Base station antenna arrangement
24 claims: 13 independent, 11 dependent
- 1PATENTKRAV 1 . En antennanordning (10;20;30;40;50;60;70;80;90;100) innefattande ett ledande jordplan (16;26;36;46;102) , ett antal första strålningselement (11,-21,-31,-41,-51,-61,-71^...,719,81A, . . . , 81E;91-l, . . . , 91 13 ) som strålar vid en första frekvens eller i ett första frekvensband och ett antal andra strålningselement (12-15;22-25;32-35;42-45;52-55;62-65;72 1 -75 1 ;82A,83A-82E,83E;92 3 95 x ) som strålar vid en andra frekvens eller i ett andra frekvensband, där till varje första strålningselement en grupp av andra strålningselement är anordnade, kännetecknad därav att de första respektive andra strålningselementen är anordnade i olika plan, där de andra strålningselementen (12-15;22-25;3235;42-45;52-55;62-65;72 1 -75 1 ;82A,83A-82E,83E;92 1 -95 1 ) i en grupp är symmetriskt anordnade, åtminstone parvis, i förhållande till motsvarande första strålningselement (11;21;31;41;51;61;71 x , . . . , 71 9 ;81A, . . . , 81E;91^...,91^) på ett sådant sätt att varje andra strålningselement delvis överlappar motsvarande första strålningselement och att varje strålningselement har åtminstone en effektiv resonansdimension där den effektiva resonansdimensionen för det(de) elementet (elementen) första strålningsär väsentligen två gånger de effektiva resonansdimensionerna för de andra strålningselementen (a 3 Q,*a2o,’13oj2r 4 0,*2rgQ,*a7Q,-agQ) så att de andra strålningselementen strålar vid en frekvens eller i ett frekvensband som är ungefär två gånger den för det(de) första strålningselementet(elementen). 508 356
- 2En anordning enligt patentkrav 1, kännetecknad därav att varje strålningselement innefattar en patch av ledande material.
- 3En anordning enligt patentkrav 1 eller 2, kännetecknad därav att det är ett lager av luft mellan de första och de andra strålningselementen.
- 4En anordning enligt patentkrav 1 eller 2, kännetecknad därav att ett dielektriskt material är anordnat som åtminstone delvis upptar utrymmet mellan lagren av första och andra strålningselement.
- 5En anordning enligt något av föregående patentkrav, kännetecknad därav att mellan jordplanet och det understa lagret av strålningselement ett luftlager är anordnat.
- 6En anordning enligt något av patentkraven 1-4, kännetecknad därav att mellan jordplanet och det understa lagret av strålningselement är ett dielektriskt material (103) anordnat vilket åtminstone delvis upptar utrymmet mellan jordplanet och det understa lagret av strålningselement.
- 7En anordning enligt något av föregående patentkrav, kännetecknad därav 5 Ο 8 3 56 att de första och/eller andra strålningselementen (31,32,33,34,35) består av rektangulära patchar.
- 8En anordning enligt något av patentkraven 1-6, 5 kännetecknad därav att de första och/eller andra strålningselementen (11,12,13,14,15;21,22,23,24,25;51 ;61,62,63,64,65,•71 1 ,72 1 ,73 1 ,74 1 ,75 1 , ... ;81A,82A, 83 A, . . . ;91 x , 92 1 ,93 x , 94 x ) består av kvadratiska patchar.
- 910 9. En anordning enligt något av patentkraven 1-6, kännetecknad därav att de första och/eller andra strålningselementen består av cirkulära patchar (41,42,43,44,45,-52,53,54,55). 15 10. En anordning enligt något av föregående patentkrav, kännetecknad därav att den består av ett första strålningselement och fyra andra strålningselement. 20 11. En anordning enligt något av patentkraven 1-10, kännetecknad därav att ett antal första strålningselement är anordnade, till vardera av vilka det finns fyra motsvarande andra strålningselement och att de är anordnade i ett gruppgitter. 508 356
- 1013. En anordning enligt något av patentkraven 1-10 eller 12, kännetecknad därav att ett antal första strålningselement med motsvarande andra strålningselement (80A,80B,80C,80D,80E) är anordnade i en kolumn således bildande en sektorantenn (80).
- 1114. En anordning enligt något av föregående patentkrav, kännetecknad därav att bara en linjär polarisation användes.
- 1215. En anordning enligt något av patentkraven 1-13, kännetecknad därav att dubbla polarisationer används och att varje strålningselement har två resonanta dimensioner.
- 1316. En anordning enligt patentkrav 14 eller 15, kännetecknad därav att samma polarisation(polarisationer) genereras i båda f rekvensbanden.
- 1417. En anordning enligt patentkrav 14 eller 15, kännetecknad därav att resonanta dimensionerna för de första respektive de andra strålningselementen (A 70 ;a 70 ) bildar en vinkel på ungefärligen 45° med varandra så att polarisationen som genereras i det första respektive det andra frekvensbandet skiljer sig 45°.
- 1518. En anordning enligt något av föregående patentkrav, kännetecknad därav 508 356 att åtminstone en resonant dimension för det första strålningselementet är ungefärligen halva våglängden motsvarande den första frekvensen och att den åtminstone en resonanta dimension för de andra strålningselementen är ungefärligen halva våglängden (λ 2 /2) , svarande mot den andra strålningsfrekvensen. något av d ä r a lager föregående patentkrav, en lägre frekvens strålande elementen . ;91 x , . . . ;104;81A, . . .) är anordnade i ett med andra strålningselement (12,13,14,15 ,-32,33,34,35 ,-42,43,44,45,-52,53,54,55,-62,63,64,65,-72^ 73 x , 74 x , 75 x , 92 1;93 x , 94 lf 95 lz · 105,106,107,108;82A, 83A) . En anordning enligt något av patentkraven 1-18, etecknad därav att de ovanför
- 1621. En anordning enligt något av föregående patentkrav, kännetecknad därav att slitsar (17',18',19';114,115,116,117,118;104,105,106,107, 108,-204,205,-214,215,216) som har resonanta längder av ungefärligen samma storlek som motsvarande resonanta dimensioner är anordnade i jordplanet och att slitsmatning används.
- 1722. En anordning enligt patentkrav 21, kännetecknad därav 508 656 att de andra strålningselementen är anordnade under de första strålningselementen och att matningen åstadkommes av en första 17 1 ;124) och en andra mikrostripledare (18^19^-125,12 6,12 7,128) som exciterar de första och andra strålningselementen genom sagda slitsar så att de avsedda frekvenserna erhålles.
- 1823. En anordning enligt patentkrav 21, kännetecknad därav att för varje strålningselement är en första slits (204,-214) och en andra slits (205,·215A,215B) anordnade i jordplanet, där den första slitsen ger en signal som har en första polarisation och en första frekvens, och den andra ger en signal som har en andra polarisation.
- 1924. En anordning enligt patentkrav 23, kännetecknad därav att de två slitsarna (204,205;214;215A, 215B) för ett strålningselement är anordnade vinkelrätt i förhållande till varandra.
- 2025. En anordning enligt något av patentkraven 1-20, kännetecknad därav att probmatning används.
- 2126. Basstationsantennanordning för mobil telekommunikation innefattande ett antal första antenner (11;21;31;41;51;61;71 T , . . . , 71 9 ;81A, . . . , 81E;91 lr . . . , 91 13 ) avsedda för ett mobiltelekommunikationssystem som arbetar i ett första frekvensband, kännetecknad därav att den dessutom innefattar ett antal andra antenner (12-15,-2225 ;32-35 ;42-45 ;52-55 ;62-65 ;72 1 -75 1 ;82A, 83A-82E, 83E;92 1 -95 1 ) för ett 508 356 32 mobiltelekommunikationssystem som arbetar i ett andra frekvensband som är väsentligen två gånger det första frekvensbandet så att antennerna för de första och de andra systemen använder samma antennapertur, där de första och de andra antennerna består av en antennanordning i vilken gruppvis till ett antal första strålningslement ett antal andra strålningselement är anordnade i ett annat plan så att gruppen av andra strålningselement delvis överlappar motsvarande första strålningselement, där resonansdimensionen för de första strålningselementen är ungefär två gånger den för de andra strålningselementen.
- 2227. Basstationsantennanordning enligt patentkrav 26, kännetecknad därav att frekvenserna i det andra frekvensbandet är omkring 1.6-2.25 gånger frekvenserna i första frekvensbandet.
- 2328. Basstationsantennanordning enligt patentkrav 26 eller 27, kännetecknad därav att antennerna är sektorantenner (80) eller multilob-gruppantenner (60,-70;90).
- 2429. Basstationsantennanordning enligt något av patentkraven 26-28, kännetecknad därav att det första systemet arbetar i frekvensbandet 800-900 MHz, såsom exempelvis NMT 900, AMPS, TACS, GSM eller PDC och att det andra systemet arbetar i frekvensbandet ungefärligen 1800-1900 MHz såsom t ex DCS 1800 eller PCS 1900. 508 356 1/11 FE. 1A FE 1B 22 23 FE 2A FE. 2B 508 356 2/11
Independent claims24
130 paragraphs in 9 sections, as filed
(54) (56) (57)
INVENTOR
REPRESENTATIVE TITLE
Anders Derneryd, Hisings Backa SE, Martin Johansson, Mölndal SE, Zvonimir Sipus, Gothenburg SE
Cegumark AB
Antenna Installations
CALLED PUBLICATIONS: - - SUMMARY:
The present invention relates to an antenna device (10) comprising a plurality of first radiation elements (11) radiating in a first frequency band and a plurality of second radiating elements (12, 13, 14, 15) radiating in a second frequency band. The first and second radiation elements are arranged in different planes. The second radiation elements (12, 13, 14, 15) are arranged relative to the first radiation elements (11) in such a way that each second radiation element partially overlaps with the corresponding first radiation element. Each radiation element has at least one resonant dimension (A<sub>10</sub>, -ai<sub>0</sub>) and the resonant dimension (A<sub>lo</sub>) for the first radiation element (11) is approximately twice the resonant dimension (a,<sub>0</sub>) for the second radiation elements and the second radiation elements radiate at a frequency or in a frequency band approximately twice that of the first radiation element (s).
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The numbers in brackets indicate international identification code, INID code. Letters in clamps indicate international document code.
508 356
FIELD OF THE INVENTION
The present invention relates to an antenna device comprising a number of radiation elements of which some beams at a first frequency or in a first frequency band and some beams at a second frequency or in a second frequency band so that one and the same antenna device can be used for different frequencies or frequency bands.
The invention also relates to a base station antenna device which can be used for a first and a second frequency band so that one and the same base station antenna device can be used for different mobile communication systems operating in different frequency bands.
BACKGROUND OF THE ART
The mobile telecommunications field is growing rapidly in a large number of countries and new markets and further countries are constantly introducing cellular communication systems. In addition, new services and applications are continuously being introduced to the rapidly expanding mobile telecommunications in every respect.
<td>market.</td><td>The</td><td>is</td><td>well</td>
<td colspan="2">frequency</td><td>on</td><td>ca</td>
<td>TACS, GSM</td><td>and</td><td>PDC</td><td>has</td>
among other things has led to the knowledge that a number of systems operating in
900 MHz, for example NMT 900, (D) -AMPS, has become very successful. This has systems operating in other frequency bands needed.
Therefore, new systems have been designed for the frequency bands around 1800 MHz and 1900 MHz.
Examples are DCS 1800 and PCS
508 356
1900. There are of course also a number of other systems in
900 The MHz band (and so on) as well as at 1800 or 1900
MHz and the like that have not been explicitly mentioned here. With the latest developments in mind, it is also obvious that even more systems will be developed.
However, a large number of base station antenna installations have been necessary for the operation of cellular mobile communication systems. Base station antenna devices must be provided throughout the area to be covered by the cellular communication system and how they are arranged depends, among other things, on the quality required and the geographical coverage, distribution of mobile devices, etc. Since radio propagation depends very much on terrain and irregularities in the landscape and cities, the base station antenna devices must be arranged more or less tightly.
However, the installation of base station antennas has given rise to protests, including from an aesthetic point of view, both in the country and in the cities. Already the installations of masts with antennas for, for example, the 900 MHz frequency band have given rise to a lot of discussions and protests. The installation of additional base station antenna devices for another frequency band would cause even more resistance and in some cases it would certainly cause inconvenience not only from the aesthetic point of view. In addition, the design of antenna devices is expensive.
The introduction of new base station antenna devices would be greatly facilitated if the infrastructure already in place, for example for the 900 MHz frequency band, could be used. Because both systems operating in the lower as well as the higher
508 In addition, the frequency band will be used in parallel, it would be very attractive if the antennas for the different frequency bands could coexist on the same master and especially use (share) the same antenna aperture. Today, several examples of microstrip antenna elements that are capable of operating in two different frequency bands are known. One way to achieve this is to put patches on top of each other. This works satisfactorily if the different frequency bands are close to each other, for example up to a ratio of about 1.5: 1. However, this concept does not work when the frequency bands are less close to each other. An example of this is a layered double frequency patch element comprising a ground plane on which, for example, a circular or rectangular low frequency patch is arranged and on top of which a high frequency patch of a similar shape is arranged. Again, another structure, as shown, for example, in the Dual band circularly polarized microstrip array element by A. Abdel Aziz et al, School of El. Engineering and Science The Royal Military College of Science, Shrivenham, England, is a large low frequency patch element arranged in which a number of windows (four windows) are arranged. In these windows smaller patch elements are provided. The windows do not significantly interfere with the properties of the larger patch element. By this arrangement it is possible to use one and the same antenna device for two different frequency bands which are however separated by a factor of four. This is a frequency band separation that is far too high to be used for the, today, relevant mobile communication systems operating at around 900 MHz and 1800 (1900-1950) MHz.
Yet another prior art utilizes the frequency selective nature of periodic structures. It has been shown that when one
508 5 5 6 low frequency patch elements are printed as a mask conductor or as a perforated screen, it can be placed on top of another group antenna operating at a higher frequency, for example, compare Superimposed dichroic microstrip antenna arrays by JR James et al, IEE 5 Proceedings, Vol. 135, Pt. H, No. 5, Oct. 1988. This works satisfactorily for double-band operation where the bands are even more separated than in the previous case and thus with quotas exceeding 6: 1. In addition, US-A-5,001,493 discloses a multiple tuned focal plane group grid antenna which provides simultaneous beams of multiple frequencies. A metallization pattern gives a first set of second sets of first separately at the conductive sides and a first length and a conductive sides having a second length. The and the second set of conductive sides are fed to give first and second simultaneously transmitted rays first and second are also not possible here at about two operating frequencies. However, as the mobile communication systems, it has a frequency band separation which is thus useful for those referred to as beams above.
at an intermediate second frequency which is 2.3 times a first frequency and the third radiation elements radiate at a high frequency which is about 1.1 the second frequency.
Thus, as shown in said document, the antenna device is not applicable to the mobile communication systems referred to above or generally when the frequency band separation is about a factor of two.
In group antennas, the element periodicity is between about 0.5 and wavelength in the free space. The smaller distance is used in scanned group antennas. The number of radiation elements in the 1800 / 1900MHz band will be twice as many as in the 900 MHz band
0 8 ό5 6 if the same surface is used.
This means that the high frequency antenna will have between 3 and 6 dB higher gain than the low frequency antenna.
This partially removes the increased road losses at higher frequencies, causing the coverage areas to be approximately the same for the two bands.
Diversity antenna configurations are used today to reduce fading effects. Reception diversity in the base station is achieved with two antennas that are separated a few meters apart. Today, mainly vertically polarized transmitter antennas and reception antennas are used. Polarization diversity is another way to reduce fading effects.
DISCLOSURE OF THE INVENTION
What is needed, therefore, is an antenna device that can be used for a frequency band separation of about a factor of two, or more particularly, an antenna radiation element which can be used for a first and a second frequency, the frequencies differing by approximately a factor of two. In particular, what is needed is an antenna device and a base station antenna device that can be used for two frequency bands with a separation factor of between about 1.6 - 2.25.
What is thus particularly needed is an antenna device or, in particular, a base station antenna device that can be used for cellular mobile telecommunication systems operating in the 900 MHz band such as NMT 900, (D) -AMPS, TACS, GSM, PDC, etc. and another mobile communication system operating in the frequency band of about 1800 or 1900 MHz such as, for example, DCS 1800, PCS 1900, etc.
508 356
In particular, a device is needed by which either vertically / horizontally polarized antennas or antennas polarized at ± 45 ° can be provided.
Thus, what is needed is an antenna device or a base station antenna device where the same master can be used for two different systems operating in two different frequency bands that differ by about a factor of two, in particular the masts or infrastructure already in place can be used for both types of systems and also for future systems working in one or the other of the two frequency bands.
In particular, a dual, or a multi-frequency antenna device is needed to support different polarization states.
In particular, sector antenna devices and multilob group antenna devices are also needed, which at least combine to operate at at least two different frequency bands that differ from one another.
Therefore, an antenna device comprising a conductive ground plane is provided, at least a number of first radiation elements radiating at the first frequency and a number of second radiation elements radiating at a second frequency, with at least one group of second radiating elements being provided. The at least first and second radiation elements are arranged in different planes.
The second radiation elements in a group are advantageously symmetrically arranged in relation to the corresponding first radiation element in such a way that each second radiation element partially overlaps with the corresponding first radiation element.
Each radiation element, ie first as well as
508 356 second radiation elements, has at least one effective resonance dimension and the effective resonance dimension of the first radiation element is substantially twice the effective resonance dimension of the second radiation elements such that the second radiation elements radiate at a frequency or in a frequency band which is approximately twice that first radiation element radiates.
Advantageously, each radiation element comprises a patch made of conductive material. According to various embodiments, an air layer is provided between the layers of the first and second radiation elements and / or between the ground plane and the lowest layer of radiation elements. As an alternative to air, dielectric layers can be used. Such a dielectric layer may be arranged between the respective layers of radiation elements and it may also be arranged between the lowest layer of radiation elements and the ground plane. For example, the ground plane may consist of a Cu layer. Advantageously, at least one resonant dimension for the first radiation element is substantially half of the wavelength corresponding to a first frequency and at least one resonant dimension for a second radiation element is approximately half the wavelength corresponding to the second radiation frequency.
The first radiation elements are fed to radiate at the lower frequency (or in the lower the second radiant elements are fed to radiate at the higher frequency). Both options are possible.
In addition, according to various embodiments, the radiation elements may comprise rectangular patches, square
508 356 patches or circular patches. In general, both the first and second radiation elements in an antenna device have the same shape, but it is also possible, for example, that a first radiation element is square or rectangular while the second radiation elements are circular or vice versa. However, rectangular patches are preferred if only one linear polarization is used, although the invention is not limited thereto. On the other hand, rectangular patches are not used for double polarization cases.
For rectangular patches, it is sufficient that a dimension is effectively resonant, for example the length of the rectangle. Of course, if square radiating elements are used, the side of the patch is resonant and if circular patches are used, it is the diameter that forms the resonant dimension. Advantageously, square patches or circular patches are used for dual polarization applications. In particular, reference is made to linear polarization. However, as is known per se, it is possible to combine two linear polarizations into one or two orthogonal circular polarizations. In another alternative embodiment, the resonance dimensions of the radiation elements of the first and second elements are rotated differently relative to the embodiments described above. This is applicable to single as well as dual polarizations. In yet another embodiment, the first and second radiation elements are differently rotated relative to each other so that the polarization of the first and second elements, respectively, does not coincide. This form can also be applied to single as well as double polarization cases.
508 356
In one embodiment, the antenna device comprises a first radiation element and four second radiation elements, thus forming a single double frequency patch antenna element.
However, in an alternative embodiment, a number of first radiation elements are provided to which the corresponding second radiation elements are arranged in groups to form a group grid. In one group, any of the elements described above can be used.
In one embodiment, the elements are arranged in rows and columns in such a way that the resonant dimensions are parallel / orthogonal to the rows / columns. In another embodiment, the elements are rotated to form an angle of approximately 45 ° to the rows / columns in which they are arranged.
In yet another embodiment, two second radiation elements are provided for each first radiation element, the second radiation elements being arranged opposite to each other and partially overlapping the first element. This is particularly advantageous for sector antennas which include a column of such elements.
In particular, the device comprises a double frequency, double polarized antenna or even more particularly a multi frequency, multi polarized antenna.
The feeding of the radiation elements can be accomplished in a number of different ways. According to one embodiment, so-called slot feeding is applied. This is particularly advantageous when low-frequency radiation elements are arranged above high-frequency (smaller) radiation elements. The other radiation elements
508 356 is then slotted from below through slots arranged in relation to the corresponding radiation elements in the ground plane. By this embodiment, manufacturing costs and potential passive intermodulation (PIM) sources are reduced. Of course, the first radiation element is also supplied via a slot arranged centrally in relation thereto in the ground plane. The feed as such is provided by a first and a second microstrip conductor which excites the radiation elements through respective apertures without any physical contact. In an alternative embodiment, so-called probe feed is used. If the high frequency radiation elements are arranged above the low frequency radiation elements, the probes (here) supply the other radiation elements eccentrically.
A base station antenna device is also indicated which comprises at least a number of first antennas for a first mobile telecommunication system operating in a first frequency band and a number of second antennas for a second mobile communication system operating in a second frequency band approximately twice the first frequency band and where the antennas for the first and second systems coexist on one and the same mast. The antenna elements or radiation elements are of the kind described above. Advantageously, the separation ratio between the frequency bands is about 1.6 - 2.25: 1. According to various embodiments, the antennas are sector antennas or multiple-lob group antennas.
It is an advantage of the invention that the existing infrastructure that already exists for the 900 MHz frequency band can also be used for new frequency bands that are around 1800 MHz or 1900 MHz. It is also an advantage of the invention that the antenna elements or radiation elements are simple and flexible
0 8,356 and enables a simple feed, etc. A particular advantage is that the same type of radiation element can be used for both frequencies, where only the size given by the resonance dimensions differs. It is also an advantage that dual polarization states can be supported.
However, it is also an advantage that not only dual-tuned, dual-polarized antenna devices can be provided, but also multiple-tuned devices; ie with more than two frequencies. Then, for example, another layer of radiation elements may be arranged above the top layer in a similar manner. For example, if four second radiation elements are arranged above a first radiation element, sixteen third radiation elements may be arranged over the second radiation elements radiating in a third frequency band at a frequency of about twice the second frequency.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in a non-limiting manner with reference to the accompanying figures in which:
Figure 1 is a top view of a dual tuned antenna device comprising square shaped patches;
Figure 1B is a schematic cross-sectional view of the antenna device of Figure 1A along lines 1B-1B;
Figure 2A is a top view of an alternate dual-tuned antenna device comprising square shaped patches;
508 356
Figure 2B
Figure 3A is a schematic cross-sectional view of the antenna device of Figure 2A along lines 2B-2B, is a top view of a double-tuned antenna device with rectangular patches;
<td>Figure</td><td>3B</td><td>is a cross-sectional view of lines 3B-3B,</td>
<td>Figure</td><td>4A</td><td>is a top view of tuned antenna device</td>
<td>Figure</td><td>4B</td><td>is a cross-sectional view of lines 4B-4B,</td>
the device of Figure 3A along yet another double-barred patch is circular, the device of Figure 4A along
Figure 5 is yet another example of an antenna device in which the first and second radiation elements have different shapes;
Figure 6 is an example of a dual-tuned / double-polar group antenna.
Figure 7 is another example of a group antenna where the resonance dimensions of the first and second radiation elements form an angle of 45 ° with each other;
Figure 8 is yet another embodiment of an antenna array.
508 356
Figure 9 illustrates schematically an example of slot feeding of, for example, the radiation elements of Figure 1A;
Figure 10 shows a schematic probe feed of the radiation elements of Figure 2A;
Figure 11 is a cross-sectional perspective view illustrating slot feeding of a device as illustrated in Figure
1A,
Figure 12 is a top plan view of the ground plane including feed slots for a single polarized case, and
Figure 13 is an example of a sector antenna device,
Figure 14A is an example of a slot according to an embodiment of a double polarization, and
Figure 14B is another example of a slot for a dual-polarized device.
DETAILED DESCRIPTION OF THE INVENTION
Figure 1 shows a first example of a microstrip antenna device 10 operating (receiving / transmitting) at two different frequencies or in two different frequency bands. In Figure 1A, which is a top view of the antenna device 10, a first radiation element 11 is arranged at the top. The first radiating element 11 is here square. Under the first radiation element, four second radiation elements 12, 13, 14, 15 are provided. Of course, the other radiation elements need not be arranged in a centralized manner under the corners of the first
508 356 the radiation element. They may also be more tightly arranged (or vice versa) in one or both directions. This also applies to the exemplary embodiments which will be described below with reference, for example, to Figures 3A, 4A, 5, etc. The first and second radiation elements, respectively, consist of so-called patch elements. A patch element is a patch of a conductive material, for example Cu. The second radiation elements 12, 13, 14, 15 are arranged symmetrically in relation to the first radiation element and partially overlap the first radiation element 11. The distance between the center of two second radiation elements is approximately 0.5-1 times the wavelength in free space corresponding to the frequency of the second radiation elements. . For example, the distance may correspond to 0.8 x wavelength. For example, between the first radiation element 11 and the group of second radiation elements 12, 13, 14, 15 may be an air layer. Alternatively, a dielectric layer may be provided between the first and second radiation elements, respectively. If there is air between the first and second radiation elements, plastic pins or the like may be provided as spacers (not shown in the figure). Under the other radiation elements, a conductive layer 16 is provided. This is illustrated in a simplified way in Figure 1B which is a cross section along lines 1B-1B of Figure 1A. According to one embodiment, an air layer is arranged between the other radiation elements and the conductive layer 16. Alternatively, a dielectric layer is arranged between the other radiation elements 12, 13, 14, 15 and the conductive layer 16. The first and second radiation elements, respectively, are energized (excited) or fed separately to re-radiate the energy or to simultaneously emit rays at a first, lower, frequency and a second, higher, frequency. The first and second frequencies differ by a factor of
508 356 is approximately 1.6-2.25 or it is approximately a factor of two between the first and second operating frequencies so that a first patch element or radiation element 11 can be used for a communication system operating in the frequency band of about 800-900 MHz while the second radiation elements 12, 13, 14, 15 can be used for a communication system operating in the frequency band of about 1800-1900 MHz. The first and second radiation elements have a first and a second effective resonance dimension, respectively. For the first radiation element 11, the effective resonant dimension of side A is given<sub>10</sub> on the square shaped element. Similarly, the effective resonance dimensions of the other radiation elements 12, 13, 14, 15 are given by the side a<sub>10</sub> on the equally square shaped other radiation elements. The resonant dimensions A<sub>10</sub> and a<sub>10</sub> is about half the wavelength of the relevant first and second frequencies, respectively. If air is used, the resonant dimensions are given (here, for example, A<sub>10</sub>, a<sub>10</sub>) of
A-10 - λχ / 2 also <sup>A</sup>io λ<sub>2</sub>/ 2 where λ<sub>1(</sub> λ<sub>2</sub> are the wavelengths in air. However, if a dielectric material is disposed between the first and second radiation elements and the soil layer, the dimension can be made smaller and depends on the effective dielectric constant of the dielectric material, i.e.
508 356 where £<sub>r</sub> is the relative dielectric constant; corresponding to a<sub>10</sub>. Feeding may be provided in any suitable manner which will be further discussed below. According to one embodiment, so-called slot feed is used. In other embodiments, probe feed is used or alternatively, electromagnetic energy can be coupled through resonators.
In an advantageous embodiment, the lower second radiation elements are slotted, i.e., the high frequency patches are slotted from below. Also, the first radiation element is fed from below. As a result, manufacturing costs can be reduced and, in addition, potential passive intermodulation (PIM) sources can be reduced.
Figure 2A illustrates an alternative dual-tuned antenna device 20. In Figure 2B, a simplified cross-sectional view along lines 2B-2B of Figure 2A is illustrated.
Also in this case, square patches are used for both the first and the second radiation elements. However, in this case, the second radiation elements 22, 23, 24, 25 are arranged above the first radiation element 21. Thus, the high frequency radiation elements are arranged above the lower frequency radiation element in contrast to the exemplary embodiments illustrated with reference to Figures 1A and 1B. Also in this case, either a dielectric layer can be arranged between the first radiation element 21 and the conductive ground plane 26 or alternatively air is present therebetween. Similarly, a dielectric layer may be provided between the first and second radiation elements or alternatively air may be present therebetween as well. Also in this case, the resonant dimensions are given by the sides A<sub>20 </sub>and a<sub>20</sub> on the square shaped patches forming the first 21
503 356 and the other 22, 23, 24, 25 radiation elements, respectively. Here, too, different measurement techniques can be used, although it is less advantageous to use slot feeding here compared to the embodiment examples described with reference to Figure 1A.
In Figure 3A, another dual frequency antenna device 30 is shown. In this case, the first radiation element 31 is arranged at the top, i.e. the element radiating at the lower frequency. The shape of the first radiation element 31 is rectangular and the effective resonant dimension L<sub>30</sub> is given by the length of the rectangle. As in the embodiments described above, the second radiation elements 32, 33, 34, 35 have the same shape as the first radiation element 31 and are arranged in a symmetrical and partially overlapping manner. The other radiation elements, which radiate at a higher frequency, are here also rectangularly shaped (although this is not necessarily the case; they may also take other or different shapes) and they have an effective resonant dimension 1.<sub>30</sub> which is the length of the respective rectangles. Figure 3B illustrates a simplified cross-section along lines 3B-3B of Figure 3A and also, similar to the embodiments described above, a dielectric or air may be provided between the conductive ground layer 36 and the second radiation elements and between the first and second radiation elements, respectively. Here too, the effective resonant dimensions L correspond<sub>30</sub> and l<sub>30 </sub>substantially half the wavelength corresponding to the desired frequencies which, as referred to above, differs by approximately a factor of 2 so that the device 30 can be used for the communication systems discussed above. Rectangular patches are particularly advantageous if only a linear polarization is used. In principle, square shaped patches (or at least symmetrical patches) are particularly advantageous for dual polarization applications in which two dimensions are resonant and thus have given dimensions. For single polarization cases, one dimension is not resonant. The non-resonant dimension can then determine the lobe width of the non-resonant dimension plane.
However, it should be noted that of course, the embodiment as described with reference to Figure 3A may be arranged differently so that the second, or the radiating elements at the higher frequency, are arranged on top of the first, at the lower frequency, the radiating elements.
Figure 4A illustrates yet another dual frequency antenna device 40. A simplified cross-sectional view along lines 4B-4B is schematically illustrated in Figure 4B. In this device, the first and second radiation elements, respectively, consist of circular patches. The first radiation element 41 is arranged above the second radiation elements 42, 43, 44, 45 which are arranged centrally with respect to the first radiation element and in a partially overlapping manner.
Here again, air or dielectric material (at least partially covering the space between the elements) is provided between the ground plane 46 and the second radiation elements and / or between the second radiation elements and the first radiation element 41.
The resonance dimensions are given here by the diameters of the radiation elements. The resonance dimension of the first radiation element 41 is given by the diameter (twice the radius) of the circular patch, where the radius is here designated R<sub>40</sub>,
R<sub>40</sub> = 1.841λ<sub>1</sub>/ 2π<sup>Λ</sup>/ ε<sub>Γ</sub> «0.29λ<sub>1</sub>/ Ι / ε<sub>Γ</sub>.
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Similarly, the resonance dimensions of the other radiation elements are given by corresponding diameters 2xr<sub>40</sub> for respective other radiation elements. In other respects, the same as discussed above applies with reference to the square-shaped embodiments. Of course, the first radiation element may be arranged below the second or the radiating elements at the higher frequency. Like square patches, circular patches are particularly advantageous for dual polarization applications, although they can of course be used even if only a linear polarization is used.
Figure 5 shows yet another example of a dual frequency antenna device 50. Here, the first and second radiation elements have different shapes. In this, the first radiation element 51 is arranged at the top and consists of a square shaped patch, the resonance dimension A<sub>50</sub> is given by the side of the square. The second radiation elements 52, 53, 54, 55 are circular and symmetrically arranged with respect to the first radiation element 51 in a partially overlapping manner. For the other radiation elements, the resonance dimensions of the diameters, i.e. twice the radii, are given.<sub>50</sub>. Of course, the first radiation element could have been arranged under the second radiation elements. Also in this case, air and / or dielectric is arranged between the first and second radiation elements and between the lower radiation elements and the conductive ground plane (not shown in the figure).
The discussions referring to Figure 1A which relate to the relationship between the operating frequencies and thus the resonance dimensions, of course, also apply to the embodiments.
508 356 in Figures 2A, 3A, 4A, 5 as well as for the figures that will follow.
Figure 6 illustrates an antenna device 60 in the form of a group grid. The antenna device 61 comprises (here) first radiation elements 60<sub>x</sub>, 60<sub>2</sub>, . . . , 60<sub>3O</sub> which are regularly arranged in a rectangular grid structure. For each first radiation element 60<sub>LZ</sub> 60<sub>2</sub>, ..., four other radiation elements 62, 63, 64, 65 are arranged in a manner similar to that of the device as described in Figure 1A. The first radiation elements are arranged at the top here as well as Figure 1A and the discussion concerning Figure 1A is also relevant here. In particular, the device 60 consists of a double-tuned, double-polarized device, since the radiation elements are regular and comprise two resonant dimensions, i.e. the sides of the square. Of course, a group grid can be formed by any means, for example, triangular, circular, elliptical, etc., including any of the antenna devices 10, 20, 30, 40, 50 or any variation thereof with respect to any kind of radiation elements disposed at the top. etc. and how they are twisted. For the dual-tuned, dual-polarized antenna device 60, a common ground plane is used which, however, is not shown here and the feed can be provided in an appropriate manner as discussed above. Of course, the number of radiation elements can be any suitable number. In one embodiment, the distance between other radiation elements is the same within a group as between adjacent other elements in adjacent groups, both horizontally and vertically. In an advantageous embodiment, the distance between other radiation elements is between about 0.5-1λ. Especially is
0 as little as possible, for example about 0.5λ to provide high scanning angle performance for the group, ie to avoid
508 356 grid lobes. In another embodiment, the distance is not exactly the same in the vertical direction as in the horizontal direction but, for example, slightly smaller in the horizontal direction.
Figure 7 illustrates another antenna device in the form of a group grid 70 comprising (in this particular case) nine dual frequency antenna elements 70<sub>1</sub>,...,70<sub>9</sub>. Also in this case, the first radiation elements are 71<sub>1</sub>,71<sub>2</sub>, . . , 71<sub>9</sub> arranged above the corresponding second radiation elements 72 ^ 73 ^ 74- ^ 75 ^ ..., for the sake of clarity only the second radiation elements of the first dual frequency antenna 70<sub>x</sub> are provided with reference numbers. Of course, the second radiation elements could have been arranged on top of the first radiation elements instead; any variation is possible as in the preceding discussed examples. The first and second radiation elements are also in this case square, both the first and the second second radiation elements. In addition, the other radiation elements are 72<sub>LZ</sub>73<sub>LZ</sub>74<sub>LZ</sub>75<sub>LZ</sub> ... , also arranged symmetrically in relation to the first radiation elements 71<sub>LZ</sub>...,71<sub>9</sub> with the difference that the respective resonant dimensions Δ<sub>70</sub> and a<sub>70</sub> forming an angle of about 45 ° with each other. The radiation elements are symmetrical and each radiation element has, as described above, two resonant dimensions, ie the sides of the squares. However, the resonance dimensions of the first and second radiation elements respectively form an angle of 45 ° with each other.
Figure 8 shows an alternative embodiment of a group 90 comprising a plurality of dual frequency antenna elements 90<sub>LZ</sub>...,90<sub>13</sub> which are polarized in +/- 45 °. The first radiation elements
508 356
91<sub>x</sub>,...,91<sub>13</sub> are arranged above the corresponding second radiation element 92<sub>x</sub>, 93<sub>x</sub>, 94<sub>x</sub>, 95<sub>x</sub>; . . . , but in an alternative embodiment (not shown), the first radiation elements are arranged below the second radiation elements. The polarization of the first and second radiation elements is similar in the first and second frequency bands, respectively. Antennas polarized at ± 45 ° have been found to be advantageous because (for dual polarization cases) the propagation properties of the same electromagnetic waves for the two polarizations and a similar attenuation (which is substantially the same for both polarizations) are obtained as compared to the case in which the vertical and horizontal polarization is used.
Figure 9 is a simplified cross-sectional view similar to that of Figure 1B, the radiation device is here designated 10 '. This is an example of slot feeding. In the ground plane 16 ', a number of slots are provided for each first and second radiation elements. In Figure 9, the slot corresponding to the first radiation element 11 'is shown, but only two of the slots corresponding to the second radiation elements are shown; slot 18 'corresponding to the second radiation element 12' and slot 19 'corresponding to the second radiation element 13'. Of course, there are also slots for the other radiation elements. Via microstrip conductor 17<sub>1</sub>,18<sub>1</sub>,19<sub>1</sub> however, the first radiation element 11 'and the second radiation elements 12', 13 'are excited through the slots, however, without any physical contact with the microstrip conductors. The slots have substantially the same length as the resonance dimensions of the corresponding radiation elements and are arranged perpendicular to the resonant length.
Figure 10 is a cross-sectional view similar to Figure 2B showing an antenna device 20 '(corresponding antenna device 20 in Figure 2B)
508 356 which is fed by probe feeding which as such is a feeding method known per se. Via probes 27 ', 28', 29 ', the first radiation element 21' and the second radiation elements 22 'and 23' are supplied via coaxial conductors (for example). Here, too, the other radiation elements are fed in a similar manner.
In Figure 11, a cross-sectional view is illustrated in perspective of an antenna device 100. The antenna device comprises a first radiation element 104 and four second radiation elements 105, 106, 107, 108, the first radiation element 104 being disposed above the second radiation elements. Of course it could also be a group grid but this is not shown here for reasons of clarity. A ground plane 102, for example of Cu, is provided on a dielectric substrate 103. On top of the conductive ground plane 102 is a dielectric layer 103. In an alternative embodiment, there could have been air, in which case the distance between the other radiation elements and the ground plane could have been achieved by using plastic pins or the like. For reasons of clarity, no dielectric layer is shown between the first and second radiation elements, although such a layer is normally present (which at least covers part of the space). Here, too, it can alternatively take the form of an air bearing. In the conductive ground plane 102 a number of feed slots 114,115,116,117,118 are provided. The sizes of the feed slots relate to the sizes of the radiation elements and are essentially the same. Microstrip conductors 124,125,126,127,128 feed the first and second radiation elements. The feed is provided by the microstrip conductors 124,125,126,127,128 which laterally cross the slots in a perpendicular manner without any physical contact. If there is only one slot for each radiation element, a single polarized beam is obtained. Two examples of slots for
508 356 double polarization cases are shown very schematically in Figures 14A and 14B.
Figure 12 shows the conductive ground plane 102 in which the slots are arranged more clearly. The slots 104,105,106,107,108 correspond to the first and second radiation elements, respectively.
The microstrip conductor 124 is disposed beneath the ground plane 102 and intersects the slot 104 in a perpendicular manner as described above and the microstrip conductors 125,126,127,128 pass under the slits 105,106,107,108 in a similar manner.
Figure 13 schematically illustrates an example of a sector antenna 80 in accordance with the invention. The sector antenna consists of a column with a number of first radiation elements 81A, ..., 81E, where for each first radiation element two second radiation elements
82A, 83A; ...; 82E, 83E are provided. The other radiation elements are all arranged along a common vertical center line.
In alternative embodiments of sector antennas (not shown), a column of elements, for example as described with reference to any of Figures 1A - Figure 5 or any variant thereof, some type of rotation, etc., may be used, i.e. with two or four other radiation elements for each first radiation element.
For double polarization cases, the slots in the ground plane may take a shape as illustrated in Figures 14A and 14B, respectively. In Figure 14A, two slots 204, 205 intersect in a perpendicular manner. They are fed by microstrip conductors 224 and 225, respectively.
In Figure 14B, one of the slots can be said to be divided into two slots 215A, 215B arranged in a perpendicular manner on either side
508 356 about the slot 214. Slots as described in Figures 14A, 14B are then arranged in the ground plane corresponding to each radiation element, the sizes of which depend on the size of the respective radiation elements.
There is a feeding microstrip conductor for each polarization. The first microstrip conductor 234 crosses perpendicular to the central slot 214 and a first and a second branch microstrip 235A, 235B cross the slots 215A and 215B, respectively. The branches are interconnected to form a common second microstrip conductor which produces a second polarization. The ground plane 236 is only schematically indicated.
The invention is only limited to the exemplary embodiments, but it can be varied in a number of ways as shown and is the scope of the claims.
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Contents9
13 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5 Sheet 6 Sheet 7 Sheet 8 Sheet 9 Sheet 10 Sheet 11 Sheet 12 Sheet 13
13 members in 9 offices
Priority claims2
| Document | Office | Kind | Date |
|---|---|---|---|
| 9700630 | Sweden | A | |
| SE19970000630 | – | – | – |
Members13
| Document | Office | Kind | |
|---|---|---|---|
| SE9700630D0 | Sweden | D0 | |
| SE9700630L | Sweden | L | |
| CA2282599A1 | Canada | A1 | |
| WO9837592A1 | World Intellectual Property Organization (WIPO) | A1 | |
| AU6126998A | Australia | A | |
| SE508356C2This record | Sweden | C2 | |
| EP0962033A1 | European Patent Office (EPO) | A1 | |
| CN1248348A | China | A | |
| US6091365A | United States of America | A | |
| JP2001512640A | Japan | A | |
| EP0962033B1 | European Patent Office (EPO) | B1 | |
| DE69837530D1 | Germany | D1 | |
| DE69837530T2 | Germany | T2 |
1 legal event, as the office reported them to INPADOC
Events
| Event | Code | |
|---|---|---|
| Patent has lapsedLapsedNUG | NUG |
Numbers
- Publication, DOCDB
- 508356
- Publication, EPODOC
- SE508356
- Application
- 9700630
- Application, DOCDB
- 9700630
- Application, EPODOC
- SE19970000630
Titles2
- Swedish
- Antennanordningar
- English
- Antenna Installations
Classification
- CPC, 4
- H01Q21/24
- H01Q1/246
- H01Q9/0457
- H01Q5/42
- IPC, 6
- H01Q21 30
- H01Q1 24
- H01Q5 00
- H01Q9 04
- H01Q13 08
- H01Q21 24
