BACKGROUND OF THE INVENTION GB-A-2 332 119 discloses an antenna unit for a portable communication terminal, wherein a helical antenna element 33 is positioned inside the cavity of an antenna cap. A housing connecting portion has a male screw formed on its outside surface. The housing connecting portion is coupled to the antenna element and provides connection between the antenna element and a PCB of the portable communication terminal.

Assembly of the prior art antenna unit necessitates assembly of several elements by axial displacement thereof with respect to each other in order to produce the antenna unit for subsequent mounting on the portable communication terminal.

This normally results in well functioning antenna units even though it has been discovered that the economy compare to antenna elements being integral inside the'housing of a portable telephone is such that the integral, antenna normally is economically more advantageous. With respect to the antenna function, however, the solution with an antenna unit extending from a portable terminal is normally advantageous over the solution with the integral antenna.

SUMMERY AND ADVANTAGES OF THE INVENTION It is an aim of this invention to provide a solution, wherein the economy of an antenna unit, which extends from the outside of a portable radio communication device, such as a portable telephone, is enhanced.

This aim is obtained according to the invention in an antenna assembly according to the above through the features of the characterising portion of claim 1.

It is also an aim of the invention to provide a method of assembling and mounting an antenna assembly of the above kind, whereby the economy of the resulting product is enhanced.

This aim is obtained in a method according to the above through the features of the characterising portion of claim 22.

With these features it is achieved that the antenna assembly may be readily assembled and mounted in a simple assembly plant for example for a radio communication devices without the need of special handling of the different elements being included in the antenna assembly. In particular it is now possible to reduce the degree of manipulation of the included elements such as turning and pivoting movements. The invention makes the assembly easy to mount on a radio communication device, especially on a portable one. Normally the assembly of such a device is a sandwiching process, wherein the elements are stacked on top of each other. According to the invention the process of assembling the antenna assembly may be. carried out in a similar manner, thus, increasing the economy of the resulting product. It is also possible to make thin antennas being only a few mm thick, including a support structure,

having an internal compartment for the antenna element (-s).

Normally the inventive antenna assembly is relatively flat, and the flat surfaces thereby constitute first and second sides of the assembly. It is however not excluded that the first and second sides are clearly curved.

By the fasteners being snap-lock fasteners, mounting of the antenna assembly is facilitated.

By the antenna element being provided on the resilient substrate, several advantages are obtained such as simplified production and assembly.

By the antenna element being substantially plane or slightly curved in operation, a particularly advantageous antenna function may be obtained.

In a preferred embodiment the support structure is comprised of two parts that are hinged to each other. This reduces the number of elements to be included in the antenna assembly and facilitates manufacture and assembly. In particular this is obtained when the support structure is manufactured in a plastic material if the hinge is an integral element of the structure.

According to another embodiment, the support structure comprises a first substantially rigid part and a second resilient part, which in particular is an adhesive tape. This embodiment provides enhanced economy and simplified assembly.

Further, the resulting antenna assembly may be particularly thin, which is often desired if the antenna assembly is a flat or almost flat construction.

The provision of a substantially rigid guide tongue on the support structure results in better stability. The provision of a feed line on the guide tongue provides easy coupling.

Coupling is simplified when a contact spring is present in this position. Hereby contact is easily obtained with a PCB or other circuits of the radio communication device when mounting it thereon. Preferably the contact spring is pressed between two parts of the support structure against an antenna feed line for enhanced contact.

It is preferred that the support structure comprises elements for rendering the antenna element the desired form, be it flat or curved. By thus controlling the shape and the fixing the position of the antenna element, the antenna function is advantageously stabilised.

By providing more than one antenna element dual or multi band function is more easily obtained.

It is preferred that each antenna element is a meander element. This results in possibility of enhanced antenna function over other types of elements such as helical antennas.

When the antenna element is comprised of printed pattern the production and thereby the economy is enhanced.

Further advantages are obtained through other aspects of the invention.

BRIEF DESCRIPTION OF DRAWINGS Further advantages will be apparent from the following detailed description of embodiments with reference to the drawings, wherein: Fig. 1 shows, in an exploded view, an antenna assembly according to the invention, Fig. 2 shows the assembly of Fig. 1 in an assembled state, Fig. 3 shows a part of a portable telephone for the antenna assembly of Figs. 1 and 2, Figs 4a and 4b show an alternative antenna carrying substrate, Figs 5a and 5b show a further embodiment of the invention, Figs 6a and 6b show a still further embodiment of the invention, and Figs 7a and 7b show yet another embodiment of the invention.

DESCRIPTION OF EMBODIMENTS An antenna assembly 1 is shown in Fig. 1 in a not yet assembled state. A support structure is comprised of a first part 2a and a second part 2b. The first and the second parts 2a and 2b define together a compartment wherein a flexible substrate 3 is intended to be contained. The flexible substrate is made from a material, which is per se known in the art and is provided with a printed or etched pattern defining a first antenna element 4 and a second antenna element 5 for plural band operation. The antenna elements 4 and 5 are fed through a feed line 6, which is printed on a

thin extended portion 33 of the substrate. A contact spring 7 is provided for contacting the feed line 6 when the support structure is assembled. A free part of the contact spring defines a feeding point 8 for co-operation with corresponding contact parts inside a mobile phone (not shown), whereon the assembly is intended to be mounted. Typically the corresponding contact part is arranged on a PCB inside the mobile telephone.

A guide tongue consisting of two parts 10a and lOb, each extending from one part of the, support structure, forms a channel 34 for reception of the extending part 33 of a substrate as well as the contact spring 7. The guide tongue 10a and lOb stabilises the connection between the support structure and the telephone on which it is intended to. be mounted. The first and the second parts of the support structure 2a and 2b are locked together by any per se known method such as ultra sound welding, gluing, snap-in fastening or any other suitable method. The lines 32 indicate elements moulded into the first part of the support structure 2a, which elements are comprised of slightly curved rims, which are adapted to provide the flexible substrate with a desired curved shape and also to fix the substrate against movements inside the support structure. Assembling the assembly 1 is simply obtained by placing the parts 2b, 3,7 and 2a in a sandwich manner on top of each other, thus in the directions D1 and D2 of the respective sides. The first and second sides thus being assembled form a compartment into which the antenna element is positioned from a sideways direction prior to the completion of the assembly of the support structure parts.

Fig. 2 shows the antenna assembly 1 in the assembled state whereby fasteners 9, in this case rectangular holes, are

shown. These holes are intended to receive corresponding protruding fasteners extending from a mobile telephone or the like. The guide tongue consisting of the parts 10a and 10b together form the channel 34 is shown in this Figure as is the protruding part of the contact spring 7, with the feeding point 8.

One advantage of the embodiment shown in Fig. 2 is that it is possible to obtain a sealed connection between the support structure parts and thereby protect the antenna elements from incoming water or moist. In order to further increase stability the support structure comprises a portion 35 extending below a bottom 36 formed by the wall parts including the fasteners 9. The extending envelope portion 35 provides possibility of securely anchoring the support structure to the portable telephone.

In Fig. 3 a part of a portable telephone 15 is shown. 16 indicates a seat for the antenna assembly according to Figs. 1 and 2, wherein the protruding envelope surface 37 matches the extending envelope portion 35, (see Fig. 2). 17 indicates fastenings, in this case consisting of two pairs of resilient snap-in hooks for co-operation with the holes 9 (see Fig. 2) of the support structure. A hole for the guide tongue 10a and 10b is denoted 18.

Figs 4a and 4b show an embodiment wherein the substrate 11 consists of a resilient portion 12a and a substantially rigid portion 12b. No complete support structure is shown here. The resilient portion 12a carries an antenna element 13 having a feed line 14. The substantially rigid part 12b extents over the length of the substrate 11 (indicated with broken lines) in Fig. 4a. The substrate 11 according to this embodiment may

be used together with a support structure without a tongue as the one shown in Figs. 1 and 2. In this case the substantially rigid part 12b operates as a tongue and the feed line 14 may co-operate with connecting elements provided inside a telephone.

In Figs 5a and 5b, a further embodiment is shown wherein there is provided a rigid planar substrate 19 carrying antenna elements 20 and 21 and a feed line ending in a feeding point 23. Recesses or holes 22 are provided at the bottom part of the substrate for co-operation with corresponding snap-in fastener hooks inside the radio communication device (not shown). 44 denotes shoulders for resting against the outside of a radio communication housing when the assembly is mounted thereon., In Fig. 5b the substrate is shown together with first and second parts 24 and 25 of a cover or a support structure for the upper part of the substrate 19 and of the whole assembly together with the substantially rigid part 19b.

In Fig. 6a an embodiment is shown wherein a hinge 27 connects a first part 28a and a second part 28b of the support structure. This support structure is made from a suitable plastics material and the hinge is an integral part of this structure which thus is manufactured in one piece. 29 denotes a substrate which is positioned in a compartment inside a closed support structure, and a meander antenna element is denoted 30 whereas the feeding point is denoted 31. The first part 28a of the support structure is provided with three forming elements 45, which are adapted to come into contact with a substrate 29 in order to fix it and render it a chosen

form let be plane or slightly curved, in particular with a shallow C shaped cross section.

Assembly of the device of fig 6a is obtained by placing the substrate in one of the parts, whereafter the second part is pivoted around the hinge to a state, where the parts form an enclosure similar to the one shown in fig 2. The resulting assembly will then have a sandwich configuration corresponding to the embodiment in figs 1 and 2.

Fig. 6b shows a detail of a support structure, which may well be used in different embodiments of support structures. 42a and 42b denote first and second parts of support structures and 43a and 43b denote interlocking snap rims, which may be placed along the entire edge of for example the parts of Fig.

6a.

In Figs 7a and 7b a further embodiment is shown, wherein 32 denotes a rigid part of a support structure including a feeding point 35 and being adapted to receive, sideways, a substrate 33 having thereon an antenna element pattern. The substrate is covered by a flexible portion 34, which in this case is comprised of a self-adhesive tape. As can be seen in Fig. 7b from the section A-A in Fig. 7a, the rigid part 32 is provided with a two step shallow recess for reception of the substrate 33 as well as the larger adhesive tape comprising the flexible portion 34. The resulting support structure will have substantially even surfaces on both sides.

The invention can be modified within the scope the following claims. For example it is preferred that the fastening elements, which are protruding from one of the parts-antenna assembly-portable telephone, is provided on the former and

not the latter since a possible breakage of protruding portions, which are situated on the portable telephone is more serious than breakage of elements protruding from the antenna assembly, since the antenna assembly is relatively cheap and easily replaced. In any case, various different co-operating fasteners may be envisaged for attaching the assembly onto the radio communication device.

The antenna elements may be of different configuration, even though it is preferred that they are comprised of meander elements, which are printed on a substrate-flexible or rigid. It is, however, within the scope of the invention to use other types of antenna patterns and to use alternative coupling parts for achieving the desired coupling between circuits of the communication device and the antenna. It is also within the scope of the invention to apply, for example print, the antenna pattern directly on one of the halves of the support structure. It is also within the scope of the invention that the antenna element is self-supporting, i. e. is not applied on a. substrate.