Inverted-F antenna for flip-style mobile terminals

ABSTRACT

A flip or calm-shell style mobile terminal comprises a mechanical hinge that doubles as an inverted-F antenna for auxiliary communication purposes such as with a Bluetooth transceiver or a GPS receiver.

INFORMATION

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION

The present invention is directed to an antenna for use in a mobile terminal and particularly to an auxiliary antenna for use in a mobile terminal.

Mobile terminals, such as cellular phones, pagers, personal digital assistants, and the like have exploded into the public's consciousness. One recent innovation pioneered by a consortium of mobile terminal manufacturers is a communication technology called Bluetooth that operates in the ISM band at 2.4 to 2.485 GHz in the electromagnetic spectrum. Mobile terminals are being adapted to incorporate this technology. Mobile terminals are also being adapted to operate with position detection systems, such as the Global Positioning System (GPS). GPS operates at 1.57542 GHz.

Due to the fact that these technologies operate at frequencies different from those normally associated with wireless communications, mobile terminals need additional, or at least different, antennas to function properly with these technologies.

BRIEF SUMMARY OF THE INVENTION

The present invention comprises using a mechanical hinge in a flip or clam-shell style mobile terminal as an inverted-F antenna for auxiliary communication purposes such as with a Bluetooth transceiver or a GPS receiver. In one embodiment, a first part of the hinge (a first hinge plate) is attached to the signal line of the RF printed circuit board of the mobile terminal by a fastener such as a screw. A second screw adjacent to the first screw is attached between the ground of the RF printed circuit board and the hinge. Together the first part and the two screws form an inverted-F antenna. A second part of the hinge (a second hinge plate) is coupled to the first part and forms the remainder of the mechanical hinge. In some embodiments, meanders are used to lengthen the electrical length of the first part so as to achieve an optimal operating frequency.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to an improved antenna arrangement in flip-type mobile terminals. In particular, the present invention provides an inverted F-antenna integrated into a hinge. A “hinge” as used herein includes both hinge plates and pivot area. It should be appreciated that while the hinges illustrated herein include a pin as the pivot, they may also be living hinges if needed or desired. This additional antenna allows the mobile terminal to communicate at another frequency while allowing isolation between the antennas of the mobile terminal to reduce crosstalk and other electromagnetic interference.

As illustrated in , a communication environment may include a mobile network , a location detection network , and a Bluetooth network . A mobile terminal may be positioned in one or more of these networks.

Mobile network may comprise, amongst other elements, an MSC and a base station . MSC may be communicatively coupled to the Public Switched Telephone Network (PSTN) or other mobile networks within the Public Land Mobile Network (PLMN, not shown) as is conventional. The operation of mobile network , and mobile terminal within the mobile network , are well documented in various standards such as TIA/EIA-136, Digital Advance Mobile Phone Service (D-AMPS), European Total Access Communication System (ETACS), Code Division Multiple Access (CDMA), Global System for Mobile Communication (GSM), Pacific Digital Cellular (PDC), and the like, the standards and documentation of which are herein incorporated by reference.

Location detection network may be a satellite-based system, a terrestrial system or some hybrid thereof. Location detection network is illustrated as a satellite system comprising one or more satellites . The most common location detection system is the Global Positioning System (GPS), although the Russian equivalent, GLONASS, is another option. Other systems may likewise be available. Typically, satellites communicate with mobile terminals over a different frequency than that on which the mobile terminals communicate with the mobile network . For example, GPS satellites communicate at 1.57542 GHz. The GPS standards are partially publicly available at http://www.navcen.uscg.mil/pubs/gps/icd200/icd200c.pdf and are hereby incorporated by reference.

Bluetooth network may comprise a Bluetooth enabled computer or other Bluetooth enabled device such as another mobile terminal , a vehicle or the like as needed or desired. Bluetooth is well documented at www.bluetooth.com. In particular, the specifications, volumes 1 and 2 are hereby incorporated by reference in their entirety. These are publicly available at http://www.bluetooth.com/developer/specification/specification.asp. Bluetooth communications likewise communicate with mobile terminals over a different frequency than that on which the mobile terminals communicate with the mobile network . In particular, Bluetooth enabled devices communicate at approximately 2.4 GHz in the ISM band.

The present invention is adapted for use in the mobile terminal to enable mobile terminal to communicate with the various networks within communication environment . However, a more complete understanding of the mobile terminal may be helpful. Turning now to , a block diagram of a mobile terminal is illustrated. Mobile terminal typically includes a controller , an operator interface , a transmitter , a receiver , and a primary antenna assembly . Operator interface typically includes a display , keypad , interface control , microphone , and a speaker . Display allows the operator to see dialed digits, call status, and other service information. Keypad allows the operator to dial numbers, enter commands, and select options. Interface control interfaces the display and keypad with the controller . Microphone receives acoustic signals from the user and converts the acoustic signals to an analog electrical signal. Speaker converts analog electrical signals from the receiver to acoustic signals that can be heard by the user.

The analog electrical signal from the microphone is supplied to the transmitter . Transmitter includes an analog to digital converter , a digital signal processor , and a phase modulator and RF amplifier . Analog to digital converter changes the analog electrical signal from the microphone into a digital signal. The digital signal is passed to the digital signal processor (DSP) , which contains a speech coder and channel coder . Speech coder compresses the digital signal and the channel coder inserts error detection, error correction and signaling information. DSP may include, or may work in conjunction with, a DTMF tone generator (not shown). The compressed and encoded signal from the digital signal processor is passed to the phase modulator and RF amplifier , which are shown as a combined unit in FIG. . The modulator converts the signal to a form that is suitable for transmission on an RF carrier. RF amplifier then boosts the output of the modulator for transmission via the primary antenna assembly .

Receiver includes a receiver/amplifier , digital signal processor , and a digital to analog converter . Signals received by the primary antenna assembly are passed to the receiver/amplifier , which shifts the frequency spectrum, and boosts the low-level RF signal to a level appropriate for input to the digital signal processor .

Digital signal processor typically includes an equalizer to compensate for phase and amplitude distortions in the channel corrupted signal, a demodulator for extracting bit sequences from the received signal, and a detector for determining transmitted bits based on the extracted sequences. A channel decoder detects and corrects channel errors in the received signal. The channel decoder also includes logic for separating control and signaling data from speech data. Control and signaling data are passed to the controller . Speech data is processed by a speech decoder and passed to the digital to analog converter . Digital signal processor , may include, or may work in conjunction with, a DTMF tone detector (not shown). Digital to analog converter converts the speech data into an analog signal that is applied to the speaker to generate acoustic signals that can be heard by the user.

Together, the transmitter and the receiver are referred to herein as a voice communication transceiver.

Primary antenna assembly is connected to the RF amplifier of the transmitter and to the receiver/amplifier of the receiver . Primary antenna assembly typically includes a duplexer and an antenna . Duplexer permits full duplex communications over the antenna .

Controller coordinates the operation of the transmitter and the receiver , and may for instance take the form of a typical microprocessor. This microprocessor may be a dedicated or shared microprocessor and may be a single processor or multiple parallel processors as needed or desired. This coordination includes power control, channel selection, timing, as well as a host of other functions known in the art. Controller inserts signaling messages into the transmitted signals and extracts signaling messages from the received signals. Controller responds to any base station commands contained in the signaling messages, and implements those commands. When the user enters commands via the keypad , the commands are transferred to the controller for action. Memory stores and supplies information at the direction of the controller and preferably includes both volatile and non-volatile portions. It is expected that controller and memory as well as many of the other processing components described herein will be positioned on a printed circuit board () as is conventional.

In addition to the above-described elements, the mobile terminal may also include a location detector in communication with the controller . Location detector may have its own antenna discussed below. Location detector may be a Global Positioning System (GPS) receiver or other satellite or terrestrial system as needed or desired. Typically, the location detector will output a geocoordinate expressed as longitude, latitude, and, optionally, altitude coordinates corresponding to the present location of the mobile terminal .

Mobile terminal may also include a Bluetooth module together with Bluetooth antenna . Bluetooth is discussed above and reference is made thereto. Bluetooth module is designed to comply with the standards set forth for Bluetooth and enable wireless communication at approximately 2.4 GHz between Bluetooth enabled devices. Controller may control Bluetooth module as needed or desired.

As noted, various antennas maybe associated with the mobile terminal . Antennas operate most efficiently when they are one quarter the length of the signal desired to be received. Thus, to facilitate proper communication in a mobile terminal amongst the various networks , , and , it may be desirable to have three different antennas. Further, many mobile terminals are already designed to operate in two or three modes so as to communicate with different mobile networks that may employ different standards alternatively requiring more antennas. Typically, a mobile terminal may operate at one or more of the following frequency ranges: 824-894 MHz, 880-960 MHz, 1710-1880 MHz, and 1850-1990 MHz, depending on which standards with which it complies.

It is known to add antennas having the desired length to mobile terminals to add additional functionality. However, these additional antennas require additional circuitry and additional space in or about the mobile terminals. Further, the antennas must be separated sufficiently to insure proper mutual isolation so as to reduce crosstalk or other forms of electromagnetic interference. While filters can be used to reduce crosstalk, filters for closely spaced antennas tend to be bulky and relatively expensive to achieve the performance required. Alternatively a “window” may be created which allows an internally positioned antenna to communicate through the body () of the mobile terminal . However, this imposes additional undesirable constraints on circuit board design. Thus, for antennas for Bluetooth or GPS applications, especial care must be taken to not interfere with the primary cellular antenna assembly .

A mobile terminal incorporating the present invention is illustrated in a perspective view in FIG. . Mobile terminal is a flip-type or clamshell-type mobile terminal having a body and a flip portion hingedly connected one to the other by hinges and . It should be appreciated that in some embodiments, only one hinge may connect the flip portion to the body . Display may be mounted on the mobile terminal , and, in this case, on the flip portion . However, it should be appreciated, that in some mobile terminals , such as a cellular phone, the flip portion may have no additional components. Mobile terminal may also comprise a keypad , a microphone and a speaker mounted on body . Again, it should be appreciated that some or all of these components instead could be mounted on the flip portion if needed or desired. Primary antenna assembly is shown as a stub antenna, but may include other classes of external or internal antennas designed to operate at conventional cellular frequencies or the like.

It should be appreciated that the term “mobile terminal” may include a cellular radiotelephone with or without a multi-line display, a Personal Communications System (PCS) terminal that may combine a cellular radiotelephone with data processing, facsimile and data communications capabilities; a PDA that can include a radiotelephone, pager, Internet/intranet access, Web browser, organizer, and/or calendar; and a conventional laptop and/or palmtop receiver or other appliance that includes a radiotelephone transceiver. Mobile terminals may also be referred to as “pervasive computing” devices. Thus, while the present discussion may be couched in terms of a phone and/or a laptop computer, the present invention is equally applicable to these other sorts of devices. The previous discussion was by way of example, and not intended to be limiting on the definition of a mobile terminal.

The present invention uses hinges and/or to act as the antennas for location detector and/or the Bluetooth module . While such applications may be of primary commercial importance at the present time, it should be appreciated that an antenna created within the hinges or may equally be adapted for other purposes or devices within the mobile terminal , such as Asia's i-Mode, another frequency antenna to make the mobile terminal dual-mode or even tri-mode, or the like as needed or desired. Further, in mobile terminals that include two hinges , , both hinges may be changed to antenna hinges according to the present invention. For example, a first hinge could be adapted for Bluetooth performance and a second hinge adapted for GPS reception. Other permutations on this concept will be readily apparent to those of ordinary skill in the art.

illustrates a first embodiment of the present invention. In particular, a hinge, for the purposes of illustration, hinge , connects the flip portion to the body of the mobile terminal . Hinge is formed from two parts, a first part and a second part . In the event the flip portion includes a display , hinge is constructed to allow a flex-film line (constructed of a suitable polyimide material) to carry signals to the display from the body and particularly from the controller on the printed circuit board .

First part is spaced from and attached to the printed circuit board by two fasteners and respectively. Together, the first part and the fasteners , form an inverted-F antenna. Suitable fasteners include screws or the like. Thus, the shank of the screw may space the first part from the printed circuit board . One fastener acts as a connection to the ground plane of the printed circuit board . The other fastener acts as a the RF feed for the antenna , connecting antenna to the appropriate circuitry on the printed circuit board such as the location detector or the Bluetooth module . Note that choosing which fastener acts as the ground connection and which acts as the RF signal connection is well understood. It should be appreciated that the ground feed and the RF feed could alternatively be provided by another structure that does not fasten the antenna to the printed circuit board and that the antenna may be held in place by fastening the antenna to the body of the mobile terminal . It should be appreciated that the first part and the fasteners and need to be capable of receiving electromagnetic signals, and thus are likely to be metal. Further, the spacing of the fasteners , may be varied to achieve impedance matching or otherwise improve performance.

While dimensions of the hinge are not critical to the present invention, sample appropriate dimensions are as follows: first part length 25 mm, height 4 mm, and width 5 mm; second part length 30 mm, height 0.02 mm, and width 7 mm. In general, the size of the two parts and will be dictated by the mechanical strength requirements of the hinge . Angle Θ represents the angle between first part and second part . In one embodiment, antenna should function as desired regardless of the angle Θ. This, however, may be somewhat dependent upon the operating frequency of the antenna .

A second embodiment is illustrated in FIG. . In this embodiment, especially adapted for GPS reception, antenna comprises a first part and a second part . Similarly to the previous embodiment, one fastener (not shown) may connect part to the signal line of the RF printed circuit board and another fastener (not shown) may connect the ground of the RF printed circuit board to part is required. This has been achieved here using plates , respectively as illustrated. Note that plate may be thicker than plate . First part includes a meander to make it electrically longer without changing the axial length of the first part . Second part may likewise be coated with a plastic film so as not to short out the meanders when the hinge is in a closed position. For a further discussion of meander antennas in the field of mobile terminals, reference is made to application Ser. No. 09/089,433, which is hereby incorporated by reference in its entirety. Alternatively, a film may be positioned atop meanders to perform the same function. Other alternate techniques to isolate the parts and may also occur to those of ordinary skill in the art.

The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the scope and the essential characteristics of the invention. The present embodiments are therefore to be construed in all aspects as illustrative and not restrictive and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

CLAIMS

1. A mobile terminal comprising: a body; a flip portion; and a hinge connecting said body to said flip portion, said hinge comprising hinge plates that function as an inverted-F antenna for use by an electronic circuit positioned within said mobile terminal.

2. The mobile terminal of claim 1 wherein said antenna is operative at frequencies between 2.4 and 2.485 GHz.

3. The mobile terminal of claim 1 wherein said antenna operates within the ISM band.

4. The mobile terminal of claim 1 wherein said antenna receives a GPS signal.

5. The mobile terminal of claim 1 further comprising a second hinge, said second hinge comprising second hinge plates that function as a second antenna.

6. The mobile terminal of claim 5 wherein said first antenna is adapted for use at frequencies ranging from 2.4 to 2.485 GHz and said second antenna is adapted for receiving a GPS signal.

7. The mobile terminal of claim 1 further comprising a printed circuit board adapted to hold said electronic circuit.

8. The mobile terminal of claim 7 further comprising a fastener attaching said antenna to said printed circuit board.

9. The mobile terminal of claim 8 wherein said fastener is a screw.

10. The mobile terminal of claim 9 further comprising a second fastener attaching said antenna to said printed circuit board.

11. The mobile terminal of claim 10 wherein one of said fasteners acts as a connection to ground for said antenna and the other of said fasteners acts as an RF feed for said antenna.

12. A method of constructing a mobile terminal, comprising: positioning a printed circuit board in the mobile terminal; fastening an inverted-F antenna to said printed circuit board; and using said inverted-F antenna to function as hinge plates of a hinge for a flip portion of said mobile terminal.

13. The method of claim 12 further comprising receiving and transmitting Bluetooth communications through said antenna.

14. The method of claim 12 further comprising receiving a GPS signal through said antenna.

15. The method of claim 12 wherein fastening an antenna to said printed circuit board comprises using a first fastener as a connection to ground and using a second fastener as an RF feed.

16. The method of claim 12 further comprising opening and closing said hinge during operation of the mobile terminal.

17. A mobile terminal comprising: a body; a printed circuit board positioned inside said body; a flip portion; and a hinge, said hinge functioning as an inverted-F antenna and hingedly securing said flip portion to said body, said hinge electrically coupled to said printed circuit board.

18. The mobile terminal of claim 17 further comprising a voice communication transceiver and a second antenna adapted for use with said voice communication transceiver, said voice communication transceiver positioned within said body, and said second antenna spaced from said inverted-F antenna.

COPYRIGHT

User acknowledges that Fairview Research and its third party providers retain all right, title and interest in and to this xml under applicable copyright laws. User acquires no ownership rights to this xml including but not limited to its format. User hereby accepts the terms and conditions of the License Agreement.