EP1493206B1 - Dual band antenna - Google Patents

Abstract

The device has a two periodic linear arrangements of first (14) and second (15,16) individual antennas for two frequency bands. The period of the first arrangement is essentially twice that of the second. The second antennas are arranged alternately between and above the first antennas. The two antennas are patch radiators and each contains a printed plate and several stacked patch plates at intervals in a rectangular conducting open box.

Description

TECHNICAL AREA

The present invention relates to the field of antenna technology. she relates to a dual band antenna for a Base station.

A dual band antenna according to the preamble of claim 1 is known from document US-A-6,239,750.

STATE OF THE ART

The increasing need for data to be transmitted in the field of mobile communications has led in the past for the definition of the UMTS standard (UMTS = U niversal M obile T elecommunication S ystem). Applications based on this standard require a new mobile network. One component of this network are antennas, which, as the UMTS standard assumes new frequency ranges for transmission and reception, must also be redeveloped. The existing mobile networks according to the conventional GSM 900/1800 standard, as well as a large number of other networks according to other standards, will continue to operate in parallel to the newly created UMTS standard for a not yet foreseeable period. In order to realize the fastest possible construction of a UMTS network, network operators have an interest in using existing antenna sites both for the existing networks and to integrate them into the new UMTS network. The development of antennas that cover both the frequency ranges of existing networks and the UMTS frequency ranges enables network operators to reduce or even save time for approval procedures. Furthermore, a higher public acceptance of a single antenna covering all local mobile radio standards can be assumed compared to different individual antennas for each standard.

Dual polarized (dual slant) antennas for base stations consisting of an array of dual polarized individual emitters (individual antennas) have been known for a long time. Likewise, dual polarized broadband antennas are known which consist of a Array composed of the same dual polarized single radiators, which broadband are tuned to frequencies of 1710-2170 MHz, so that the Antenna covers both the GSM 1800 and the UMTS band. A special effective and proven in practice single radiator of this kind is out WO-A1-01 / 76010 of the Applicant known. There are also dual polarized antennas known the GSM 900 and the GSM 1800 or GSM 1800 / UMTS band cover and derive from an array of appropriately tuned dual consist of polarized individual emitters.

In US-B1-6,211,841 is a multi-band antenna for cellular base stations has been proposed in which the frequency bands of GSM-900, GSM-1800 and UMTS by a combination of two arrays with two different ones Single radiators in the form of cross dipoles (low band dipoles, high band dipoles) be covered.

In WO-A2-99 / 59223 a dual-band antenna is disclosed in which a first linear array of patch emitters for the GSM band (860-970 MHz) with a second linear array of cross dipoles for the PCN band (1710-1880 MHz) is combined, wherein the cross dipoles in a first embodiment between the patch radiators and in a second embodiment directly over the Patch radiators are arranged.

In the cited document US-B1-6,239,750 finally becomes a Antenna arrangement proposed for the multi-band operation, in which (Fig. 4) two Linear arrays of two different patch radiators combined are, with the first patch radiators on the frequency band of 1800-1900 MHz and the second patch emitters tuned to the 800-900 MHz frequency band are and the first Patchstrahler alternately between and directly over the second patch radiators are arranged.

On the one hand, the existing antenna sites at the base stations for the previous Bands and the new UMTS band to use equally and, on the other hand, the advantages of the single emitter developed by the Applicant According to WO-A1-01 / 76010, it was desired to use them Single emitter to use in a dual-band antenna.

PRESENTATION OF THE INVENTION

It is therefore an object of the invention to a broadband dual band antenna for both the GSM 900 and the GSM 1800 and UMTS bands is suitable, and based on a single radiator type, as in its kind in WO-A1-01 / 76010 is disclosed.

The object is solved by the entirety of the features of claim 1. The essence of the invention is first and second individual antennas in one to arrange a linear periodic array, the second individual antennas alternately between the first and above the first individual antennas are arranged, and wherein the first and second individual antennas respectively are formed as patch radiators, each one in a rectangular, electrically conductive, upwardly open box arranged printed circuit board and multiple patch panels include, which above the printed circuit board and parallel to the printed circuit board at a distance are arranged one above the other. The special feature of this arrangement is that here not individual patch panels for different frequency bands one above the other and are arranged side by side, but that each of the Patch radiator with its arranged in the box PCB in the array used becomes.

The patch panels of a single antenna are preferably each with each other and to the printed circuit board by means of electrically insulating spacers Distance kept.

A preferred embodiment of the invention is characterized in that in the case of the second individual antennas, in each case three patch plates spaced one above the other are arranged that in the first individual antennas each two patch plates are arranged one above the other at a distance, and that at the first individual antennas in each case instead of a third patch plate, a second individual antenna with its box spaced above the top of the two patch panels. Thus, the second individual antenna is also an integral part of the first at the same time Single antenna over which it is placed.

Preferably, the first and second individual antennas are above one another in the antenna longitudinal direction extending, common base plate arranged. The Base plate may be non-metallic. But the base plate can also be designed as a (metallic) reflector.

In particular, the first individual antennas are for coverage of the frequency range from 806-960 MHz and the second single antennas for the coverage of the Frequency range of 1710-2170 MHz designed.

In the general case, a balanced dual band antenna results when in the Dual band antenna in total N first individual antennas and 2N ± 1 second individual antennas are arranged (N = integer> 0). A proven design results for N = 7.

BRIEF EXPLANATION OF THE FIGURES

Fig. 1

in der Draufsicht von oben eine Dualbandantenne gemäss einem bevorzugten Ausführungsbeispiel der Erfindung mit abgenommener Abdeckhaube;

Fig. 2

den Schnitt durch die zwei benachbarten ersten und zweiten Einzelantennen der Dualbandantenne aus Fig. 1 entlang der Linie A-A in Fig. 1;

Fig. 3

die Oberseite der Printplatte einer ersten Einzelantennen aus Fig. 1 bzw. 2;

Fig. 4

die Unterseite der Printplatte einer ersten Einzelantenne aus Fig. 1 bzw. 2;

Fig. 5

die Oberseite der Printplatte einer zweiten Einzelantennen aus Fig. 1 bzw. 2; und

Fig. 6

die Unterseite der Printplatte einer zweiten Einzelantenne aus Fig. 1 bzw. 2;

The invention will be explained in more detail with reference to embodiments in conjunction with the drawings. Show it

Fig. 1

in top plan view of a dual-band antenna according to a preferred embodiment of the invention with removed cover;

Fig. 2

the section through the two adjacent first and second individual antennas of the dual band antenna of Figure 1 along the line AA in Fig. 1.

Fig. 3

the upper side of the printed circuit board of a first individual antenna from FIGS. 1 and 2;

Fig. 4

the underside of the printed circuit board of a first individual antenna of FIGS. 1 and 2;

Fig. 5

the upper side of the printed circuit board of a second individual antenna from FIGS. 1 and 2; and

Fig. 6

the underside of the printed circuit board of a second individual antenna of FIGS. 1 and 2;

WAYS FOR CARRYING OUT THE INVENTION

In Fig. 1 is a top plan view of a dual-band antenna according to a preferred Embodiment of the invention with removed cover shown. The dual band antenna 10 includes an elongated housing 11 a Linear periodic arrangement (array) of first individual antennas (single beam) 14 and second individual antennas (single radiators) 15 and 16 over one the whole Housing 11 filling, elongated base plate 12. The width of the base plate but can also be reduced to the width of the individual antennas. The base plate 12 can be non-metallic. But it can also be metallic and then as a reflector Act. The arrangement of the individual antennas 14, 15, 16 over a Reflector optimizes the forward / reverse ratio.

The first individual antennas 14 and a part of second individual antennas 15 are in the linear Array arranged alternately. In addition, concentric over the first Single antennas 14, the remaining second individual antennas 16 placed (see also Fig. 2). The distance between the second individual antennas 15, 16 is on this Half the size of the distance between the first individual antennas the minimum size of the second and first individual emitters results from this a distance of 0.78 and 0.87 times the wavelength, respectively, based on the midband frequency - between the first and second individual antennas.

The basic structure of the first and second individual antennas 14, 15 and 16 can best be explained by the cross-sectional view of FIG. 2: The second individual antennas 15 and 16 are largely identical in construction. With you is in a square, upwardly open box 21, 26 of sheet metal respectively parallel to the ground at a distance from the bottom of the box 21, 26 a printed circuit board 22 and 27 arranged, the two-sided Leiterbahn- or conductor surface configuration in Fig. 5 and 6 is shown. Above the printed circuit board 22, 27 are parallel to the printed circuit board 22, 27 at different distances from each other three patch panels 23, 24, 25 and 28, 29, 30, respectively, which are excited by the printed circuit board 22, 27 and couple with the electromagnetic radiation. The second single antennas 15, 16 are for the frequency band 1710-2170 MHz (GSM 1800, UMTS) and adjusted (UMTS spotlight). Their external dimensions and Patchblechabstände are therefore smaller than in the first individual antennas 14. The UMTS radiators 15 and 16 are each in height above the base plate 12th arranged offset (Fig. 2).

The first individual antennas 14, for the frequency band 806-960 MHz (GSM 900 et seq.) (900 MHz emitters) are similar the second individual antennas 15, 16 constructed: With them is in a larger square, upwardly open box 17 of sheet metal in each case parallel to Floor at a distance from the bottom of the box 17 a printed circuit board 18 is arranged, the two-sided conductor or conductor surface configuration in FIGS. 3 and 4 reproduced is. About the printed circuit board 18 are parallel to the printed circuit board 18 in different Distance from each other two patch plates 19 and 20 are provided, the be excited by the printed circuit board 18 and with the electromagnetic radiation couple. Instead of a third patch plate is over the two patch plates 19, 20 arranged at a distance a second individual antenna 16 with its box 21.

The printed circuit boards 18 of the first individual antennas 14 and 22 and 27 of the second individual antennas 16 and 15 have on their upper side according to FIG. 3 or 5 different Conductor tracks 31, 32 and 34, 35 on. On the subpages are respectively Ground surfaces 33 and 36, respectively, in which in a crossed arrangement slit-shaped conductor structures 37, 38 and 39, 40 are formed. The feed the individual antennas 14, 15, 16 can be made by any network.

The individual antennas 14, 15 and 16 shown in FIGS. 1 and 2 have - differently the patch radiator of WO-A1-01 / 76010 - none used to increase the bandwidth Tabs on the four sides of the box 17, 21, 26. The necessary bandwidth is realized by the third (upper) patch plate 25, 30. The box 21 of the UMTS emitter (single antenna 16) on the 900 MHz emitter (single antenna 14) has an effect comparable to a third patch plate, that is, through the UMTS spotlight is also increasing the bandwidth (due to capacitive Coupling between the UMTS box 21 and the two patch plates 19, 20 the 900 MHz box or slot structure (conductor structure 37, 38) of the printed circuit board 18 additional resonance frequencies are excited, which lead to an extension of the Lead bandwidth).

To the function of the base plate 12 is still to mention that it is already in Prior art was known Patchstrahler over a metallic base plate to arrange. In such known constructions this had the function a reflector and thus caused a specification of the radiation direction. This task already fulfilled in the present arrangement, the box 17, 26, which the single antenna encloses. The reflector plate serves as a base plate on the one hand 12 for mounting the boxes 17, 26 and the other is with the distance a Box optimized over such a reflector plate, the front / back ratio.

The optimal distance of the individual antennas 14 and 15, 16 in the array of the dual band antenna 10 is 0.7 times the wavelength of the respective band. from that follows that the distance between the UMTS emitters 15, 16 about half as large what the 900 MHz emitter 14 has to be. This rule follows the configuration in the present case. The setup starts and ends with a 900 MHz emitter 14. In this way, a maximum number of both 900Mhz emitters 14 as well as UMTS emitters 15, 16 are housed. As a result, the profit can be maximized for a given antenna length and the Radiation diagrams are optimized. In the example of Fig. 1 are a total of seven 900 MHz emitter 14 and thirteen UMTS emitters 15, 16 are provided in the array. In the generalized case, 10 total N are first in the dual band antenna Single antennas 14 and 2N ± 1 second individual antennas 15, 16 are arranged, where N = integer> 0. So are variants of the inventive dual-band antenna conceivable in which, for example, 5 first individual antennas and 9 second individual antennas or 9 first individual antennas and 17 second individual antennas combined are.

• Die Einzelantennen (Strahler) sind Patchstrahler und haben eine in einer Box angeordnete Printplatte mit mehreren über der Printplatte liegenden Patchblechen.
• Es gibt zwei unterschiedliche Typen von Einzelantennen, nämlich für das Frequenzband 806-960 MHz (900-MHz-Strahler) und für das Frequenzband 1710-2170 MHz (UMTS-Strahler).
• Beide Strahlertypen sind in einem linearen Array angeordnet, wobei die Periode der UMTS-Strahler halb so gross ist wie die Periode der 900-MHz-Strahler.
• Die UMTS-Strahler sind zwischen und über den 900-MHz-Strahlern angeordnet.
• Dabei ergibt sich eine "aufgestockte" Anordnung von Strahlem, bei der die Box des UMTS-Strahlers fester Bestandteil des 900-MHz-Strahlers ist und zu dessen Anpassung beiträgt.
• Die UMTS-Strahler sind höhenversetzt angeordnet, wobei auftretende Phasendifferenzen durch unterschiedliche Längen der Speiseleitungen ausgeglichen werden.
• Die Positionierung der Patchstrahler in einem definierten Abstand über einem Reflektor bewirkt dabei eine Verbesserung des Vor/Rückverhältnisses.

Overall, the notified solution is characterized by the following features:

• The individual antennas (spotlights) are patch radiators and have a printed circuit board arranged in a box with a plurality of patch plates located above the printed circuit board.
• There are two different types of single antennas, namely the frequency band 806-960 MHz (900 MHz emitter) and the frequency band 1710-2170 MHz (UMTS emitter).
• Both types of radiators are arranged in a linear array, wherein the period of the UMTS radiator half the size of the period of the 900-MHz radiator.
• The UMTS emitters are arranged between and above the 900 MHz emitters.
• This results in a "spiked" arrangement of Strahlem, in which the box of the UMTS emitter is an integral part of the 900-MHz emitter and contributes to its adaptation.
• The UMTS radiators are arranged offset in height, occurring phase differences are compensated by different lengths of the feeders.
• The positioning of the patch radiator at a defined distance above a reflector causes an improvement of the forward / reverse ratio.

LIST OF REFERENCE NUMBERS

10

Dual-band antenna

11

casing

12

Base plate (reflector)

13

terminal side

14,15,16

Single antenna (Patchstrahler)

17,21,26

box

18,22,27

PCB

19,23,28

patch plate

20,24,29

patch plate

25,30

patch plate

31.32

conductor path

33

ground plane

34.35

conductor path

36

ground plane

37.38

conductor structure

39.40

conductor structure

Claims (8)

1. Dual-band antenna (10) comprising a first linear periodic array of first individual antennas (14) for a first frequency band and a second linear periodic array of second individual antennas (15, 16) for a second frequency band, the period of the first linear periodic array being essentially twice as large as the period of the second linear periodic array and the second individual antennas (15, 16) being arranged alternately between the first and above the first individual antennas (14) and the first individual antennas (14) and second individual antennas (15, 16) being constructed as patch radiators, characterized in that the first and second individual antennas (14, 15, 16) in each case comprise a printed-circuit board (18, 22, 27) arranged in a rectangular, electrically conductive box (17, 21, 26) open to the top and a number of patch plates (19, 20; 23, 24, 25; 28, 29, 30) which are arranged at a distance above one another above the printed-circuit board (18, 22, 27) and in parallel with the printed circuit board (18, 22, 27).
2. Dual-band antenna according to Claim 1, characterized in that the patch plates (19, 20; 23, 24, 25; 28, 28, 30) of an individual antenna (14, 15, 16) are held in each case at a distance below one another and from the printed-circuit board (18, 22, 27) by means of electrically insulating spacing elements.
3. Dual-band antenna according to either of Claims 1 and 2, characterized in that in the case of the second individual antennas (15, 16) in each case three patch plates (23, 24, 25; 28, 29, 30) are arranged at a distance above one another, in that in the case of the first individual antennas (14) in each case two patch plates (19, 20) are arranged at a distance above one another and in that in the case of the first individual antennas (14) in each case, instead of a third patch plate, a second individual antenna (16) with its box (21) is arranged at a distance above the top one of the two patch plates (19, 20).
4. Dual-band antenna according to one of Claims 1 to 3, characterized in that the first and second individual antennas (14, 15, 16) are arranged above a common base plate (12) extending in the longitudinal direction of the antenna.
5. Dual-band antenna according to Claim 4, characterized in that the base plate (12) is constructed as a reflector.
6. Dual-band antenna according to one of Claims 1 to 5, characterized in that the first individual antennas (14) are designed for covering the frequency range of 806-960 MHz and the second individual antennas (15, 16) are designed for covering the frequency range of 1710-2170 MHz.
7. Dual-band antenna according to one of Claims 1 to 6, characterized in that a total of N first individual antennas (14) and 2N±1 second individual antennas (15, 16) are arranged in the dual-band antenna (10) (N = integral number > 0).
8. Dual-band antenna according to Claim 7, characterized in that N = 7.

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