EP0391634A1 - Microstrip antenna with parasitic elements - Google Patents

Microstrip antenna with parasitic elements Download PDF

Info

Publication number
EP0391634A1
EP0391634A1 EP19900303494 EP90303494A EP0391634A1 EP 0391634 A1 EP0391634 A1 EP 0391634A1 EP 19900303494 EP19900303494 EP 19900303494 EP 90303494 A EP90303494 A EP 90303494A EP 0391634 A1 EP0391634 A1 EP 0391634A1
Authority
EP
Grant status
Application
Patent type
Prior art keywords
antenna
radiator
patch radiator
patch
beam
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.)
Granted
Application number
EP19900303494
Other languages
German (de)
French (fr)
Other versions
EP0391634B1 (en )
Inventor
Nunzio M. Cavallaro
John F. Toth
Cleo J. Alexander
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.)
Raytheon Co
Original Assignee
Raytheon Co
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

Links

Images

Classifications

    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01QANTENNAS, i.e. RADIO AERIALS
    • H01Q19/00Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
    • H01Q19/005Patch antenna using one or more coplanar parasitic elements
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01QANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00Details of, or arrangements associated with, antennas
    • H01Q1/27Adaptation for use in or on movable bodies
    • H01Q1/28Adaptation for use in or on aircraft, missiles, satellites, or balloons
    • H01Q1/285Aircraft wire antennas
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01QANTENNAS, i.e. RADIO AERIALS
    • H01Q19/00Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
    • H01Q19/28Combinations 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 a secondary device in the form of two or more substantially straight conductive elements
    • H01Q19/30Combinations 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 a secondary device in the form of two or more substantially straight conductive elements the primary active element being centre-fed and substantially straight, e.g. Yagi antenna

Abstract

A microstrip antenna (100) has a patch radiator (30) and parasitic elements (32, 34, 36) and is flush-mounted and conforming to the side of a guided missile. The antenna (100) produces an antenna beam which is tilted in a required direction, so that the antenna serves as a link or fuse antenna, by the presence of the elements (32, 34, 36) which direct the beam away from the antenna normal to the desired direction. The parasitic elements include a reflector (32) and one or more directors (34, 36).

Description

    Background of the Invention
  • This invention pertains generally to antennas for radio frequency energy, and more particularly to directional antennas wherein parasitic elements are used to control the direction of a beam from an antenna.
  • In guided missile (or simply missile) applications, fuse and link antennas often are required to be mounted conformally with the generally cylindrical shape of a missile. Antennas which adapt easily to conformal mounting usually produce beams with main lobes directed normally (or broadside to) the missile, whereas the required direction of main lobes of beams for fuse and link antennas is usually not normal (or broadside) to the missile. Thus, the main lobes of fuse antenna beams are typically pointed forward of the missile, while the main lobes of link antenna beams are usually pointed aft, say in a beam direction approximately twenty degrees off of normal. To accomplish such an end, known link antennas are usually made of components that occupy critical area internally of the missile. The mass and volume of all components within the missile are critical to performance, and any decrease in the size and number of components is highly desirable.
  • It is known in the art that microstrip patch antennas have a low profile and may be made conformal to a missile. Unfortunately, most patch antennas produce an antenna beam normally disposed to the aperture of the antenna. Different approaches have been used to change the antenna beam direction. Multiple patch antenna arrays have been used to steer the antenna beam direction. Such arrays have been built by using a stripline distribu­tion network; however, such a network is complicated, with many connections required. A less complicated technique is desirable.
  • It is also known in the art that parasitic elements may be used to control the direction of the beam of an antenna. For example, the well-known "Yagi" antenna uses parasitic elements in combination with at least one active element to control the direction of a beam. A similar technique is known for use with parasitic slot array antennas, as described in an article by R. J. Coe and G Held, I.E.E.E. Transactions on Antennas and Propagation, Vol. Ap-12, No. 1, pp. 10-16, January 1964. In such an array, a reflector element and a director element are formed by cavity-tuned parasitic slots so that when a driven element (a slot) is excited, a beam is formed in the direction of the director in the plane of the elements. The parasitic slot array provides a flush mounting antenna suitable for an application where no projection above a plane surface is required. However, as noted previously, a fuse or link antenna usually requires an antenna beam direction approximately twenty degrees off of normal or broadside of the face of the antenna so the parasitic slot array is hardly one to be used in a missile.
  • Summary of the Invention
  • Therefore, it is a primary object of this invention to provide an improved antenna which has a beam with a main lobe tilted approximately twenty degrees from a normal to a missile, such while retaining the low profile, low volume attributes.
  • Another object of this invention is to provide an improved antenna which is readily adaptable to flush-­mounting on a missile.
  • These and other objects of this invention are attained generally by providing a microstrip patch antenna with parasitic elements flush-mounted to the side of a missile to produce an antenna beam with a main lobe directed approximately twenty degrees off of the normal to the missile, such antenna here including a driven patch antenna, a reflector element and two director elements, with the reflector and director elements being parasitic elements in combination with appropriate connector elements.
  • Brief Description of the Drawings
  • For a more complete understanding of this invention, reference is now made to the following description of the accompanying drawings, wherein:
    • FIG. 1 is a sketch showing generally the contemplated location of the microstrip antenna and the direction of the antenna beams;
    • FIG. 2 is a sketch showing an isometric view, partially cut away for clarity of illustration, of the microstrip antenna according to the invention; and
    • FIG. 3 is a plan view of the microstrip antenna according to the invention.
    Description of the Preferred Embodiment
  • Referring now to FIG. 1, a missile 10, here a semi-­active missile, is shown to include a fuse antenna 12 and a link antenna 16. It is well known in the art that the main lobe of the beam from fuse antenna 12 must typically point forward from a normal to the missile 10 as illustrated by beam 14 because any target (not shown) would be ahead of the missile 10. In contrast, the main lobe of a link antenna 16 must typically point aft of a normal as illus­trated by beam 18 because signals to (or from) the link antenna 16 come from (or are directed to) a station (not shown) located to the rear of missile 10.
  • Referring now to FIG. 2, a microstrip antenna 100 as here contemplated is shown to include antenna elements 30,32,34,36 disposed on a slab 28 fabricated from a dielectric material. Such dielectric material may, for example, be the material known as "Duriod," or other teflon-fiberglass material. The antenna elements 30,32, 34,36 are formed by depositing an electrically conducting material (here copper) in any conventional manner as shown on the slab 28. The second side of slab 28 is covered with an electrically conductive coating to form a metallic ground plane 26. The antenna elements 30,32,34,36 are arranged in an array where a driven element (herein also referred to as "patch 30˝) here is the second antenna element from the right. It will be observed that the patch 30, when actuated by itself, is operative to form a beam by reason of fringing fields around the periphery of such patch and that the main lobe of such beam is broadside to such patch. Further, it will be observed that the patch 30, when matched to a feed, is effectively equivalent to a resonant cavity. A shorting pin 38 in electrical contact centrally of the patch 30 is passed through the slab 28 to be attached to ground plane 26. The shorting pin 38 has no effect on radiation or impedance of the antenna being described, but simply allows a low frequency path between the patch 30 and the ground plane 36. The patch 30 here is fed by a coaxial line 20 affixed to the ground plane 26. Thus, an outer shield 24 of the coaxial line 20 is attached in any known fashion to ground plane 26. A center conductor 22 of the coaxial line 20 is attached to the patch 30 in any known fashion. Although the location of the point of connection between the patch 30 and the center conductor 22 does not affect the frequency of resonance, such location does affect input impedance of the antenna being described, so care should be taken to provide a proper impedance match with the impedance of the coaxial line 20. A reflector element 32, a first director element 34 and a second director element 36 make up the parasitic elements of the microstrip antenna 100. The parasitic elements are here effective to cause the direction of the main lobe in the beam radiated by the patch 30 to be changed as desired.
  • Parasitic elements are inactive elements, meaning not fed or driven with a signal, placed on the face of the microstrip antenna 100 in close proximity to the patch 30. The advantage of this approach is that the direction of the main lobe in the beam may be changed without the penalty of beam narrowing associated with antenna feed networks. By varying the length, width, location and number of the parasitic elements, the direction of the main lobe in the beam is changed as required from the normal. There are two types of parasitic elements, a director type element and a reflector type element. The length of the parasitic element with respect to the narrow edge of the patch 30 determines the type of element, where shorter elements act as directors, while longer elements act as reflectors. Reflector element 32, here a parasitic element of the reflector type, tips the beam (not shown) away from the parasitic element. Director elements 34, 36, respectively, here parasitic elements of the director type, tip the beam (not shown) in the direction of the parasitic elements.
  • The presence of the parasitic elements affect the impedance matching of the patch 30. A resulting mismatch of impedance can be compensated for by retuning the patch 30 with the parasitic elements present. This is easily accomplished either by changing the dimensions of the patch 30, or adjusting the location of the feed point. In connection with the latter method of adjustment, it will be noted that the feed point, i.e., the point at which the center conductor 22 is attached to the patch 30, is on a centerline of the patch 30. However the feed point is adjusted, the point of attachment should remain on that centerline.
  • A high thermal protection window 50 (hereinafter also referred to as "window 50˝) is attached to the missile 10 to overlie the slab 28 and antenna elements 30,32,34,36 when the microstrip antenna 100 is mounted on missile 10 (FIG. 1). The window 50 here is a ceramic, rigid, composite-fiber, insulation material, known as "HTP 12-22," developed by Lockheed Missiles and Space Company, Inc., Sunnyvale, California. HTP 12-22 provides good thermal shock resistance, low thermal conductivity, good strength and low dielectric constant for the window 50. The window 50 protects the microstrip antenna 100 from a harsh environment experienced while missile 10 (FIG. 1) is in flight. For further protection the window 50 may be treated with a silane polymer solution for moisture-proofing and an external reaction-cured glass-based coating for increased surface toughness and crack propagation resistance.
  • Referring now to FIG. 3, a plan view of the micro­strip antenna 100 is shown. It can be seen that patch 30 has a width C and a length D. Patch 30 is constructed such that the width C is equal in wavelength "L" to .380L and the length D is equal to .494L. Reflector element 32 has a width A and a length B. Reflector element 32 is constructed such that the width A is equal to .494L and the length B is equal to .304L. It should be noted that the center of reflector element 32 is separated from the center of patch 30 by the distance H which is equal to .570L. Microstrip antenna 100 also includes director element 34 and director element 36. Director element 34 has a width F and a length G. Director element 34 is constructed such that the width F is equal to .266L and the length G is equal to .114L. The center of director element 34 is separated from the center of patch 30 by the distance I which is equal to .456L. Director element 36 has a width F′ and a length G′. Director element 36 is constructed such that the width F′ is equal to .266L and the length G′ is equal to .114L. The center of director element 34 is operated from the center of director element 36 by the distance J which is equal to .228L.
  • Having described this invention, it will now be apparent to one of skill in the art that the number and disposition of the parasitic elements may be changed without affecting this invention. For example, the number of director elements could be reduced to one or increased to three, thus further controlling the desired direction of the beam. It is felt, therefore, that this invention should not be restricted to its disclosed embodiment, but rather should be limited only by the spirit and scope of the appended claims.

Claims (4)

1. A microstrip antenna for flush-mounting on a missile, the antenna being fabricated as an array of antenna elements on a first surface of a slab of dielectric material, the second surface of said slab being covered with an electrically conductive coating and said antenna being actuated through a feed port to produce a beam of radio frequency energy having a main lobe directed away from the normal to such missile at the location of the antenna, the microstrip antenna comprising:
(a) a patch radiator disposed on the first surface of the slab, said radiator being a rectangular sheet of electrically conducting material having length and width dimensions between 0.3 and 0.5 wavelengths of the radio frequency energy;
(b) means for actuating the patch radiator to produce a beam of radio frequency energy, the main lobe of such beam nominally being orthogonal to the patch radiator; and
(c) parasitic antenna elements disposed on the slab, each one of such elements being a rectangular sheet of electrically conducting material having length and width dimensions differing from corresponding dimensions of the patch radiator, each one of such elements further being spaced from the patch radiator on either side of such radiator to cause the main lobe of the beam of electromagnetic energy from such radiator to be rotated in a plane away from the normal to such radiator.
2. A microstrip antenna as in claim 1 wherein:
(a) the or each parasitic antenna element on one side of the patch radiator is a reflector element with the dimension of the side nearest to the patch radiator being greater than the corresponding dimension of the patch radiator; and
(b) the or each parasitic antenna element on the other side of the patch radiator is a director element with the dimension of the side nearest to the patch radiator being less than the corresponding dimension of the patch radiator.
3. A microstrip antenna as in claim 2 having, additionally, a high thermal protection window attached to the first surface of the slab.
4. A microstrip antenna as in claim 3 having, additionally, means for mounting the slab, including the patch radiator and the parasitic elements, and the high thermal protection window in an opening formed in a guided missile to permit radiation through such opening.
EP19900303494 1989-04-03 1990-04-02 Microstrip antenna with parasitic elements Expired - Lifetime EP0391634B1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US332145 1981-12-18
US33214589 true 1989-04-03 1989-04-03

Publications (2)

Publication Number Publication Date
EP0391634A1 true true EP0391634A1 (en) 1990-10-10
EP0391634B1 EP0391634B1 (en) 1995-06-21

Family

ID=23296898

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19900303494 Expired - Lifetime EP0391634B1 (en) 1989-04-03 1990-04-02 Microstrip antenna with parasitic elements

Country Status (2)

Country Link
EP (1) EP0391634B1 (en)
DE (2) DE69020215D1 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4239785A1 (en) * 1992-11-26 1994-06-01 Forschungsgesellschaft Fuer In Strip conductor group antenna - has flat conductive arrangement with stepped surface area variation which varies antenna band width
DE19523694A1 (en) * 1995-06-29 1997-01-02 Fuba Automotive Gmbh Planar antenna, esp. for frequencies in GHz region
WO1999005754A1 (en) * 1997-07-23 1999-02-04 Allgon Ab Antenna device with improved channel isolation
US7253777B2 (en) 2003-12-03 2007-08-07 Eads Deutschland Gmbh Outside structure conformal antenna in a supporting structure of a vehicle
GB2445592A (en) * 2007-01-12 2008-07-16 E2V Tech Driven and parasitic patch antenna structure with an inclined beam
US20110260925A1 (en) * 2010-04-23 2011-10-27 Laurian Petru Chirila Multiband internal patch antenna for mobile terminals
DE102012112218A1 (en) * 2012-12-13 2014-07-10 Endress + Hauser Gmbh + Co. Kg level meter

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3577196A (en) * 1968-11-25 1971-05-04 Eugene F Pereda Rollable slot antenna
US3713162A (en) * 1970-12-18 1973-01-23 Ball Brothers Res Corp Single slot cavity antenna assembly
DE2138384A1 (en) * 1971-07-31 1973-02-08 Licentia Gmbh Yagi antenna
EP0018878A1 (en) * 1979-04-26 1980-11-12 Thomson-Csf Airborne IFF system having a radar and an interrogation antenna
US4304603A (en) * 1980-08-11 1981-12-08 Corning Glass Works Glass-ceramic compositions designed for radomes

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3577196A (en) * 1968-11-25 1971-05-04 Eugene F Pereda Rollable slot antenna
US3713162A (en) * 1970-12-18 1973-01-23 Ball Brothers Res Corp Single slot cavity antenna assembly
DE2138384A1 (en) * 1971-07-31 1973-02-08 Licentia Gmbh Yagi antenna
EP0018878A1 (en) * 1979-04-26 1980-11-12 Thomson-Csf Airborne IFF system having a radar and an interrogation antenna
US4304603A (en) * 1980-08-11 1981-12-08 Corning Glass Works Glass-ceramic compositions designed for radomes

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
INTERNATIONAL SYMPOSIUM DIGEST ANTENNAS AND PROPAGATION *

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4239785A1 (en) * 1992-11-26 1994-06-01 Forschungsgesellschaft Fuer In Strip conductor group antenna - has flat conductive arrangement with stepped surface area variation which varies antenna band width
DE19523694A1 (en) * 1995-06-29 1997-01-02 Fuba Automotive Gmbh Planar antenna, esp. for frequencies in GHz region
WO1999005754A1 (en) * 1997-07-23 1999-02-04 Allgon Ab Antenna device with improved channel isolation
US7253777B2 (en) 2003-12-03 2007-08-07 Eads Deutschland Gmbh Outside structure conformal antenna in a supporting structure of a vehicle
GB2445592A (en) * 2007-01-12 2008-07-16 E2V Tech Driven and parasitic patch antenna structure with an inclined beam
GB2445592B (en) * 2007-01-12 2012-01-04 E2V Tech Uk Ltd Antenna structure
US20110260925A1 (en) * 2010-04-23 2011-10-27 Laurian Petru Chirila Multiband internal patch antenna for mobile terminals
DE102012112218A1 (en) * 2012-12-13 2014-07-10 Endress + Hauser Gmbh + Co. Kg level meter

Also Published As

Publication number Publication date Type
EP0391634B1 (en) 1995-06-21 grant
DE69020215D1 (en) 1995-07-27 grant
DE69020215T2 (en) 1996-02-29 grant

Similar Documents

Publication Publication Date Title
US6043785A (en) Broadband fixed-radius slot antenna arrangement
US6025811A (en) Closely coupled directional antenna
US6624787B2 (en) Slot coupled, polarized, egg-crate radiator
US5748153A (en) Flared conductor-backed coplanar waveguide traveling wave antenna
US7196674B2 (en) Dual polarized three-sector base station antenna with variable beam tilt
US4700197A (en) Adaptive array antenna
Herscovici A wide-band single-layer patch antenna
US5646633A (en) Microstrip antenna having a plurality of broken loops
US5557291A (en) Multiband, phased-array antenna with interleaved tapered-element and waveguide radiators
US4792809A (en) Microstrip tee-fed slot antenna
US6480167B2 (en) Flat panel array antenna
US6842158B2 (en) Wideband low profile spiral-shaped transmission line antenna
US5274391A (en) Broadband directional antenna having binary feed network with microstrip transmission line
US6307524B1 (en) Yagi antenna having matching coaxial cable and driven element impedances
US4827271A (en) Dual frequency microstrip patch antenna with improved feed and increased bandwidth
US4074270A (en) Multiple frequency microstrip antenna assembly
US4336543A (en) Electronically scanned aircraft antenna system having a linear array of yagi elements
US6121930A (en) Microstrip antenna and a device including said antenna
US5175560A (en) Notch radiator elements
US6127987A (en) Antenna and manufacturing method therefor
US5006859A (en) Patch antenna with polarization uniformity control
US6307510B1 (en) Patch dipole array antenna and associated methods
US4839663A (en) Dual polarized slot-dipole radiating element
US5726666A (en) Omnidirectional antenna with single feedpoint
US4853704A (en) Notch antenna with microstrip feed

Legal Events

Date Code Title Description
AK Designated contracting states:

Kind code of ref document: A1

Designated state(s): DE FR GB IT NL

17P Request for examination filed

Effective date: 19910404

17Q First examination report

Effective date: 19930506

AK Designated contracting states:

Kind code of ref document: B1

Designated state(s): DE FR GB IT NL

REF Corresponds to:

Ref document number: 69020215

Country of ref document: DE

Date of ref document: 19950727

Format of ref document f/p: P

ITF It: translation for a ep patent filed

Owner name: BARZANO E ZANARDO ROMA S.P.A.

ET Fr: translation filed
26N No opposition filed
PGFP Postgrant: annual fees paid to national office

Ref country code: FR

Payment date: 19970318

Year of fee payment: 08

PGFP Postgrant: annual fees paid to national office

Ref country code: DE

Payment date: 19970324

Year of fee payment: 08

Ref country code: NL

Payment date: 19970324

Year of fee payment: 08

PGFP Postgrant: annual fees paid to national office

Ref country code: GB

Payment date: 19970326

Year of fee payment: 08

PG25 Lapsed in a contracting state announced via postgrant inform. from nat. office to epo

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19980402

PG25 Lapsed in a contracting state announced via postgrant inform. from nat. office to epo

Ref country code: FR

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19980430

PG25 Lapsed in a contracting state announced via postgrant inform. from nat. office to epo

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19981101

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19980402

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 19981101

PG25 Lapsed in a contracting state announced via postgrant inform. from nat. office to epo

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990202

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state announced via postgrant inform. from nat. office to epo

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050402