CA1190639A - Antenna for an omnidirectional range - Google Patents
Antenna for an omnidirectional rangeInfo
- Publication number
- CA1190639A CA1190639A CA000407761A CA407761A CA1190639A CA 1190639 A CA1190639 A CA 1190639A CA 000407761 A CA000407761 A CA 000407761A CA 407761 A CA407761 A CA 407761A CA 1190639 A CA1190639 A CA 1190639A
- Authority
- CA
- Canada
- Prior art keywords
- slot
- antenna
- radiating elements
- slots
- antennas
- 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
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q21/00—Antenna arrays or systems
- H01Q21/28—Combinations of substantially independent non-interacting antenna units or systems
-
- 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
- H01Q13/10—Resonant slot antennas
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q21/00—Antenna arrays or systems
- H01Q21/24—Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction
- H01Q21/26—Turnstile or like antennas comprising arrangements of three or more elongated elements disposed radially and symmetrically in a horizontal plane about a common centre
Landscapes
- Variable-Direction Aerials And Aerial Arrays (AREA)
- Waveguide Aerials (AREA)
Abstract
Abstract The omnirange antenna consists of two crossed slot antennas (50) and two horizontal Alford loops (51, 54) arranged, respectively, above and below the slot an-tennas. Interposed between the slot antenna (50) and the Alford loops (51, 54) are horizontal metal sheets (52, 53). All radiating elements and the metal sheets are supported by a tube (7) which is connected with a counterpoise (55) and disposed around the axis of symmetry of the antenna. The slot antennas are fed so that a rotating figure-8 pattern is produced.
The antenna is suitable for a VOR (VOR = VNF omni-directional range).
The antenna is suitable for a VOR (VOR = VNF omni-directional range).
Description
H~Wurth-G.Greving 2-1 Antenna for an Omnidirectional Range 8ackground of the Invention The present invent;on relates to an antenna for an omni-directional range. An antenna of this kind is disclosed in German Patent 19 o2 884.
Omnidirectional ranges, such as the well-known VOR ~VOR =
VHF omnidirectional range, described in a book by E.
Kramar, "Funksysteme fur Ortung und Navigation", Verlag Berliner Union GmbH~ Stuttgart, 1973, pages 131 139), transmit a direction-dependent signal which is interpreted by a suitable airborne receiver to determine the azimuth of the aircraft. In the ~OR, the direction-dependent sig-nal is produced by rotating a lima,con-shaped radiation pattern formed by superimposing a figure 8 radiation pattern on a circular pat-tern.
To generate the rotating figure-8 pattern, two orthogonal antennas each having a figure~8 radiation pattern may be fed throu9ha goniometer, as described in the book by E.Kramar~
In such omn;directional ranges, the vertically polarized radiation components should be as small as possible for signal interpretation reasons. If the antenna disclosed in German Patent 1~ 02 884 is used in a VOR, a polariz-ation cage must be used to compensate for the vertical components.
Object The object of the invention is to provide an an-tenna for an omnidirectional range in which the vertical com-~ ~3063~
ponents of -the radiated signals are as small as possible.
This object is attained by antenna for an omnidirectional range comprising several radiating elements at least one of which has a circular radiation pattern in the horizontal plane, and at least two of which have a figure-8 radiation pattern in the horizontal plane, characterized in that the radiating elements with the figure-8 radiation patterns are slot antennas formed by a slot ln a conducting surface, with the distance between one end of the slot and the edge of the conducting surface in the longitudinal direction of the slot being consider-ably greater than the distance between the slot and the edge of the conducting surface in the transverse direction of the slot~ and that the two slot antennas are arranged to intersect at right angles, with the longitudinal axes of the slots lying on a straight line.
In a prefexred embodiment, to permit adjustment to the frequency of the signals to be radiated, the conducting surface of a slot antenna, designed as a sheet metal surface, is provid-ed with additional, small slots in the regions of the two ends of a slot which lead into another slot and whose electrical lengths are determined by the positions of short-circuiting bridges in the small slots.
~dditional radiating elements with circular radiating patterns may be provided above and below the slots of the two slot antennas and horizontal conducting surfaces may be provided between the slots of the two slot antennas and upper and lower radiating elements.
~9C~63~
Advantages achieved by the invention are the very small size oE the vertical components in the radiated signals, the relatively small size (about + 30) of the cone of silence -i.e., the angular region, directly over the omnidirectional range, in which the signals received by -the aircraf-t must not be interpreted and the avoidance of the need for a polarization cage.
Preferred embodiments of the invention will now be explained in more detail with reference to the accompanying drawings, in which:
Figure 1 sho~s a slot antenna;
Figure 2 shows idealized radiation patterns of a slot antenna in the horizontal and vertical directions;
Figure 3 shows two mutually perpendicular slot antennas;
Figure 4 shows a slot antenna with inductive end loads and a supporting tube, and Figure 5 shows a cross section through the antenna in the plane of a slot radiator.
Figure 1 shows an individual slot antenna. It consists of a slot 2 oE length L and width b in a metal sheet 1 of length H and width C. The longitudinal axis of the slot lies on the longitudinal axis of symmetry of the metal - 2a -~g~63~
H.W~irth-G.Greving 2-1 sheet. The distances of the slot from the edge of the metal sheet in the longitudinal and transverse directions are designated l and ~, respectively. Such a slot antenna is shown in a book by Meinke/Gundlach, "Taschenbuch der Hochfrequen~technik", Springer-Verlag, Berlin, 1968, page 608.
If the slot antenna is perpendicular to the earth's sur-face, its radiation pattern in the hori~ontal plane is a figure-8 pattern (Fig.2a). Its idealized radiation pattern in the vertical plane has the shape shown in Fig~2b.
To produce a figure-8 radiation pattern in thehorizontal plane, a first slot antenna is combined with a second slot antenna in such a way that the two antennas inter-sect at right angles and give a configuration symmetrical with respect -to their longitudinal axes (in the top view, an equal-armed cross is obtained).
The length of the slots is approximately equal to half the wavelength at the operating frequency. To permit fine adjustment to the frequency to be transmitted, ad-ditional, small slots 8, 81, 82, 83 are formed in the metal sheet 6 near the ends of the slot 12 (Fig.4)(the tube 7 must be thought of as being not present for the time being). In the embodiment, each of these small slocs has the shape of a "~" whose legs run parallel to the lonyitudinal axis of the slot 12. One leg of each of these small slots then runs perpendicular to the longitudinal axis of the slot 1~ and into the latter. The small slots 8, 81, 82, 83 are inductive end loads whose values are adjustable by means of short-circuiting bridges 41~ 42, 43, 44, which can be inserted into -the U-shaped slots.
~ 4 --~063~
H.Wurth-G.Greving 2-1 This permits the slot antenna to be adjusted to the trans-mitter frequency in a manner familiar to those skilled in the art.
The slot antennas are fed via a coaxial cable 11. The conductors of the coaxial cabLe are connected to the long sides of the slot 12 through a balun 40. A phase difference of 180 exists between the two points of connection. The representation in Fig.4 is only schematic.
If the two sLot antennas 3 and ~ (Fig.3) are fed w;th the signals U3 = UO.cos~t . cos Q t and Ul = U .sin~t . cos Q t, t O
respectively, where Q J2~ is equal to the frequency of the carrier wave of the signal to be radiated, a figure-8 pattern will be produced which rotates at the angular velocity ~ .
A small cone of silence will be obtained in an advantage-ous manner if the dimensions of a slot antenna meet the following requirements:
- The clistance l between the slot and the edge of the metal sheet in the longitudinal direction must be greater than or equal to a fi-fth of the wavelength at the operating frequency, and - the distance l must be considerably greater tnan the distance B.
In a pratical example, the following dimensions were chosen:
_ 5 63~
H.W~irth-G.Greving 2-1 C = 0.36 m L = 1.31 m b = 0.04 m B = 0.16 m l = 0.6 m H = 2.51 m To generate the circular radiation pattern required in VOR in addition to the rotating figure-8 pattern, Alford loops are provided above and below the slots of the two slot antennas.
Fig.5 shows a schematic cross section through the complete antenna in the plane of a slot antenna 50. The two Alford loops 51, 5~, are so disposed with respect to the crossed slot antennas that the slot antennas and the two Alford loops have approximatively a common phase centre. The common phase centre need not necessarily coincide with the geometric centre or the feed point of the antenna.
The common phase centre is a prerequisite for agreement between the elevation phase diagrams of the radiating elements 3, 4, 51, 54.
The vertical patterns of the crossed slot antennas are disturbed by the azimuthally asymmetrical structure of the Alford loops.To eliminate this disturbance, circular conducting surfaces, e.g., metal sheets 52, 53, are ad-vantageously provided in horizontal planes between the Alford loops 51, 54, and the slots of -the slot antennas.
The slot aneennas couple with the circular metal sheets more closely than with the Alford loops; hence, the circular metal sheets have a balancing field effect on the slot antennas. In this manner, good congruence of the vertical patterns is obtained. If the width of a metal sheet of a .Wl;rth-G.Greving 2-1 slot antenna is C = 0.36 m (Fig.1),the diameter of a circular sheet will be chosen to be o.74 m. This will aLso be the diameter of an Alford loop.
To improve the supression of the disturbing vertical components particuLarly at high elevation angles, the metal sheets 6 of the slot antennas are widened from the width C to the width D above and below the conducting metal sheets 52, 53. The width D is approximately equal to the diameter of the metal sheets 52, 53.
The Alford loops 51, 5~t, the circular metaL sheets 5~, 53, and the slot antennas are supported by a tube 7 connected with a circular counterpoise 55~ The diameter of the counterpoise is 6 m~ By suitable choice of the height of the antenna above the counterpoise and of the counter-poise above the earth's surface, the congruence of amplitude and phase response in the elevation direction can be optinized.
The tube is located around the axis of symmetry oF the crossed slot antennas and the Alford loops and, i~ its diameter is sufficien-tly small, has no appreciable in~
fluence on the radiation patterns.
In this case, the effective slot width b is composed of the widths of the openings ~5, ~,6 between the tube 7, which has the diameter d, and the metal sheet 6. Each of these openinys is b/2 wide~ The slot of width b is thus formed by two effective partial slots each of which is b/2 wide. The width of the slot radiator shown schematical-ly in Fig 1 then becomes C = B+b2-~d+b2+B = 2s+b+d. If the dimensions of L, B, b, l and ~ are t~ose giJen on page 7, and d = o 15 m, then C = 0.51 m.
3~
il.Wurth-G.Greving 2-1 The feeders for the slot antennas and the Alford loops are led through the tube 7~
Omnidirectional ranges, such as the well-known VOR ~VOR =
VHF omnidirectional range, described in a book by E.
Kramar, "Funksysteme fur Ortung und Navigation", Verlag Berliner Union GmbH~ Stuttgart, 1973, pages 131 139), transmit a direction-dependent signal which is interpreted by a suitable airborne receiver to determine the azimuth of the aircraft. In the ~OR, the direction-dependent sig-nal is produced by rotating a lima,con-shaped radiation pattern formed by superimposing a figure 8 radiation pattern on a circular pat-tern.
To generate the rotating figure-8 pattern, two orthogonal antennas each having a figure~8 radiation pattern may be fed throu9ha goniometer, as described in the book by E.Kramar~
In such omn;directional ranges, the vertically polarized radiation components should be as small as possible for signal interpretation reasons. If the antenna disclosed in German Patent 1~ 02 884 is used in a VOR, a polariz-ation cage must be used to compensate for the vertical components.
Object The object of the invention is to provide an an-tenna for an omnidirectional range in which the vertical com-~ ~3063~
ponents of -the radiated signals are as small as possible.
This object is attained by antenna for an omnidirectional range comprising several radiating elements at least one of which has a circular radiation pattern in the horizontal plane, and at least two of which have a figure-8 radiation pattern in the horizontal plane, characterized in that the radiating elements with the figure-8 radiation patterns are slot antennas formed by a slot ln a conducting surface, with the distance between one end of the slot and the edge of the conducting surface in the longitudinal direction of the slot being consider-ably greater than the distance between the slot and the edge of the conducting surface in the transverse direction of the slot~ and that the two slot antennas are arranged to intersect at right angles, with the longitudinal axes of the slots lying on a straight line.
In a prefexred embodiment, to permit adjustment to the frequency of the signals to be radiated, the conducting surface of a slot antenna, designed as a sheet metal surface, is provid-ed with additional, small slots in the regions of the two ends of a slot which lead into another slot and whose electrical lengths are determined by the positions of short-circuiting bridges in the small slots.
~dditional radiating elements with circular radiating patterns may be provided above and below the slots of the two slot antennas and horizontal conducting surfaces may be provided between the slots of the two slot antennas and upper and lower radiating elements.
~9C~63~
Advantages achieved by the invention are the very small size oE the vertical components in the radiated signals, the relatively small size (about + 30) of the cone of silence -i.e., the angular region, directly over the omnidirectional range, in which the signals received by -the aircraf-t must not be interpreted and the avoidance of the need for a polarization cage.
Preferred embodiments of the invention will now be explained in more detail with reference to the accompanying drawings, in which:
Figure 1 sho~s a slot antenna;
Figure 2 shows idealized radiation patterns of a slot antenna in the horizontal and vertical directions;
Figure 3 shows two mutually perpendicular slot antennas;
Figure 4 shows a slot antenna with inductive end loads and a supporting tube, and Figure 5 shows a cross section through the antenna in the plane of a slot radiator.
Figure 1 shows an individual slot antenna. It consists of a slot 2 oE length L and width b in a metal sheet 1 of length H and width C. The longitudinal axis of the slot lies on the longitudinal axis of symmetry of the metal - 2a -~g~63~
H.W~irth-G.Greving 2-1 sheet. The distances of the slot from the edge of the metal sheet in the longitudinal and transverse directions are designated l and ~, respectively. Such a slot antenna is shown in a book by Meinke/Gundlach, "Taschenbuch der Hochfrequen~technik", Springer-Verlag, Berlin, 1968, page 608.
If the slot antenna is perpendicular to the earth's sur-face, its radiation pattern in the hori~ontal plane is a figure-8 pattern (Fig.2a). Its idealized radiation pattern in the vertical plane has the shape shown in Fig~2b.
To produce a figure-8 radiation pattern in thehorizontal plane, a first slot antenna is combined with a second slot antenna in such a way that the two antennas inter-sect at right angles and give a configuration symmetrical with respect -to their longitudinal axes (in the top view, an equal-armed cross is obtained).
The length of the slots is approximately equal to half the wavelength at the operating frequency. To permit fine adjustment to the frequency to be transmitted, ad-ditional, small slots 8, 81, 82, 83 are formed in the metal sheet 6 near the ends of the slot 12 (Fig.4)(the tube 7 must be thought of as being not present for the time being). In the embodiment, each of these small slocs has the shape of a "~" whose legs run parallel to the lonyitudinal axis of the slot 12. One leg of each of these small slots then runs perpendicular to the longitudinal axis of the slot 1~ and into the latter. The small slots 8, 81, 82, 83 are inductive end loads whose values are adjustable by means of short-circuiting bridges 41~ 42, 43, 44, which can be inserted into -the U-shaped slots.
~ 4 --~063~
H.Wurth-G.Greving 2-1 This permits the slot antenna to be adjusted to the trans-mitter frequency in a manner familiar to those skilled in the art.
The slot antennas are fed via a coaxial cable 11. The conductors of the coaxial cabLe are connected to the long sides of the slot 12 through a balun 40. A phase difference of 180 exists between the two points of connection. The representation in Fig.4 is only schematic.
If the two sLot antennas 3 and ~ (Fig.3) are fed w;th the signals U3 = UO.cos~t . cos Q t and Ul = U .sin~t . cos Q t, t O
respectively, where Q J2~ is equal to the frequency of the carrier wave of the signal to be radiated, a figure-8 pattern will be produced which rotates at the angular velocity ~ .
A small cone of silence will be obtained in an advantage-ous manner if the dimensions of a slot antenna meet the following requirements:
- The clistance l between the slot and the edge of the metal sheet in the longitudinal direction must be greater than or equal to a fi-fth of the wavelength at the operating frequency, and - the distance l must be considerably greater tnan the distance B.
In a pratical example, the following dimensions were chosen:
_ 5 63~
H.W~irth-G.Greving 2-1 C = 0.36 m L = 1.31 m b = 0.04 m B = 0.16 m l = 0.6 m H = 2.51 m To generate the circular radiation pattern required in VOR in addition to the rotating figure-8 pattern, Alford loops are provided above and below the slots of the two slot antennas.
Fig.5 shows a schematic cross section through the complete antenna in the plane of a slot antenna 50. The two Alford loops 51, 5~, are so disposed with respect to the crossed slot antennas that the slot antennas and the two Alford loops have approximatively a common phase centre. The common phase centre need not necessarily coincide with the geometric centre or the feed point of the antenna.
The common phase centre is a prerequisite for agreement between the elevation phase diagrams of the radiating elements 3, 4, 51, 54.
The vertical patterns of the crossed slot antennas are disturbed by the azimuthally asymmetrical structure of the Alford loops.To eliminate this disturbance, circular conducting surfaces, e.g., metal sheets 52, 53, are ad-vantageously provided in horizontal planes between the Alford loops 51, 54, and the slots of -the slot antennas.
The slot aneennas couple with the circular metal sheets more closely than with the Alford loops; hence, the circular metal sheets have a balancing field effect on the slot antennas. In this manner, good congruence of the vertical patterns is obtained. If the width of a metal sheet of a .Wl;rth-G.Greving 2-1 slot antenna is C = 0.36 m (Fig.1),the diameter of a circular sheet will be chosen to be o.74 m. This will aLso be the diameter of an Alford loop.
To improve the supression of the disturbing vertical components particuLarly at high elevation angles, the metal sheets 6 of the slot antennas are widened from the width C to the width D above and below the conducting metal sheets 52, 53. The width D is approximately equal to the diameter of the metal sheets 52, 53.
The Alford loops 51, 5~t, the circular metaL sheets 5~, 53, and the slot antennas are supported by a tube 7 connected with a circular counterpoise 55~ The diameter of the counterpoise is 6 m~ By suitable choice of the height of the antenna above the counterpoise and of the counter-poise above the earth's surface, the congruence of amplitude and phase response in the elevation direction can be optinized.
The tube is located around the axis of symmetry oF the crossed slot antennas and the Alford loops and, i~ its diameter is sufficien-tly small, has no appreciable in~
fluence on the radiation patterns.
In this case, the effective slot width b is composed of the widths of the openings ~5, ~,6 between the tube 7, which has the diameter d, and the metal sheet 6. Each of these openinys is b/2 wide~ The slot of width b is thus formed by two effective partial slots each of which is b/2 wide. The width of the slot radiator shown schematical-ly in Fig 1 then becomes C = B+b2-~d+b2+B = 2s+b+d. If the dimensions of L, B, b, l and ~ are t~ose giJen on page 7, and d = o 15 m, then C = 0.51 m.
3~
il.Wurth-G.Greving 2-1 The feeders for the slot antennas and the Alford loops are led through the tube 7~
Claims (13)
1. Antenna for an omnidirectional range comprising several radiating elements at least one of which has a circular radiation pattern in the horizontal plane, and at least two of which have a figure-8 radiation pattern in the horizontal plane, characterized in that the radiating elements with the figure-8 radiation patterns are slot antennas formed by a slot in a conducting surface, with the distance between one end of the slot and the edge of the conducting surface in the longitudinal direction of the slot being considerably greater than the distance between the slot and the edge of the conducting surface in the transverse direction of the slot, and that the two slot antennas are arranged to intersect at right angles, with the longitudinal axes of the slots lying on a straight line.
2. An antenna as claimed in claim 1, characterized in that, to permit adjustment to the frequency of the signals to be radiated, the conducting surface of a slot antenna, designed as a sheet metal surface, is provided with additional, small slots in the regions of the two ends of a slot which lead into another slot and whose electrical lengths are determined by the positions of short-circuiting bridges in the small slots.
3. An antenna as claimed in claim 1 or 2, characterized in that additional radiating elements with circular radiation patterns are provided above and below the slots of the two slot antennas.
4. An antenna as claimed in claim 1 or 2, characterized in that additional radiating elements with circular radiation patterns are provided above and below the slots of the two slot antennas, horizontal conducting surfaces being provided between the slots of the two slot antennas and upper and lower radiating elements.
5. An antenna as claimed in claim 1 or 2, characterized in that additional radiating elements with circular radiation patterns are provided above and below the slots of the two slot antennas, horizontal conducting surfaces being provided between the slots of the two slot antennas and upper and lower radiating elements, in at least part of the regions between the additional conducting surfaces and the respective ends of the slot antenna, the width of the conducting surface of a slot antenna being approximately equal to the diameter of the additional radiating elements with circular radiation patterns.
6. An antenna as claimed in claim 1, characterized in that a tube having a diameter smaller than the slot width is disposed around the axis of symmetry of the antenna, and that the feeders for the radiating elements run through said tube.
7. An antenna as claimed in claim 1 or 2, characterized in that additional radiating elements with circular radiation patterns are provided above and below the slots of the two slot antennas, horizontal conducting surfaces being provided between the slots of the two slot antennas and upper and low radiating elements, a tube having a diameter smaller than the slot width being disposed around the axis of symmetry of the antenna, and that the feeders for the radiating elements run through said tubs.
8. An antenna as claimed in any one of claims 1 or 2, characterized in that the distance between one end of the slot and the edge of the conducting surface in the longitudinal direction of the slot is greater than or equal to a fifth of the wavelength at the operating frequency.
9. An antenna as claimed in claim 1 or 2, characterized in that additional radiating elements with circular radiation patterns are provided above and below the slots of the two slot antennas, the distance between one end of the slot and the edge of the conducting surface in the longitudinal direction of the slot being greater than or equal to a fifth of the wavelength at the operating frequency.
10. An antenna as claimed in claim 1 or 2, characterized in that additional radiating elements with circular radiation patterns are provided above and below the slots of the two slot antennas, horizontal conducting surfaces being provided between the slots of the two slot antennas and upper and lower radiating elements, the distance between one end of the slot and the edge of the conducting surface in the longitudinal direction of the slot being greater than or equal to a fifth of the wavelength at the operating frequency.
11. An antenna as claimed in claim 1 or 2, characterized in that additional radiating elements with circular radiation patterns are provided above and below the slots of the two slot antennas, horizontal conducting surfaces being provided between the slots of the two slot antennas and upper and lower radiating elements, in at least part of the regions between the additional conducting surfaces and the respective ends of the slot antenna, the width of the conducting surface of a slot antenna being approximately equal to the diameter of the additional radiating elements with circular radiation patterns, the distance between one end of the slot and the edge of the conducting surface in the longitudinal direction of the slot being greater than or equal to a fifth of the wavelength at the operating frequency.
12. An antenna as claimed in claim 6, characterized in that the distance between one end of the slot and the edge of the conducting surface in the longitudinal direction of the slot is greater than or equal to a fifth of the wavelength at the operating frequency.
13. An antenna as claimed in claim 1 or 2, characterized in that additional radiating elements with circular radiation patterns are provided above and below the slots of the two slot antennas, horizontal conducting surfaces being provided between the slots of the two slot antennas and upper and lower radiating elements, a tube having a diameter smaller than the slot width being disposed around the axis of symmetry of the antenna, and that the feeders for the radiating elements run through said tube, the distance between one end of the slot and the edge of the conducting surface in the longitudinal direction of the slot being greater than or equal to a fifth of the wavelength at the operating frequency.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3128952.5 | 1981-07-22 | ||
| DE19813128952 DE3128952A1 (en) | 1981-07-22 | 1981-07-22 | "ANTENNA FOR A TURNAR FIRE" |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1190639A true CA1190639A (en) | 1985-07-16 |
Family
ID=6137479
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000407761A Expired CA1190639A (en) | 1981-07-22 | 1982-07-21 | Antenna for an omnidirectional range |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0070462B1 (en) |
| CA (1) | CA1190639A (en) |
| DE (2) | DE3128952A1 (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2832955A (en) * | 1953-03-24 | 1958-04-29 | Jasik Henry | Antenna system |
| GB1258656A (en) * | 1969-01-22 | 1971-12-30 | ||
| FR2104689B1 (en) * | 1970-07-17 | 1975-01-10 | Thomson Csf | |
| DE2753661A1 (en) * | 1977-12-02 | 1979-06-07 | Philips Patentverwaltung | Notch aerial with two orthogonal excitation elements - formed as recesses and/or frames with one supplied directly and other via phase adjuster |
-
1981
- 1981-07-22 DE DE19813128952 patent/DE3128952A1/en not_active Withdrawn
-
1982
- 1982-07-08 DE DE8282106108T patent/DE3274703D1/en not_active Expired
- 1982-07-08 EP EP82106108A patent/EP0070462B1/en not_active Expired
- 1982-07-21 CA CA000407761A patent/CA1190639A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE3274703D1 (en) | 1987-01-22 |
| EP0070462A3 (en) | 1984-03-28 |
| EP0070462B1 (en) | 1986-12-10 |
| EP0070462A2 (en) | 1983-01-26 |
| DE3128952A1 (en) | 1983-02-10 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEC | Expiry (correction) | ||
| MKEX | Expiry |