An accessory for digital portable electronic appliances having hardware and software resources for displaying an image and executing at least one application, such as, for example: a portable multimedia player (PMP); a smart phone; a personal digital assistant (PDA); a laptop computer; . . .
Enabling a portable electronic appliance to receive and/or transmit radio signals with the help of means that are compact and self-contained and that can be used while mobile.
Computer peripheral accessories are known that are in the form of a USB “stick” and that enable television to be received by a laptop computer.
Antenna diversity techniques are known that enable radio signal reception to be improved in the context of wireless digital transmission.
The accessories provided for digital TV reception in the state of the art are fitted with a connector that enables the accessory to be connected to an external signal source. That might be a connection to a collective antenna installation or to one or two remotely-located individual antennas.
In general, having antennas located remotely offers numerous advantages, such as simplifying the mechanical design of the accessory and greater universality for the shape of the accessory relative to the shape of the appliance to which it is connected. In addition, keeping antennas separate from the electronic appliance is favorable for reception, in that antennas that can be positioned freely make it easier to find a position in which the signal is picked up better. It is also favorable for the antennas to be spaced apart from the portable electronic appliance and/or the accessory device of the invention in that electronic subassemblies generally constitute sources of noise. That said, such an installation is not suitable for mobile use.
Prior art solutions provide a partial and unsatisfactory response to the problem of receiving and/or transmitting radio signals with the help of compact and self-contained means suitable for use while mobile.
The device of the invention enables a portable electronic appliance to receive and/or transmit radio signals. The device comprises at least one electronic subassembly, means for connecting the at least one electronic subassembly of the device to the electronic appliance, at least two non-removable antennas used in diversity mode that are secured to the device by implementing means that conserve the relative positions between said antennas and the device in the absence of external forces being applied between said elements.
The device may be an accessory that is dedicated to one type or model of portable electronic appliance, or it may be a universal accessory that can be used as a periphery with a variety of electronic appliances.
The term “at least one electronic subassembly” should be understood as meaning one or more functional units capable of being implemented in the form of one or more printed circuits. For example, this may involve performing all or some of the functions in the following non-limiting list, possibly in a different order: amplifying the signal coming from the antennas; combining signals; demodulation; managing diversity; decoding; and managing the interface with the portable appliance.
The term “at least two antennas used in diversity mode” should be understood as implementing at least one diversity technique seeking to increase the performance of a wireless digital transmission system. By way of example, the increase in performance provided by the antenna diversity is particularly advantageous for receiving digital radio and/or TV under good conditions while mobile. This applies in particular if the antenna diversity is associated with a dedicated reception channel per antenna and suitable signal processing. When the portable electronic appliance is to be given connectivity with networks by means of the device of the invention, the antenna diversity may also be operated in transmission, e.g. in the context of MIMO type solutions such as those implemented in the IEEE 802.lln standard. Antenna diversity can involve an unlimited number of antennas, and it is merely constraints of cost, size, and/or appearance that limits this number, usually to two or three antennas only. Implementation of the invention may involve no more than diversity in terms of the locations of identical antennas, however it may also involve polarization diversity, antenna type diversity, and more generally it may involve implementing any technique that makes it possible to increase the probability at any given instant of at least one antenna being in satisfactory operating conditions. Nevertheless, it remains within the ambit of the invention to implement so-called microdiversity techniques, i.e. when the distance between the antennas is of the same order as the wavelength used.
In certain embodiments of the invention, provision is made for the device further to comprise at least one separable rigid mechanical connection for fastening the device to the portable electronic appliance.
The at least one separable rigid mechanical connection may advantageously include contacts for connecting the at least one electronic subassembly of the device to the portable electronic appliance to which it is fastened. This may be provided, for example, by a specific connector or indeed by a standard connector that is sufficiently robust, for example a type A USB connector.
Provision is made for the connection between the device and the antenna to take place via a separable rigid mechanical connection that includes contacts in addition to at least one other separable rigid mechanical connection that does not include contacts and that serves to reinforce the mechanical robustness of the assembly.
Provision is also made for the connection between the device and the appliance to make use of wired means, such as at least one cable fitted with at least one connector, or indeed wireless means, e.g. using the ad hoc WiFi, WUSB, or Bluetooth standards.
The term “at least two non-removable antennas secured to the device by implementing means that conserve the relative positions between said antennas and the device in the absence of external forces being applied between said elements” should be understood as meaning that in the device of the invention the antennas are fastened to the body of the device by making use of techniques that are not suitable for being taken apart. When at least one degree of freedom is available, then provision is made for friction forces to conserve the positions of the elements relative to one another so long as no other force of greater magnitude is applied. The purpose is to ensure that when any change in the positioning of an element of the system relative to the others is possible, it should be conserved so long as no other action countermands it. This purpose may be achieved, for example, by connecting together the elements of the system of the invention by means that are rigid, semirigid, or flexible so as to conserve relative positions from a given position. Degrees of freedom may advantageously be incorporated in the assemblies, both to facilitate storage of the accessory and to enable adjustments of orientation to be optimized.
In addition, the use of flexible and/or hinge elements reduces the fragility of the accessory, and/or of the system it constitutes with the electronic appliance to which it is connected. Systems made up of deformable elements are less fragile in that they can be subjected to the effects of external forces without irreversible damage.
The device of the invention also provides for at least one non-removable antenna of the device to be arranged to improve its performance by the presence of a nearby ground plane and/or conductor element connected to ground. The term “ground plane” is used to designate any solid or perforated conductive surface, optionally connected to a determined potential such as the ground of the associated reception and/or transmission electronics. Depending on the context in which it is implemented, a ground plane of the invention may for example act as the other half-dipole when using a so-called half-dipole or “whip” antenna, as a reflector (for a “quad” antenna), as a support for a dielectric (for a “patch” antenna), or as shielding against undesirable radiation.
The invention also makes provision for said ground plane and/or said conductor element to be deployable. The ground plane and/or the conductor element may be deployed as a result of deploying an antenna. It is also possible for deployment of the ground plane and/or the conductor element to be handled in a manner that is completely or partially separate from deploying the antenna, without thereby going beyond the ambit of the invention.
In a first embodiment of the invention, at least one non-removable antenna of the device is of the monopole or dipole wire type, e.g. a whip operating as a quarter-wave or a half-wave antenna.
In a second embodiment, at least one non-removable antenna of the device is of the magnetic loop type.
In a third embodiment, at least one non-removable antenna of the device is of the plane type.
In each of these three embodiments of the device, at least one other antenna may be of the same type or of a different type.
The term “plane antenna” is used to mean an antenna constituted by a plurality of individual surface area elements that are arranged in air or on a suitable solid dielectric in a common plane in order to form a composite antenna, e.g. a so-called “quad” antenna or indeed a so-called “patch” antenna. These antennas also require respectively a metal reflector or a ground plane.
In all of the above-mentioned types of antenna, the wire elements or surface area elements can be implemented using shapes that are simple, or shapes that are complex such as so-called space-filler techniques, without thereby going beyond the ambit of the invention. So-called space-filler techniques such as those relying on fractal mathematics and made available by the supplier Fractus SA, make it possible, other things being equal, and in particular wavelength being equal, to obtain dimensions that are more compact than when using traditional shapes.
In a preferred embodiment of the invention, at least one non-removable antenna of the device is deployable.
The term “deployable” is used to designate any technique making it possible to distinguish between a state of the system of the invention that is more compact for transport or storage and a utilization state that takes up more space. For example, this may involve techniques based on elements that are foldable and/or telescopic and/or suitable for rolling up, or indeed any combination of such techniques. Deployment may make use of any type of relative movement between the elements making up the antenna and/or between the antenna as a whole and the body of the accessory of the invention. These movements may be in translation and/or rotation or in any combination of these elementary types of movement.
It is possible for each antenna to make use of different deployment techniques.
In this preferred variant of the invention, the device has a plurality of deployable antennas so as to make it more compact in the storage position, so as to give it the ability to adapt to the dimensions of the portable electronic appliance to which it is fastened so as to form a one-piece assembly, and/or so as to give it the ability to orient the antennas so as to optimize operation when the portable electronic appliance is in a given orientation.
It is possible for at least one antenna out of at least two to be stationary relative to the body of the accessory of the invention. The shorter the wavelengths being used, the smaller is the need to make the antennas deployable, since they are small in size. All or some of the antennas may even be incorporated within the body of the device without thereby going beyond the ambit of the invention.
It is known that the performance of stationary antennas is improved when the radiating portion thereof is situated at a location relative to a ground plane or a metal element optionally connected to ground, depending on the technical options implemented. Deployable antennas in the state of the art do not make use of this possibility for improving their performance.
The invention provides for at least one non-removable and deployable antenna to have its performance, e.g. its gain, improved by the presence of a nearby ground plane and/or of a conductor element connected to ground. In a preferred embodiment, at least one non-removable and deployable antenna comprises both a radiating portion and a portion connected to ground.
Advantageously, the portion of the at least one non-removable and deployable antenna of the device that is connected to ground potential is situated between the radiating portion of the antenna and its attachment point situated on the body of the device.
Provision is also made for the portion that is connected to ground potential of at least one non-removable and deployable antenna of the device to include conductor elements firstly to feed the radiating portion of the antenna and secondly to shield the feed line.
In an even more advantageous embodiment of the invention, the conductors for establishing electrical continuity between the deployable antenna and the reception electronics form a connection of impedance that is substantially matched when the antenna is fully deployed. It is difficult and expensive to implement a technique that enables a deployable connection to be established that is continuously matched regardless of the amplitude of its deployment. In practice, the intermediate deployment positions are of little interest and performance is generally maximized at maximum deployment, when the antennas are the farthest apart from one another and the farthest away from the sources of noise constituted by the electronic assemblies of digital appliances.
In a first embodiment relating to the power supply to the electronic subassemblies, the device of the invention is powered by the portable electronic appliance to which it is connected.
In a second embodiment, it is the device of the invention that powers the portable electronic appliance to which it is connected. This can be done by using an energy source contained in the device and/or by using an external energy source, such as a mains power supply unit for use in a building or indeed a power supply fitted with a plug suitable for connection to the cigar lighter for use in a vehicle.
The invention provides for the device further to include a support function. This may be a function of supporting the device on its own and/or of supporting the electronic appliance when the device and the appliance are assembled together by means of a rigid connection. The term “support function” is used to cover any means for placing and/or fastening the element(s) in question on a surface, in a manner that is stable and appropriate for use and/or storage thereof. For example, the support might comprise a fixed or retractable stand, a suction cup, a magnetic fastener, or fastening by clamping between jaws.
Including a support function in the device of the invention is particularly relevant when it is used as an accessory for a portable electronic appliance that is fastened on top of the device. With such an assembly, raising the appliance relative to the support plane makes any support that might be integrated in the portable appliance inoperative, e.g. legs of length that is designed for the appliance resting directly on a plane.
In another aspect of the invention, a system is provided for receiving and/or transmitting radio signals and for making use of them while mobile, the system comprising:
a reception device as defined above; and
a portable electronic appliance to which the device is connected.
In a first application of the system of the invention, it serves to receive digital television by means of an electronic appliance and an accessory including at least two non-removable antennas. The invention seeks also to make the system constituted by the portable electronic appliance and the reception accessory more compact in that the antennas are retractable or foldable, at least in part, and can be deployed depending on requirements. The term “deployed depending on requirements” is used to mean deployed so as to take account of the size of the housings of the portable appliance and of the accessory, and/or that enables satisfactory reception to be obtained under given positioning conditions. The term “use while mobile” should be understood as enabling digital TV to be received while the entire reception system of the invention is mobile because it is held, carried, or secured by appropriate means to a user who is moving. This may equally involve fastening or placing the system of the invention in a moving assembly that contains the user, such as private or public means for transport on land, in the air, or at sea. Mobility may also involve mobility of the user and of the system of the invention prior to use, followed by the system being used in a manner that is actually static. Such mobility prior to use may take place for example within premises, whether professional or domestic.
The term “reception of digital TV” is used to mean receiving digital TV signals broadcast by infrastructure means in application of standards such as, for example: DVB-T; DVB-H; T-DMB; CDMB; etc.
The term “reception of digital TV” is also used to mean reception of any signal transmitted by wireless means and compatible with the device, being suitable for conveying video to the system of the invention. This may involve, for example, receiving a video stream coming from a point having access to a local network or to a remote network using standards such as, for example: WiFi, WiMax, WUSB, or Bluetooth. This may also apply to a stream coming directly from another appliance in the context of a point-to-point or point-to-multipoint connection. Most such standards or variants thereof, e.g. a 802.11n, can take advantage of the antenna diversity characteristic of the accessory of the invention in order to improve the performance of the connection.
By way of example, the signal source may be a digital video recorder/player, a so-called “set top box” receiver/decoder, or indeed an appliance on board transport means, for example in the trunk of a car or in an equipment compartment of public transport means for storing content and/or for receiving streams coming from a primary connection such as a terrestrial or satellite digital broadcast network.
The signal received and made use of by the accessory of the invention may be associated with a single channel or with a plurality of channels subdivided in packets or multiplexed in time division or frequency division without going beyond the ambit of the invention.
Naturally, it remains within the ambit of the invention if only the digital audio stream is processed in an application of the invention restricted solely to receiving and/or transmitting sound.
In a second application of the system of the invention, it is possible to receive geolocation information by means of an electronic appliance and an accessory having at least two non-removable antennas. The application of the system of the invention to this context enables a quality of service to be obtained that is greater than that made available by state of the art techniques. Increased quality of service leads to greater availability of the service in contexts where state of the art techniques are no longer functional and/or leads to an increase in the accuracy of the information delivered.
The system of the invention is suitable for pedestrian use and/or for use on board a vehicle.
In a third application of the system of the invention, it is possible to connect a portable electronic appliance to a local and/or infrastructure network by means of an electronic appliance and an accessory having at least two non-removable antennas.
Other advantages and characteristics of the invention appear on examining the detailed description of a non-limiting embodiment and the accompanying drawings, in which:
Advantageously, the device 1 powers the portable appliance 7 via conductors included in the cable 19 so that the resulting system is not limited in battery life.
Even when the device 1 of the invention is not implemented for best reception of satellite geolocation signals, in particular so as to benefit from the additional gain provided by the antenna diversity, for example when the invention is implemented to receive digital TV in a vehicle, it is still advantageous to add a GPS and/or GALILEO reception subassembly to the functions of the device in that the marginal cost of this extra subassembly is small compared with the advantage of the function it provides. This optional additional reception subassembly can itself implement the invention or can make use of prior art techniques without that causing the system incorporating it to go beyond the ambit of the invention.
Naturally, the invention is not limited to the examples described above, and numerous variations can be applied thereto, it being possible to select other combinations of characteristics and/or implementation techniques without going beyond the ambit of the invention. Furthermore, the technical standards and techniques that are mentioned are those that are in force at the time of filing the patent application. They may disappear or be replaced rapidly by others without that making the invention itself obsolete.
Number | Date | Country | Kind |
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07/07684 | Oct 2007 | FR | national |