214 is inserted into the column 203 with a spacing of three quarters of a guided wavelength, 4, which is about 42 mm, to the centre of the first slot 208, while the short circuiting end geometry at the first end is arranged with a spacing of one quarter of the guided wavelength, 4, which is at least about 12,4 mm, to the centre of the coupling probe 214.
The distance between the centres of adjacent positioned waveguides columns 203, 303a, 303b is set to be 20 mm, which is about two third of the free-space wavelength o. This distance leaves a free space of about 6 mm between the sidewalls of neighbouring columns 203, 303a, 303b.
The spacing between the centres of adjacent plate blinds 212, 312a, 312b is set equal to the distance between the centres of neighbouring slots 208, which is 25 mm, to be about half the guided signal wavelength, 4, and the distance between the first and second outer surfaces of the plate blinds 212, 312a, 312b may be set to 9,86-12 mm, which is in between one third and half of the free-space signal wave length, o. The spacing left between opposite outer surfaces of neighbouring plate blinds 212, 312a, 312b is then about 12,66-14,8 mm, which is below half the free-space signal wave length of 15,5 mm, in order to effectively reduce the cross-polarization radiation. The height of the parallel outer surfaces of the plate blinds 212, 312a, 312b above the outer front surface of the columns 203, 303a, 303b may be set to be 15,5 mm, which is substantial equal to 1/2 of the free-space signal wave length, to thereby further reduce the cross-polarization radiation. The U-shaped plate blinds 212, 312a, 312b are made in aluminium with a sidewall thickness of 1,8 mm. The bottom part of the U-shaped plate blinds 212, 312 has
DK 180435 B1 33 a wall thickness of 1,7 mm, and holds the tail of the dovetail joint to fit with the socket of the dovetail joint formed in part of the waveguide columns 203, 303a, 303b. The total length of the arrays 300a, 300b and the columns 303a, 303b is 414 mm, and the total width of the first array 300a is 105 mm while the total width of the second array is 185 mm. The length of the plate blinds 312a covering the four columns 303a of the radiating array 300a is 80 mm, and the length of the plate blinds 312b covering the eight columns 303b of the receiving array 300b is 160 mm. The distance between closest side walls of neighboring plate blinds 312a, 312b is 14,5 mm, and the distance between the first and — second outer surfaces of the plate blinds 312a, 312b is set to 11,5 mm. Further measures indicating the positioning of the first radiating array 300a and the second receiving array 300b according to an embodiment of the antenna module 310 of Fig. 7 are given below with reference to Fig. 11.
In Fig. 11, L1 indicates the perpendicular array distance, which is set to 75 mm, equal to 7,5 times the internal width of the waveguide columns 303a, 303b; L2 indicates the parallel column distance, which is set to 197 mm, equal to 19,7 times the internal width of the waveguide columns 303a, 303b; L3 indicates the parallel array distance, which is set to 172 mm; L4 indicates the total width of the first array 300a set to 105 mm; L5 indicates the total width of the second array 300b set to 185 mm; L6 indicates the distance from the outer sidewall of the outermost upper waveguide column of the first array 300a to the contact point between the first shield plate 320 and the second shield plates 321, which is set to 120 mm; L7 indicates the distance from the outer sidewall of the outermost lower waveguide column of the second array 300b to the contact point between the second shield plate 321 and the first shield plates 320, which is set to 77 mm; L8 indicates the distance from the outer sidewall of the outermost lower waveguide column of the first array 300a to the outermost part of the curved third shield plate 322, which is set to 71 mm; L9 indicates the distance from a lower upper edge of the plate blinds 312a of the first array — 300a to the bottom of the support 329, which is set to 59 mm; L10 indicates the distance from a lower upper edge of the plate blinds 312b of the second array 300b to the bottom of the support 329, which is set to 345 mm, where the bottom of the support may be equal to a top part of a rotation system, to which the antenna module 310 may be secured.
DK 180435 B1 34 In fig 11, a1 indicates the first obtuse angle from the second direction of extension along the front side of the first shield plate 320 to the front side of the first array 300a, which first obtuse angle is set to 120°; a2 indicates the second obtuse angle from the second direction of extension along the front side of the second shield plate 321 to the front side ofthe second array 300b, which second obtuse is set to 120°; a3 indicates the third obtuse angle from the second direction of extension along the front side of the third shield plate 322 to the front side of the first array 300a, which third obtuse angle is set to 120°; 04 indicates the first acute angle being formed between the second direction of extension of the first shield plate 320 and the second direction of extension of the second shield plate 321, which first acute angle is set to 60°.
When an antenna modules 310 is supported by a rotation system for rotating the antenna module around a vertical axis, such as the rotation system 116 of Fig. 1, the antenna module 310 is secured to the rotation system with the first and second planar antenna arrays 300a and 300b positioned with the first and second planes holding a second acute angle a5 to the vertical axis of rotation, which second acute angle a5 may be in the range of 15° to 25°. For the embodiment illustrated in Fig.11, the second acute angle a5 is set to 20%.
tis noted that for the radar system 600 of Fig. 10, each of the modules 610a and 610b may be dimensioned according to the measures given above for the module 310 of Fig. 7 and further indicated with reference to Fig. 11. Thus, both antenna modules 610a and 610b may be supported by a rotation system with the first and second planar antenna arrays 600aa, 600ab and 600ba, 600bb positioned with the first and second planes holding a second acute angle a5 of 20° to the vertical axis of rotation.
The invention has been described in conjunction with various embodiments herein. However, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality.

Claims (6)

DK 180435 B1 35 PATENTKRAVDK 180435 B1 35 PATENTKRAV 1. Et radarsystem (101, 400, 500, 600) omfattende et første radarantennemodul (110a, 110b, 310, 610a, 610b) omfattende: en første plan slidset bølgelederantennestruktur (111a, 111b, 300a, 600aa, 600ab) konfigureret til udstråling af elektromagnetiske bølger, og en anden plan slidset bølgelederantennestruktur (112a, 112b, 300b, 600ba, 600bb) konfigureret til modtagelse af elektromagnetiske bølger, hvor: hver plan slidset bølgelederantennestruktur omfatter flere langsgående — bølgelederkolonner (203, 303a, 303b) anbragt i en parallel og tilstødende position i forhold til hinanden, hvor bølgelederkolonnerne har en forside og en bagside med en flerhed af hulrumsslidser ( 208) på forsiden, og hvor bølgelederkolonnerne yderligere har første og anden kolonneender; bølgelederkolonnerne (203, 303a, 303b) i den første og den anden — antennestruktur har samme indre højde og samme indre bredde; den første og den anden antennestruktur er arrangeret med den første antennestrukturs (300a) bølgelederkolonner (303a) anbragt i en parallel position til den anden antennestrukturs (300b) bølgelederkolonner (303b); forsiden af kolonnerne (303a), der holder den første plane antennestrukturs (300a) — hulrumsslidser, er placeret i et første plan, og forsiden af kolonnerne (303b), der holder den anden plane antennestrukturs (300b) hulrumsslidser, er placeret i et andet plan parallelt med det første plan; den første antenne og den anden antennestruktur (300a, 300b) er placeret i en afstand til hinanden med en langsgående udstrækkende ydre sidevæg af en yderste > bølgelederkolonne i den første struktur (300a) anbragt tættest på en langsgående udstrækkende ydre sidevæg af en yderste bølgelederkolonne i den anden struktur, hvilke tætteste ydre sidevægge af de yderste kolonner i den første og den anden antennestruktur er placeret med en minimum parallel kolonneafstand (L2) til hinanden i en retning, der er parallel med det første og det andet plan; den første antennestruktur (300a) har en første langsgående udstrækkende yderste struktursidevæg tættest på en anden langsgående udstrækkende yderste struktursidevæg af den anden antennestruktur (300b), hvilke tætteste første og anden yderste struktursidevægge er placeret med en minimum parallel strukturafstand (L3) til hinanden i en retning, der er parallel med det første og andet plan, idet den mindsteA radar system (101, 400, 500, 600) comprising a first radar antenna module (110a, 110b, 310, 610a, 610b) comprising: a first planar slotted waveguide antenna structure (111a, 111b, 300a, 600aa, 600ab) configured to radiate electromagnetic waves, and another planar slotted waveguide antenna structure (112a, 112b, 300b, 600ba, 600bb) configured to receive electromagnetic waves, wherein: each plane slotted waveguide antenna structure comprises a plurality of longitudinal waveguide columns (203, 303a, 303b) and arranged in parallel adjacent position relative to each other, wherein the waveguide columns have a front and a backside with a plurality of cavity slots (208) on the front, and wherein the waveguide columns further have first and second column ends; the waveguide columns (203, 303a, 303b) of the first and second antenna structures have the same internal height and the same internal width; the first and second antenna structures are arranged with the waveguide columns (303a) of the first antenna structure (300a) arranged in a parallel position to the waveguide columns (303b) of the second antenna structure (300b); the front of the columns (303a) holding the first planar antenna structure (300a) cavity slots are located in a first plane, and the front of the columns (303b) holding the cavity slots of the second planar antenna structure (300b) are located in a second plane plane parallel to the first plane; the first antenna and the second antenna structure (300a, 300b) are spaced apart with a longitudinally extending outer side wall of an outermost> waveguide column in the first structure (300a) located closest to a longitudinally extending outer sidewall of an outermost waveguide column in the second structure, which densest outer side walls of the outer columns of the first and second antenna structures are located with a minimum parallel column distance (L2) to each other in a direction parallel to the first and second planes; the first antenna structure (300a) has a first longitudinally extending outermost structure sidewall closest to a second longitudinally extending outermost structure sidewall of the second antenna structure (300b), which closest first and second outermost structure sidewalls are located at a minimum parallel structural distance (L3) to each other in a direction parallel to the first and second planes, the smallest DK 180435 B1 36 parallelle strukturafstand (L3) er mindre end eller lig med den mindste parallelle kolonneafstand (L2); og forsiderne af den første og den anden antennestruktur (300a, 300b) vender i samme retning, som er en forreste retning af antennemodulet (310); kendetegnet ved, at den mindste parallelle kolonneafstand er mindst 10 gange den indre bredde af bølgelederkolonnerne (303a, 303b); elektromagnetiske skjold (120a, 120b, 121a, 121b, 320, 321, 620a, 620b 621a, 621b) er anbragt mellem den første udstrålende antennestruktur og den anden modtagende antennestruktur; mindst en del af de elektromagnetiske skjold (120a, 120b, 121a, 121b, 320, 321, 620a, 620b, 621a, 621b) strækker sig udad fra forsiden af antennemodulet; de elektromagnetiske skjold (120a, 120b, 121a, 121b, 320, 321, 620a, 620b, 621a, 621b) omfatter en første skjoldplade (120a, 120b, 320, 620a, 620b) og en anden skjoldplade (121a, 121b , 321, 621a, 621b), hvor begge skjoldplader har en første — udstrækningsretning og en anden udstrækningsretning vinkelret på den første udstrækningsretning, og hvor den første udstrækningsretning for begge plader er parallel med den langsgående udstrækning af bølgelederne (303a, 303b); den første skjoldplade (120a, 120b, 320, 620a, 620b) har en første ydre kant i kontakt med den første yderste struktursidevæg af den første struktur (111a, 111b, 300a, 600aa, 600ab) og den anden skjoldplade ( 121a, 121b, 321, 621a, 621b) har en første ydre kant i kontakt med den anden yderste struktursidevæg af den anden struktur (112a, 112b, 300b, 600ba, 600bb); og den anden udstrækningsretning for den første skjoldplade (320) har en første stump vinkel (a1) til forsiden af den første struktur (300a), og den anden — udstrækningsretning for den anden skjoldplade (321) har en anden stump vinkel (a2) til forsiden af den anden struktur (300b); hvilket system endvidere omfatter et rotationssystem (116) konfigureret til at understøtte og rotere det første antennemodul (110a, 310a, 610a ) omkring en vertikal akse (115), hvor det første radarantennemodul (110a) er fastgjort til rotationssystemet (116) med den første og den — anden plane antennestruktur placeret således, at det første plan og det andet plan holder en anden spids vinkel (a5) til den vertikale rotationsakse; og et beskyttelseshus i form af en radom (118, 418, 518, 618), der dækker nævnte antennemodul,Parallel structural spacing (L3) is less than or equal to the smallest parallel column spacing (L2); and the faces of the first and second antenna structures (300a, 300b) face in the same direction as a front direction of the antenna module (310); characterized in that the smallest parallel column spacing is at least 10 times the inner width of the waveguide columns (303a, 303b); electromagnetic shields (120a, 120b, 121a, 121b, 320, 321, 620a, 620b 621a, 621b) are disposed between the first radiating antenna structure and the second receiving antenna structure; at least a portion of the electromagnetic shields (120a, 120b, 121a, 121b, 320, 321, 620a, 620b, 621a, 621b) extend outwardly from the front of the antenna module; the electromagnetic shields (120a, 120b, 121a, 121b, 320, 321, 620a, 620b, 621a, 621b) comprise a first shield plate (120a, 120b, 320, 620a, 620b) and a second shield plate (121a, 121b, 321, 621a, 621b), wherein both shield plates have a first extension direction and a second extension direction perpendicular to the first extension direction, and wherein the first extension direction for both plates is parallel to the longitudinal extension of the waveguides (303a, 303b); the first shield plate (120a, 120b, 320, 620a, 620b) has a first outer edge in contact with the first outer structure side wall of the first structure (111a, 111b, 300a, 600aa, 600ab) and the second shield plate (121a, 121b, 321, 621a, 621b) has a first outer edge in contact with the second outer structure sidewall of the second structure (112a, 112b, 300b, 600ba, 600bb); and the second extension direction of the first shield plate (320) has a first obtuse angle (a1) to the front of the first structure (300a), and the second - extension direction of the second shield plate (321) has a second obtuse angle (a2) to the front of the second structure (300b); the system further comprising a rotation system (116) configured to support and rotate the first antenna module (110a, 310a, 610a) about a vertical axis (115), the first radar antenna module (110a) being attached to the rotation system (116) with the first and the second planar antenna structure positioned so that the first plane and the second plane hold a second acute angle (α5) with the vertical axis of rotation; and a protective housing in the form of a radome (118, 418, 518, 618) covering said antenna module, DK 180435 B1 37 hvor radomen har en konisk formet vaegdel, der omgiver antennemodulet, hvilken veegdel er let skranende mod antennemodulet, hvorved der dannes en lille spids hældningsvinkel til rotationsaksen, hvor den lille spidsvinkel ikke er større end 10°; og hvor den første og den anden skjoldplade (620aa, 620ab, 621aa, 621ab) af et > radarantennemodul (610a, 610b) hver har en anden ydre kant nær den konisk formede vægdel af radomen (618), hvor nævnte anden ydre kanter er kurveformede for at følge det indre af den konisk formede radom (618).DK 180435 B1 37 wherein the radome has a conically shaped wall part surrounding the antenna module, which wall part is slightly sloping towards the antenna module, thereby forming a small acute angle of inclination to the axis of rotation, where the small acute angle is not greater than 10 °; and wherein the first and second shield plates (620aa, 620ab, 621aa, 621ab) of a radar antenna module (610a, 610b) each have a second outer edge near the conically shaped wall portion of the radome (618), said second outer edges being curved to follow the interior of the conically shaped radom (618). 2. Et radarsystem (101, 500, 600) ifølge krav 1, hvilket system endvidere omfatter et andet radarantennemodul (110b, 310b, 610b), der er konfigureret og dimensioneret lig med det første radarantennemodul (110a, 310a, 610a), hvor det andet radarantennemodul understøttes af rotationssystemet med det første og andet antennemodul anbragt i en ryg-til-ryg-position på modsatte sider af et plan, der skærer rotationsaksen (115), med bagsiden af bølgelederkolonnerne i antennestrukturerne i det første antennemodul (110a, 310a, 610a) vendende mod bagsiden af bølgelederkolonnerne i antennestrukturerne i det andet antennemodul (110b, 310b, 610b); og hvor det andet radarantennemodul er fastgjort til rotationssystemet med dets første og anden plane antennestrukturer anbragt således, at det første plan og det andet plan holder den anden spidse vinkel (ad) til den vertikale rotationsakse.A radar system (101, 500, 600) according to claim 1, further comprising a second radar antenna module (110b, 310b, 610b) configured and dimensioned equal to the first radar antenna module (110a, 310a, 610a), wherein it second radar antenna module is supported by the rotation system with the first and second antenna modules arranged in a back-to-back position on opposite sides of a plane intersecting the axis of rotation (115), with the back of the waveguide columns in the antenna structures of the first antenna module (110a, 310a, 610a) facing the back of the waveguide columns in the antenna structures of the second antenna module (110b, 310b, 610b); and wherein the second radar antenna module is attached to the rotation system with its first and second plane antenna structures arranged so that the first plane and the second plane hold the second acute angle (ad) of the vertical axis of rotation. 3. Et radarsystem (101, 400, 500, 600) ifølge krav 1 eller 2, hvor den mindste parallelle kolonneafstand (L2) er mindst 12 gange eller mindst 15 gange den indre bredde af bølgelederkolonnerne (303a, 303b).A radar system (101, 400, 500, 600) according to claim 1 or 2, wherein the smallest parallel column distance (L2) is at least 12 times or at least 15 times the inner width of the waveguide columns (303a, 303b). 4. Et radar system (101, 400, 500, 600) ifølge krav 1 eller 2 eller 3, hvor det første og det andet parallelle plan er forskudt med en minimum vinkelret strukturafstand (L1) til hinanden i en retning vinkelret på nævnte planer, hvilken minimum vinkelrette strukturafstand er mindst 3 gange eller mindst 5 gange den indre bredde af nævnte — bølgelederkolonner; og hvor det første plan er forskudt fra det andet plan med den vinkelrette strukturafstand (L1) i en retning modsat den forreste retning.A radar system (101, 400, 500, 600) according to claim 1 or 2 or 3, wherein the first and the second parallel planes are offset by a minimum perpendicular structural distance (L1) to each other in a direction perpendicular to said planes, which minimum perpendicular structural distance is at least 3 times or at least 5 times the inner width of said waveguide columns; and wherein the first plane is offset from the second plane by the perpendicular structural distance (L1) in a direction opposite to the front direction. DK 180435 B1 38DK 180435 B1 38 5. Et radarsystem (101, 400, 500, 600) ifølge et hvilket som helst af kravene 1 til 4, hvor den første antennestruktur (111a, 111b, 300a, 600aa, 600ab) har en anden langsgående udstrækkende ydre struktursidevæg modsat den første ydre struktursidevæg, og hvor en tredje skjoldplade (122a, 122b, 322, 622a, 622b) er — arrangeret i kontakt med den anden langsgående udstrækkende ydre struktursidevæg af den første struktur, hvilken tredje skjoldplade strækker sig udad fra forsiden af den første antennestruktur; hvor den tredje skjoldplade (322) har en første og en anden udstrækningsretning, og hvor den første udstrækningsretning for den tredje skjoldplade er parallel med den langsgående udstrækning af bølgelederne (303a, 303b); og hvor den anden udstrækningsretning for den tredje skjoldplade (322) adskiller sig fra den anden udstrækningsretning for den første skjoldplade (320), og hvor den anden udstrækningsretning for den tredje skjoldplade (322) har en tredje stump vinkel (a3) til forsiden af den første struktur (300a).A radar system (101, 400, 500, 600) according to any one of claims 1 to 4, wherein the first antenna structure (111a, 111b, 300a, 600aa, 600ab) has a second longitudinally extending outer structure sidewall opposite the first outer structure sidewall, and wherein a third shield plate (122a, 122b, 322, 622a, 622b) is - arranged in contact with the second longitudinally extending outer structure sidewall of the first structure, said third shield plate extending outwardly from the front of the first antenna structure; wherein the third shield plate (322) has a first and a second extension direction, and wherein the first extension direction of the third shield plate is parallel to the longitudinal extension of the waveguides (303a, 303b); and wherein the second direction of extension of the third shield plate (322) differs from the second direction of extension of the first shield plate (320), and wherein the second direction of extension of the third shield plate (322) has a third obtuse angle (a3) to the front of the first structure (300a). 6. Et radarsystem (101, 400, 500, 600) ifølge krav 5, hvor den tredje skjoldplade (622a, 622b) i et radarantennemodul har en anden ydre kant tæt på radomens konisk formeded vægdel ( 618), hvor den anden ydre kant er kuveformet for at følge det indre af den konisk formede radome (618).A radar system (101, 400, 500, 600) according to claim 5, wherein the third shield plate (622a, 622b) in a radar antenna module has a second outer edge close to the conically shaped wall portion (618) of the radome, the second outer edge being cube-shaped to follow the interior of the conically shaped radome (618).
DKPA201970080A 2018-05-01 2019-02-04 A radar system holding an antenna module with cavity slotted-waveguide antenna arrays for radiating and receving radar wave signals DK180435B1 (en)

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DKPA201970080A DK180435B1 (en) 2019-02-04 2019-02-04 A radar system holding an antenna module with cavity slotted-waveguide antenna arrays for radiating and receving radar wave signals
PCT/EP2019/060604 WO2019211158A1 (en) 2018-05-01 2019-04-25 A radar system comprising two back-to-back positioned radar antenna modules, and a radar system holding an antenna module with cavity slotted-waveguide antenna arrays for radiating and receving radar wave signals
US17/051,962 US11881626B2 (en) 2018-05-01 2019-04-25 Radar system comprising two back-to-back positioned radar antenna modules, and a radar system holding an antenna module with cavity slotted-waveguide antenna arrays for radiating and receiving radar wave signals
EP19719867.4A EP3788676B1 (en) 2018-05-01 2019-04-25 A radar system comprising two back-to-back positioned radar antenna modules
CN201980029619.6A CN112055916B (en) 2018-05-01 2019-04-25 Radar system comprising an antenna module with a cavity waveguide antenna array
EP24152656.5A EP4346011A3 (en) 2018-05-01 2019-04-25 A radar system comprising two back-to-back positioned radar antenna modules
US18/524,731 US20240106133A1 (en) 2018-05-01 2023-11-30 Dar system comprising two back-to-back positioned radar antenna modules, and a radar system holding an antenna module with cavity slotted-waveguide antenna arrays for radiating and receving radar wave signals

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