CA2057659A1 - Ring-type antenna, with reduced center working frequency, and vehicle equipped with at least one such antenna - Google Patents
Ring-type antenna, with reduced center working frequency, and vehicle equipped with at least one such antennaInfo
- Publication number
- CA2057659A1 CA2057659A1 CA 2057659 CA2057659A CA2057659A1 CA 2057659 A1 CA2057659 A1 CA 2057659A1 CA 2057659 CA2057659 CA 2057659 CA 2057659 A CA2057659 A CA 2057659A CA 2057659 A1 CA2057659 A1 CA 2057659A1
- Authority
- CA
- Canada
- Prior art keywords
- ring
- antenna
- ground plane
- mode
- working frequency
- 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.)
- Abandoned
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/27—Adaptation for use in or on movable bodies
- H01Q1/32—Adaptation for use in or on road or rail vehicles
- H01Q1/325—Adaptation for use in or on road or rail vehicles characterised by the location of the antenna on the vehicle
- H01Q1/3275—Adaptation for use in or on road or rail vehicles characterised by the location of the antenna on the vehicle mounted on a horizontal surface of the vehicle, e.g. on roof, hood, trunk
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
- H01Q9/04—Resonant antennas
- H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
- H01Q9/0464—Annular ring patch
Landscapes
- Engineering & Computer Science (AREA)
- Remote Sensing (AREA)
- Waveguide Aerials (AREA)
- Details Of Aerials (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
The disclosure relates to ring-type antennas, namely antennas comprising a ground plane, a conductive flat ring parallel to the ground plane and a dielectric layer separating the ring from the ground plane. These antennas work in a standard way in TM02 or TM11 mode.
The antenna is designed to work with a configuration of the electromagnetic field between the ring and the ground plane according to the TM01 mode but with a working frequency that is reduced as compared with a standard working frequency. For this purpose, the conditions of propagation of the waves between the ring and the ground plane are modified by the introduction of a short-circuit plane between one of the rims, namely the internal or the external rim, of the ring and the ground plane. The center working frequency is thus reduced by a ratio of 3 to 4 as compared with standard working in TM02 mode. The disclosed device can be applied to antennas for radio- communications made, for example, from aircraft.
The disclosure relates to ring-type antennas, namely antennas comprising a ground plane, a conductive flat ring parallel to the ground plane and a dielectric layer separating the ring from the ground plane. These antennas work in a standard way in TM02 or TM11 mode.
The antenna is designed to work with a configuration of the electromagnetic field between the ring and the ground plane according to the TM01 mode but with a working frequency that is reduced as compared with a standard working frequency. For this purpose, the conditions of propagation of the waves between the ring and the ground plane are modified by the introduction of a short-circuit plane between one of the rims, namely the internal or the external rim, of the ring and the ground plane. The center working frequency is thus reduced by a ratio of 3 to 4 as compared with standard working in TM02 mode. The disclosed device can be applied to antennas for radio- communications made, for example, from aircraft.
Description
~ j7~
RING-TYPE ANTENNA, WITH REDUCED CENTER WORKING
FREQUENCY, AND VEHIC~E EQUIPPED WITH
AT LEAST ONE SUCH ANTENNA
BACKGROUND OF THE INVENTION
The present invention relates to ring-type antennas, namely antennas comprising a conductive, flat ring and a ground plane that are positioned in parallel and separated by a layer of dielectric. The invention also relates to vehicles fitted out with such antennas.
Ring-type antennas are known. These antennas are generally excited to work in the TM11 or TM02 modes, but are not excited to work in TM01 mode for their center working frequency, which is already relatively high in TMll and TM02 mode, would be even higher in TM01 mode.
SUMMARY O~ THE INVENTION
The aim of the present invention is to make it possible to reduce their center working frequency.
This is obtained by modifying the conditions of propagation of the waves in the space between the ring and the ground plane, and by seeking to excite the TM01 mode. With adequate modifications, it then proves to be the case that the excitation frequency of the TM01 mode becomes lower than that of the oher modes and, especially, lower than that of the TM02 and TM11 modes.
According to the present invention, there is provided a ring-type antenna comprising a ground plane and a conductive flat ring that are posi~ioned in : . . . .
rl! ~ r~ ~
parallel, and a dielectric layer separating the ring from the ground plane, the ring having an internal circular rim and an external circular rim, and the antenna having working frequencies and being designed to work in TMO1 mode, with a reduced cen~er working frequency and comprising, for this purpose, short-circuit means forming an electromagnetic screen for the working requencies of the antenna, this screen connecting one of the circular rims of the ring to the ground plane.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention shall be understood more clearly and other characteristics shall appear from the following description, and from the figures relating thereto, of which:
- figures 1 and 2 show an antenna according to the invention;
- figure 3 is a graph relating to the an~enna according to the invention and to antennas according to the prior art.
MORE DETAILED DESCRIPTION
Figures 1 and 2 respectively show a sectional view and a top view of an antenna according to the invention. The plane of the section along figure 1 has been identified in figure 2 by a axial line touched by the ends of two arrows AA that indicate which one of the two planes resulting from the section is seen in figure 1.
, '~ ~3 ~
In figure 1, the respective dimensions of the different elements have not been maintained so as to make the drawing clearer and the inventlon easier to understand.
The antenna according to figures 1 and 2 is a ring-typP antenna, with a ground plane 1, a conductive flat ring 3, parallel to the ground plane, and a dielectric layer 2, interposed ~etween the ring and the ground plane. The internal radius Ri and external radii Re of the circles that respectively demarcate the internal and external rims of the ring 3 have been indi.cated in figure 1.
In the example described, the ground plane 1 is constituted by the external wall of a vehicle and, more precisely, that of an aircraft.
A feeder line, constituted by a coaxial cable 5, comes from the interior of the vehicle and crosses the ground plane 1, with which it is in contact by its external conductor. The internal conductor 50 of the coaxial cable 5 goes through the dielectric layer 2 and goes towards the ring 3 to which it i5 soldered.
The antenna of figures 1 and 2 further includes a short-circuit plane 4 which connects the external rim, with a radius Ri, of the ring to the ground plane. This short-circuit plane, which is therefore annular, is constituted by ten conductive links 40 to 49 which go through the dielectric layer 3 by means of evenly distributed holes. These holes are at a distance from , ,~ . ' ' ~;. ~ , . .
-- 2~7~3~
one another that is smaller t~lan one-twen~ieth o~ the wavelength o~ the center working frequency of the antenna. The addition of the short-circuit plane 4, by modifying the conditions in which the electromagnetic ~ield is set up in the space between the ring 3 and the ground plane 1, ma~es it possible to obtain the excitation o the TM01 mode. Without the short-circuit plane 4, only the TM02 mode could be excited and this would happen at a substantially higher frequency as is shown in figure 3.
The e~arnple described corresponds to a ring-type antenna, made according to printed circuit technology, wherei.n:
- the radii Ri and Re are respectively equal to 15 and 50 mm;
- the resonance frequency of the oscillation mode giving a hemispherical radiation is substantially equal -to 0.5 GHz and the mode in question is the TM01 mode.
With a ring--type antenna made with the same constituent elements and the same dimensions, but having no short-circuit plane 4, the resonance frequency of the oscillation mode giving a hemispherical radiation is substantially 1.85 GHz and the mode in question is the TM02 mode. It must be noted that, with a standard disk antenna obtained through the simple replacement of the ring, in the antenna having ~o short-circuit plane, by a disk without any hole, 7 ~ i ~
i.e. a disk with an internal radius Ri equal to zero, the hemispherical radiation is obtained with the TM02 mode at a resonance frequency of 1.70 GHz.
Figure 3 is a graph which shows, as a function of the external radius Ra of the ring or of the disk without a hole, the resonance frequency F of the mode giving a hemispherical radiation for three types of antenna:
- curve ~: for a ring-type antenna in TM01 mode, by means of a short-circuit plane ~ curve B: for a ring-type antenna in TM02 mode, without short-circuit plane;
- curve C: for a disk antenna in TM02 mode.
The comparison of the curves shows that, fox one and the same external radius Re of the ring or disk, the short-circuit plane makes it possible to obtain a hemispherical radiation for a frequency that is approximately three to four times lower with a ring-type antenna having short-circuit plane than with a disk antenna or a ring-type antenna having no short-circuit plane.
The invention is not limited to the example described. Thus the short-circuit plane, instead of being set up at the internal rim of the ring, may ~e set up at the external rim. To obtain the same working frequency as with an antenna having a short-circuit plane at the internal rim of the ring, the external . . . , . . ... `.
.: . . .. . .
- . ~ ~ ,, : :
. . :
- , ,, .~ .
- . . . .. .
RING-TYPE ANTENNA, WITH REDUCED CENTER WORKING
FREQUENCY, AND VEHIC~E EQUIPPED WITH
AT LEAST ONE SUCH ANTENNA
BACKGROUND OF THE INVENTION
The present invention relates to ring-type antennas, namely antennas comprising a conductive, flat ring and a ground plane that are positioned in parallel and separated by a layer of dielectric. The invention also relates to vehicles fitted out with such antennas.
Ring-type antennas are known. These antennas are generally excited to work in the TM11 or TM02 modes, but are not excited to work in TM01 mode for their center working frequency, which is already relatively high in TMll and TM02 mode, would be even higher in TM01 mode.
SUMMARY O~ THE INVENTION
The aim of the present invention is to make it possible to reduce their center working frequency.
This is obtained by modifying the conditions of propagation of the waves in the space between the ring and the ground plane, and by seeking to excite the TM01 mode. With adequate modifications, it then proves to be the case that the excitation frequency of the TM01 mode becomes lower than that of the oher modes and, especially, lower than that of the TM02 and TM11 modes.
According to the present invention, there is provided a ring-type antenna comprising a ground plane and a conductive flat ring that are posi~ioned in : . . . .
rl! ~ r~ ~
parallel, and a dielectric layer separating the ring from the ground plane, the ring having an internal circular rim and an external circular rim, and the antenna having working frequencies and being designed to work in TMO1 mode, with a reduced cen~er working frequency and comprising, for this purpose, short-circuit means forming an electromagnetic screen for the working requencies of the antenna, this screen connecting one of the circular rims of the ring to the ground plane.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention shall be understood more clearly and other characteristics shall appear from the following description, and from the figures relating thereto, of which:
- figures 1 and 2 show an antenna according to the invention;
- figure 3 is a graph relating to the an~enna according to the invention and to antennas according to the prior art.
MORE DETAILED DESCRIPTION
Figures 1 and 2 respectively show a sectional view and a top view of an antenna according to the invention. The plane of the section along figure 1 has been identified in figure 2 by a axial line touched by the ends of two arrows AA that indicate which one of the two planes resulting from the section is seen in figure 1.
, '~ ~3 ~
In figure 1, the respective dimensions of the different elements have not been maintained so as to make the drawing clearer and the inventlon easier to understand.
The antenna according to figures 1 and 2 is a ring-typP antenna, with a ground plane 1, a conductive flat ring 3, parallel to the ground plane, and a dielectric layer 2, interposed ~etween the ring and the ground plane. The internal radius Ri and external radii Re of the circles that respectively demarcate the internal and external rims of the ring 3 have been indi.cated in figure 1.
In the example described, the ground plane 1 is constituted by the external wall of a vehicle and, more precisely, that of an aircraft.
A feeder line, constituted by a coaxial cable 5, comes from the interior of the vehicle and crosses the ground plane 1, with which it is in contact by its external conductor. The internal conductor 50 of the coaxial cable 5 goes through the dielectric layer 2 and goes towards the ring 3 to which it i5 soldered.
The antenna of figures 1 and 2 further includes a short-circuit plane 4 which connects the external rim, with a radius Ri, of the ring to the ground plane. This short-circuit plane, which is therefore annular, is constituted by ten conductive links 40 to 49 which go through the dielectric layer 3 by means of evenly distributed holes. These holes are at a distance from , ,~ . ' ' ~;. ~ , . .
-- 2~7~3~
one another that is smaller t~lan one-twen~ieth o~ the wavelength o~ the center working frequency of the antenna. The addition of the short-circuit plane 4, by modifying the conditions in which the electromagnetic ~ield is set up in the space between the ring 3 and the ground plane 1, ma~es it possible to obtain the excitation o the TM01 mode. Without the short-circuit plane 4, only the TM02 mode could be excited and this would happen at a substantially higher frequency as is shown in figure 3.
The e~arnple described corresponds to a ring-type antenna, made according to printed circuit technology, wherei.n:
- the radii Ri and Re are respectively equal to 15 and 50 mm;
- the resonance frequency of the oscillation mode giving a hemispherical radiation is substantially equal -to 0.5 GHz and the mode in question is the TM01 mode.
With a ring--type antenna made with the same constituent elements and the same dimensions, but having no short-circuit plane 4, the resonance frequency of the oscillation mode giving a hemispherical radiation is substantially 1.85 GHz and the mode in question is the TM02 mode. It must be noted that, with a standard disk antenna obtained through the simple replacement of the ring, in the antenna having ~o short-circuit plane, by a disk without any hole, 7 ~ i ~
i.e. a disk with an internal radius Ri equal to zero, the hemispherical radiation is obtained with the TM02 mode at a resonance frequency of 1.70 GHz.
Figure 3 is a graph which shows, as a function of the external radius Ra of the ring or of the disk without a hole, the resonance frequency F of the mode giving a hemispherical radiation for three types of antenna:
- curve ~: for a ring-type antenna in TM01 mode, by means of a short-circuit plane ~ curve B: for a ring-type antenna in TM02 mode, without short-circuit plane;
- curve C: for a disk antenna in TM02 mode.
The comparison of the curves shows that, fox one and the same external radius Re of the ring or disk, the short-circuit plane makes it possible to obtain a hemispherical radiation for a frequency that is approximately three to four times lower with a ring-type antenna having short-circuit plane than with a disk antenna or a ring-type antenna having no short-circuit plane.
The invention is not limited to the example described. Thus the short-circuit plane, instead of being set up at the internal rim of the ring, may ~e set up at the external rim. To obtain the same working frequency as with an antenna having a short-circuit plane at the internal rim of the ring, the external . . . , . . ... `.
.: . . .. . .
- . ~ ~ ,, : :
. . :
- , ,, .~ .
- . . . .. .
2 ~ ~ ~ 6 ~ ~
radius o the ring should be substantially gr~ater. But such an antenna may he useful in certain cases.
It is also possible to make the antenna otherwise than by the technology of printed circuits, for example by the bonding or soldering of the differen-t elements constituting the antenna. In this case, the short-circuit plane could be an annular element, soldered by one side to the ground plane and, by the other side, to the internal or external edge of the ring; and it must be no-ted that, unlike in the case of structures made by printed circuit technology, where the dielectric layer may extend on either side of the short-circuit plane 4, preferably, in order to facilitate the manufacture oE the antenna, the dielectric layer should not extend beyond the under part of the ring, a~ least on the short-circuit plane side.
The antenna accord.ing to the invention can be applied in particular to all vehicles equipped with radio-communications devices necessitating one or more antennas, the radiation pattern of which is that of a vertical dipole placed before a horizontal plane reflector.
.:. .
~ .
radius o the ring should be substantially gr~ater. But such an antenna may he useful in certain cases.
It is also possible to make the antenna otherwise than by the technology of printed circuits, for example by the bonding or soldering of the differen-t elements constituting the antenna. In this case, the short-circuit plane could be an annular element, soldered by one side to the ground plane and, by the other side, to the internal or external edge of the ring; and it must be no-ted that, unlike in the case of structures made by printed circuit technology, where the dielectric layer may extend on either side of the short-circuit plane 4, preferably, in order to facilitate the manufacture oE the antenna, the dielectric layer should not extend beyond the under part of the ring, a~ least on the short-circuit plane side.
The antenna accord.ing to the invention can be applied in particular to all vehicles equipped with radio-communications devices necessitating one or more antennas, the radiation pattern of which is that of a vertical dipole placed before a horizontal plane reflector.
.:. .
~ .
Claims (4)
1. A ring-type antenna comprising a ground plane and a conductive flat ring that are positioned in parallel, and a dielectric layer separating the ring from the ground plane, the ring having an internal circular rim and an external circular rim, and the antenna having working frequencies and being designed to work in TMO1 mode, with a reduced center working frequency and comprising, for this purpose, short-circuit means forming an electromagnetic screen for the working frequencies of the antenna, this screen connecting one of the circular rims of the ring to the ground plane.
2. An antenna according to claim 1, made according to the technology of printed circuits.
3. An antenna according to claim 2, wherein the dielectric layer overlaps the ground plane on a surface located within the circumference constituted by a projection of the internal rim of the ring on the ground plane.
4. An antenna according to claim 1, designed for a vehicle having an external wall and wherein the ground plane is constituted by the external wall of the vehicle.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9015684A FR2670611B1 (en) | 1990-12-14 | 1990-12-14 | RING TYPE ANTENNA WITH REDUCED CENTRAL FREQUENCY AND VEHICLE EQUIPPED WITH AT LEAST ONE SUCH ANTENNA. |
| FR9015684 | 1990-12-14 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2057659A1 true CA2057659A1 (en) | 1992-06-15 |
Family
ID=9403254
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2057659 Abandoned CA2057659A1 (en) | 1990-12-14 | 1991-12-13 | Ring-type antenna, with reduced center working frequency, and vehicle equipped with at least one such antenna |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0490760A1 (en) |
| JP (1) | JPH06120724A (en) |
| CA (1) | CA2057659A1 (en) |
| FR (1) | FR2670611B1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11101565B2 (en) | 2018-04-26 | 2021-08-24 | Neptune Technology Group Inc. | Low-profile antenna |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10025130A1 (en) * | 2000-05-20 | 2001-11-22 | Volkswagen Ag | Car aerial integrated in car body component |
| US20040021606A1 (en) * | 2002-07-11 | 2004-02-05 | Alps Electric Co., Ltd. | Small plane antenna and composite antenna using the same |
| US8994594B1 (en) | 2013-03-15 | 2015-03-31 | Neptune Technology Group, Inc. | Ring dipole antenna |
| JP6421769B2 (en) * | 2016-02-26 | 2018-11-14 | 株式会社Ｓｏｋｅｎ | Antenna device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4821040A (en) * | 1986-12-23 | 1989-04-11 | Ball Corporation | Circular microstrip vehicular rf antenna |
-
1990
- 1990-12-14 FR FR9015684A patent/FR2670611B1/en not_active Expired - Fee Related
-
1991
- 1991-12-10 EP EP91403346A patent/EP0490760A1/en not_active Withdrawn
- 1991-12-12 JP JP32906291A patent/JPH06120724A/en active Pending
- 1991-12-13 CA CA 2057659 patent/CA2057659A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11101565B2 (en) | 2018-04-26 | 2021-08-24 | Neptune Technology Group Inc. | Low-profile antenna |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2670611B1 (en) | 1993-07-30 |
| JPH06120724A (en) | 1994-04-28 |
| EP0490760A1 (en) | 1992-06-17 |
| FR2670611A1 (en) | 1992-06-19 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |