WO2001076005A1

WO2001076005A1 - An antenna device and a portable communication device comprising such an antenna device

Info

Publication number: WO2001076005A1
Application number: PCT/SE2001/000715
Authority: WO
Inventors: Annika Yidong Hu; Istvan Bartha; Daniel Sundberg
Original assignee: Allgon Mobile Communications Ab
Priority date: 2000-04-03
Filing date: 2001-04-02
Publication date: 2001-10-11
Also published as: SE0001193L; SE0001193D0; AU2001244986A1; SE517850C2

Abstract

The present invention relates to an antenna device for a portable radio communication device, comprising: a first antenna (4; 26) supported by a support structure (6; 20), and being connectable to RF circuitry of the portable radio communication device, a second antenna (8; 23) being movable between an extended end position and a retracted end position, and arranged to be slidable through an opening of said support structure, said second antenna being connectable to RF circuitry of the portable radio communication device, a third antenna (24; 24') fixedly attached within the housing (3) of the portable radio communication device, and being connectable to RF circuitry of the portable radio communication device, and said support structure being movable between an extended end position and a retracted end position, and arranged to be slidable through an opening of a housing (3) of the portable radio communication device.

Description

AN ANTENNA DEVICE AND A PORTABLE COMMUNICATION DEVICE COMPRISING SUCH AN ANTENNA DEVICE

FIELD OF INVENTION The present invention relates generally to an antenna device for a radio communication device and a portable radio communication device and more particularly to an extendable/retractable external antenna in a portable radio communication device, such as a mobile telephone, and a portable radio communication device comprising such an antenna device.

BACKGROUND

In recent years, mobile telephones have become increasingly popular. At present time, mobile systems in different places in the world utilize different frequency bands for radio communication. Some widely used systems are AMPS (Advanced Mobile Phone Service) , GSM 900 (Global System for Mobile communications) , DCS 1800 (Digital Cellular System) and PCS 1900 (Personal Communications Services). Several solutions exist where combinations of frequency bands are used in one telephone.

It is easy to provide protruding antennae that function in more than one frequency band, and protruding antennae are therefore frequently used in mobile telephones. However, a problem with protruding antennae is that they can be experienced as annoying if they get entangled in a pocket for example.

A solution to this problem is to use an extendable/retractable whip antenna that is active only in an extended position, but such an antenna does not function sufficiently well in more then one frequency band. A problem witn antennae that are not permanently connected is that a mirror effect arises m a transceiver when no antenna is connected thereto.

Another problem with whip antennae is that they usually are fragile.

OBJECTS OF THE INVENTION

An object of the present invention is to provide an antenna device that has no protruding antenna in standby mode.

Another object of the present invention is to provide an antenna device that is capable of operating in more than one frequency band.

A further object of the present invention is to provide an antenna device that decreases mirror effects in a transceiver.

Yet another object of the present invention is to provide an antenna device that is less fragile than prior art external antennae, such as a whip antenna together with an internal antenna or a whip antenna together with a top- helix antenna.

SUMMARY OF THE INVENTION

The above-mentioned objects among others are, according to the present invention, attained by an antenna device and by a portable radio communication device as claimed m the appended claims.

According to the present invention there is provided an antenna device as defined in claim 1. There is further provided a portable radio communication device according to the present invention as defined m claim 11.

Further advantages are achieved by features defined in the dependent claims.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will become more fully understood from the detailed description of embodiments of the present invention given hereinafter and the accompanying figures, which are given by way of illustration only, and thus are not limitative of the present invention, m which:

FIG. 1 shows a cross-section and partially broken view of an antenna according to the invention,

FIG. 2 shows a view of an antenna device according to the invention,

FIG. 3 shows a schematic illustration of an extendable/retractable bottom-helix antenna, and

FIG. 4 shows a connector of an antenna device m two different positions.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, for purposes of explanation and not limitation, specific details are set fourth, such as particular hardware, applications, techniques, etc. in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be utilized in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known methods, protocols, apparatuses, and circuits are omitted so as not to obscure tne description of the present invention with unnecessary details.

Reference will now be made to FIG. 1, wherein a first embodiment of the present invention is shown m detail. In this figure an antenna device comprises an extendable/retractable meander antenna 4 and an extendable/retractable wnip antenna 8, whicn both are in retracted position. The whip antenna 8 has a knob 1 that is positioned slightly outside of a housing 3 of a portable radio communication device, such as a mobile telephone. This position is to make it feasible for a user of a mobile telephone to extend the whip antenna 8.

It is also possible to provide an extendable/retractable antenna completely within a general outline of the housing of a mobile telephone, if the extendable/retractable antenna is provided with a pop-up function.

The meander antenna 4 is supported by a support structure 6, and covered by a nonconductive cover or coating 2. A holder 5 keeps the meander antenna 4 in place, such that it is movable vertically and fixedly positioned horizontally as shown m the figure. At the bottom of the meander antenna 4 a contact area 7 is arranged. This contact area 7 is preferably conically shaped for easy interaction with a corresponding area 10 on the whip antenna 8.

The whip antenna 8 has at its lower end a conductive stopper 11, which in extended position interacts with a connector 9, such as a flexible tongue. The connector is connected to a transceiver circuitrv (not shown) . The whip antenna 8 is slidable through the support structure 6. The wnip antenna 8 is connected m extended position when the conductive stopper 11 is in contact witn the connector 9, which is connected to the transceiver. When tne whip antenna 8 is extended the meander antenna 4 is extended along with the whip antenna 8 towards an extended position. Due to the interaction between the contact area 7 on the meander antenna 4 and the corresponding area 10 on the whip antenna 8 the meander antenna is connected in its extended position .

When the whip antenna 8 is in other positions than in the extended position it is not connected to the transceiver. Consequently the meander antenna 4 is also disconnected from the transceiver in all positions except when the whip antenna 8 is in its extended position.

The holder 5 stops the extension of the meander antenna 4, and the support structure 6 stops the extension of the whip antenna 8 at the conical contact area 7. The holder 5 also stops the retraction of the meander antenna 4, and the knob 1 stops the retraction of the whip antenna 8.

In order for a mobile telephone to function continuously an internal antenna (not shown), i.e. an antenna fixedly attached inside the housing 3 of the mobile telephone, could be connected when the extendable/retractable antennae are disconnected, and vice versa. This could be achieved with a switch, such as a mechanical, an electric, or a magnetic switch.

A second embodiment of the present invention will now be described with reference to FIG. 2. According to this embodiment the antenna device comprises an extendable/retractable meander antenna 26, an extendable/retractable whip antenna 23, and an internal planar antenna 24. The meander antenna 26 is supported by a support structure 20. When the meander antenna 26 is in retracted position the planar antenna 24 is connected to a transceiver through a conductive portion 25 of the support structure 20 and a connector 21. The connection to the conductive portion is through a flexible connector 22, such as a flexible tongue.

The internal antenna 24 is permanently connected to a ground plane (not shown) through a grounding portion 27. The meander antenna 26 is continuously connected to the transceiver through the conductive portion 25 and a flexible connector 21. Although it is here shown a flexible connector 21, which the conductive portion 25 of the support structure 20 is continuously connected to, it could be the opposite with a conductive part connected to RF circuitry and continuously connected to a flexible connector on the support structure 20.

It is also possible to disconnect the meander antenna 26 when in retracted position after the planar antenna 24 is connected. To make this possible a switch could replace the flexible connector 22 and connect/disconnect the planar antenna directly to/from the transceiver, and the flexible connector 21 could be coupled to the transceiver through a switch, which could disconnect the meander antenna 26 after the planar antenna 24 is connected and disconnect the planar antenna 24 after the meander antenna 26 is connected. It is obviously also possible to let the internal antenna being permanently connected if desirable.

As in the first embodiment of the present invention described with reference to FIG. 1, it is possible to either let the whip antenna 23, when in retracted position, be slightly outside a general outline of a housing of a mobile telephone, or let the whip antenna 23, when in retracted position, be completely inside the general outline of the housing of the mobile telephone with a popup function.

The support structure 20 preferably has a ramped form for stopping the meander antenna 26 in its extended position. The whip antenna 23 connects to the transceiver through the conductive portion 25 when extended. As in the first embodiment the whip antenna 23 is also here slidable through the support structure 20.

Since there always is at least one antenna connected to the transceiver the risk of getting a mirror effect in the transceiver is decreased, compared to antennae without this solution.

With the support structure mentioned above the whip antenna gets a mechanical support in extended position, which makes it less fragile compared to other antenna devices without protruding antennae in standby mode.

FIG. 3 shows to the left a helix antenna and a whip antenna in extended position, and to the right in retracted position. In this figure it is shown more of a mobile telephone then in previous figures in connection with an antenna device to get a clear overview of extended and retracted positions.

An alternative connector for an internal antenna 24' is shown in FIG. 4. Here a connector has two positions 40, 41. When a support structure 20' is in retracted position the connector is in the first position 40 and the internal antenna 24' is therewitn connected to the transceiver. When the support structure 20' is ιr other positions the connector is m the second position 1 and the internal antenna 24' is therewitn disconnected from the transceiver.

In all the above-described embodiments each antenna could be either a single band antenna or a multi band antenna, either solution easily accomplished for a person skilled m the art.

In the description it is occasionally mentioned a helix or a meander antenna, which could be replaced by each other or by a stub antenna with the same general function maintained. Similarly it is occasionally mentioned a whip antenna, which could be replaced by a rod antenna with the same general function maintained. It is also occasionally mentioned an internal antenna, which could be replaced by a built-in, a PIFA or a planar antenna with the same general function maintained.

It is in the description also mentioned that antennae are connectable to transceiver circuitry since the most usual solution is to use an antenna for both radiating and receiving electromagnetic waves. However, it is easy for a person skilled n the art to use an antenna for either transmission or reception if for example reception diversity is desired. Therefore the term "RF circuitry" is used to describe either solution.

It will be obvious that the present invention may be varied in a plurality of ways. Such variations are not to be regarded as a departure from the scope of the invention. All such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the appended claims .

Claims

1. An antenna device for a portable radio communication device, comprising:

- a first antenna (4; 26) supported by a support structure (6; 20), and being connectable to RF circuitry of the portable radio communication device,

- a second antenna (8; 23) being movable between an extended end position and a retracted end position, and arranged to be slidable through an opening of said support structure,

- said second antenna being connectable to RF circuitry of the portable radio communication device,

characterized by

- a third antenna (24; 24') fixedly attached within the housing (3) of the portable radio communication device, and being connectable to RF circuitry of the portable radio communication device, and

- said support structure being movable between an extended end position and a retracted end position, and arranged to be slidable through an opening of a housing (3) of the portable radio communication device.

2. The antenna device according to claim 1, wherein said first antenna is a helix, a meander, or a stub antenna .

3. The antenna device according to claim 1 or 2, wherein said second antenna is a wnip or a rod antenna.

4. The antenna device according to any of claims 1- 3, wherein said third antenna is connected to said RF circuitry essentially only when said first antenna is disconnected from said RF circuitry, and said third antenna is disconnected from said RF circuitry essentially only when said first antenna is connected to said RF circuitry.

5. The antenna device according to claim 4, wherein a disconnection of the first or third antenna is performed after a connection of the third or first antenna, respectively.

6. The antenna device according to any of the preceding claims, wherein said first antenna is galvanically connectable to said RF circuitry only in an extended position.

7. The antenna device according to any of claims 1- 5, wherein said first antenna is galvanically connectable to said RF circuitry in both a retracted and an extended position and continuously galvanically connectable to said RF circuitry during retraction and extension of said support structure.

8. The antenna device according to any of claims 1 to 6, wherein said first antenna is galvanically connectable to said RF circuitry through said second antenna .

9. The antenna device according to any of the preceding claims, wherein said second antenna is connectable to said RF circuitry only in extended position.

10. The antenna device according to any of the preceding claims, wherein said first antenna is connectable to said RF circuitry through a continuously connected connector .

11. A portable radio communication device comprising the antenna device according to any of the preceding claims.