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WO1997047055A1 - Antenna arrangement - Google Patents

Antenna arrangement Download PDF

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Publication number
WO1997047055A1
WO1997047055A1 PCT/SE1997/000994 SE9700994W WO9747055A1 WO 1997047055 A1 WO1997047055 A1 WO 1997047055A1 SE 9700994 W SE9700994 W SE 9700994W WO 9747055 A1 WO9747055 A1 WO 9747055A1
Authority
WO
WIPO (PCT)
Prior art keywords
antenna arrangement
dielectric element
guiding
arrangement according
socket
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/SE1997/000994
Other languages
French (fr)
Inventor
Arne Olofsson
Renato Ricci
Mauro Cinti
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
EL-MARIN AB
Original Assignee
EL-MARIN AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by EL-MARIN AB filed Critical EL-MARIN AB
Priority to AU31994/97A priority Critical patent/AU3199497A/en
Publication of WO1997047055A1 publication Critical patent/WO1997047055A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q19/00—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
    • H01Q19/10—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces
    • H01Q19/12—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces wherein the surfaces are concave
    • H01Q19/13—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces wherein the surfaces are concave the primary radiating source being a single radiating element, e.g. a dipole, a slot, a waveguide termination
    • H01Q19/134—Rear-feeds; Splash plate feeds
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
    • H01Q3/02—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system using mechanical movement of antenna or antenna system as a whole
    • H01Q3/08—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system using mechanical movement of antenna or antenna system as a whole for varying two co-ordinates of the orientation
    • H01Q3/10—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system using mechanical movement of antenna or antenna system as a whole for varying two co-ordinates of the orientation to produce a conical or spiral scan
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
    • H01Q3/12—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system using mechanical relative movement between primary active elements and secondary devices of antennas or antenna systems
    • H01Q3/14—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system using mechanical relative movement between primary active elements and secondary devices of antennas or antenna systems for varying the relative position of primary active element and a refracting or diffracting device

Definitions

  • the present invention relates to an antenna arrangement of the kind, which includes a reflector, preferably provided on supporting means, a central unit comprising means for guiding collected electromagnetic waves by said reflector and guiding said waves to receiving means and methods for improving the reception quality.
  • An antenna is basically a device for sending and/or receiving electromagnetic radiation.
  • the simplest form of an antenna is a straight metallic wire, through which an electrical (AC) current flow is effected.
  • the current flow generates an electromagnetic field. and generally between the different parts of the wire, which penodically have different voltages in relation to each other, an electric field will be generated. Both magnetic and electric helds radiate from the wire and compose an electromagnetic wave, a so-called radio wave 11 another conductive wire is arranged in the radiation path, current and voltage will be induced in said w ire, and if the wire is connected to a receiver, it will be acting as a receiver antenna.
  • antennae Presently, several types of antennae are used for sending and receiving digital and analogous information from and to mobile and stationary transmitters/receivers, respectively.
  • the antenna types are different, in respect of the information to be sent, position of the transmitter/rcceiver and conditions related to the mobility of the transmitters/receivers.
  • antennae within microwave technology .
  • special types of antennae comprising a sheet metal arrangement.
  • This area it is desired to direct the electromagnetic radiation in a certain direction.
  • Special metallic reflectors collect the radiation and radiate them in a beam cluster
  • This antenna types are specially used in television link stations, where the reflectors have a parabolic form, so-called parabolic antennae.
  • a television antenna is the most complicated type of antenna, as the TV-signai contains a large amount of frequencies, and therefor it must be a broad band antenna.
  • parabolic antennae Specially at reception from the satellites, parabolic antennae are usually used.
  • a parabolic antenna consists of the metallic reflector or dish, which reflects and focuses the received signals to a wave guide hom, so-called feedhorn, guiding the waves through a wave guide to a device for converting and amplifying the signals.
  • wave guide is a metallic tube bend towards the reflector or provided by arrangement to be fed by the received signal.
  • the invention concerns an antenna, preferably a parabolic antenna that presents solutions for above problems.
  • the antenna arrangement according to the present invention has an efficient control of signals, e.g. satellite signals, received using a parabolic antenna, specially mounted on mobile sites. It permits to always have a correct aiming of the parabolic dish at the satellite, in spite of site movements, thanks to a new tracking servosystem, and allows to automatically control the right polarisation angle and/or to change the polarisation, e.g. from circular to linear and vice-versa by remote control.
  • the antenna according to the present invention also introduces improvements in the field of technology, which will be evident through the description.
  • Fig. 1 is a schematic cross-sectional view, according to one preferred embodiment of the present invention.
  • Fig. 2 shows schematically an enlargement of the receiver part of the antenna, according to fig. 1.
  • Fig. 3 is an enlarged schematic view of the conical scanning assembly, according to the present invention.
  • Fig. 4 is an enlarged schematic view of the polarisation rotation assembly, according to the present invention.
  • Fig. 5 is an enlarged schematic view of the circular/linear commutation polarisation assembly, according to the present invention.
  • the following description will be referred to a particular case of a marine system installed on board ships to receive television broadcast via satellite, but the example is general and the antenna arrangement can be applied to all cases of signal reception and/or transmission at stationary and/or mobile sites.
  • a schematic cross-section of the antenna arrangement l ⁇ is illustrated in fig. 1.
  • the main structure of the antenna 10, according to this embodiment, comprises a parabolic reflector or dish 1 1.
  • the holder 12 by means of the framework 13 is rotatably connected to the support 14 through axis 17. which allows the holder and consequently the dish 1 1 rotate around said axis 17, i.e. a vertical displacement with respect to the plane of the drawing, by means of a driving motor 18, in a conventional way.
  • the support 14 is further rotatably attached to the site, preferably through a platform 16.
  • a motor 19 is provided to rotate the support 14 and antenna around axis 20, i.e. into and out of the plane of the drawing, by means of gearwheel 21, in a known way.
  • a unit 22 is, substantially mounted in the centre of the dish 11.
  • the unit 22, besides acting as a receiving unit is arranged to obtain following primary functions, according to the present invention:
  • the unit 22 as shown in fig. 2, comprises housing 23 enclosing groups of components for performing abovementioned functions. For the clarity reasons, each block 24, 33 and 41 performing above functions will be described individually.
  • This assembly 24 showed schematically and more closely in fig. 3, includes an electric motor 25 controlled by an electronic speed control 26 (not enclosed in detail) and is connected through an electronic position control 27 via a shaft 28 to a dielectric element 29, having variable thickness (wedgeshaped), which is put in rotation by means of said motor 25.
  • the radio frequency collected by the parabolic dish 11 is focused directly or indirectly, e.g. via a subreflector 32, suitably forming one part of the carrier 30, into the feedhom 31 and to wave processing means (fig. 2) to transform the signal into frequencies suited for the reception apparatus.
  • the subreflector 32 is made of a material able to reflect the electromagnetic waves, e.g. an aluminum plate, while the carrier 30 is, for example made of en electrically insulating material.
  • the radiofrequency, concentrated in front of the feedhom 31 passes through the dielectric element, formed as a disc with variable thickness. This effects a deviation of the radiofrequency beam that enters the feedhom 31 with a small angle in respect of its centre line. Then, by rotating the dielectric element 29 by means of the electric motor 25, it is possible to control the rotation of the beam according to a conical shape, which enables the conical scanning principle.
  • the beam of radiofrequency turning around the axis ot the parabolic dish 11 with a small deviation from the centre line, performs a conical scanning around the satellite position, when the antenna arrangement is in movement, a control unit is able to register the misalignments of the parabolic antenna in relation to the position of the satellite and to pilot the axes ot the stabilised antenna to contrast this misalignment to obtain a maximum ot the received signal.
  • the antenna according to this embodiment is a three axes stabilised antenna, which is considered the best servosystem to use in, e.g marine applications, because ii permits to receive satellite signals having a correct tracking at any latitude.
  • a two axes stabilised antenna has difficulties to follow the servo-control information when the ship is located near the equator, and the satellite appears over it, because it is constrained to effect large and quick movements ot the vertical axis to maintain the correct aiming. This is not a problem, when using a three axes stabilised antenna which also at the equator may aim the satellite dunng the movements of the ship, acting with the correct cooperation of the three axes movements.
  • the angle of the polansation of the received signal appears variable with the displacement of the mobile site.
  • the present arrangement is provided with an assembly to rotate the polarisation automatically.
  • the assembly 33 includes a mechanical rotation of the receiving group, comprising at least one orthomode 34 and elements 35, e.g. so-called LNB (Low Noise Block).
  • An orthomode transducer enables a dual-polarization antenna to be fed simultaneously from two feed lines, which corresponds to the two orthogonal polarizations.
  • the LNB is used to receive and separate the vertical and horizontal polarisations of the signal. It may also contain means for separating channels etc.
  • the signal processed by the LNBs is then transmitted to the receiver via cables 49.
  • two LNBs are shown in this embodiment, it is possible to use only one or several ones, as long as the desired signal processing is achieved.
  • the mechanical polarotor will provide the correct angle in the entire received band. Moreover, the mechanical polarotor does not attenuate the RF signal.
  • the assembly 33 for polarisation rotation is shown in fig. 4.
  • the assembly 33 includes a socket 36, provided with a bearing 37 arranged on the housing 23.
  • the bearing 37 permits the rotation of a sleeve 40, connected to the LNBs 35 through the orthomode 34.
  • an electric motor 38 with driving device 50 are arranged to rotate at least one of the LNB's 35.
  • a control unit 39 is arranged connected with an internal or external GPS-unit 48 which can obtain the coordinates of the system at any moment through conventional GPS positioning methods.
  • the control unit 39 calculates the correct angle of polarisation and actuates the motor 38. preferably a step motor, turning the assembly constituted by the LNBs 35, orthomode 34 and sleeve 40. and reestablishes the correct angle of the reception of the polarised signal.
  • a linear polarization is the polarisation of an electromagnetic wave such that the extremity of the electric flux density vector relative to a given point describes a fixed straight line whose centre coincides with this point.
  • the extremity of the electric field strength vector or of a specified field vector at a fixed point in space describes a circle.
  • a second socket 42 is arranged rotatably in relation to the sleeve 40 by means of balls or bearing 43, on which it is joumaled. Further, a shaped dielectric 44 is arranged inside the said second socket 42.
  • the dielectric element 44 is shaped as a polygonal having substantially two parallel long sides and two inwardly bend, short sides.
  • the socket 42 is positioned with respect to the sleeve 40 by means of a gearwheel 45, operated bv a rotation actuator 46, e.g. a step motor, which is controlled by a control unit 47.
  • a rotation actuator 46 e.g. a step motor
  • the functioning of the arrangement is based on the fact that the dielectric 44, when oriented at 45° relative the orthomode input, transforms the incoming signal from the circular to linear polarisation. No effect is experienced when the dielectric 44 is oriented at 0o, which allows the undisturbed reception of linear polarised signals.
  • This assembly permits to change the linear/circular polarisation without changing components in the reception assembly, which is common in satellite receiving systems that are generally from the beginning arranged for circular or linear polarisation.
  • a radar filter (not shown), e.g. high pass filter, in the polarisation assembly.

Landscapes

  • Variable-Direction Aerials And Aerial Arrays (AREA)
  • Aerials With Secondary Devices (AREA)

Abstract

An antenna arrangement (10) of the kind, which includes a reflector (11), preferably provided on supporting means (12, 13, 14, 15), a central unit (22) comprising means (31) for guiding collected electromagnetic waves by said reflector (11) and guiding said waves to receiving means (34, 35). Said antenna (10) further includes: at least one dielectric element (29), having property to vary the rotation of said electromagnetic waves, and/or means to radially displace said receiving means (34, 35) relative said wave guiding means (31), and/or a sleeve (40), a socket (42) arranged rotatably in relation to said sleeve (40) and a dielectric element (44) provided inside said socket (42). The invention also includes methods of improving conical scanning, polarisation rotation and circular/linear commutation polarisation in said antenna.

Description

ANTENNA ARRANGEMENT
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an antenna arrangement of the kind, which includes a reflector, preferably provided on supporting means, a central unit comprising means for guiding collected electromagnetic waves by said reflector and guiding said waves to receiving means and methods for improving the reception quality.
BACKGROUND OF THE INVENTION
An antenna is basically a device for sending and/or receiving electromagnetic radiation. The simplest form of an antenna is a straight metallic wire, through which an electrical (AC) current flow is effected.
Around a transmitting antenna, the current flow generates an electromagnetic field. and generally between the different parts of the wire, which penodically have different voltages in relation to each other, an electric field will be generated. Both magnetic and electric helds radiate from the wire and compose an electromagnetic wave, a so-called radio wave 11 another conductive wire is arranged in the radiation path, current and voltage will be induced in said w ire, and if the wire is connected to a receiver, it will be acting as a receiver antenna.
Presently, several types of antennae are used for sending and receiving digital and analogous information from and to mobile and stationary transmitters/receivers, respectively The antenna types are different, in respect of the information to be sent, position of the transmitter/rcceiver and conditions related to the mobility of the transmitters/receivers.
Within microwave technology . in which for instance radar stations and TV-links operate, special types of antennae are used, comprising a sheet metal arrangement. In this area it is desired to direct the electromagnetic radiation in a certain direction. Special metallic reflectors collect the radiation and radiate them in a beam cluster This antenna types are specially used in television link stations, where the reflectors have a parabolic form, so-called parabolic antennae.
A television antenna is the most complicated type of antenna, as the TV-signai contains a large amount of frequencies, and therefor it must be a broad band antenna.
Specially at reception from the satellites, parabolic antennae are usually used. Generally, a parabolic antenna consists of the metallic reflector or dish, which reflects and focuses the received signals to a wave guide hom, so-called feedhorn, guiding the waves through a wave guide to a device for converting and amplifying the signals. Generally said wave guide is a metallic tube bend towards the reflector or provided by arrangement to be fed by the received signal.
When arranging an antenna, specially for reception of directed waves, on a mobile sue. such as vehicles, ships, aeroplanes etc. some problems occur. Due to the movements of the said mobile site, there is a need to direct the antenna to the transmission source, e.g. a satellite. Different transmitters use different modulation/polarisation to send the signal, implying a need for antennae able to receive the different signals.
SUMMARY OF THE INVENTION The invention concerns an antenna, preferably a parabolic antenna that presents solutions for above problems. The antenna arrangement according to the present invention has an efficient control of signals, e.g. satellite signals, received using a parabolic antenna, specially mounted on mobile sites. It permits to always have a correct aiming of the parabolic dish at the satellite, in spite of site movements, thanks to a new tracking servosystem, and allows to automatically control the right polarisation angle and/or to change the polarisation, e.g. from circular to linear and vice-versa by remote control.
The antenna according to the present invention also introduces improvements in the field of technology, which will be evident through the description.
Above improvements and solutions are achieved through arrangements and methods according to the characterising parts of claims 1, 10, 14, 17, 18, 19 and 20.
Other preferred embodiments of the invention are detailed in depending claims. BRIEF DESCRIPTION OF THE DRAWINGS
In the following the invention will be described with reference to enclosed drawings, in which:
Fig. 1 is a schematic cross-sectional view, according to one preferred embodiment of the present invention.
Fig. 2 shows schematically an enlargement of the receiver part of the antenna, according to fig. 1.
Fig. 3 is an enlarged schematic view of the conical scanning assembly, according to the present invention.
Fig. 4 is an enlarged schematic view of the polarisation rotation assembly, according to the present invention.
Fig. 5 is an enlarged schematic view of the circular/linear commutation polarisation assembly, according to the present invention.
DETAILED DESCRIPTION OF EMBODIMENT
For the best understanding, the following description will be referred to a particular case of a marine system installed on board ships to receive television broadcast via satellite, but the example is general and the antenna arrangement can be applied to all cases of signal reception and/or transmission at stationary and/or mobile sites.
A schematic cross-section of the antenna arrangement lϋ is illustrated in fig. 1. The main structure of the antenna 10, according to this embodiment, comprises a parabolic reflector or dish 1 1. holder unit 12, frame work 13, support means 14 and attachment 15. The holder 12 by means of the framework 13 is rotatably connected to the support 14 through axis 17. which allows the holder and consequently the dish 1 1 rotate around said axis 17, i.e. a vertical displacement with respect to the plane of the drawing, by means of a driving motor 18, in a conventional way. The support 14 is further rotatably attached to the site, preferably through a platform 16. A motor 19 is provided to rotate the support 14 and antenna around axis 20, i.e. into and out of the plane of the drawing, by means of gearwheel 21, in a known way.
A unit 22 is, substantially mounted in the centre of the dish 11. The unit 22, besides acting as a receiving unit is arranged to obtain following primary functions, according to the present invention:
- conical scanning tracking,
- remote change of polarisation mode from circular to linear and vice-versa, and
- automatic skew control of polarisation.
The unit 22, as shown in fig. 2, comprises housing 23 enclosing groups of components for performing abovementioned functions. For the clarity reasons, each block 24, 33 and 41 performing above functions will be described individually.
CONICAL SCANNING ASSEMBLY 24
This assembly 24, showed schematically and more closely in fig. 3, includes an electric motor 25 controlled by an electronic speed control 26 (not enclosed in detail) and is connected through an electronic position control 27 via a shaft 28 to a dielectric element 29, having variable thickness (wedgeshaped), which is put in rotation by means of said motor 25.
A carrier 30, having a hole, through which the shaft 28 extends, is detachably provided on a wave feedhom 31.
The radio frequency collected by the parabolic dish 11 is focused directly or indirectly, e.g. via a subreflector 32, suitably forming one part of the carrier 30, into the feedhom 31 and to wave processing means (fig. 2) to transform the signal into frequencies suited for the reception apparatus. The subreflector 32 is made of a material able to reflect the electromagnetic waves, e.g. an aluminum plate, while the carrier 30 is, for example made of en electrically insulating material. According to the present invention the radiofrequency, concentrated in front of the feedhom 31 passes through the dielectric element, formed as a disc with variable thickness. This effects a deviation of the radiofrequency beam that enters the feedhom 31 with a small angle in respect of its centre line. Then, by rotating the dielectric element 29 by means of the electric motor 25, it is possible to control the rotation of the beam according to a conical shape, which enables the conical scanning principle.
It is also possible to provide a substantially through groove or slits extending from the centre to the periphery of the dielectric plate 29, or forming the plate 29 by combining material having different dielectrical properties.
Following this principle the beam of radiofrequency, turning around the axis ot the parabolic dish 11 with a small deviation from the centre line, performs a conical scanning around the satellite position, when the antenna arrangement is in movement, a control unit is able to register the misalignments of the parabolic antenna in relation to the position of the satellite and to pilot the axes ot the stabilised antenna to contrast this misalignment to obtain a maximum ot the received signal.
The antenna according to this embodiment is a three axes stabilised antenna, which is considered the best servosystem to use in, e.g marine applications, because ii permits to receive satellite signals having a correct tracking at any latitude. In fact a two axes stabilised antenna has difficulties to follow the servo-control information when the ship is located near the equator, and the satellite appears over it, because it is constrained to effect large and quick movements ot the vertical axis to maintain the correct aiming. This is not a problem, when using a three axes stabilised antenna which also at the equator may aim the satellite dunng the movements of the ship, acting with the correct cooperation of the three axes movements.
POLARISA TION ROTA TION ASSEMBLY 33
When using the antenna arrangement 10 according to the present invention in mobile condition, the angle of the polansation of the received signal appears variable with the displacement of the mobile site. To receive the signal, always with the correct polarisation angle, the present arrangement is provided with an assembly to rotate the polarisation automatically.
The assembly 33 includes a mechanical rotation of the receiving group, comprising at least one orthomode 34 and elements 35, e.g. so-called LNB (Low Noise Block). An orthomode transducer enables a dual-polarization antenna to be fed simultaneously from two feed lines, which corresponds to the two orthogonal polarizations. The LNB is used to receive and separate the vertical and horizontal polarisations of the signal. It may also contain means for separating channels etc. The signal processed by the LNBs is then transmitted to the receiver via cables 49. Although, two LNBs are shown in this embodiment, it is possible to use only one or several ones, as long as the desired signal processing is achieved.
This arrangement allows to always have a correct alignment to receive the signal from the transmitter. Unlike the magnetic polarotors that have a limited frequency band with an assured correct skew angle, the mechanical polarotor according to the present invention will provide the correct angle in the entire received band. Moreover, the mechanical polarotor does not attenuate the RF signal.
The assembly 33 for polarisation rotation, is shown in fig. 4. The assembly 33 includes a socket 36, provided with a bearing 37 arranged on the housing 23. The bearing 37 permits the rotation of a sleeve 40, connected to the LNBs 35 through the orthomode 34. Also, an electric motor 38 with driving device 50 are arranged to rotate at least one of the LNB's 35.
A control unit 39 is arranged connected with an internal or external GPS-unit 48 which can obtain the coordinates of the system at any moment through conventional GPS positioning methods. When the system is in movement, the control unit 39, with the position information obtained from the GPS-unit 48 and the known (stored) position of the satellite, calculates the correct angle of polarisation and actuates the motor 38. preferably a step motor, turning the assembly constituted by the LNBs 35, orthomode 34 and sleeve 40. and reestablishes the correct angle of the reception of the polarised signal. CIRCULAR/LINEAR COMMUTA TION POLARISA TION ASSEMBLY 41
A linear polarization is the polarisation of an electromagnetic wave such that the extremity of the electric flux density vector relative to a given point describes a fixed straight line whose centre coincides with this point. In case of circular polarization, the extremity of the electric field strength vector or of a specified field vector at a fixed point in space describes a circle.
As shown in fig. 5 in the internal side of the rotating sleeve 40, used to change the polarisation as described above, a second socket 42 is arranged rotatably in relation to the sleeve 40 by means of balls or bearing 43, on which it is joumaled. Further, a shaped dielectric 44 is arranged inside the said second socket 42.
The dielectric element 44 is shaped as a polygonal having substantially two parallel long sides and two inwardly bend, short sides.
The socket 42 is positioned with respect to the sleeve 40 by means of a gearwheel 45, operated bv a rotation actuator 46, e.g. a step motor, which is controlled by a control unit 47.
The functioning of the arrangement is based on the fact that the dielectric 44, when oriented at 45° relative the orthomode input, transforms the incoming signal from the circular to linear polarisation. No effect is experienced when the dielectric 44 is oriented at 0º, which allows the undisturbed reception of linear polarised signals.
This assembly permits to change the linear/circular polarisation without changing components in the reception assembly, which is common in satellite receiving systems that are generally from the beginning arranged for circular or linear polarisation.
By operating the rotation actuator 46 connected to the servocontrol 47, it is possible to remotely commutate the received signals from the circular to linear polarisation and vice-versa.
When polarisation rotation is in progress, the assembly of movement circular/linear polarisation, i.e. sleeve 40, gearwheel 45 and the actuator 46 are moved rigidly simultaneously with the system.
Although each function block is described individually, it is evident that a combination of two or three blocks gives the most preferred antenna arrangement.
It is also possible to arrange or integrate a radar filter (not shown), e.g. high pass filter, in the polarisation assembly.
Even though we have described and illustrated the invention in a preferred embodiment, it is obvious for a person skilled in the art that other embodiments and modifications within the scope of attached claims may occur.
Figure imgf000011_0001

Claims

1. An antenna arrangement (10) of the kind, which includes a reflector (11), preferably provided on supporting means (12, 13, 14, 15), a central unit (22) comprising means (31) for guiding collected electromagnetic waves by said reflector (11) and guiding said waves to receiving means (34, 35), characterised in,
that said central unit (22) further comprises at least one dielectric element (29), having property to vary the rotation of said electromagnetic waves.
2. An antenna arrangement according to claim 1,
characterised in,
that said dielectric element (29) an a wave guiding means (31) are arranged rotatablv relative each other.
3. An antenna arrangement according to claim 2,
characterised in,
that said dielectric element (29) is mounted on shaft (28) connected to driving motor (25).
4. An antenna arrangement according to claim 3,
characterised in,
that said motor (25) is provided with speed control means (26).
5. An antenna arrangement according to claim 3,
characterised in,
that said motor (25) is a motor including position detecting means (27).
6. An antenna arrangement according to claim 2,
characterised in,
that said dielectric element (29) is arranged between a subreflector (32) and said wave guiding means (31).
7. An antenna arrangement according to any of claims 1 to 6,
characterised in,
that said dielectric element (29) has variable thickness.
8. An antenna arrangement according to any of claims 1 to 6,
characterised in,
that said dielectric element (29) is provided with a substantially through groove.
9. An antenna arrangement according to any of claims 1 to 6,
characterised in,
that said dielectric element (29) consists of a materials having different dielectric properties.
10. An antenna arrangement (10) of the kind, which includes a reflector ( 1 1), preferably provided on supporting means (12, 13, 14, 15), a central unit (22) comprising means (31 ) for guiding collected electromagnetic waves by said reflector (1 1) and guiding said waves to receiving means (34, 35). characterised in,
that said antenna (10) further includes means to radially displace said receiving means (34, 35) relative said wave guiding means (31).
1 1. An antenna arrangement according to claim 10,
characterised in,
that a socket (36) communicating with wave guiding means (31 ) and a sleeve (40) are arranged rotatably relative each other, said sleeve (40) connected to said receiving means (35, 34). and means
(38) to rotate said sleeve (40) and said receiving means (35, 34) with respect to said socket (36).
12. An antenna arrangement according to claim 10,
characterised in,
that said receiving means comprises at least one LNB (35) and one orthomode (34).
13. An antenna arrangement according to claim 10.
characterised in, that a control unit (39) is arranged communicating with a position determination means (48), which control unit (39) with position information from the position determination means (48) and position of a transmission station calculates the correct angle of polarisation and actuates said rotation means (38), resulting in displacement of the receiving means (34, 35) relative said wave guiding means (31) and reestablishing a correct angle of reception of a polarised signal.
14. An antenna arrangement (10) of the kind, which includes a reflector (11 ), preferably provided on supporting means (12, 13, 14, 15), a central unit (22) composing means (31 ) for guiding collected electromagnetic waves by said reflector (11) and guiding said waves to receiving means (34, 35), characterized in,
that said antenna (10) further includes a sleeve (40), a socket (42) arranged rotatablv in relation to said sleeve (40), and a dielectric element (44) provided inside said socket (42).
15. An antenna arrangement according to claim 14,
characterised in,
that means (44, 46) are arranged to displace said socket (42)
16 An antenna arrangement according to claim 14,
characterised in,
that said dielectnc element (44) is shaped as a polygonal having substantially two parallel long sides and two inwardly bend, short sides
17. An antenna arrangement (10) of the kind, which includes a reflector (1 1 ), preferabh provided on supporting means (12, 13, 14, 15), a central unit (22) comprising means (31 ) tor guiding collected electromagnetic waves by said reflector (11) and guiding said waves to receiving means (34, 35). characterised in,
that said antenna (10) further includes:
- at least one dielectric element (29), having property to vary the rotation ol said electromagnetic waves, and/or
- means to radially displace said receiving means (34, 35) relative said wave guiding means
(31), and/or - a sleeve (40), a socket (42) arranged rotatably in relation to said sleeve (40) and a dielectric element (44) provided inside said socket (42).
18. Method of improving conical scanning in an antenna arrangement (10) of the kind, which includes a reflector (11), preferably provided on supporting means (12, 13, 14, 15), a central unit (22) comprising means (31) for guiding collected electromagnetic waves by said reflector (11) and guiding said waves to receiving means (34, 35),
characterised in,
- arranging said central unit (22) with at least one dielectric element (29), having property to vary the rotation of said electromagnetic waves,
- arranging means to rotate said dielectric element (29),
- concentrating said waves in front of a wave guiding means (31 ) passes through said dielectric element (29), which effects a deviation of the radiofrequency beam that enters the wave guiding means (31), with a small angle in respect of its centre line.
- then rotating the dielectric element (29) to control the rotation of the beam according to a conical shape, which enables the conical scanning.
19. Method of improving polarisation rotation in an antenna arrangement ( 10) of the kind, which includes a reflector (11), preferably provided on supporting means ( 12, 13, 14, 15), a central unit (22) comprising means (31) for guiding collected electromagnetic waves by said retlector (1 1 ) and guiding said waves to receiving means (34, 35),
characterised in,
- arranging means to radially displace said receiving means (34, 35) relative said wave guiding means (31)
- arranging a control unit (39) communicating with a position determination means (48), retrieving the position information from the position determination means (48) and position of a transmission station,
- calculating the correct angle of polarisation and actuates said rotation means (3S), resulting in displacement of the receiving means (34, 35) relative said wave guiding means (31 ) and reestablishing a correct angle of reception of a polarised signal.
20. Method of improving circular/linear commutation polarisation in an antenna arrangement (10) of the kind, which includes a reflector (11), preferably provided on supporting means (12, 13, 14, 15), a central unit (22) comprising means (31) for guiding collected electromagnetic waves by said reflector (11) and guiding said waves to receiving means (34, 35),
characterised in,
- arranging a sieeve (40), a socket (42) rotatable in relation to said sleeve (40), and a dielectric element (44) provided inside said socket (42)
- arranging means (44, 46) to displace said socket (42), and
- displacing said socket (42) according to instruction from a control unit.
AMENDED CLAIMS
[recei ved by the Internationa l Bureau on 6 November 1997 (06. 1 1 .97 ) ; orig inal c l a ims 1 -20 repl aced by amended c l aims 1 - 17 ( 4 pages ) ]
1. An antenna arrangement (10) of the kind, which includes a reflector (11), preferably provided on supporting meam (12, 13, 14, 15), a central unit (22) comprising means (31) for guiding collected electromagnetic waves by said reflector (1 1) and guiding said waves to receiving means (34, 35),
characterised in,
that said antenna (10) further includes
- at least one dielectric element (29), having property to vary the rotation of said electromagnetic waves, and/or
- means to radially displace said receiving means (34, 35) relative said wave gutdtng means (31), and/or
- a sleeve (40), a socket (42) arranged rotatably in relation lo said sleeve (40) and a dielectric element (44 j provided inside said socket (42) .
2. An antenna arrangement according to claim 1 ,
characterised in,
that tend dielectric element (29) an a wave guiding means (31 ) are arranged rυtatabh relative each other.
3. An antenna arrangement according to claim 2,
characterised in,
thai said dielectric element (29) is mounted on shajt (28) c onnected lo driving motor (25) .
4. An antenna arrangement according to claim 3,
characterised in,
that said motor (25) is provided with speed control means (26).
5. An antenna arrangement according to claim 3,
characterised in,
that scud motor (25) is a motor including position detecting means (27).
6. An antenna arrangement according to claim 2,
characterised in,
that said dielectric element (29) is arranged between a subreflector (32) and scud wave guiding means (31).
7. An antenna arrangement according to any of claims 1 to 6,
characterised in,
that said dielectric element (29) has variable thickness.
8. An antenna arrangement according to any of claims 1 to 6,
characterised in,
that said dielectric element (29) is provided with a substantially through grυos e
9. An antenna arrangement according to any of claims 1 to 6,
characterised in,
that said dielectric element (29) consists oJ a materials having different dielec tric properties.
10. An antenna arrangement according to claim 1.
characterised in,
that a socket (36) communicating with w ave guiding means (31) and a sleeve ( 40) are arranged r otatahh relative each other, said sleeve (40) connected to scud receiving means (35. 34). and means (38) to rotate said sleeve (40) and saia rec eiving means (35. 34) witn respect to said socket (36).
11. An antenna arrangement according to claim 1,
characterised in,
that said receiving means comprises at least one LNB (35) and one orthomode (34).
12. An antenna arrangement according to claim 1.
characterised in,
that a control unit (39) is arranged communicating with a position determination means (48). which control unit (39) with position information from the position determination means (48) and position of a transmission station calculates the correct angle of polarisation and actuates said rotation means (38), resulting in displacement of the receiving means (34, 35) relative said wave guiding means (31) and reestablishing a correct angle of reception of a polarised signal,
13. An antenna arrangement according to claim 1,
characterised in,
that means (44, 46) are arranged to displace said socket (42) ,
14. An ante nna arrangement according to laim 1,
characterised in,
that said dielectric element (44) is shaped as a polygonal having substantially two parallel long sides and two inwardly bend short sides.
15. Method of improving conical scanning in an antenna arrangement (10) of the kind. w hich includes a reflector (11), preferably provided on supporting means (12 , 13 , 14, 15), a cemral unit (22) comprising means (31) for guiding collected electromagnetic waves Ή said reflector (11) and guiding said waves to recen mg means (34.35),
characterised in,
- arranging said central unit (22) with at least one dielectric element (29) having property to vary the rotation of said electromagnetic waves.
- arranging means to rotate said dielectric element (29) .
- concentrating said waves in fr ont of a wave guiding means (31) pas ses through sa id dielectric element (29). which effects a deviation of the radiof equency beam thet enters the wave guiding means (31) , with a small angle in respect of its centre line.
- then rotating the dielectric element (29) to control the rotation of the beam according to a conical shape which enables the conical scanning.
16. Method according to claim 15 and fltrther provided for improving polarisation rotation in the antenna arrangement
characterised in,
- arranging means to radially displace said receiving means (34, 35) relative said wave guiding means (31)
- arranging a control unit (39) communicating with a position determination means (48), retrieving the position information from the position determination means (48) and position of a transmission station,
- calculating the correct angle of polarisation and actuates said rotation means (38), resulting in displacement of the receiving means (34, 35) relative said wave guiding means (31) and reestablishing a correct angle of reception of a polarised signal.
17. Method according to any one of claims 15 - 16 and further provided for improving circular/linear commutation polarisation in the antenna arrangement (10),
characterised in,
- arranging a sleeve (40), a socket (42) rotatable in relation to said sleeve (40), and a dielectric element (44) provided inside said socket (42)
- arranging means (44, 46) to displace said socket (42), and
- displacing said socket (42) according to instruction from a control unit.
PCT/SE1997/000994 1996-06-05 1997-06-05 Antenna arrangement Ceased WO1997047055A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU31994/97A AU3199497A (en) 1996-06-05 1997-06-05 Antenna arrangement

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE9602261A SE9602261L (en) 1996-06-05 1996-06-05 Antenna
SE9602261-1 1996-06-05

Publications (1)

Publication Number Publication Date
WO1997047055A1 true WO1997047055A1 (en) 1997-12-11

Family

ID=20402926

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE1997/000994 Ceased WO1997047055A1 (en) 1996-06-05 1997-06-05 Antenna arrangement

Country Status (3)

Country Link
AU (1) AU3199497A (en)
SE (1) SE9602261L (en)
WO (1) WO1997047055A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1100146A3 (en) * 1999-11-12 2002-02-13 RR ELEKTRONISCHE GERÄTE GmbH & Co. KG Method for tracking on a selected satellite and control unit for directing a pivotable antenna
WO2003058755A1 (en) * 2001-12-21 2003-07-17 The Boeing Company Antenna arrangement with rf components mounted to the back surface of a reflector element
US9507978B2 (en) 2012-10-08 2016-11-29 Nordic Id Oy Antenna device for RFID reader/writer

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1918084A1 (en) * 1969-04-09 1970-10-29 Kathrein Werke Kg Reception system with parabolic antenna and frequency converter
DE1766103B2 (en) * 1968-04-03 1980-02-14 Siemens Ag, 1000 Berlin Und 8000 Muenchen Mirror antenna and method for adjusting such
DE3820920C2 (en) * 1988-03-31 1990-02-22 Franz Eisenhofer

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1766103B2 (en) * 1968-04-03 1980-02-14 Siemens Ag, 1000 Berlin Und 8000 Muenchen Mirror antenna and method for adjusting such
DE1918084A1 (en) * 1969-04-09 1970-10-29 Kathrein Werke Kg Reception system with parabolic antenna and frequency converter
DE3820920C2 (en) * 1988-03-31 1990-02-22 Franz Eisenhofer

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1100146A3 (en) * 1999-11-12 2002-02-13 RR ELEKTRONISCHE GERÄTE GmbH & Co. KG Method for tracking on a selected satellite and control unit for directing a pivotable antenna
WO2003058755A1 (en) * 2001-12-21 2003-07-17 The Boeing Company Antenna arrangement with rf components mounted to the back surface of a reflector element
US9507978B2 (en) 2012-10-08 2016-11-29 Nordic Id Oy Antenna device for RFID reader/writer

Also Published As

Publication number Publication date
SE9602261L (en) 1997-12-06
SE9602261D0 (en) 1996-06-05
AU3199497A (en) 1998-01-05

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