The invention relates to an antenna arrangement as claimed in the precharacterizing clause of claim 1.
An antenna arrangement of this generic type has been disclosed, for example, in DE 201 11 229 U 1. This prior publication describes an antenna arrangement for motor vehicles which has a chassis above which a printed circuit board is arranged, to be precise in order to accommodate circuit components. One or more vertically projecting antenna elements, which is or are at least partially flat, is or are provided vertically with respect to the printed circuit board, which is aligned essentially horizontally, to be precise in order to receive different services or for different frequencies in the mobile radio band.
The entire antenna arrangement is covered by a shroud which may have a shape similar to a fin. Antennas such as these are normally fitted to the motor vehicle bodywork plate, for example at the junction between the motor vehicle roof and the rear windshield.
A multiple frequency antenna arrangement in particular for motor vehicles having a corresponding shroud has been disclosed in EP 0 862 239 A1. By way of example, two printed circuit boards, which are aligned vertically and are offset laterally transversely with respect to the vertical plane are provided in the housing, which is in the form of a shroud, for accommodation of the electronic components. A connecting adapter is provided at the upper end of the housing, that is to say at the uppermost point of the shroud, in order to make it possible to attach an antenna in the form of a whip antenna there.
An antenna which can preferably be used for cars has likewise been disclosed in DE 694 19 080 C2. This antenna also has a housing in the form of a shroud, at whose uppermost projection point a connecting point is provided for a whip antenna. One or more printed circuit board elements, which are aligned vertically or horizontally, can be arranged within the antenna housing. In one embodiment, these printed circuit board elements are likewise arranged parallel to one another and are arranged alongside one another transversely with respect to the plane of the printed circuit board, to be precise aligned transversely with respect to the vehicle longitudinal axis. However, they may also likewise be arranged with a lateral offset parallel to one another, to be precise aligned longitudinally with respect to the vehicle axis.
Furthermore, antenna arrangements are also known in which the printed circuit board which has been mentioned is first of all provided with electronic circuitry components, filter circuits etc. formed on a more or less horizontal chassis, and the antenna elements are once again positioned vertically at right angles to this, in the vertical direction. These antenna elements may, for example, not only be composed of metalically conductive self-supporting antenna element devices but, for example, may likewise once again be formed from a printed circuit board element, that is to say in general from a dielectric material, on which metalized surfaces are provided in order to form the antenna elements.
If the aim is now to receive in only one frequency band range, then one antenna element is sufficient. If the aim is to provide two or more services or one service more than once, or if the aim is, for example, to communicate in various frequency bands in the mobile radio range, then, of course, two or more antenna elements are provided, which are offset with respect to one another or are flat.
The object of the present invention, against the background of this prior art, is to provide a further improved antenna arrangement which, in principle, hes good antenna characteristics with reduced production and material costs overall.
According to the invention, the object is achieved on the basis of the features specified in claim 1. Advantageous refinements of the invention are specified in the dependent claims.
It has now surprisingly been found that there is no need for a horizontal, separate printed circuit board with the matching circuit required for the antenna. Specifically, according to the invention, one or more printed circuit boards are used, which are preferably aligned alongside one another vertically on a common plane and are provided adjacent to the at least one antenna element. The appropriate components for a radio-frequency circuit, which may possibly be provided, are, for example, accommodated on this vertically aligned printed circuit board.
According to the invention, the use of a vertically aligned printed circuit board once again allows the overall design of a corresponding antenna arrangement to be simplified considerably. One surprising feature of this embodiment is that the vertically aligned printed circuit board, which rests on the antenna element at the side, does not influence the antenna polar diagram disadvantageously in the manner which would intrinsically be expected.
The solution according to the invention is distinguished inter alia in that, in contrast to the prior art, the at least one antenna element arrangement is not provided above the printed circuit boards but at the side, alongside this at least one printed circuit board. This prevents any disadvantageous influence on the polar diagram characteristic. This is also particularly surprising, and is not obvious, because an antenna such as this with as broad a bandwidth as possible for the mobile radio field is designed for wavelengths in the range from around 15 cm to 30 cm, so that the size of the vertically arranged printed circuit board is in the range that is relevant for these wavelengths.
Furthermore, it is preferably possible to provide only a single printed circuit board on which not only the radio-frequency circuit which may possibly be provided is accommodated but on which, for example, flat conductive sections can then also be formed on other section areas, forming the relevant antenna element. In this case, widely differing geometric shapes are possible to form the antenna element, for example including whip embodiments, which have a vertically running, flat antenna section, which merges at the top into, for example, an antenna section at the rear.
If, by way of example, a further antenna element is intended to be provided for a second frequency band for the mobile radio area, or in order to provide further services, then this likewise can preferably be provided as a flat antenna element in an area of the printed circuit board that is offset with respect to the first antenna element. However, in precisely the same way, it is also possible to use a further printed circuit board element, which is located on the same plane as the first printed circuit board element or, for example, is offset laterally parallel to it, in order to accommodate the at least one further antenna element here.
Thus, overall, the antenna elements and the radio-frequency circuit which may possibly be provided can be accommodated in a preferred manner on a single, common printed circuit board arrangement.
A cap, which is used for mechanical retention, is required only for installation on the motor vehicle and for mechanical anchoring of the printed circuit board and of the antenna elements located on it.
Further advantages, details and features of the invention will become evident from the “described exemplary embodiments” in the following text. In this case, in detail:
a: shows an exemplary embodiment corresponding to
b: shows an exemplary embodiment which is once again modified from that shown in
With the opening 3 in the bodywork plate 1 having an appropriately large size, a cap plate or base plate 7 with a printed circuit board 5 that is aligned vertically with respect to it and has electrically conductive surface sections 9′ on it is mounted from underneath on the bodywork plate 1, thus forming an antenna element arrangement 9. The flat elements 9′ are in this case normally aligned in the vehicle longitudinal direction. The entire antenna element arrangement 9 is normally fitted on the line of symmetry of the motor vehicle.
In the illustrated exemplary embodiment, the antenna element arrangement 9 (starting from the lower cap plate or base plate 7 which is arranged essentially horizontally or at a slight angle to the horizontal on the motor vehicle bodywork plate 1) comprises a vertically running first flat section 9′, to which a whip antenna section 9″, which extends to the rear, can then be connected. In the illustrated exemplary embodiment, both antenna sections 9′ and 9″ are electrically connected to one another via a combination comprising an inductance and capacitance 13.
A printed circuit board 15 is provided on the same plane, directly adjacent to the antenna element arrangement 9, that is to say in the illustrated exemplary embodiment in the same vertical plane on the first antenna element section 9′ which extends vertically, on which the radio-frequency circuit of the antenna arrangement, which may possibly be provided, is accommodated. In other words, all of the necessary electrical components and assemblies, filter modules, etc. are seated on this printed circuit board section 15.
The corresponding connecting cables can then be introduced into the motor vehicle interior through an opening 16, which may possibly be provided in the cap plate or base plate 7. This is not illustrated in any more detail in the second exemplary embodiment.
In the exemplary embodiment shown in
The radio-frequency circuit which may possibly be provided is then in turn accommodated, with the appropriate components and parts, in a space 15′ which, for example, is bounded by a rectangular shape.
In the exemplary embodiment shown in
In contrast to the exemplary embodiment illustrated in
As mentioned, the entire arrangement is held mechanically by means of the cap or the so-called base plate 7.
If required, certain sections on the printed circuit board 15 may also be omitted or knocked out, if, for example, it is intended to accommodate an antenna element there which, in contrast to the illustrated exemplary embodiment, is not aligned vertically, for example in the case of a GPS antenna.
As a supplement to the illustrated and described
The exemplary embodiment shown in
Number | Date | Country | Kind |
---|---|---|---|
102 21 877.3 | May 2002 | DE | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/EP03/04843 | 5/8/2003 | WO |