GB2244600A - Microwave antenna unit - Google Patents

Microwave antenna unit Download PDF

Info

Publication number
GB2244600A
GB2244600A GB9106554A GB9106554A GB2244600A GB 2244600 A GB2244600 A GB 2244600A GB 9106554 A GB9106554 A GB 9106554A GB 9106554 A GB9106554 A GB 9106554A GB 2244600 A GB2244600 A GB 2244600A
Authority
GB
United Kingdom
Prior art keywords
antenna
microwave
reflector
antenna according
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Withdrawn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
GB9106554A
Other versions
GB9106554D0 (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 GB9106554D0 publication Critical patent/GB9106554D0/en
Publication of GB2244600A publication Critical patent/GB2244600A/en
Withdrawn legal-status Critical Current

Links

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

Description

1 -I- MICROWAVE ANTENNA UNIT 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 socalled 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 artifi- cially 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 in 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
1-0 a correct alignment of a dish independent from te 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 desired attenuation properties in the frequen cy 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.
1 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. Three supports are shown as an example only. The function of the support or supports is to fix the position of the antenna 2 relative to the reflector 1. This function can be met by a single support, or by any number of supports. The attenuating member 4 may be attached to either a single support or to any combination or to all of the supports. 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 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.
i

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 In 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.
Published 1991 at Tbe Patent Office. Concept House. Cardiff Road. Newport. Gwent NP9 I RH. Further copies inky be obtained from Sales Branch, Unit 6, Nine Mile Point. Cwrafelinfach, Cross Keys. Newport. NP I 7HZ. Printed by Multiplex techniques ltd. St Mary Cr;kv. Kent.
GB9106554A 1990-03-27 1991-03-27 Microwave antenna unit Withdrawn GB2244600A (en)

Applications Claiming Priority (1)

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

Publications (2)

Publication Number Publication Date
GB9106554D0 GB9106554D0 (en) 1991-05-15
GB2244600A true GB2244600A (en) 1991-12-04

Family

ID=10673279

Family Applications (2)

Application Number Title Priority Date Filing Date
GB909006752A Pending GB9006752D0 (en) 1990-03-27 1990-03-27 Microwave antenna unit
GB9106554A Withdrawn GB2244600A (en) 1990-03-27 1991-03-27 Microwave antenna unit

Family Applications Before (1)

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

Country Status (4)

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

Families Citing this family (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
US6816739B1 (en) * 2000-03-03 2004-11-09 Alcatel Canada Inc. Radio system attenuator for an antenna

Citations (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
GB1359266A (en) * 1972-04-21 1974-07-10 Thomson Csf Capped antenna of the offset cassegrainian type
EP0066455A1 (en) * 1981-05-26 1982-12-08 Andrew Corporation Reflector-type microwave antennas with absorber lined conical feed
EP0140598A1 (en) * 1983-10-17 1985-05-08 Andrew Corporation Horn-reflector microwave antennas with absorber lined conical feed
WO1985004527A1 (en) * 1984-04-02 1985-10-10 Gabriel Electronics Incorporated Horn reflector antenna with absorber lined conical feed

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2947910C2 (en) * 1979-11-28 1982-05-27 Siemens AG, 1000 Berlin und 8000 München Cassegrain antenna
DE2947987C2 (en) * 1979-11-28 1982-03-04 Siemens AG, 1000 Berlin und 8000 München Cassegrain antenna
JPS612432A (en) * 1984-06-14 1986-01-08 Mitsubishi Electric Corp Receiving device

Patent Citations (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
GB1359266A (en) * 1972-04-21 1974-07-10 Thomson Csf Capped antenna of the offset cassegrainian type
EP0066455A1 (en) * 1981-05-26 1982-12-08 Andrew Corporation Reflector-type microwave antennas with absorber lined conical feed
EP0140598A1 (en) * 1983-10-17 1985-05-08 Andrew Corporation Horn-reflector microwave antennas with absorber lined conical feed
WO1985004527A1 (en) * 1984-04-02 1985-10-10 Gabriel Electronics Incorporated Horn reflector antenna with absorber lined conical feed

Also Published As

Publication number Publication date
EP0449107A3 (en) 1991-10-30
CN1055448A (en) 1991-10-16
GB9106554D0 (en) 1991-05-15
EP0449107A2 (en) 1991-10-02
JPH05114814A (en) 1993-05-07
GB9006752D0 (en) 1990-05-23

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Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)