EP1198026A2 - Antenna arrangement for mobile phones - Google Patents

Abstract

The arrangement has radiators parallel to and at a distance from an earth plate. Each radiators has a first connection near one end connected to the earth plate and a feed connection for a supply line. Each is a flat loop with two adjacent lines connected at adjacent ends by a short conductor; the second connection is near the other end and the whole length of each radiator corresponds to about half the wavelength of the defined frequency range. The arrangement has radiators (13,14) parallel to and at a distance from an earth plate (12). The radiators for covering a defined frequency range are of similar length, adjacent and parallel to each other. Each has a first connection near one end connected to the earth plate and a feed connection for a supply line. Each radiator is a flat loop with two closely adjacent lines connected at adjacent ends by a short conductor; the second connection is near the other end of each radiator and the whole length of each individual radiator corresponds to about half the wavelength of the defined frequency range. Independent claims are also included for the following: a mobile telephone.

Description

The invention relates to an antenna arrangement with a ground plate and with a plurality of radiators in parallel are arranged at a distance from the mass plate, the radiator covering a predetermined frequency range have a similar length and are adjacent to each other and parallel to each other, a first connection each Spotlight in the area of one end of each Spotlight arranged and with the ground plate over a first Connection is connected, the first connections mentioned are close to each other or coincide, and wherein on each radiator at a distance from its first connection a second connection is provided for a feed line is, according to the preamble of claim 1.

Such an antenna arrangement is for example from the Document EP 0 884 796 A2, Fig. 61 known. With the known The arrangement is two for two frequency bands Spotlights of slightly different lengths essentially parallel to each other at a distance from a ground plate and arranged parallel to this. The spotlights are bent, so they are on a relatively small piece of land can be accommodated. The feeding of every spotlight takes place at a small distance from that end of the radiator, which is connected to the ground plate. The other ends of the emitters are free. The length of each The emitter should be about a quarter of the operating wavelength correspond.

The well-known antenna is very low-impedance with the lambda / 4 resonance, therefore a separate feed point with a higher one Impedance level can be chosen, which is generally additional needs to be adjusted. The range of known Order is restricted. (lambda is the wavelength in the frequency range of interest.)

The invention is therefore based on the object of an arrangement of the type described at the beginning, in which no adaptation measures are required that the Could limit bandwidth.

This object is achieved in the invention according to the preamble of claim 1 by the features of the characterizing part of claim 1 in that each radiator (13, 14; 51a, 51b; 52a, 52b) in the form of a flat loop with two closely adjacent long conductors that are at adjacent ends are connected by a short conductor, and the second connections in the area of the other End of each radiator are provided and that the entire Length of each individual radiator about 1/2 wavelength (= lambda / 2) for the specified frequency range.

If you look at a single one of the emitters, then at the invention of this thus fed at one of its ends, while its other end is connected to the ground plate. In deviation from half a folding dipole, the right angle is arranged to a ground plate or conductive plane, one of its two ends being connected to the ground plate the other end is used as a feed connection, whereby the total conductor length is lambda / 2, is in the invention the radiator parallel to the ground plate and in relative small distance from this (compared to the wavelength) arranged. This half folding dipole is also referred to below Folded monopoly. By guiding the radiator element the input resistance becomes parallel to a ground plate smaller than when arranged at right angles to one Ground plane. On the other hand, this property affects the provided that a folding monopoly in the Compared to a conventional dipole one by a factor of 4 has higher input resistance. This will additionally the parallel connection of several radiator elements (namely Folding monopolies) to increase the bandwidth, without the input resistance due to this parallel connection sinks too far. In particular, the input resistance be brought into a size for feeding of antennas is common and therefore easy to use with one Serving circuit, for example a transmitter output circuit or a receiving circuit is.

In one embodiment of the invention have two or more Emitter provided for a single frequency range are the same length and therefore, taken individually, the same resonance frequency. It arises as a result of the narrow Coupling a widened compared to a single radiator resulting resonance curve. The broadening of the resonance curve can be supported that according to one embodiment the lengths of the individual radiators are different and therefore the individual emitters one have different resonance frequency.

In embodiments of the invention, the radiators are bent. This enables a space-saving arrangement.

To cover an additional deviating frequency range is another in embodiments of the invention A plurality of radiators are provided, the length of which is connected to the others Frequency range is adjusted, and the rest of the invention are trained.

The invention also includes a mobile phone, which is an inventive Has antenna arrangement.

Fig. 1a

eine vereinfachte Darstellung einer Antennenanordnung für ein einziges Frequenzband mit zwei Strahlern

Fig. 1b

eine der Fig. 1a ähnliche Anordnung, bei der jedoch die Anschlüsse des hinteren Strahlers gegenüber Fig. 1a vertauscht sind,

Fig. 1c

eine aus der Fig. 1b abgeleitete Anordnung, bei der die beiden einander unmittelbar benachbarten Teile der beiden Strahler zu einem einzigen Leitungszug mit gegenüber Fig. 1a und 1b verdoppelter Breite zusammengefasst sind,

Fig. 2

eine Antennenanordnung mit insgesamt vier Strahlern, wobei zwei Strahler für ein Band mit niedrigerer Frequenz und zwei weitere Strahler für ein Band mit höherer Frequenz bestimmt sind,

Fig. 3

eine vereinfachte Ansicht eines Mobiltelefons, teilweise aufgebrochen, mit einer im oberen Teil des Mobiltelefons untergebrachten Antennenanordnung nach Fig. 2,

Fig. 4

eine Antennenanordnung mit insgesamt vier Strahlern, wobei zwei Strahler für ein Band mit niedrigerer Frequenz und zwei weitere Strahler für ein Band mit höherer Frequenz bestimmt sind, und alle Strahler mehrfach abgebogen sind und teilweise über eine Masseplatte hinausragen.

Further features and advantages of the invention result from the following description of exemplary embodiments of the invention with reference to the drawing, which shows details essential to the invention, and from the claims. The individual features can be implemented individually or in any combination in any combination in one embodiment of the invention. Show it:

Fig. 1a

a simplified representation of an antenna arrangement for a single frequency band with two radiators

Fig. 1b

1 a arrangement similar to FIG.

Fig. 1c

1b, in which the two immediately adjacent parts of the two radiators are combined to form a single line with a width which is double that of FIGS. 1a and 1b,

Fig. 2

an antenna arrangement with a total of four radiators, two radiators for a band with a lower frequency and two further radiators for a band with a higher frequency,

Fig. 3

2 shows a simplified view of a mobile phone, partially broken away, with an antenna arrangement according to FIG. 2 accommodated in the upper part of the mobile phone,

Fig. 4

an antenna arrangement with a total of four radiators, two radiators for a band with a lower frequency and two further radiators for a band with a higher frequency, and all radiators are bent several times and partially protrude from a ground plate.

1a has an antenna arrangement 11 a conductive ground plate 12, and parallel at a distance of these are two completely identical radiators 13 and 14 spaced apart. It is therefore sufficient to discuss the radiator 13. This essentially exists from an elongated loop of two in parallel mutually arranged conductor sections 13a (in FIG. 1a front) and 13b (in Fig. 1a rear), which in Fig. 1a on the right side through a section 13c conductive to each other are connected. The left end of the radiator section 13a is conductively connected to the ground plate 12, the left end of the other radiator section 13b forms the feed connection of the radiator 13. The arrangement in such a way that in 1a the rear radiator section 13b has the supply connection also strikes the radiator 14 to. In practice, the arrangement shown is like this realized that one was originally metallized on two sides Insulation plate made of low-loss material its upper side is etched so that the conductor tracks the radiators 13 and 14 result. The with the ground plate 12th Connections to be connected then become the ground plate forming lower metallization of this insulating plate plated through. It is in embodiments of the invention provided, the other two connections, namely the supply connections, through the insulating plate to lead down and of course the metallization on the bottom in the area of passage of this implementation recess so that a feed line is connected there can be.

Since the insulating material plate has a uniform thickness, are all radiator parts 13a, 13b, 14a and 14b from the circuit board arranged at the same distance, so are to this parallel; they are also parallel to each other; finally, is the mutual distance between the two radiator parts each individual radiator 13 and 14 compared to the wavelength in the frequency range of interest small, especially smaller than a tenth of the wavelength. Also the mutual distance between the two radiators 13 and 14 is chosen so small that there is between the two emitters results in a coupling to the desired extent.

Although the two emitters 13 and 14, each individually seen the same resonance frequency, is by the Coupling a broadening of the resonance curve compared to the Case of a single radiator, as is the case with band filters is known per se. The length of each of the heater parts 13a and 13b has approximately the length of a quarter wavelength when operating in the intended frequency range.

The developed length of the entire radiator therefore corresponds half a wavelength. The high frequency currents in the long radiator sections running parallel to the circuit board flow in the same direction. The antenna arrangement 11 behaves with regard to its radiation characteristics due to the mirroring of the antenna arrangement on the ground plate 12 as if the ground plate 12 were not would exist and instead would be mirror symmetric to the Radiators 13 and 14 have two more radiators, their Currents in the opposite direction to the real ones Radiator sections flow.

In the arrangement according to Fig. 1b, the two connections of the radiator further back, which here is the reference symbol 13 'carries, with respect to ground connection and feed line connection reversed. This is where the two radiator sections 13a and 14a directly next to each other and are together on their left in Fig. 1b End connected to the feed line.

In the arrangement according to Fig. 1c, these two are each other adjacent radiator sections 13a and 14a of FIG. 1b replaced by a common conductive section 16 which twice the width as the conductor tracks that the Form radiator parts 13a and 14a of Fig. 1b each.

Figures 1a to 1c show antenna arrangements that for operation in a single band are suitable. Instead of the there radiators 13 or 14 of exactly the same length could Spotlights also have a different length, so that the spotlights are already different in themselves Have resonance frequency in order to achieve a Resonance curve in the desired width with the participation of a to support the tight coupling of the radiators.

2 are two different ones Antenna arrangements for two different Frequency bands are dimensioned together an insulating plate with a ground plate underneath intended. Each of these antenna arrangements has as in FIGS. 1a to 1c, two radiators, which, like already explained, two closely adjacent and parallel to each other have running conductor sections which on a End connected together, and at the other ends these conductor sections are these with the ground plate or to connect to a feed line.

So that the antenna arrangements in the frequency ranges common today and the sizes of mobile phones that are common today can be accommodated in such a device, especially when connected to an operation in the range of around 900 MHz and is thought of around 1800 MHz are the individual Spotlights in contrast to FIGS. 1a to 1c, where they are straight run, bent once or several times by 90 °. When the arrangement is made so that the ends and beginnings the radiator with a largely parallel arrangement a rectangular mass plate at the same distance end from the edge of the ground plate as shown in FIG. 2 is, the two emitters point to one belong to individual antenna arrangement, a slightly different Length because, so to speak, the one spotlight is a bit inside from the other. The smaller the distance between the the two radiator sections, the smaller the The distance between the two emitters is, and the smaller the conductor width of the individual radiator sections is all the more the difference in length between the two is also smaller Radiator.

In Fig. 2, the upper antenna arrangement is general is designated by the reference numeral 21 for a low one Frequency range provided, in the example for a range for mobile phones in the 900 MHz band, e.g. according to the standard GSM900. The individual radiators of this antenna arrangement have a longer length than in the other antenna arrangement 22 in Fig. 2. The lengths of the radiators of the radiator arrangement 22 are about half the length of the radiators at the arrangement 21, because the antenna arrangement 22 for one Frequency range determined in the band 1800 MHz. It goes without saying that with only minor changes the antenna arrangement instead 22 also for a frequency range for GSM1900 (range 1900 MHz) can be provided.

FIG. 2 also schematically shows one shown as a coaxial cable 30 Feed cable that from below with the antenna arrangement is connected, the jacket of the coaxial cable 30 is to be connected to the ground plate and the center conductor of the coaxial cable with the supply connections of the individual Is to be connected.

When operating the antenna arrangement of FIG. 2 in the lower Frequency range (as mentioned e.g. GSM 900) becomes the antenna arrangement 21 operated at least near the resonance frequency, the antenna arrangement 22 becomes far below its resonance frequency operated so that the antenna arrangement 22 like a load on the connection of the antenna arrangement 21 acts. This influence can occur when feeding the antenna arrangement 21 can be taken into account without further ado. Will the antenna arrangement 2, however, at the high resonance frequency operated, for which the antenna assembly 22 is provided the other antenna arrangement may be located 21 at such a frequency in a higher one Resonance.

1. Orthogonale Platzierung der Strahlerelemente der Antennenanordnungen 21 und 22.

2. Verringerung der Kopplung zwischen den Strahlerelementen der Antennenanordnungen 21 und 22 durch eine größtmögliche räumliche Trennung.

3. Platzierung der Strahlerelemente der Antennenanordnung 22 so, dass sie über die Masseplatte hinausragen; dies gilt auch für die Antennenanordnung 21.

If this leads to undesired influences, for example a sharp resonance curve or a reduced bandwidth, these influences can be counteracted by several measures (individually or in combination):

1. Orthogonal placement of the radiator elements of the antenna arrangements 21 and 22.

2. Reduction of the coupling between the radiator elements of the antenna arrangements 21 and 22 through the greatest possible spatial separation.

3. placement of the radiator elements of the antenna arrangement 22 such that they protrude beyond the ground plate; this also applies to the antenna arrangement 21.

3 shows the position of an antenna arrangement in a highly simplified manner 2 in a mobile phone that is convenient in a Can be held by hand. The antenna arrangement is in the top Area of the mobile phone housed, and orientation the antenna arrangement is such that the feed connections, which are also the points of greatest current flow are in the spotlights, as high up in the Device.

It is understood that the type of kink in the form of a Letter L, as provided for the antenna assembly 22 is, or as in the form of a letter U, as for the antenna arrangement 21 is provided, is exemplary and by others Configurations in which the spotlights are in any Are kinked or wound up, are replaced can.

According to the arrangement provided for two frequency bands FIG. 4 is the structure of the radiators in FIG. 4 that is visible in FIG Form of different layers or layers of a carrier material arranged. However, to simplify the illustration all spotlights are shown as fully visible to the viewer. The multilayer plate 41 thus formed lies on one Earth plate 42 on. In the example, the ground plate 42 is in the essentially continuous metallization on the back a circuit board, the other side at least Forms parts of a circuit of a mobile phone. The circuit elements this circuit is therefore in the 4 below the mass plate 42.

All radiator elements are supplied via a connection 43, and the ground connection for all radiator elements takes place via a connection 44 which is connected to the ground plate 42 connected is. For the operating frequency range with larger An antenna arrangement 51 is provided at the wavelength two radiator elements 51a and 51b. Each of these radiator elements is essentially by two closely spaced and parallel guided conductor tracks formed, and at the end of the radiator are the two conductor tracks mentioned by one each Short circuit 51c and 51d connected to each other. For the operating frequency range with a shorter wavelength is an antenna arrangement 52 provided in the viewing direction of the 4 lies above the plane in which the antenna arrangement 51 is located. This spatial arrangement is also clearly recognizable from the drawing.

The following are the description of the configuration 4 the terms top and bottom and left and on the right, however, not the actual spatial arrangement, but on Fig. 4 as it affects the viewer represents related. According to this expression, for example the connection 43 further down and further left than the short-circuit connection 52c of the radiators 52a.

The two radiators 51a and 51b of the antenna arrangement 51 go seamlessly over each other without kinking, with respect to the a conductor this transition between the two emitters through the connection point at which the connection with the connection 43 is made, is formed. For the other The conductor of the two radiator elements 51a and 51b finds this Transition at the connection of the named conductor with the connection 44 instead. This last-mentioned connection lies as well as the first-mentioned connection with connection 43, above the connections 43 and 44 in Fig. 4. Below this The connections mentioned make the connection with the two Radiators 52a and 52b of the antenna arrangement 52. In the entire Figure 4 means no crossing of lines one electrical connection.

The antenna arrangement 51 is a total of one at their both ends short-circuited arrangement of two closely adjacent parallel conductor formed a total of seven times are bent at right angles, always in the same Sense, so that a spiral arrangement with a little less than two turns. The two are there Radiators 51a and 51b are spaced from each other, which is much smaller than the short side of the Rectangle that from this antenna array 51 essentially is filled out.

The antenna arrangement 52 lies partly inside and partly outside (seen in the plan view of FIG. 4) the Antenna arrangement 51. The two at a close distance from each other parallel conductors that this antenna arrangement 52 form, start entirely at the short circuit 52c 4 first parallel to the top branch of the Antenna assembly 51 to the left, with a right angle Then bend down, then right into the Close to the vertical part of the interior radiator 51a, then with a 90 ° turn in the same sense as before up to the same height as the first Section 52a of this antenna arrangement, then with a Turn 90 ° further to the right in another sense and finally with a 90 ° turn down. This last-mentioned downward section of the Radiator 52b ends approximately where the upper edge of the Earth plate 42 ends. As a result, it extends from the antenna arrangement 52 more than half of the total emitter length in an area (in the actual spatial arrangement) is not above the mass plate 52, but is laterally offset from this. Also in this Area is the antenna arrangement through the multilayer circuit board 41 supported. From the former antenna arrangement 51 runs the top, the long side of a rectangle engaging radiator part outside of the ground plate, moreover the one following the short circuit 51c parallel to the just mentioned part of the radiator part of the radiator element 51a, as well as those immediately adjacent to these elements, perpendicular to them and the connection with the remaining parts producing sections of the conductor elements.

Overall, the mutual arrangement of the antenna arrangements can be 51 and 52 also partially describe such that the two arrangements are eccentric relative to each other, the arrangement for the area with short operating wavelength in percentage terms a lot further via the mass plate 52 protrudes than the other antenna arrangement.

The antenna arrangement 52 is thus located with some of them Parts relatively far from neighboring parts of the Antenna arrangement 51, and wherever crossovers between the different antenna arrangements are required these take place at right angles and therefore with little coupling. The antenna arrangement 4 is for a mobile phone according to the Standards GSM 900 and GSM 1800 are provided, but can be done without is further understandable without difficulty for the area GSM 900 and GSM 1900 can be modified.

Because a parallel guidance of the radiator elements in small Distance is largely avoided, is a strong coupling prevented. Therefore, even when operating in the 1800 MHz range, in which the antenna arrangement intended for the 900 MHz range can resonate, not serious Interference on.

Claims (6)

Antenna arrangement with a ground plate and with a plurality of radiators, which are arranged parallel to the ground plate at a distance therefrom, the radiators for covering a predetermined frequency range having a similar length and being adjacent and mutually parallel, a first connection of each radiator in Area of each end of each radiator is arranged and connected to the ground plate via a first connection, said first connections are closely adjacent to one another or coincide, and a second connection for a feed line is provided on each radiator at a distance from its first connection .
characterized in that
each radiator (13, 14; 51a, 51b; 52a, 52b) is designed in the form of a flat loop with two closely adjacent long conductors, which are connected at adjacent ends by a short conductor, and the second connections in the area of the other End of each radiator are provided
and that the total length of each individual radiator corresponds to approximately 1/2 wavelength (= lambda / 2) for the given frequency range. Antenna arrangement according to claim 2, characterized in that the radiators are bent. Antenna arrangement according to one of the preceding claims, characterized in that the radiators are of different lengths. Antenna arrangement according to one of the preceding claims, characterized in that a further plurality of radiators according to one of the preceding claims is provided to cover an additional deviating frequency range, the length of which is adapted to the further frequency range. Antenna arrangement according to claim 4, characterized in that at least one of the following measures is provided in order to avoid undesired influences of the longer radiators when operating the antenna arrangement in the region of the resonance frequency of the shorter radiators: a) separate feed lines for the two frequency ranges, b) orthogonal placement of the radiator elements of the antenna arrangements, c) reducing the coupling between the radiator elements of the antenna arrangements by means of the greatest possible spatial separation, d) placement of the radiator elements of at least one antenna arrangement so that they protrude beyond the ground plate. Mobile phone, characterized by an antenna arrangement according to one of the preceding claims.

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