EP2166614A1

EP2166614A1 - An antenna device and a portable radio communication device comprising such antenna device

Info

Publication number: EP2166614A1
Application number: EP08164510A
Authority: EP
Inventors: Andrei Kaikkonen; Peter Lindberg; Mattias Südow
Original assignee: Laird Technologies AB
Current assignee: Laird Technologies AB
Priority date: 2008-09-17
Filing date: 2008-09-17
Publication date: 2010-03-24
Also published as: WO2010033071A1; CN102160234A

Abstract

The present invention relates to an antenna device for a portable radio communication device adapted for simultaneous FM, BT and GPS operation. The antenna device comprises a first elongated radiating element (1) having a first end (2) and a second end (3), a second elongated radiating element (4) having a first end (5) and a second end (6), and filtering means (7), wherein the first end (2) of the first elongated radiating element (1) is configured for connection to a GPS receiver (9) and to a BT transceiver (10), the second end (3) of the first elongated radiating element (1) is connected to the filtering means (7), the first end (5) of the second elongated radiating element (4) is connected to the filtering means (7), the second end (6) of the second elongated radiating element (4) is configured for grounding, and the first radiating element (1) is configured for connection to a FM transceiver (11) close to the first end (2) of the first elongated radiating element, and the filtering means (7) is configured to pass FM and GPS operating frequencies and to stop BT operating frequencies.

Description

FIELD OF INVENTION

The present invention relates generally to antenna devices and more particularly to an antenna device for use in a portable radio communication device, such as a mobile phone.

BACKGROUND

Internal antennas have been used for some time in portable radio communication devices. There are a number of advantages connected with using internal antennas, of which can be mentioned that they are small and light, making them suitable for applications wherein size and weight are of importance, such as in mobile phones, PDA, portable computer or similar devices.
However, the application of internal antennas in a mobile phone puts some constraints on the configuration of the antenna element. In particular, in a portable radio communication device the space for an internal antenna device is limited. These constraints may make it difficult to find a configuration of the antenna device that provides for desired use. This is especially true for antennas intended for use with radio signals of relatively low frequencies as the desired physical length of such antennas are large compared to antennas operating with relatively high frequencies.
One specific application operating in a relatively low frequency band is the FM radio application. The FM operating band is defined as frequencies between 88-108 MHz in most of the world and frequencies between 76-90 MHz in Japan. Prior art conventional antenna configurations, such as loop antennas or monopole antennas, fitted within the casing of a portable radio communication device will result in unsatisfactory operation in that the antenna either has too bad performance over a sufficiently wide frequency band or sufficient performance over a too narrow frequency band.
Instead, a conventional FM antenna for portable radio communication devices is usually provided in the headset wire connected to the communication device. This configuration with a relatively long wire permits an antenna length that is sufficient also for low frequency applications. However, if no external antenna is permitted this solution is obviously not feasible.
Further, a portable radio communication device is today many times provided with frequency operational coverage for other frequency bands then FM, such as GSM900, GSM1800, GPS, Bluetooth, WLAN, WCDMA and GPS. A portable radio communication device has limited space and it is thus desirable to, if possible, add multiple functionality to an antenna device.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an antenna device for a portable radio communication device, which efficiently utilizes available space of the portable radio communication device and provides for at least FM frequency band operation.
This object, among others, is according to the present invention attained by an antenna device and a portable radio communication device, respectively, as defined by the appended claims.
By providing an antenna device for a portable radio communication device adapted for simultaneous FM, BT and GPS operation, the antenna device comprises a first elongated radiating element having a first end and a second end, a second elongated radiating element having a first end and a second end, and filtering means, wherein the first end of the first elongated radiating element is configured for connection to a GPS receiver and to a BT transceiver, the second end of the first elongated radiating element is connected to the filtering means, the first end of the second elongated radiating element is connected to the filtering means, the second end of the second elongated radiating element is configured for grounding, and the first radiating element is configured for connection to a FM transceiver close to the first end of the first elongated radiating element, and the filtering means is configured to pass FM and GPS operating frequencies and to stop BT operating frequencies, an antenna device enabling simultaneous FM, GPS and BT operation is provided, which antenna device efficiently utilizes available space, since GPS and BT operation is added without significant increases of space.
By preferably providing the antenna device with a dielectric carrier supporting the first and second elongated radiating element, a robust installation of the antenna device is provided. The dielectric carrier is preferably part of the back cover of the portable radio communication device, which provides for a cost efficient and robust solution.
By preferably providing the first filtering means as a RF choke, the BT antenna efficiently is an IFA antenna.
By preferably providing the second filtering means as a capacitor, a simple, low cost and efficient filtering means is achieved.
By preferably providing the third filtering means as a capacitor, a simple, low cost and efficient FM tuning is achieved, at the same time efficiently working as a BT and GPS grounding.
By preferably providing the first and second radiating element to together have a length configured for the FM operation, the antenna device is based on the operation requiring most space.
By preferably providing the first elongated radiating element to have a length configured for the BT operation, BT operation can be configured without much interference for FM and GPS configuration.
By preferably providing the length between the first end of the first radiating element and the connection to the FM transceiver configured for GPS receiver tuning, GPS operation can be configured without much interference for BT and FM configuration. The length between the first end of the first radiating element and the connection to the FM transceiver is preferably also for configuration for GPS receiver and BT transceiver matching.
A portable radio communication device comprising an antenna device as described above is also provided.
Further preferred embodiments are defined in the dependent claims.

BRIEF DESCRIPTION OF DRAWINGS

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

FIG. 1 is a schematic diagram showing a first embodiment of an antenna device according to the present invention.
FIG. 2 is a perspective partially cut-away view of an antenna device according to the present invention mounted in a portable radio communication device.
FIG. 3 is a schematic diagram showing a second embodiment of an antenna device of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, for purpose of explanation and not limitation, specific details are set forth, such as particular techniques and applications in order to provide a thorough understanding of the present invention. However, it will be apparent for a person skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed description of well-known methods and apparatuses are omitted so as not to obscure the description of the present invention with unnecessary details.
In the following description and claims, the term radiating element is used. It is to be understood that this term is intended to cover electrically conductive elements arranged for receiving and/or transmitting radio signals.
An antenna device for a portable radio communication device according to a first embodiment of the present invention will now be described with reference to Figs. 1 and 2.
The antenna device comprises a first elongated radiating element 1, having a first end 2 and a second end 3, and a second radiating element 4, having a first end 5 and a second end 6. The antenna device further comprises first filter means 7 connected between the second end 3 of the first elongated radiating element 1 and the first end 5 of the second elongated radiating element 4. The first end 2 of the first elongated radiating element 1 is connected to second filtering means 12, which in turn is connected to a GPS (Global Positioning System) receiver 9 and a BT (Bluetooth) transceiver 10. The second end 6 of the second elongated radiating element 4 is connected to ground. A FM transceiver 11 is connected to a point 8 of the first elongated radiating element 1 close to the first end 2 thereof. The connection point 8 is further connected to ground through third filtering means 13.
The first and second elongated radiating elements 1 and 4 together have a length 14 configured for FM operation and GPS tuning, about 90 mm. The first elongated radiating element 1 have a length 15 configured for BT operation, about 40 mm. The length 16 between the connection point 8 and the first end 2 of the first elongated radiating element 1 is configured for matching of the GPS receiver 9 and the BT transceiver 10, about 10 mm. The exemplary lengths given above are dependent on e.g. distance above a ground plane device 17, in this case based on the distance of about 7 mm.
The first and second radiating elements are preferably planar elements supported by a dielectric carrier. The dielectric carrier is e.g. a portion of the back cover of the portable radio communication device 20. Alternatively the dielectric carrier is e.g. a portion of the middle deck the portable radio communication device 20. Further, the first and second radiating elements are alternatively e.g. self-supported.
The first filtering means 7 is preferably provided as an RF choke of about 20 nH, but cold alternatively be provided as parallel resonant circuit. The first filtering means 7 is in such a way configured to pass FM and GPS operation and to stop BT operation. The second filtering means 12 is preferably provided as a capacitor of about 1 pF. The second filtering means 12 is in such a way configured to pass BT and GPS operation and to stop FM operation. The third filtering means 13 is preferably provided as a capacitor of about 30 pF. The third filtering means 13 is in such a way configured to tune the FM transceiver 11 and to ground BT and GPS operation. The antenna device is in such a way configured to simultaneously with FM frequencies operate at BT and GPS frequencies.
The antenna device preferably forms a half-loop radiating element for FM operation. A half-loop antenna is a virtual loop antenna, by being provided over a ground plane device 17. The antenna device effectively forms an IFA antenna for BT operation, and effectively utilizes the first and second elongated radiating elements for GPS operation.
A second embodiment of an antenna device according to the present invention is illustrated in Fig. 3. The second embodiment of the antenna device is identical with the first embodiment of the antenna device described above apart from the following.
The antenna device comprises a BT/GPS duplex filter 18, which e.g. is implemented as a standard component or integrated on chips.
It will be obvious that the present invention may be varied in a plurality of ways. Such variations are not to be regarded as departure from the scope of the present invention as defined by the appended claims. All such variations as would be obvious for a person skilled in the art are intended to be included within the scope of the present invention as defined by the appended claims.

Claims

An antenna device for a portable radio communication device adapted for simultaneous FM, BT and GPS operation, characterized in that
said antenna device comprises a first elongated radiating element (1) having a first end (2) and a second end (3), a second elongated radiating element (4) having a first end (5) and a second end (6), and filtering means (7), wherein said first end (2) of said first elongated radiating element (1) is configured for connection to a GPS receiver (9) and to a BT transceiver (10), said second end (3) of said first elongated radiating element (1) is connected to said filtering means (7), said first end (5) of said second elongated radiating element (4) is connected to said filtering means (7), said second end (6) of said second elongated radiating element (4) is configured for grounding, and said first radiating element (1) is configured for connection to a FM transceiver (11) close to said first end (2) of said first elongated radiating element, and
said filtering means (7) is configured to pass FM and GPS operating frequencies and to stop BT operating frequencies.
An antenna device for a portable radio communication device adapted for simultaneous FM, BT and GPS operation, characterized in that
said antenna device comprises a first elongated radiating element (1) having a first end (2) and a second end (3), a second elongated radiating element (4) having a first end (5) and a second end (6), and filtering means (7), wherein said first end (2) of said first elongated radiating element (1) is connected to a GPS receiver (9) and to a BT transceiver (10), said second end (3) of said first elongated radiating element (1) is connected to said filtering means (7), said first end (5) of said second elongated radiating element (4) is connected to said filtering means (7), said second end (6) of said second elongated radiating element (4) is grounded, and said first radiating element (1) is connected to a FM transceiver (11) close to said first end (2) of said first elongated radiating element, and
said filtering means (7) is configured to pass FM and GPS operating frequencies and to stop BT operating frequencies.
An antenna device for a portable radio communication device adapted for simultaneous FM, BT and GPS operation, characterized in that
said antenna device comprises a first elongated radiating element (1) having a first end (2) and a second end (3), a second elongated radiating element (4) having a first end (5) and a second end (6), first filtering means (7), second filtering means (12) third filtering means (13), a GPS receiver (9), a BT transceiver (10) and a FM transceiver (11), wherein said first end (2) of said first elongated radiating element (1) is connected to said GPS receiver (9) and to said BT transceiver (10) through said second filtering means (12), said second end (3) of said first elongated radiating element (1) is connected to said first filtering means (7), said first end (5) of said second elongated radiating element (4) is connected to said first filtering means (7), said second end (6) of said second elongated radiating element (4) is grounded, and said first radiating element (1) is connected to said FM transceiver (11) through said third filtering means (13) close to said first end (2) of said first elongated radiating element, and
said first filtering means (7) is configured to pass FM and GPS operating frequencies and to stop BT operating frequencies, said second filtering means (12) is configured to pass BT and GPS operating frequencies and to stop FM operating frequencies, and said third filtering means (13) is configured to pass BT and GPS operating frequencies to ground and to tune FM operating frequencies.
The antenna device according to any of claims 1-3, comprising a dielectric carrier supporting said first and second elongated radiating element.
The antenna device according to claim 4, wherein said dielectric carrier is part of the back cover of the portable radio communication device.
The antenna device according to any of claims 1-5, wherein said first filtering means (7) is a RF choke.
The antenna device according to any of claims 1-6, wherein said second and third filtering means are capacitors.
The antenna device according to any of claims 1-7, wherein said first and second radiating element together have length (14) configured for said FM operation.
The antenna device according to claim 8, wherein said first elongated radiating element having a length (15) configured for said BT operation.
The antenna device according to any previous claim, wherein the length between the first end (2) of the first radiating element (1) and the connection (8) to the FM transceiver is configured for GPS receiver tuning.
The antenna device according to any previous claim, wherein the length between the first end (2) of the first radiating element (1) and the connection (8) to the FM transceiver is configured for GPS receiver and BT transceiver matching.
A portable radio communication device, characterized in that it comprises an antenna device according to any of the preceding claims and a ground plane device (18), wherein said first (1) and second (4) elongated radiating element are arranged over said ground plane device (18).