WO2000051201A1 - Apparatus for suppressing mutual interference between antennas - Google Patents

Apparatus for suppressing mutual interference between antennas Download PDF

Info

Publication number
WO2000051201A1
WO2000051201A1 PCT/FI2000/000138 FI0000138W WO0051201A1 WO 2000051201 A1 WO2000051201 A1 WO 2000051201A1 FI 0000138 W FI0000138 W FI 0000138W WO 0051201 A1 WO0051201 A1 WO 0051201A1
Authority
WO
WIPO (PCT)
Prior art keywords
antennas
quarter
suppressing
suppressing element
wavelength
Prior art date
Application number
PCT/FI2000/000138
Other languages
French (fr)
Inventor
Veijo Haapanen
Original Assignee
Nokia Networks Oy
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 Nokia Networks Oy filed Critical Nokia Networks Oy
Priority to DE60035772T priority Critical patent/DE60035772T2/en
Priority to BR0008466-2A priority patent/BR0008466A/en
Priority to US09/914,211 priority patent/US6542131B1/en
Priority to JP2000601706A priority patent/JP2002538648A/en
Priority to EP00906397A priority patent/EP1155473B1/en
Priority to AU28083/00A priority patent/AU2808300A/en
Publication of WO2000051201A1 publication Critical patent/WO2000051201A1/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/48—Earthing means; Earth screens; Counterpoises
    • 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
    • H01Q1/521—Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure reducing the coupling between adjacent antennas
    • H01Q1/523—Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure reducing the coupling between adjacent antennas between antennas of an array
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/06—Arrays of individually energised antenna units similarly polarised and spaced apart
    • H01Q21/08—Arrays of individually energised antenna units similarly polarised and spaced apart the units being spaced along or adjacent to a rectilinear path
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/06—Arrays of individually energised antenna units similarly polarised and spaced apart
    • H01Q21/08—Arrays of individually energised antenna units similarly polarised and spaced apart the units being spaced along or adjacent to a rectilinear path
    • H01Q21/10—Collinear arrangements of substantially straight elongated conductive units

Definitions

  • the present invention relates to an apparatus for suppressing mutual in- terference between antennas located close to each other, said apparatus consisting of at least one elongated suppressing element of conductive material fitted between antenna radiators, disposed in a plane transverse to the connecting line between the antennas.
  • the base transceiver stations of mobile communication networks use superposed dipole antennas, each antenna being connected to a separate transmitter-receiver apparatus.
  • Such superposed antennas placed closely together produce interference in each other.
  • superposed antennas must be placed at a relatively large dis- tance from each other to achieve a sufficient insulation level, e.g. 26 dB, between the antennas. Therefore, the antenna structures currently used in base transceiver stations are relatively high. This is a disadvantage especially in cities, where there are many base transceiver stations within a small area and they are placed on residential and office buildings in city blocks.
  • WO 98 /01923 presents a vertical cross-polarized antenna array which comprises a vertical suppression bar placed between superposed radiator modules, in a plane transverse to the direction of radia- tion, to suppress mutual interference between the antennas.
  • the length of the bar is at least 25% of the distance between the radiator modules.
  • the suppression bars are placed in a plane transverse to the direction of radiation and transversely to the connecting line between the antennas. The problem with these prior-art solutions for the suppression of interference is that they have a low interference suppression capability.
  • the object of the present invention is to eliminate the drawbacks associ- ated with prior-art solutions and to achieve a new type of apparatus for suppressing mutual interference between antennas placed close to each other.
  • the apparatus of the invention is characterized in that the suppressing element is disposed in the direction of radiation and its length equals a quarter of one of the wavelengths in the frequency range of the antennas or its multiple, the suppressing element thus functioning as a resonator tuned at least to the frequency range in question and radiating in a plane transverse to the direction of radiation of the antennas.
  • the apparatus of the invention it will be possible to place antennas considerably more closely together than at present. This will reduce the size of the antenna structures of e.g. base stations, allowing more inconspicuous disposition of the base stations of mobile communication networks especially in an urban environment.
  • the antenna system comprises two dipole antennas 1 , 2 placed one above the other in the same vertical plane, each of which is provided with a vertical radiator 11 , 21 attached to a horizontal arm 10, 20. Placed behind these is a vertical reflector 3, the upper end of which extends slightly above the upper end of the radiator 11 of the upper antenna while the lower end extends slightly below the lower end of the radiator 21 of the lower antenna.
  • Each antenna is connected by an antenna cable 13, 23 to a separate receiver-transmitter (Rx/Tx) apparatus.
  • the antenna system is mounted on a supporting structure (not shown) and enclosed in a protective casing 4.
  • the antenna system is provided with a round bar or a strip 5 having the shape of an elongated rectangle, placed between the antennas despite the small distance between them and made of the same electrically conductive material as the reflector and the radiators, said bar or strip being connected to the reflector 3 in a direction parallel to the supporting arms 10, 20 of the antennas.
  • the length L of this bar or strip equals a quarter of the wavelength or this quantity multiplied by an odd integer, i.e.
  • ⁇ is the wavelength and n is an odd integer (1 ,3,5,).
  • the strip 5 is placed at a distance from the radiators and it functions as a resonator tuned to the frequency of 900 MHz and radiating omnidirectionally in a plane transverse to the direction of radiation (to the right in the plane of the paper sheet) of the antennas 1 ,2, so that only a very small proportion of the signal it receives can get from one antenna to the other. Thus, interference transmitted from one antenna to the other is substantially reduced, and still the strip 5 does not interfere with the operation of any one of the antennas.
  • An antenna construction of electrically conductive film comprising the antennas and the suppressing element 5 can be etched on a fiberglass circuit plate.
  • the length of the strip or bar is equal to half the wavelength or half the wavelength multiplied by an integer.

Abstract

Apparatus for suppressing mutual interference between antennas placed close to each other, said apparatus consisting of at least one elongated suppressing element (5) of electrically conductive material, fitted between the antenna radiators (11, 21) and disposed in a plane transverse to the connecting line between the antennas. The suppressing element is disposed in the direction of radiation and its length equals a quarter or a multiple of a quarter of one of the wavelengths in the frequency range of the antennas, thus functioning as a resonator tuned at least to the frequency range in question, radiating in a plane transverse to the direction of radiation of the antennas (1, 2).

Description

APPARATUS FOR SUPPRESSING MUTUAL INTERFERENCE BETWEEN ANTENNAS
The present invention relates to an apparatus for suppressing mutual in- terference between antennas located close to each other, said apparatus consisting of at least one elongated suppressing element of conductive material fitted between antenna radiators, disposed in a plane transverse to the connecting line between the antennas.
The base transceiver stations of mobile communication networks use superposed dipole antennas, each antenna being connected to a separate transmitter-receiver apparatus. Such superposed antennas placed closely together produce interference in each other. For this reason, at present, superposed antennas must be placed at a relatively large dis- tance from each other to achieve a sufficient insulation level, e.g. 26 dB, between the antennas. Therefore, the antenna structures currently used in base transceiver stations are relatively high. This is a disadvantage especially in cities, where there are many base transceiver stations within a small area and they are placed on residential and office buildings in city blocks.
Specification WO 98 /01923 presents a vertical cross-polarized antenna array which comprises a vertical suppression bar placed between superposed radiator modules, in a plane transverse to the direction of radia- tion, to suppress mutual interference between the antennas. The length of the bar is at least 25% of the distance between the radiator modules. In a dipole antenna structure presented in US patent specification 3,541 ,559, the suppression bars are placed in a plane transverse to the direction of radiation and transversely to the connecting line between the antennas. The problem with these prior-art solutions for the suppression of interference is that they have a low interference suppression capability.
The object of the present invention is to eliminate the drawbacks associ- ated with prior-art solutions and to achieve a new type of apparatus for suppressing mutual interference between antennas placed close to each other. The apparatus of the invention is characterized in that the suppressing element is disposed in the direction of radiation and its length equals a quarter of one of the wavelengths in the frequency range of the antennas or its multiple, the suppressing element thus functioning as a resonator tuned at least to the frequency range in question and radiating in a plane transverse to the direction of radiation of the antennas.
Using the apparatus of the invention, it will be possible to place antennas considerably more closely together than at present. This will reduce the size of the antenna structures of e.g. base stations, allowing more inconspicuous disposition of the base stations of mobile communication networks especially in an urban environment.
In the following, the invention will be described in detail by the aid of an example with reference to the attached drawing, which presents a side view of a protected dipole antenna system for a base transceiver station in the 900 MHz GSM mobile telephone network.
The antenna system comprises two dipole antennas 1 , 2 placed one above the other in the same vertical plane, each of which is provided with a vertical radiator 11 , 21 attached to a horizontal arm 10, 20. Placed behind these is a vertical reflector 3, the upper end of which extends slightly above the upper end of the radiator 11 of the upper antenna while the lower end extends slightly below the lower end of the radiator 21 of the lower antenna. Each antenna is connected by an antenna cable 13, 23 to a separate receiver-transmitter (Rx/Tx) apparatus. The antenna system is mounted on a supporting structure (not shown) and enclosed in a protective casing 4.
To reduce interference between the antennas 1 , 2 and to achieve an adequate noise level, the antenna system is provided with a round bar or a strip 5 having the shape of an elongated rectangle, placed between the antennas despite the small distance between them and made of the same electrically conductive material as the reflector and the radiators, said bar or strip being connected to the reflector 3 in a direction parallel to the supporting arms 10, 20 of the antennas. The length L of this bar or strip equals a quarter of the wavelength or this quantity multiplied by an odd integer, i.e.
L = n *_λ_ (1) 4
where λ is the wavelength and n is an odd integer (1 ,3,5,...).
The strip 5 is placed at a distance from the radiators and it functions as a resonator tuned to the frequency of 900 MHz and radiating omnidirectionally in a plane transverse to the direction of radiation (to the right in the plane of the paper sheet) of the antennas 1 ,2, so that only a very small proportion of the signal it receives can get from one antenna to the other. Thus, interference transmitted from one antenna to the other is substantially reduced, and still the strip 5 does not interfere with the operation of any one of the antennas.
An antenna construction of electrically conductive film comprising the antennas and the suppressing element 5 can be etched on a fiberglass circuit plate.
It is obvious to a person skilled in the art that different embodiments of the invention are not restricted to the example described above, but that they may be varied within the scope of the claims presented below. If no reflector is used, then the length of the strip or bar is equal to half the wavelength or half the wavelength multiplied by an integer.

Claims

1. Apparatus for suppressing mutual interference between antennas placed close to each other, said apparatus consisting of at least one elongated suppressing element (5) of electrically conductive material, fitted between the antenna radiators (11,21) and disposed in a plane transverse to the connecting line between the antennas, c h a r a ct e r i z e d in that said suppressing element is disposed in the direction of radiation and has a length equal to a quarter or a multiple of a quarter of one of the wavelengths in the frequency range of the antennas, thus functioning as a resonator tuned at least to the frequency range in question, radiating in a plane transverse to the direction of radiation of the antennas (1,2).
2. Apparatus as defined in claim 1, c h a r a ct e r i z e d in that the length of the suppressing element (5) equals half the wavelength or a multiple of half the wavelength.
3. Apparatus as defined in claim 2, comprising a reflector (3) fitted behind the antennas, c h a ra ct e r i z e d in that the length of the suppressing element (5) equals a quarter of the wavelength or an odd multiple of a quarter of the wavelength.
4. Apparatus as defined in claim 3, comprising a reflector (3) or a corre- sponding frame disposed in conjunction with the antennas, c h a ra ct e r i z e d in that the suppressing element (5) is connected to the reflector or corresponding frame.
PCT/FI2000/000138 1999-02-24 2000-02-22 Apparatus for suppressing mutual interference between antennas WO2000051201A1 (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
DE60035772T DE60035772T2 (en) 1999-02-24 2000-02-22 ARRANGEMENT FOR SUPPRESSING MUTUAL INTERFERENCE BETWEEN ANTENNAS
BR0008466-2A BR0008466A (en) 1999-02-24 2000-02-22 Apparatus to suppress mutual interference between antennas
US09/914,211 US6542131B1 (en) 1999-02-24 2000-02-22 Apparatus for suppressing mutual interference between antennas
JP2000601706A JP2002538648A (en) 1999-02-24 2000-02-22 Apparatus for suppressing mutual interference between antennas
EP00906397A EP1155473B1 (en) 1999-02-24 2000-02-22 Apparatus for suppressing mutual interference between antennas
AU28083/00A AU2808300A (en) 1999-02-24 2000-02-22 Apparatus for suppressing mutual interference between antennas

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI990395 1999-02-24
FI990395A FI990395A (en) 1999-02-24 1999-02-24 Hardware for attenuating interference between antennas

Publications (1)

Publication Number Publication Date
WO2000051201A1 true WO2000051201A1 (en) 2000-08-31

Family

ID=8553927

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI2000/000138 WO2000051201A1 (en) 1999-02-24 2000-02-22 Apparatus for suppressing mutual interference between antennas

Country Status (9)

Country Link
US (1) US6542131B1 (en)
EP (1) EP1155473B1 (en)
JP (1) JP2002538648A (en)
CN (1) CN1168180C (en)
AU (1) AU2808300A (en)
BR (1) BR0008466A (en)
DE (1) DE60035772T2 (en)
FI (1) FI990395A (en)
WO (1) WO2000051201A1 (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002071546A1 (en) * 2001-03-05 2002-09-12 Nokia Corporation Enhancement of the field pattern of a device for transferring electromagnetic waves
US6882317B2 (en) 2001-11-27 2005-04-19 Filtronic Lk Oy Dual antenna and radio device
WO2006018711A1 (en) 2004-08-20 2006-02-23 Nokia Corporation Improving antenna isolation using grounded microwave elements
WO2009101417A1 (en) * 2008-02-14 2009-08-20 Zinwave Limited Communication system
EP2323216A1 (en) * 2009-11-12 2011-05-18 Alcatel Lucent Antenna apparatus and antenna selection method
US8094079B2 (en) 2007-01-04 2012-01-10 Apple Inc. Handheld electronic devices with isolated antennas
US8106836B2 (en) 2008-04-11 2012-01-31 Apple Inc. Hybrid antennas for electronic devices
WO2012140586A1 (en) * 2011-04-12 2012-10-18 Vodafone Ip Licensing Limited Omnidirectional antenna with a null in a selected direction
US8350761B2 (en) 2007-01-04 2013-01-08 Apple Inc. Antennas for handheld electronic devices
EP2780979A4 (en) * 2011-11-15 2015-06-03 Saab Ab Antenna assembly with shielding structure

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004214820A (en) * 2002-12-27 2004-07-29 Honda Motor Co Ltd On-board antenna
US7450080B2 (en) * 2003-07-03 2008-11-11 Navcom Technology, Inc. Decoherence plate for use in a communications system
US20050088340A1 (en) * 2003-10-22 2005-04-28 Inpaq Technology Co., Ltd. GPS/DAB and GSM hybrid antenna array
US8104165B1 (en) 2004-03-02 2012-01-31 Motion Computing Inc. Method of forming an apparatus used for reducing electromagnetic interference
US7164933B1 (en) * 2004-03-02 2007-01-16 Motion Computing, Inc. Apparatus and method for reducing the electromagnetic interference between two or more antennas coupled to a wireless communication device
DE102004039439A1 (en) * 2004-08-13 2006-02-23 Rohde & Schwarz Gmbh & Co. Kg Receiving antenna system with multiple active antennas
KR100695328B1 (en) * 2004-12-21 2007-03-15 한국전자통신연구원 Ultra Isolation Antennas
JP4563328B2 (en) * 2006-03-07 2010-10-13 日本電信電話株式会社 Wireless communication device
JP4738380B2 (en) * 2007-05-10 2011-08-03 株式会社東芝 Electronics
JP5123751B2 (en) * 2008-06-20 2013-01-23 ソフトバンクモバイル株式会社 Shield and repeater station
DE112010001529A5 (en) * 2009-04-06 2012-10-25 Conti Temic Microelectronic Gmbh RADAR SYSTEM WITH ARRANGEMENTS AND METHOD FOR DECOUPLING TRANSMISSION AND RECEPTION SIGNALS AND SUPPRESSING NOISE EMISSIONS
FR2946805B1 (en) * 2009-06-11 2012-03-30 Alcatel Lucent RADIANT ELEMENT OF ANTENNA
US20130119033A1 (en) * 2011-11-11 2013-05-16 Lincoln Global, Inc. Mobile welding system and method
RU2488926C1 (en) * 2011-11-17 2013-07-27 Открытое акционерное общество Российская корпорация ракетно-космического приборостроения и информационных систем (ОАО "Российские космические системы") Metamaterial-based narrow beam antenna radiator
US11145968B2 (en) 2017-03-29 2021-10-12 Nihon Dengyo Kosaku Co., Ltd. Array antenna and sector antenna
JP6771790B2 (en) * 2017-05-16 2020-10-21 日本電業工作株式会社 Antennas, array antennas, sector antennas and dipole antennas

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3681770A (en) * 1970-01-14 1972-08-01 Andrew Alford Isolating antenna elements
US4460899A (en) * 1981-01-24 1984-07-17 Metalltechnik Schmidt Gmbh & Co. Shield for improving the decoupling of antennas
US5039994A (en) * 1984-12-20 1991-08-13 The Marconi Company Ltd. Dipole arrays
EP0973231A2 (en) * 1998-07-06 2000-01-19 Ace Technology Dual polarization directional antenna having choke reflectors for minimizing side lobe

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3541559A (en) 1968-04-10 1970-11-17 Westinghouse Electric Corp Antenna for producing circular polarization over wide angles
US4812855A (en) * 1985-09-30 1989-03-14 The Boeing Company Dipole antenna with parasitic elements
DE19627015C2 (en) 1996-07-04 2000-07-13 Kathrein Werke Kg Antenna field
US6054961A (en) * 1997-09-08 2000-04-25 Andrew Corporation Dual band, glass mount antenna and flexible housing therefor
US6307524B1 (en) * 2000-01-18 2001-10-23 Core Technology, Inc. Yagi antenna having matching coaxial cable and driven element impedances

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3681770A (en) * 1970-01-14 1972-08-01 Andrew Alford Isolating antenna elements
US4460899A (en) * 1981-01-24 1984-07-17 Metalltechnik Schmidt Gmbh & Co. Shield for improving the decoupling of antennas
US5039994A (en) * 1984-12-20 1991-08-13 The Marconi Company Ltd. Dipole arrays
EP0973231A2 (en) * 1998-07-06 2000-01-19 Ace Technology Dual polarization directional antenna having choke reflectors for minimizing side lobe

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6828945B2 (en) 2001-03-05 2004-12-07 Nokia Corporation Enhancement of the field pattern of a device for transferring electromagnetic waves
WO2002071546A1 (en) * 2001-03-05 2002-09-12 Nokia Corporation Enhancement of the field pattern of a device for transferring electromagnetic waves
US6882317B2 (en) 2001-11-27 2005-04-19 Filtronic Lk Oy Dual antenna and radio device
WO2006018711A1 (en) 2004-08-20 2006-02-23 Nokia Corporation Improving antenna isolation using grounded microwave elements
US8872708B2 (en) 2007-01-04 2014-10-28 Apple Inc. Antennas for handheld electronic devices
US8094079B2 (en) 2007-01-04 2012-01-10 Apple Inc. Handheld electronic devices with isolated antennas
US8350761B2 (en) 2007-01-04 2013-01-08 Apple Inc. Antennas for handheld electronic devices
US8907850B2 (en) 2007-01-04 2014-12-09 Apple Inc. Handheld electronic devices with isolated antennas
WO2009101417A1 (en) * 2008-02-14 2009-08-20 Zinwave Limited Communication system
US10186770B2 (en) 2008-02-14 2019-01-22 Zinwave Limited Flexible distributed antenna system using a wideband antenna device
US9960487B2 (en) 2008-02-14 2018-05-01 Zinwave Limited Flexible distributed antenna system using a wide band antenna device
EP3128608A1 (en) * 2008-02-14 2017-02-08 Zinwave Limited Communication system
US8994597B2 (en) 2008-04-11 2015-03-31 Apple Inc. Hybrid antennas for electronic devices
US8410986B2 (en) 2008-04-11 2013-04-02 Apple Inc. Hybrid antennas for electronic devices
US8106836B2 (en) 2008-04-11 2012-01-31 Apple Inc. Hybrid antennas for electronic devices
US8688108B2 (en) 2009-11-12 2014-04-01 Alcatel Lucent Antenna apparatus and antenna selection method
WO2011057840A1 (en) * 2009-11-12 2011-05-19 Alcatel Lucent Antenna apparatus and antenna selection method
EP2323216A1 (en) * 2009-11-12 2011-05-18 Alcatel Lucent Antenna apparatus and antenna selection method
WO2012140586A1 (en) * 2011-04-12 2012-10-18 Vodafone Ip Licensing Limited Omnidirectional antenna with a null in a selected direction
EP2780979A4 (en) * 2011-11-15 2015-06-03 Saab Ab Antenna assembly with shielding structure
US9368865B2 (en) 2011-11-15 2016-06-14 Saab Ab Antenna assembly with shielding structure

Also Published As

Publication number Publication date
EP1155473A1 (en) 2001-11-21
CN1168180C (en) 2004-09-22
US6542131B1 (en) 2003-04-01
DE60035772T2 (en) 2008-04-30
DE60035772D1 (en) 2007-09-13
CN1341285A (en) 2002-03-20
AU2808300A (en) 2000-09-14
BR0008466A (en) 2002-01-29
JP2002538648A (en) 2002-11-12
FI990395A0 (en) 1999-02-24
EP1155473B1 (en) 2007-08-01
FI990395A (en) 2000-08-25

Similar Documents

Publication Publication Date Title
EP1155473B1 (en) Apparatus for suppressing mutual interference between antennas
US5872544A (en) Cellular antennas with improved front-to-back performance
US5940044A (en) 45 degree polarization diversity antennas
EP2245699B1 (en) Communication system
US10270152B2 (en) Broadband transceiver and distributed antenna system utilizing same
US20210351500A1 (en) Low profile high performance integrated antenna for small cell base station
CA3172688A1 (en) Radiating elements having angled feed stalks and base station antennas including same
CA2371708A1 (en) Transreflector antenna for wireless communication system
EP0691703B1 (en) Communications antenna structure
CN103825106A (en) Multi-antenna assembly and wireless equipment thereof
US20230223709A1 (en) Antenna device, array of antenna devices, and base station with antenna device
EP1566857B1 (en) Dual polarized antenna module
KR200235289Y1 (en) Directivity antenna for suppressing sideband in side direction
US20230231319A1 (en) Antenna device, array of antenna devices
KR100998153B1 (en) Antenna system
KR101372704B1 (en) Antenna assembly for updating isolation degree
US5914688A (en) Device in antenna units
KR100517291B1 (en) Planar microstrip array antenna
JPH08181538A (en) Antenna system for two frequencies in common
CN110112583B (en) Multi-frequency wide-beam antenna device
RU197751U1 (en) DIRECTED ANTENNA
JPH08125435A (en) Antenna for equipment for personal communication base station
JPH0766626A (en) Microstrip array antenna
Mostafavi et al. Design of a high isolation dual-polarized offset parabolic reflector
JP2004023257A (en) Antenna system

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 00804132.6

Country of ref document: CN

AK Designated states

Kind code of ref document: A1

Designated state(s): AE AL AM AT AU AZ BA BB BG BR BY CA CH CN CR CU CZ DE DK DM EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG US UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW SD SL SZ TZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
WWE Wipo information: entry into national phase

Ref document number: 2000906397

Country of ref document: EP

ENP Entry into the national phase

Ref document number: 2000 601706

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 09914211

Country of ref document: US

WWP Wipo information: published in national office

Ref document number: 2000906397

Country of ref document: EP

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

WWG Wipo information: grant in national office

Ref document number: 2000906397

Country of ref document: EP