EP0449107A2 - Microwave antenna unit - Google Patents

Microwave antenna unit Download PDF

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Publication number
EP0449107A2
EP0449107A2 EP91104405A EP91104405A EP0449107A2 EP 0449107 A2 EP0449107 A2 EP 0449107A2 EP 91104405 A EP91104405 A EP 91104405A EP 91104405 A EP91104405 A EP 91104405A EP 0449107 A2 EP0449107 A2 EP 0449107A2
Authority
EP
European Patent Office
Prior art keywords
antenna
microwave
reflector
dish
signal
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.)
Withdrawn
Application number
EP91104405A
Other languages
German (de)
French (fr)
Other versions
EP0449107A3 (en
Inventor
Edric Hayes Field
Reginald Edward Gray
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.)
Thomson Multimedia Sales UK Ltd
Original Assignee
Ferguson Ltd
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 Ferguson Ltd filed Critical Ferguson Ltd
Publication of EP0449107A2 publication Critical patent/EP0449107A2/en
Publication of EP0449107A3 publication Critical patent/EP0449107A3/en
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q17/00—Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems
    • H01Q17/001—Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems for modifying the directional characteristic of an aerial
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/12—Supports; Mounting means
    • H01Q1/125—Means for positioning
    • H01Q1/1264—Adjusting different parts or elements of an aerial unit
    • 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

Definitions

  • the invention concerns a microwave antenna unit in form of a dish having a reflector and an antenna converting the received microwave energy into an electrical signal.
  • dishes are used especially for reception of television signals or sound signals in the frequency range of about 10 - 20 GHz by satellite.
  • For proper reception a very careful and exact alignment of the dish in horizontal and in vertical direction is necessary. Generally such alignment is made by adjusting the position of the dish to maximum value of the output signal of the antenna.
  • the field intensity depends upon the propagation conditions. Especially high humidity in form of rain or fog may severely attenuate the field intensity whereas with fine weather a high field intensity is achieved.
  • a microwave attenuating member is removably interposed between the reflector and the antenna.
  • said member is of a material in form of glass, plastic or ceramic or a combination thereof.
  • Such material has the disered attenuation properties in the frequency range of microwave reception, that is about 10 - 20 GHz.
  • said member is turnably fastened to the antenna unit so that it may be moved into positions inside and outside the signal path between the reflector and the antenna.
  • the member may be fastened to the antenna unit by means of a hinge in order to move it into the signal path for alignment purpose and outside the signal path for optimal signal reception.
  • the member may be turnable into different positions between said positions in order to achieve different amounts of attenuation according to the special propagation condition and field intensity.
  • the size and the material of the member is chosen for example so that the member provides an attenuation of about 6 db.
  • the member may be provided with means for repeatedly fixing it to the antenna and removing it. Such means may be of general art, for example of a so called snap-in.
  • the Figure shows an antenna unit in form of a dish including a reflector 1 to which the antenna 2 is fastened via three supports 3.
  • the antenna 2 includes a transducer converting the received microwave energy into an electrical signal available at output terminals 6.
  • a microwave attenuating member 4 is fastened to the supports 3 by any suitable means, e.g. by clamping means, screws, snap-in or magnet.
  • the member 4 has the form of a flat round plate and is made of glass, plastic or ceramic.
  • the member 4 attenuates the microwave energy radiating from the reflector 1 in direction 5 to the antenna 2.
  • the member 4 may be fastened to supports 3 by means of a hinge so that it can be moved into the signal path for alignment and outside the signal path for proper reception without attenuation.
  • the member 4 may form an integral part of the structure, e.g. be soldered or forming one part with the supports 3.
  • the member 4 may manually be broken from the supports 3 and then thrown away or used for a further alignment procedure later.

Abstract

The alignment of a microwave antenna unit including a dish 1 and an antenna 2 may be difficult if in case of good propagation conditions the maximum of the provided signal with respect to the angle of position is very broad. It is an object to enable exact alignment in such cases without using complex measuring instruments. Between reflector 1 and antenna 2 a microwave attenuating member 4 is provided which attenuates the microwave energy radiated from the dish 1 to the antenna 2 so that the maximum becomes less broad. The member 4 simulates a lower field intensity for example in case of heavy rain on the received signal.

Description

  • The invention concerns a microwave antenna unit in form of a dish having a reflector and an antenna converting the received microwave energy into an electrical signal. Such so-called dishes are used especially for reception of television signals or sound signals in the frequency range of about 10 - 20 GHz by satellite. For proper reception a very careful and exact alignment of the dish in horizontal and in vertical direction is necessary. Generally such alignment is made by adjusting the position of the dish to maximum value of the output signal of the antenna.
  • Within said frequency range the field intensity depends upon the propagation conditions. Especially high humidity in form of rain or fog may severely attenuate the field intensity whereas with fine weather a high field intensity is achieved.
  • Under good propagation conditions the maximum of the signal provided by the antenna with respect to the angle of position is so broad that an exact alignment to the centre of the maximum becomes difficult. There are instruments by which even in case of such broad maximum a correct alignment can be achieved. Such instruments however are very expensive and in many cases not available.
  • It is an object of the invention to achieve exact alignment of the dish without necessity of complex instruments even in case the maximum is relatively broad due to good propagation conditions.
  • According to the invention a microwave attenuating member is removably interposed between the reflector and the antenna.
  • It was found that a very simple member of microwave attenuating material between the reflector and the antenna is able to attenuate the microwave energy received by the antenna in a desired way so that for example the effect of heavy rain on the received signal can be simulated. By so artificially decreasing the field intensity at the antenna by said member the maximum of the signal at the output of the antenna with respect to the angle of position of the antenna unit is made smaller so that a correct alignment of the dish becomes possible. After alignment said member is removed. The solution according to the invention is very simple as only a very cheap and simple member is used whereas complex instruments for measuring the maximum and finding out the centre of the maximum are no more needed. So the invention enables a correct alignment of a dish independent from the weather and the propagation conditions.
  • Preferably said member is of a material in form of glass, plastic or ceramic or a combination thereof. Such material has the disered attenuation properties in the frequency range of microwave reception, that is about 10 - 20 GHz.
  • In one embodiment of the invention said member is turnably fastened to the antenna unit so that it may be moved into positions inside and outside the signal path between the reflector and the antenna. For example the member may be fastened to the antenna unit by means of a hinge in order to move it into the signal path for alignment purpose and outside the signal path for optimal signal reception. The member may be turnable into different positions between said positions in order to achieve different amounts of attenuation according to the special propagation condition and field intensity.
  • The size and the material of the member is chosen for example so that the member provides an attenuation of about 6 db. The member may be provided with means for repeatedly fixing it to the antenna and removing it. Such means may be of general art, for example of a so called snap-in.
  • In order that the invention may more readily be understood, a description is now given by way of example only, reference being made to the sole figure showing a dish for microwave reception.
  • The Figure shows an antenna unit in form of a dish including a reflector 1 to which the antenna 2 is fastened via three supports 3. The antenna 2 includes a transducer converting the received microwave energy into an electrical signal available at output terminals 6. Between the antenna 2 and the reflector 1 a microwave attenuating member 4 is fastened to the supports 3 by any suitable means, e.g. by clamping means, screws, snap-in or magnet. The member 4 has the form of a flat round plate and is made of glass, plastic or ceramic. The member 4 attenuates the microwave energy radiating from the reflector 1 in direction 5 to the antenna 2. By this means a maximum of the signal at terminals 6 with respect to the angle in the position of the antenna unit can be made smaller in order to allow exact alignment of the antenna unit in horizontal and vertical direction.
  • The member 4 may be fastened to supports 3 by means of a hinge so that it can be moved into the signal path for alignment and outside the signal path for proper reception without attenuation. The member 4 may form an integral part of the structure, e.g. be soldered or forming one part with the supports 3. When alignment has been made by using the member 4 the member 4 may manually be broken from the supports 3 and then thrown away or used for a further alignment procedure later.

Claims (10)

  1. Microwave antenna unit in form of a dish having a reflector and an antenna converting the received microwave energy into an electrical signal, characterized by a microwave attenuating member removably interposed between the reflector and the antenna.
  2. Antenna according to Claim 1, characterized in that said element is of glass, plastic and/or ceramic plate material.
  3. Antenna according to Claim 1, characterized in that the element is turnably fastened to the antenna so that it may be moved into positions inside and outside the signal path between the reflector and the antenna.
  4. Antenna according to Claim 1, characterized in that said element is fastened to the antenna by means of a hinge.
  5. Antenna according to Claim 1, characterized in that the member is turnable into different positions in order to achieve different amounts of attenuation.
  6. Antenna according to Claim 1, characterized in that the member is attached to the antenna by snap-in fastening means.
  7. Antenna according to Claim 1, characterized in that the attenuation of the signal effected by said member has a value of about 6 db.
  8. Member according to Claim 1, characterized by fastening means for fixing it to a microwave antenna.
  9. Member according to Claim 1, characterized in that it consists of a material having appropriate microwave attenuating properties.
  10. Antenna or member as described within the specification and the drawing.
EP19910104405 1990-03-27 1991-03-21 Microwave antenna unit Withdrawn EP0449107A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB909006752A GB9006752D0 (en) 1990-03-27 1990-03-27 Microwave antenna unit
GB9006752 1990-03-27

Publications (2)

Publication Number Publication Date
EP0449107A2 true EP0449107A2 (en) 1991-10-02
EP0449107A3 EP0449107A3 (en) 1991-10-30

Family

ID=10673279

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19910104405 Withdrawn EP0449107A3 (en) 1990-03-27 1991-03-21 Microwave antenna unit

Country Status (4)

Country Link
EP (1) EP0449107A3 (en)
JP (1) JPH05114814A (en)
CN (1) CN1055448A (en)
GB (2) GB9006752D0 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0997976A1 (en) * 1998-10-27 2000-05-03 TRT Lucent Technologies (SA) Attenuator for attenuation of a radio link for a terminal adaptor with integrated antenna
EP0997977A1 (en) * 1998-10-27 2000-05-03 TRT Lucent Technologies (SA) Radio link attenuator for an integrated antenna adapter terminal
EP1130681A2 (en) * 2000-03-03 2001-09-05 Alcatel Canada Inc. Radio system using attenuators for an antenna

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2947910A1 (en) * 1979-11-28 1981-06-04 Siemens AG, 1000 Berlin und 8000 München Near field cassegrain antenna - has lobe widened using extra reflector or dielectric lens in path of primary radiation
DE2947987A1 (en) * 1979-11-28 1981-09-03 Siemens AG, 1000 Berlin und 8000 München Cassegrain near-field aerial with reversible radiation propagation - uses dielectric disc and rings to provide wave phase shift at aerial aperture
JPS612432A (en) * 1984-06-14 1986-01-08 Mitsubishi Electric Corp Receiving device

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1326210A (en) * 1969-09-16 1973-08-08 Kokusai Denshin Denwa Co Ltd Antenna using at least one reflector
FR2180585B1 (en) * 1972-04-21 1974-12-20 Thomson Csf
US4410892A (en) * 1981-05-26 1983-10-18 Andrew Corporation Reflector-type microwave antennas with absorber lined conical feed
EP0140598B1 (en) * 1983-10-17 1989-03-01 Andrew Corporation Horn-reflector microwave antennas with absorber lined conical feed
US5317328A (en) * 1984-04-02 1994-05-31 Gabriel Electronics Incorporated Horn reflector antenna with absorber lined conical feed

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2947910A1 (en) * 1979-11-28 1981-06-04 Siemens AG, 1000 Berlin und 8000 München Near field cassegrain antenna - has lobe widened using extra reflector or dielectric lens in path of primary radiation
DE2947987A1 (en) * 1979-11-28 1981-09-03 Siemens AG, 1000 Berlin und 8000 München Cassegrain near-field aerial with reversible radiation propagation - uses dielectric disc and rings to provide wave phase shift at aerial aperture
JPS612432A (en) * 1984-06-14 1986-01-08 Mitsubishi Electric Corp Receiving device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 10, no. 137 (E-405)(2194) May 21, 1986 & JP-A-61 2 432 (MITSUBISHI ) January 8, 1986 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0997976A1 (en) * 1998-10-27 2000-05-03 TRT Lucent Technologies (SA) Attenuator for attenuation of a radio link for a terminal adaptor with integrated antenna
EP0997977A1 (en) * 1998-10-27 2000-05-03 TRT Lucent Technologies (SA) Radio link attenuator for an integrated antenna adapter terminal
EP1130681A2 (en) * 2000-03-03 2001-09-05 Alcatel Canada Inc. Radio system using attenuators for an antenna
EP1130681A3 (en) * 2000-03-03 2004-06-30 Alcatel Canada Inc. Radio system using attenuators for an antenna
US6816739B1 (en) 2000-03-03 2004-11-09 Alcatel Canada Inc. Radio system attenuator for an antenna

Also Published As

Publication number Publication date
JPH05114814A (en) 1993-05-07
CN1055448A (en) 1991-10-16
GB9006752D0 (en) 1990-05-23
EP0449107A3 (en) 1991-10-30
GB9106554D0 (en) 1991-05-15
GB2244600A (en) 1991-12-04

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