US3534377A - Horn aerials - Google Patents
Horn aerials Download PDFInfo
- Publication number
- US3534377A US3534377A US611916A US3534377DA US3534377A US 3534377 A US3534377 A US 3534377A US 611916 A US611916 A US 611916A US 3534377D A US3534377D A US 3534377DA US 3534377 A US3534377 A US 3534377A
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- US
- United States
- Prior art keywords
- horn
- cone
- aerial
- section
- cross
- 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.)
- Expired - Lifetime
Links
- 230000005855 radiation Effects 0.000 description 9
- 230000005670 electromagnetic radiation Effects 0.000 description 7
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 230000005284 excitation Effects 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000009291 secondary effect Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
- H01Q13/02—Waveguide horns
Definitions
- the aerial also comprises a means for launching plane polarised electromagnetic waves into, or receiving plane polarised electromagnetic waves from, the cone.
- the waveguide is so oriented that the E vector of the waves is at 45 degrees to the axes of the cone or is parallel to the major axis of the cone.
- the present invention relates to horn aerials.
- the resulting radiation pattern tends to have a beam width which is different for different planes of measurement. Also, the resulting radiation pattern has many side lobes and is sensitive to changes in frequency.
- a horn aerial in the form of a cone having an oval crosssection, the oval cross-section being symmetrical about its major and minor axes, and including means for feeding plane polarised electromagnetic waves to, or for receiving plane polarised electramagnetic waves from, the cone.
- the E vector of the electromagnetic radiation may be at substantially forty-five degrees to the axes of the oval crosssection.
- the E vector of the electromagnetic radiation may lie substantially along the major axis of the oval cross-section.
- the cone may have an elliptical cross-section and the feeding means may be a rectangular waveguide. It will, of course, be realised that in accordance with the reciprocity theorem the above-defined horn aerial and its feeding means may equally well be used for the transmission and for the reception of electromagnetic radiation.
- FIG. 1 is an elevation view of a horn aerial
- FIG. 2 is a perspective view of the horn aerial shown in FIG. 1, and
- FIG. 3 is an elevation view of a modified form of horn aerial.
- FIGS. 1 and 2 show a horn aerial including a metallic cone 1 of elliptical cross-section which is open at the mouth 6 of the cone.
- the major and minor axes of the cone 1 are indicated at 2 and 3 respectively.
- the end of the Waveguide 4 remote from the cone 1 is coupled to a transmitter/receiver 7.
- the sides of the rectangular waveguide 4 are at forty-five degrees to the major and minor axes of the cone. It follows that the E vector (shown in FIG.
- any plane polarised electromagnetic radiation launched into the cone 1 by the waveguide 4 will be at forty-five degrees to the major and minor axes of the cone. It has been found that the abovedescribed horn aerial has radiation patterns in planes parallel to the major and minor axes of the cone, and including the longitudinal axis of the cone, which are nearly the same and are relatively substantially independent of charges of frequency of excitation. Also the number of significant side lobes of the radiation patterns is small.
- the longer sides of the waveguide 4 are arranged to be parallel to the minor axis 3 as shown in FIG. 3. It follows that the E vector of any plane polarised electromagnetic radiation launched into the cone 1 by the waveguide will be parallel to the major axis of the cone. It has been found that with this orientation of the waveguide 4 the side lobes of the resulting radiation patterns are even further reduced.
- small charges in the aspect ratio (that is to say, the ratio of the major axis 2 to the minor axis 3) of the aerial may be used to change side lobe levels.
- the aspect ratio is approximately 3:1, small changes therein have only a secondary effect on beam width but may usefully be made to minimise side lobe levels or to minimise changes in beam width with frequency.
- the aspect ratio was increased to 5:1. This resulted in a substantial reduction in side lobe levels but greater changes in beam width with frequency were experienced.
- the construction of the horn aerial lends itself to controlled deformation. That is to say, the aspect ratio can be readily adjusted. This deformation is preferably done with the aid of templates.
- the conical form of horn therefore, makes it possible economically to achieve a required performance.
- the means for feeding electromagnetic waves to the metallic cone 1 is a rectangular waveguide, clearly and other means of launching plane polarised electromagnetic radiation into the cone 1 may be employed.
- the horn aerial is hereinbefore stated to be elliptical in cross-section, this cross-section need not be a perfect ellipse.
- the cross-section of the horn aerial may be of any oval shape which is symmetrical about two axes at right angles, herein termed the major and minor axes.
- a horn aerial comprising:
- said oval cross-section being symmetrical about its major and minor axes
- feeding means placed at the apex of said conical horn and oriented relative to said axes to launch electromagnetic waves into the cone with their electric field vector oriented at substantially 45 to said axes.
- a horn aerial as claimed in claim 2 wherein the aspect ratio of said cone is 3:1.
- a horn aerial comprising a metallic conical horn having an oval cross-section, said oval cross-section being substantially symmetrical about its major and minor axes, a rectangular wave guide disposed with its sides at substantially a 45 angle with respect to the axes of said cross-section and receiving means for receiving plane polarized electromagnetic waves from said cone through said rectangular wave guide.
Landscapes
- Waveguide Aerials (AREA)
Description
Oct. 13, 1970 w. F. BROWN 3,534,377
HORN AERIALS Filed Jan. 26, 1967 TRANSMITTER! RECEIVER m lZventor torneys awakrww United States Patent Oflice 3,534,377 Patented Oct. 13, 1970 U.S. Cl. 343786 7 Claims ABSTRACT OF THE DISCLOSURE A horn aerial in the form of a metallic cone having an oval cross-section which is symmetrical about its major and minor axes. The aerial also comprises a means for launching plane polarised electromagnetic waves into, or receiving plane polarised electromagnetic waves from, the cone. Preferably the waveguide is so oriented that the E vector of the waves is at 45 degrees to the axes of the cone or is parallel to the major axis of the cone.
BACKGROUND OF THE INVENTION Field of the invention The present invention relates to horn aerials.
When the horn aerials of conventional shape are energised in a conventional manner, the resulting radiation pattern tends to have a beam width which is different for different planes of measurement. Also, the resulting radiation pattern has many side lobes and is sensitive to changes in frequency.
Description of the prior art United States patent specification No. 3,173,146 describes aerial horns of rectangular cross-section and having metallic fillets at their corners for narrowing the radiation pattern in the E-plane of the aerials. The optimum cross-sectional area for these corner fillets is found experimentally and empirically. This operation can be both time-consuming and costly.
It is an object of the present invention to provide a horn aerial which may be more easily constructed so that its radiation patterns are nearly the same when measured in two planes at right angles to one another.
It is a further object of the present invention to provide a horn aerial which may be constructed so that its radiation pattern has only a small number of significant side lobes.
It is a still further object of the present invention to provide a horn aerial which may be constructed so that its radiation pattern is relatively substantially independent of the frequency of excitation.
SUMMARY OF THE INVENTION According to the present invention, there is provided a horn aerial in the form of a cone having an oval crosssection, the oval cross-section being symmetrical about its major and minor axes, and including means for feeding plane polarised electromagnetic waves to, or for receiving plane polarised electramagnetic waves from, the cone. The E vector of the electromagnetic radiation may be at substantially forty-five degrees to the axes of the oval crosssection. Alternatively, the E vector of the electromagnetic radiation may lie substantially along the major axis of the oval cross-section. The cone may have an elliptical cross-section and the feeding means may be a rectangular waveguide. It will, of course, be realised that in accordance with the reciprocity theorem the above-defined horn aerial and its feeding means may equally well be used for the transmission and for the reception of electromagnetic radiation.
In order that the invention may be more clearly understood, embodiments thereof will now be described with reference to the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation view of a horn aerial,
FIG. 2 is a perspective view of the horn aerial shown in FIG. 1, and
FIG. 3 is an elevation view of a modified form of horn aerial.
DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 show a horn aerial including a metallic cone 1 of elliptical cross-section which is open at the mouth 6 of the cone. The major and minor axes of the cone 1 are indicated at 2 and 3 respectively. At the apex of the cone 1, there is a rectangular waveguide 4 coupled to the cone 1 through a coupling member 5, so that plane polarised electromagnetic radiations may be launched into the cone 1. The end of the Waveguide 4 remote from the cone 1 is coupled to a transmitter/receiver 7. The sides of the rectangular waveguide 4 are at forty-five degrees to the major and minor axes of the cone. It follows that the E vector (shown in FIG. 1 of any plane polarised electromagnetic radiation launched into the cone 1 by the waveguide 4 will be at forty-five degrees to the major and minor axes of the cone. It has been found that the abovedescribed horn aerial has radiation patterns in planes parallel to the major and minor axes of the cone, and including the longitudinal axis of the cone, which are nearly the same and are relatively substantially independent of charges of frequency of excitation. Also the number of significant side lobes of the radiation patterns is small.
In a modification of the horn aerial shown in FIGS. 1 and 2, the longer sides of the waveguide 4 are arranged to be parallel to the minor axis 3 as shown in FIG. 3. It follows that the E vector of any plane polarised electromagnetic radiation launched into the cone 1 by the waveguide will be parallel to the major axis of the cone. It has been found that with this orientation of the waveguide 4 the side lobes of the resulting radiation patterns are even further reduced.
It has been found that in the embodiment described with reference to FIGS. 1 to 3, small charges in the aspect ratio (that is to say, the ratio of the major axis 2 to the minor axis 3) of the aerial may be used to change side lobe levels. For example, it has been found that when the aspect ratio is approximately 3:1, small changes therein have only a secondary effect on beam width but may usefully be made to minimise side lobe levels or to minimise changes in beam width with frequency. In one case involving the embodiment hereinbefore described with reference to FIG. 3, the aspect ratio was increased to 5:1. This resulted in a substantial reduction in side lobe levels but greater changes in beam width with frequency were experienced.
Provided with material of which the horn is made is suitable, for example, well-tempered copper, the construction of the horn aerial lends itself to controlled deformation. That is to say, the aspect ratio can be readily adjusted. This deformation is preferably done with the aid of templates. The conical form of horn, therefore, makes it possible economically to achieve a required performance.
Although in the above-described embodiment and the modification thereof, the means for feeding electromagnetic waves to the metallic cone 1 is a rectangular waveguide, clearly and other means of launching plane polarised electromagnetic radiation into the cone 1 may be employed.
As hereinbefore intimated, although the above-described embodiments are described and the invention claimed in the following claims are claimed, as if the horn aerial were used in the transmitting mode, it is clear, by the reciprocity theorem, that they will act equally well and with the same advantages in a receiving mode.
Although the horn aerial is hereinbefore stated to be elliptical in cross-section, this cross-section need not be a perfect ellipse. The cross-section of the horn aerial may be of any oval shape which is symmetrical about two axes at right angles, herein termed the major and minor axes.
I claim:
1. A horn aerial comprising:
a metallic conical horn having an oval cross-section,
said oval cross-section being symmetrical about its major and minor axes, and
feeding means placed at the apex of said conical horn and oriented relative to said axes to launch electromagnetic waves into the cone with their electric field vector oriented at substantially 45 to said axes.
2. A horn aerial as claimed in claim 1 wherein said feeding means is a rectangular waveguide havings its sides at substantially 45 degrees to said axes.
3. A horn aerial as claimed in claim 2 wherein the aspect ratio of said cone is 3:1.
4. A horn aerial as claimed in claim 1 wherein said horn is made of a controllable deformable metal so that the aspect ratio of its cross section may be empirically adjusted by a controlled deformation.
5. A horn aerial comprising a metallic conical horn having an oval cross-section, said oval cross-section being substantially symmetrical about its major and minor axes, a rectangular wave guide disposed with its sides at substantially a 45 angle with respect to the axes of said cross-section and receiving means for receiving plane polarized electromagnetic waves from said cone through said rectangular wave guide.
6. A horn aerial as claimed in claim 5 and wherein said horn is made of a controllable deformable metal so that the aspect ratio of its cross-section may be empirically adjusted by a controlled deformation.
7. A horn aerial as claimed in claim 5 wherein the said cone is made of tempered copper.
References Cited UNITED STATES PATENTS 2,851,686 9/1958 Hagaman 343786 2,933,731 4/1960 Foster et a1. 343-786 2,206,923 7/ 1940 Southworth 343-783 2,607,849 8/ 1952 Purcell et al. 343-781 2,907,034 9/ 1959 Brown 343-78l ELI LIEBERMAN, Primary Examiner
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB4117/66A GB1179392A (en) | 1966-01-31 | 1966-01-31 | Improvements in or relating to Horn Aerials |
Publications (1)
Publication Number | Publication Date |
---|---|
US3534377A true US3534377A (en) | 1970-10-13 |
Family
ID=9771085
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US611916A Expired - Lifetime US3534377A (en) | 1966-01-31 | 1967-01-26 | Horn aerials |
Country Status (2)
Country | Link |
---|---|
US (1) | US3534377A (en) |
GB (1) | GB1179392A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0023933A1 (en) * | 1979-08-13 | 1981-02-18 | Messerschmitt-Bölkow-Blohm Gesellschaft mit beschränkter Haftung | Antenna system for transmitting circularly or linearly polarized microwaves |
DE2939562A1 (en) * | 1979-09-29 | 1981-04-02 | Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt | ANTENNA EXCITER WITH ELLIPTICAL APERTURE |
DE3009254A1 (en) * | 1980-03-11 | 1981-10-01 | Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt | ANTENNA EXTENSION WITH ELLIPTIC RADIATION DIAGRAM |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE356641B (en) * | 1972-04-24 | 1973-05-28 | Ericsson Telefon Ab L M | |
CN108134204A (en) * | 2017-12-08 | 2018-06-08 | 中国船舶重工集团公司第七二四研究所 | A kind of 90 ° of corrugated horns of elliptic aperture |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2206923A (en) * | 1934-09-12 | 1940-07-09 | American Telephone & Telegraph | Short wave radio system |
US2607849A (en) * | 1943-10-02 | 1952-08-19 | Edward M Purcell | Control of polarization in wave guides and wave guide systems |
US2851686A (en) * | 1956-06-28 | 1958-09-09 | Dev Engineering Corp | Electromagnetic horn antennas |
US2907034A (en) * | 1957-03-28 | 1959-09-29 | Gabriel Co | Wave-guide antenna |
US2933731A (en) * | 1954-12-08 | 1960-04-19 | Cossor Ltd A C | Electromagnetic wave radiators |
-
1966
- 1966-01-31 GB GB4117/66A patent/GB1179392A/en not_active Expired
-
1967
- 1967-01-26 US US611916A patent/US3534377A/en not_active Expired - Lifetime
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2206923A (en) * | 1934-09-12 | 1940-07-09 | American Telephone & Telegraph | Short wave radio system |
US2607849A (en) * | 1943-10-02 | 1952-08-19 | Edward M Purcell | Control of polarization in wave guides and wave guide systems |
US2933731A (en) * | 1954-12-08 | 1960-04-19 | Cossor Ltd A C | Electromagnetic wave radiators |
US2851686A (en) * | 1956-06-28 | 1958-09-09 | Dev Engineering Corp | Electromagnetic horn antennas |
US2907034A (en) * | 1957-03-28 | 1959-09-29 | Gabriel Co | Wave-guide antenna |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0023933A1 (en) * | 1979-08-13 | 1981-02-18 | Messerschmitt-Bölkow-Blohm Gesellschaft mit beschränkter Haftung | Antenna system for transmitting circularly or linearly polarized microwaves |
DE2939562A1 (en) * | 1979-09-29 | 1981-04-02 | Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt | ANTENNA EXCITER WITH ELLIPTICAL APERTURE |
DE3009254A1 (en) * | 1980-03-11 | 1981-10-01 | Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt | ANTENNA EXTENSION WITH ELLIPTIC RADIATION DIAGRAM |
Also Published As
Publication number | Publication date |
---|---|
GB1179392A (en) | 1970-01-28 |
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