EP0837520B1 - Apparatus forming a transmit and/or receive antenna for radio signals - Google Patents

Abstract

The transceiver has first and second distinct areas (2,3). The first area holds the transmitter and receiver, and the second area contains the power supply (12). There is an electrical connection arrangement between the two units (14) and the power supply. Each unit has a conductor plate area (11,13), with the earth and transmitter connected to one of the plates forming an antenna. There are oils (17,18) in the transmitter section to block currents in the nominal frequency band, or to prevent unwanted resonances.

Description

The present invention relates to an autonomous device transmission and / or reception of radio signals.

Autonomous devices for transmitting and / or receiving radio signals usually include a circuit electronics of which a component is formed by an oscillator, a source autonomous electrical energy consisting of at least one battery or one battery and a wire antenna.

So that the emission and / or the reception of a wave electomagnetic can be done correctly, or we have the battery on the card carrying the electronic circuit and an antenna is placed which extends from the card, or we have the stack and the card with the electronic circuit in an electrically conductive envelope and metallic in order to create an electromagnetic short circuit between the battery and the card and we install the antenna outside of this envelope.

In both cases, we try to avoid any resonance electromagnetic of the battery and the electronic circuit one with respect to the other.

The document EP-A-0 297 790 describes a cell shaped as U and flat, creating a radio frame which, by itself, constitutes an antenna and document EP-A-0 339 629 describes a portable telephone in which the battery part and the electronic part are arranged so as not to disturb an independently constructed antenna.

The object of the present invention is in particular to simplify and optimize the use of the basic components of a device transmitting and / or receiving radio signals by making them preferably perform several functions at the same time.

The device for transmitting and / or receiving signals at least one nominal frequency (f), depending on the invention comprises on the one hand a first volume which comprises in particular a transmitter and / or receiver circuit and which has a part conductor of electricity or metallic main and on the other hand a second volume which includes in particular an autonomous source of energy electric and which has an electrically conductive part or main metallic including the conductive or metallic envelope of said source of electrical energy, said conductive part of said first volume and said conductive portion of said second volume being distant from each other.

The device according to the invention further comprises means of electrical connection between said volumes, comprising links to connect the poles of said energy source electric to the power poles of said transmitter circuit and / or receiver, input and / or output terminals for electrical energy radio frequency of said transmitter and / or receiver circuit being one connected to said conductive part of said first volume and the other being connected to said conductive part of said second volume via one of the connections said connecting means, the other connections of which include means for stopping the currents in the band of said nominal frequency, in particular tuned filters, shock or stop chokes or by resonance of the connecting wire (s) themselves.

Thus, according to the invention, said conductive parts respectively said first and second volumes constitute a antenna.

According to the invention, the connections of the poles of said source of electrical energy at the supply poles of said transmitter circuit and / or receiver and the connection of said conductive part of said second volume at one of the input and / or output terminals of said transmitter circuit and / or receiver can be separate.

According to an embodiment of the invention, a first pole of said source of electrical energy is connected to said conductive part of said second volume. Said connecting means include preferably a link which connects said first pole of said source of electrical energy on the one hand at the power pole of the same polarity of said transmitter and / or receiver circuit via a stop means and other leaves at one of said input and / or output terminals of said transmitter circuit and / or receiver, and another link which connects the second pole of said electric power source at the other power pole of said circuit transmitter and / or receiver via a stop means. The other input terminal and / or output of said transmitter and / or receiver circuit is preferably connected to the conductive part of said first volume.

According to the invention, said other input and / or output terminal of said transmitter and / or receiver circuit is preferably connected to the pole (-) power supply to this circuit.

According to the invention, said connecting means can advantageously include coaxial wires or the wires of a cable shielded multiconductor

According to the invention, said conductive parts or metallic of said volumes are preferably geometrically sized and / or electrically tuned to resonate on said nominal frequency (f).

According to the invention, said connecting means are of preferably geometrically shaped so as to constitute a self agreement of the resonance of said metal parts on said nominal frequency.

According to the invention, the conductive or metallic part of said second volume can advantageously include a receptacle for said source of electrical energy.

According to the invention, the conductive or metallic part of said first volume can advantageously comprise a layer conductor of a support or printed circuit board carrying said circuit transmitter and / or receiver, such as a ground plane.

• la figure 1 représente schématiquement un dispositif selon la présente invention ;
• la figure 2 représente schématiquement un autre dispositif selon la présente invention ;
• la figure 3 représente schématiquement un autre dispositif selon la présente invention.

The present invention will be better understood from the study of autonomous devices for transmitting and / or receiving radioelectric signals described by way of nonlimiting examples and illustrated by the drawings in which:

• Figure 1 schematically shows a device according to the present invention;
• FIG. 2 schematically represents another device according to the present invention;
• FIG. 3 schematically represents another device according to the present invention.

Referring to Figure 1, we see that we have represented schematically a device for transmitting and / or receiving signals which includes on the one hand a first volume 2 and on the other share a second volume 3.

The first volume 2 includes a printed circuit board 4 which carries the components of an electronic circuit 5 for transmission and / or for receiving radio signals, this electronic circuit 5 for this purpose comprising an oscillator 6. Of course, this circuit 5 further preferably comprises logic circuits for delivering to this oscillator 6 signals to be transmitted and / or to detect and / or analyze the signals received.

The electronic circuit 5 has a power pole negative (-) or ground 7 and a positive supply pole (+) 8, as well as two energy input and / or output terminals or points 9 and 10 electric radio frequency of electronic circuit 5 and more particularly its oscillator 6.

The first volume 2 also includes a part main conductor or metallic 11.

The second volume 3 includes an autonomous source electrical energy 12 such as a battery or a battery as well as a main electrically conductive or metallic part 13.

The device 1 also includes means 14 for electrical connection between the first and second volumes 2 and 3, made up by electric wires.

In the case of Figure 1, these connecting means 14 include electrical connections or wires 15 and 16 which respectively connect the poles (-) 7 and (+) 8 of the electrical energy source 12 to supply poles 7 and 8 of the electronic circuit 5, via means stop 17 and 18.

These stop means 17 and 18 can advantageously be constituted by band pass filters or choke or stop inductors adapted to prevent the passage of high frequency currents produced in the band of nominal frequency (f) of transmission and / or reception oscillator 6 of electronic circuit 5 for signal transport radioelectric, said stopping means possibly being formed by the wires 15 and 16 themselves.

The stop means 17 and 18 can advantageously be carried by the printed circuit board 4.

In the example of Figure 1, the connecting means 14 also include a connection or electrical wire 19 which connects directly the input and / or output terminal 10 of the electronic circuit 5 from the first volume 2 to the conductive part 13 of the second volume 3, while the other input and / or output terminal 9 of the electronic circuit 5 is connected to the conductive part 11 of the first volume 2 by a line board 20 electric 4.

Electrically conductive or metallic parts 11 and 13 of the first volume 2 and of the second volume 3 are separated or electromagnetically separate and are sized to constitute the dipole of a transmitting and / or receiving antenna on the nominal frequency (f) of radio signals by oscillator 6 of the electronic circuit 5.

Electrically conductive or metallic parts 11 and 13 are said to be principal in the sense that any other parts conductive of electricity or metal of volumes 2 and 3 are negligible from an electromagnetic point of view with regard to the antenna as said electrically conductive or metallic parts 11 and 13 constitute.

According to a preferred embodiment, the conductive part 11 of the first volume 2 constitutes the pole (-) 7 of the electronic circuit 2 and can advantageously be produced in the usual form of a layer electrically conductive or metallic formed on the circuit board printed 4 to constitute a ground plan. The conductive part 13 of the second volume 3 can advantageously be constituted by a electrically conductive or metallic envelope that surrounds the electric power source 12 and which is electrically isolated by compared to the poles of the latter.

Furthermore, the device 1 which has just been described can be arranged in a box shown schematically under the reference 21, consisting of a non-electrically conductive material, for example advantageously made of plastic.

It follows from the above that the device 1 described above comprises, between the first volume 2 comprising the oscillator 6 and the second volume 3 containing the source of electrical energy 12, connecting means 14 which establish, electrically separately, a galvanic connection ensuring the supply of electrical energy to the electronic circuit 5 and a radio frequency electrical connection between their respective conductive parts 11 and 13 which constitute a antenna tuned to transmit or receive signals radio frequencies on the nominal frequency (f) of emission and / or of reception of the oscillator 6.

Furthermore, it should be noted that, for example, conductive parts 11 and 13 are said to be tuned if the length of the wires which would be electromagnetically equivalent to them is substantially equal to the wavelength (λ) corresponding to the nominal frequency (f) of the oscillator divided by four (λ / 4) and if the distance between the ends of the wires which would be electromagnetically equivalent to them is substantially equal to the speed (C) of the light divided by said nominal frequency (ie: C / f).

This agreement of the antenna thus constituted can be obtained by different means and in particular by appropriate choices of volumes or surfaces of the metal parts 11 and 13, lengths of the wires 15 and 16 and lengths of wires constituting the chokes 17 and 18, or by electrical or electronic means such as capabilities.

Referring to Figure 2, we see that a radio signal transmission and / or reception device 22 which differs from the device 1 described with reference to FIG. 1 by the fact that the conductive part 13 of the second volume 3 is connected to the pole (-) of the electrical energy source 12 and also differs therefrom by the fact that the input and / or output terminal 10 of the electronic circuit 5 of the first volume 2 is connected by an electric line 23 to the link 15, between the pole (-) of the electrical energy source 12 and the stop means 17. Advantageously, the conductive part 13 can be constituted by the envelope of the electric power source 12, which in general constitutes its pole (-) or by a receptacle of this source which would connected to its envelope. Furthermore, the power line 23 is by example formed on the printed circuit board 4.

Thus, the connecting means 14 connecting the volumes 2 and 3 of the transmission and / or reception device 22 of FIG. 2 does not include more than the electrical connections 15 and 16 of the device 1 described with reference to Figure 1.

Referring to Figure 3, we see that a device for transmitting and / or receiving radio signals 24 which differs from the device 1 described with reference to FIG. 1 by the fact that the conductive part 13 of the second volume 3 is connected to the pole (+) from the electrical energy source 12 and also differs therefrom by the fact that the input and / or output terminal 10 of the electronic circuit 5 of the first volume 2 is connected by a line 25 to the link 16, between the pole (+) of the electric power source 12 and the stop means 18.

Advantageously, the conductive part 13 can be constituted by a receptacle for the electrical energy source 12, electrically isolated from the latter's envelope which general constitutes its pole (-).

Furthermore, the electrical line 25 is for example formed on the printed circuit board 4.

So we see that in the example of Figure 3 also, the connection means 14 only include connections 15 and 16 between volumes 2 and 3.

It follows from the examples described with reference to FIGS. 2 and 3 that either the galvanic connection 15 or the galvanic connection 16 between the two volumes 2 and 3 also constitute the electrical connection radio frequency between the main conductive parts 11 and 13 of the volumes 2 and 3 of the transmission and / or reception devices described, the high frequency currents at nominal frequency (f) of oscillator 6 being blocked by stop means constituted by either by the stop choke 17 either by the choke 18 or, alternatively, by the wires electrical link themselves.

Furthermore, the wire connections 14 could be consisting of coaxial wires or wires of a multi-core cable possibly shielded.

In addition, the wire connections 14 could be wound or twisted so as to constitute one or more chokes of the resonance of the metal parts 11 and 13 on the nominal frequency of circuit 5.

Of course, volume 2 could include another electrical energy source participating for example in the supply of electronic or emergency circuits. Likewise, volume 3 could include accessory electronic parts or circuits, constituted for example by a voltage regulator.

The autonomous device for transmitting and / or receiving radio signals according to the present invention constituting a antenna can advantageously be applied in particular to components of call, alarm, surveillance or remote control.

Indeed, it can advantageously make it possible to reduce the manufacturing costs of their components, reduce their size and remove anything outside of their case which is advantageously manufactured in injected or shaped plastic.

Claims (9)

1. Device for sending and/or receiving radio-frequency signals on at least one nominal frequency (f), characterized in that it comprises, on the one hand, a first volume (2) which especially comprises a sending and/or receiving circuit (5) and which features a main electrically conducting or metal part (11) and, on the other hand, a second volume (3) which especially comprises an independent electrical-energy source (12) and which features a main electrically conducting or metal part (13) including the conducting or metal casing of the said electrical-energy source (12), the said conducting part (11) of the said first volume (2) and the said conducting part (13) of the said second volume (3) being distant from one another; and that it comprises means (14) for electrical linking between the said volumes, comprising links making it possible to link the poles of the said electrical-energy source to the power-supply poles of the said sending and/or receiving circuit, one of the input and/or output terminals (9, 10) for the radio-frequency electrical energy of the said sending and/or receiving circuit (5) being linked to the said conducting part (11) of the said first volume (2) and the other (10) being linked to the said conducting part (13) of the said second volume (3) via one of the links (19; 23; 25) of the said linking means, the other links of which comprise means (17, 18) for blocking currents in the band of the said nominal frequency, in particular tuned filters, choke or blocking self-inductors, or by resonance of the linking wire or wires themselves; in such a way that the said conducting parts (11, 13) of the said first and second volumes (2,3) respectively constitute an antenna.
2. Device according to Claim 1, characterized in that the links from the poles of the said electrical-energy source (12) to the power-supply poles (7,8) of the said sending and/or receiving circuit (5) and the link (19) from the said conducting part (13) of the said second volume (3) to one (10) of the input and/or output terminals of the said sending and/or receiving circuit (5) are separate.
3. Device according to Claim 1, characterized in that a first pole of the said electrical-energy source (12) is linked to the said conducting part (13) of the said second volume (3), that the said linking means (14) comprise a link (15; 16) which links the said first pole of the said electrical-energy source (12), on the one hand, to the power-supply pole with the same polarity of the said sending and/or receiving circuit (5) via a blocking means (17; 18) and, on the other hand, to one (10) of the said input and/or output terminals of the said sending and/or receiving circuit (5), and another link..(16; 15) which links the second pole of the said electrical-energy source (12) to the other power-supply pole (8; 7) of the said sending and/or receiving circuit via a blocking means (18; 17), and that other input and/or output terminal (9) of the said sending and/or receiving circuit (5) is linked (20) to the conducting part (11) of the said first volume (2).
4. Device according to Claim 3, characterized in that the said other input and/or output terminal (9) of the said sending and/or receiving circuit (5) is linked to the (-) power-supply pole (7) of this circuit (5).
5. Device according to any one of the preceding claims, characterized in that the said linking means comprise coaxial wires or the wires of a screened multi-core cable.
6. Device according to any one of the preceding claims, characterized in that the said conducting or metal parts (11, 13) of the said volumes (2,3) are geometrically dimensioned and/or electrically tuned so as to resonate at the said nominal frequency (f).
7. Device according to any one of the preceding claims, characterized in that the said linking means (14) are geometrically shaped so as to constitute a self-inductor for tuning of the resonance of the said metal parts (11, 13) to the said nominal frequency.
8. Device according to any one of the preceding claims, characterized in that the conducting or metal part (13) of the said second volume (3) comprises a receptacle for the said electrical-energy source (12).
9. Device according to any one of the preceding claims, characterized in that the conducting or metal part (11) of the said first volume (2) comprises a conducting layer of a printed-circuit card or support carrying the said sending and/or receiving circuit (5), such as an earth plane.

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