DE102017209614A1 - Decoupling device and RFID reader with decoupling device - Google Patents

Abstract

The invention relates to a decoupling device (1) with two signal paths (21, 22). Each signal path (21, 22) has an antenna connection (3), a transmission signal input (4), an over-coupling output (6), an over-coupling input (7) and a processing device (8). In this case, a transmission signal (Tx_f1, Tx_f2) applied to the transmission signal input (4) arrives at the antenna connection (3), at the coupling-over output (6) and at the processing device (8). A reception signal (Rx_1, Rx_2) applied to the antenna connection (3) and a coupling-over signal (Tx_f2, Tx_f1) applied to the over-coupling input (7) reach the processing device (8). The processing device (8) processes the transmission signal (Tx_f1, Tx_f2), the over-coupling signal (Tx_f2, Tx_f1) and the reception signal (Rx_1, Rx_2) in such a way that a subtraction of the transmission signal (Tx_f1, Tx_f2) and the coupling signal (Tx_f2, Tx_f1 ) from the received signal (Rx_1, Rx_2). Furthermore, the over-coupling outputs (6) and the over-coupling inputs (7) of the two signal paths (21, 22) are each coupled to one another such that in each case a coupling output (6) of one of the two signal paths (21, 22) to the over-coupling input (7) of each another of the two signal paths (22, 21) is coupled for transmission of signals. Furthermore, the invention relates to an RFID reader.

Description

The invention relates to a decoupling device and to an RFID reader with a decoupling device.

An RFID reader typically emits a single carrier in the form of a fixed frequency (the so-called carrier signal) to the RFID transponder (or RFID tag). This signal is used in passive RFID transponders to generate energy for supplying the electronics (analog and digital part) when they are in range. By means of rectifier, the carrier signal is converted into a DC voltage for supplying the transponder.

To increase the conversion efficiency, several frequencies can be transmitted in parallel or modulated (see [1] to [5]). For example, this can be two adjacent frequencies f1 and f2 (eg, with some 10 kHz spacing) transmitted by the reader. It turns out that the beating of the two different frequencies results in a higher voltage level than in the same power single-carrier signal. This leads to a more efficient conversion of the high-frequency energy to the DC voltage and increases the efficiency of the rectifier. This allows a greater distance between transponder and reader. Alternatively, more power can be made available to additional consumers in the transponder even at the same distance.

If one or more carrier signals are generated in a reading device, these are coupled into the receiving circuit of the RFID reader. The coupling can be done via different paths. Regardless of the coupling path, the carrier signal is attenuated.

One possible way of coupling is crosstalk from the transmitting to the receiving antenna. Another type of coupling can be done by a parasitic path in the separation between transmit and receive paths. The power level of the injected transmit signal is typically 50 to 60 dB stronger than the modulated sidebands (transponder response) received by the transponder.

To improve the reading range, the carrier signal must be attenuated or suppressed in the RFID reader without affecting the received signal in the same band. This targeted attenuation is referred to as carrier suppression and reduces the power of the injected transmit signal. The suppressed transmitter signal can then be amplified together with the transponder response by means of a low-noise amplifier (so-called Low Noise Amplifier, LNA).

If the carrier suppression is not present or only partially present, active components (eg LNA) located in the receive path are overdriven. This, in conjunction with nonlinear behavior of the components, produces intermodulation products. These can be so strong that a demodulation of the transponder response is bad or no longer possible.

An implementation of the multi-band transmission by means of dual-band circulator disclosed z. B. the JP 10284909 A , In this case, two frequency bands, which are several 100 MHz apart, processed. Filtering is usually easily feasible for this form of signal.

The document KR 102013074585 A describes an arrangement in which two signal bands are transmitted, received and separated by means of six circulators. A problem with this is that the transmission signals of an antenna ( Tx1 ) via a circulator to the received signal of the other antenna ( Rx2 ) are damped by only one circulator.

The US 2008/0207259 A1 describes an approach for two receive paths. Both received signals are superimposed on each other, wherein each received signal contains only one useful signal. As a result, the other is suppressed from the received signal. One problem is filtering, which must be done in advance. This can only be achieved to a certain degree of complexity.

Alternatively, a carrier suppression can take place in the digital domain. For this purpose, part of the transmitted signal is coupled out, filtered with a corresponding channel model and destructively superimposed on the received signal (compare [6] or [7]).

In the prior art, however, the case is not discussed that in two or more received signals, the same useful signal is included. In this case, a destructive overlay is not possible, since otherwise the useful signals are extinguished.

The object of the invention is to propose a device which solves the problem of coupling and carrier suppression in the use of multiple transmission frequencies even in the case or at least reduces that multiple received signals have an identical useful signal.

The invention solves the problem by a decoupling device having at least two signal paths.

Each signal path has an antenna connection, a transmission signal input, a coupling-over output, an over-coupling input and a processing device. The transmission signal input and the antenna connection are coupled to one another such that a transmission signal present at the transmission signal input reaches the antenna connection. The transmission signal input and the coupling-over output are coupled to one another such that the transmission signal applied to the transmission signal input reaches the coupling-over output. The transmission signal input and the processing device are coupled to one another such that the transmission signal applied to the transmission signal input reaches the processing device. The antenna connection and the processing device are coupled to one another such that a receive signal applied to the antenna connection reaches the processing device. The over-coupling input and the processing device are coupled to one another in such a way that an over-coupling signal applied to the over-coupling input reaches the processing device. The processing device is designed in such a way to process the transmission signal, the coupling-over signal and the reception signal with one another such that a subtraction of the transmission signal and of the coupling-over signal results from the reception signal. The over-coupling outputs and the over-coupling inputs of the two signal paths are each coupled to each other such that in each case a coupling output of one of the two signal paths is coupled to the over-coupling input of the other of the two signal paths for a transmission of signals.

In the decoupling device according to the invention - an alternative designation based on the prior art would be circulator - thus a signal path is provided per transmit signal. In this signal path, the received signal is also processed, which is received by the antenna with which the transmission signal is emitted. Via the respective signal path, the transmission signal reaches an antenna connection. In addition, the transmission signal is supplied to a processing device. Moreover, the transmission signal also passes to the other signal path or to the other signal paths when more than two transmission signals are used.

The feedback of the transmission signal within the associated signal path serves to remove the carrier signal from the received signal. The received signal is received via the said antenna connection and also fed to the processing device. The transmission signal supplied to the other signal path or the other signal paths serves there to compensate the crosstalk between the antennas with respect to the transmission signals. Since all signal paths have the same structure, the signal path also receives the transmission signal of the other signal path or the transmission signals of the other signal paths. This other transmission signal is referred to as over-coupling signal. The crossover signal is also supplied to the processing device to be removed from the received signal.

One embodiment consists in that the over-coupling outputs and the over-coupling inputs of the two signal paths are connected to one another via a common transmission path. In this embodiment, the over-coupling signals are thus transmitted via a common connection between the two signal paths.

An embodiment provides that the transmission path has at least one amplitude adjusting device and / or one phase adjusting device.

An embodiment consists in that the over-coupling outputs and the over-coupling inputs of the two signal paths are connected to one another via at least two transmission paths. In this embodiment, each over-coupling signal is transmitted via its own connection.

An embodiment provides that each transmission path has at least one amplitude adjusting device and / or one phase adjusting device. The guidance of the over-coupling signals via separate Connection allows the amplitude and phase to be adjusted separately for each crossover signal.

An embodiment consists in that the processing device has at least one difference generator for forming a difference between at least two signals. The difference generator is preferably designed to remove a further signal from the respective received signal. The difference generator is configured in one embodiment as an adder. The adder receives the signals - in one embodiment of at least one Phaseneinstellvorrichtung for adjusting the phase - in such a form that results in a difference by the addition of two signals.

An embodiment provides that the processing device has at least two difference generators: One of the at least two difference generators forms a difference between the received signal and the coupling-over signal. The other of the at least two difference generators forms a difference between the received signal and the transmission signal. In this embodiment, the transmission signal and the coupling-over signal are thus removed from the received signal by a respective difference generator.

In one embodiment, the transmission signal and the over-coupling signal are successively removed from the reception signal. Therefore, depending on the configuration, the received signal is already a (previously) processed received signal for the correspondingly downstream difference generator by the subtraction.

An embodiment is that the processing device - preferably only - has a difference generator. The difference generator forms a difference between the received signal and the over-coupling signal and the transmission signal. In this embodiment, a difference generator removes the over-coupling signal and the transmission signal from the received signal.

The signals mentioned in the preceding embodiments and to be processed by the respective difference generator may have already been subjected to at least one processing step, depending on the configuration before the difference formation by the difference generator. This refers z. For example, to adjust the amplitude or phase, or to remove another signal.

An embodiment provides that the at least one difference generator has at least one hybrid as part of the processing device.

An alternative or additional embodiment is that the at least one difference generator has as part of the processing device at least one Wilkinson divider.

An embodiment provides that the processing device has at least one amplitude adjusting device for setting an amplitude of a signal.

One embodiment is that the processing device has at least one phase adjustment device for setting a phase of a signal.

An embodiment provides that each signal path has a power divider, and that the signal input is connected to a signal input of the power divider. The power divider allows the transmission signal to be supplied to the antenna connection, the processing device and the coupling output.

One embodiment is that the power divider has at least one hybrid.

An embodiment provides that the power divider has at least one Wilkinson divider.

Furthermore, the invention achieves the object by an RFID reader which has at least one antenna and a decoupling device.

The decoupling device acts on the antenna of the RFID reader with transmit signals and generates at least a reduced received signal. The decoupling device has at least two signal paths. Each signal path has an antenna connection, a transmission signal input, a coupling-over output, an over-coupling input and a processing device. The transmission signal input and the antenna connection are coupled to one another such that a transmission signal present at the transmission signal input reaches the antenna connection. The transmission signal input and the coupling output are coupled to each other such that the transmission signal applied to the transmission signal input passes to the coupling output. The transmission signal input and the processing device are coupled to one another such that the transmission signal applied to the transmission signal input reaches the processing device. The antenna connection and the processing device are coupled to one another such that a receive signal applied to the antenna connection reaches the processing device. The over-coupling input and the processing device are coupled to one another in such a way that an over-coupling signal applied to the over-coupling input reaches the processing device. The processing device is designed in such a way to process the transmission signal, the coupling-over signal and the reception signal with one another such that a subtraction of the transmission signal and the coupling-over signal results from the reception signal. The over-coupling outputs and the over-coupling inputs of the two signal paths are each coupled to each other such that in each case a coupling output of one of the two signal paths is coupled to the over-coupling input of the respective other of the two signal paths for a transmission of signals.

The RFID reader according to the invention is characterized in that the use of multiple transmission frequencies increases the energy range and at the same time ensures and improves the reception of the transponder data.

In this case, two carrier frequencies are sent out at the same time preferably narrowband.

The decoupling device is designed according to at least one of the embodiments described above, so that the above explanations apply accordingly here as well.

An embodiment provides that the antenna terminals of the signal paths of the decoupling device are each connected to a separate antenna.

An embodiment is that the antenna terminals of the signal paths of the decoupling device are connected to a common antenna.

• 1 eine schematische Darstellung eines RFID-Lesegeräts mit einer Ausgestaltung der Entkopplungsvorrichtung,
• 2 eine schematische Darstellung der bei der Vorrichtung der 1 auftretenden Signalen für den Fall, dass nur ein Sendesignal ausgesendet wird,
• 3 eine schematische Darstellung der Signale für den Fall, dass zwei Sendesignale ausgesendet werden,
• 4 eine schematische Darstellung einer ersten Realisierung der Entkopplungsvorrichtung als Blockschaltbild,
• 5 eine schematische Darstellung einer zweiten Realisierung der Entkopplungsvorrichtung,
• 6 eine schematische Darstellung einer dritten Realisierung der Entkopplungsvorrichtung,
• 7 eine schematische Darstellung einer vierten Realisierung der Entkopplungsvorrichtung,
• 8 eine schematische Darstellung einer fünften Realisierung der Entkopplungsvorrichtung,
• 9 eine schematische Darstellung einer alternativen Beschreibung der Entkopplungsvorrichtung der 1 als 6-Tor,
• 10 eine interne Beschreibung des 6-Tors der 9 mit zwei Sendefrequenzen,
• 11 ein Signalflussdiagramm ausgehend von 10 mit der Annahme einer guten Anpassung, d. h. s_xx gegen Null, an den Ports und zwischen den Komponenten des 6-Tors der 9,
• 12 ein Teilblock des 6-Tors der 9 mit den Ports P1, P2 und P3 sowie einem Übergangspunkt X zum unteren Teil des 6-Ports,
• 13 ein Signalflussgraph für den Block der 12 und
• 14 ein Signalflussgraph für einen Teilblock des Diagramms der 11.

In particular, there are a large number of possibilities for designing and developing the decoupling device according to the invention and the RFID reader according to the invention. Reference is made on the one hand to the claims, on the other hand to the following description of embodiments in conjunction with the drawings. Show it:

• 1 a schematic representation of an RFID reader with a configuration of the decoupling device,
• 2 a schematic representation of the device in the 1 occurring signals in the event that only one transmission signal is sent,
• 3 a schematic representation of the signals in the event that two transmission signals are transmitted,
• 4 a schematic representation of a first implementation of the decoupling device as a block diagram,
• 5 a schematic representation of a second implementation of the decoupling device,
• 6 a schematic representation of a third implementation of the decoupling device,
• 7 a schematic representation of a fourth implementation of the decoupling device,
• 8th a schematic representation of a fifth implementation of the decoupling device,
• 9 a schematic representation of an alternative description of the decoupling device of 1 as a 6-goal,
• 10 an internal description of the 6-gate of the 9 with two transmission frequencies,
• 11 a signal flow diagram starting from 10 assuming a good fit, ie s _xx to zero, at the ports and between the components of the 6-port the 9 .
• twelve a partial block of the 6-gate of 9 with the ports P1 . P2 and P3 and a transition point X to the bottom of the 6-port,
• 13 a signal flow graph for the block of twelve and
• 14 a signal flow graph for a sub-block of the diagram 11 ,

In the 1 is an embodiment of the decoupling device 1 shown with two antennas 100 connected is. The principle of the decoupling device 1 is expandable to any number of antennas. In the embodiment shown, the decoupling device is 1 and the antennas 100 to components of an RFID reader that uses RFID tags 200 communicated.

The two antennas 100 are each used for transmitting transmission signals and for receiving received signals in different frequency bands: So is about the drawing upper antenna 100 a transmission signal Tx_f1 the frequency f1 and over the lower antenna 100 a transmission signal Tx_f2 the frequency f2 sent out. In addition, each antenna receives 100 a received signal Rx_1 and Rx_2 as well as the transmission signal of the other antenna Tx_f2 respectively. Tx_f1 ,

The decoupling device 1 is designed such that from that of the respective antenna 100 Received signal received Rx_1 respectively. Rx_2 the disturbing components - ie the transmission signal of the same antenna Tx_f1 respectively. Tx_f2 and the transmission signal of the other antenna Tx_f2 respectively. Tx_f1 - be removed, so that each have a reduced received signal Rx results.

The decoupling device 1 has two antennas 100 over two signal paths 21 . 22 of which below the upper signal path 21 considered. The lower signal path 22 is designed identically, so apply to this the following statements accordingly.

In an alternative embodiment - not shown - the different with respect to their frequency transmission signals Tx_f1 . Tx_f2 although in each case a signal path 21 . 22 guided, but the radiation takes place via a common antenna.

The signal path 21 runs between the antenna connection 3 and the received signal output 5 , about which the reduced received signal Rx output and, for example, to another - not shown here - processing device is handed over.

Furthermore, in the signal path 21 another transmission signal input 4 present, over which the transmission signal Tx_f1 the signal path 21 is fed. This transmission signal input 4 is for this purpose associated with a corresponding - and not shown - electronics.

The transmission signal Tx_f1 is the antenna connection 3 for the radiation through the antenna 100 fed.

Furthermore, the transmission signal arrives Tx_f1 from the transmission signal input 4 to a processing device 8th and to a coupling output 6 ,

The guidance of the transmission signal Tx_f1 within the signal path 21 to the processing device 8th serves to compensate the transmission signal Tx_f1 as part of the received signal Rx_1 , This has the processing device 8th via a difference generator 80 to do that within the signal path 21 guided transmission signal Tx_f1 from the received signal Rx_1 to remove.

The coupling output 6 of the upper signal path 21 is with a Überkoppeleingang 7 of the lower signal path 22 connected so that the transmission signal Tx_f1 also to the lower signal path 22 and to the processing equipment there 8th arrives. The transmission signal Tx_f1 thus becomes the upper signal path 21 decoupled and in the lower signal path 22 coupled. Through this step, it is possible in the lower signal path 22 compensate for the effect that from the lower antenna 100 also the transmission signal Tx_f1 of the upper signal path 21 Will be received.

Between the coupling output 6 and the over-coupling input 7 there is a transmission path 10 ,

Accordingly, the upper signal path has 21 a crossover input 7 to the transmission signal Tx_f2 of the lower signal path 22 to get as a crossover signal.

In the embodiment shown are two separate transmission paths 10 intended.

In the upper signal path 21 There are thus a total of three signals: the transmission signal Tx_f1 , the received signal Rx_1 as well as the transmission signal Tx_f2 of the lower signal path 22 as a coupling signal. The signals Tx_f1 . Rx_1 and Tx_f2 become the processing device 8th fed.

The processing device 8th is configured or fulfills the function that it receives from the received signal Rx_1 the transmission signal Tx_f1 of the same frequency band and the over-coupling signal Tx_f2 the other frequency band or the other signal path 22 withdraws. This is done here via the difference generator 80 ,

The difference generator 80 can be configured as desired or by other difference generator 81 be supplemented (see the following configurations). In one embodiment, each difference generator removes 80 . 81 one signal each (transmit signal Tx_f1 or Überkoppelsignal Tx_f2 ) individually from the received signal ( Rx_1 ). In an alternative embodiment, a difference generator removes 80 both the transmission signal Tx_f1 as well as the over-coupling signal Tx_f2 from the received signal Rx_1 ,

The processing device 8th gives the signal resulting from the processing as a reduced received signal Rx to the received signal output 5 out.

For processing the signals Tx_f1 and Rx_1 has the processing device 8th in the illustrated embodiment in addition to the difference generator 80 via a phase adjustment device 82 and an amplitude adjusting device 83 , The adaptation of the signal Tx_f2 for the processing takes place in an embodiment by components of the transmission path 10 ,

The phase adjustment device 82 causes between at least one signal to be subtracted and the received signal Rx_1 a phase difference of 180 °. The amplitude adjusting device 83 then ensures that the signal corrected in terms of phase and the received signal Rx_1 have equal amplitudes. Thus, the corrected in phase and amplitude signal and the received signal Rx_1 added together, the difference between the processed signal and the received signal results Rx_1 , The difference generator 80 therefore adds, for example, the signals to be differentiated from each other. This difference is considered a reduced received signal Rx from the processing device 8th output.

In the upper signal path 21 - For example, as the first signal path 21 can be designated - is thus on the one hand from the received signal Rx_1 the carrier signal removed by the transmit signal Tx_f1 the processing device 8th is supplied. On the other hand, that of the lower (or alternatively named: second) signal path 22 outgoing transmission signal Tx_f2 from the received signal Rx_1 removed by the transmission signal Tx_f2 within the decoupling device 1 from the lower signal path 22 to the upper signal path 21 is transmitted as a crossover signal. The upper signal path also transmits accordingly 21 the transmission signal Tx_f1 as a coupling signal to the lower signal path 22 ,

The lower signal path 22 is equal to the upper signal path 21 designed. With more than two antennas 100 with correspondingly many frequency bands, the transmission signals of one signal path in each case are to be decoupled to the other signal paths. In three signal paths, for example, one received signal, one transmission signal and two over-coupling signals are processed by the two other signal paths per signal path in order to generate a reduced received signal.

In the embodiment shown are two transmission paths 10 between the two signal paths 21 . 22 present, so the two transmission signals Tx_f1 and Tx_f2 each via its own transmission path 10 as a crossover signal to the respective other signal path 22 . 21 reach.

In the 2 the signals are plotted in the arrangement of the 1 occur when only the upper signal path 21 with a transmission signal Tx_f1 is charged. In this case, the lower antenna is used 100 only as a recipient.

The 2 a ) shows the transmission signal Tx_f1 the upper antenna 100 , It becomes a carrier signal of the frequency f1 sent out.

The RFID tag 200 receives this signal and imposes data on it. This results in signals with a carrier signal and two side signals in the sidebands.

The signal of the RFID tag 200 is from the two antennas 100 receive. This creates the signals of 2 B ). On the left this is from the upper signal path 21 Received signal received Rx_1 and on the right is the lower signal path 22 Received signal received Rx_2 shown.

There are two sidebands each f _data and a carrier signal with f1 , The carrier signal is for the received signal Rx_1 of the upper signal path 21 greater than for the received signal Rx_2 of the lower signal path 22 , because the upper antenna is the corresponding transmission signal Tx_f1 sends out and from the lower antenna here only the signal of the RFID tag 200 is looked at.

In the upper signal path 21 becomes the transmission signal Tx_f1 to the processing device 8th coupled there, allowing it from the received signal Rx_1 is subtracted. Thus, remains for the upper signal path 21 the signal of 2 c ). There are the two sidebands and the reduced carrier signal. Ideally, this signal would have completely disappeared. However, due to component tolerances and setting accuracies, a residue remains that is at least smaller than the sidebands in the exemplary embodiment shown.

By the transmission signal Tx_f1 of the upper signal path 21 as a coupling signal Tx_f1 to the lower signal path 22 it can also get there from that through the lower antenna 100 received signal Rx_2 be subtracted, so for the lower signal path 22 also the signal of 2 c ).

In the event that over the two antennas 100 only one transmission signal Tx_f1 sent and from both antennas 100 the signal of the RFID tag 200 is received, therefore, has the reduced received signal Rx the in the 2 c ) illustrated form.

In the 3 the next step is shown, in which also the lower signal path 22 a transmission signal Tx_f2 sending out.

The 3 a ) shows the two transmission signals Tx_f1 and Tx_f2 with the different frequencies f1 respectively. f2 , To distinguish this is the lower signal path 22 outgoing signal shown with dotted lines.

The from the antennas 100 received signals shows the 3 b ), where on the left side the received signal Rx_1 of the upper signal path 21 and on the right side the received signal Rx_2 of the lower signal path 22 located.

The RFID tag 200 modulates the two transmission signals Tx_f1 and Tx_f2 and thus each generates a carrier signal and two sidebands. In the example shown, the difference is between the frequencies f1 and f2 the transmission signals Tx_f1 respectively. Tx_f2 approximately equal to twice the data frequency f _data , This implies that the upper sideband becomes the carrier of the frequency f1 and the lower sideband to the carrier of the frequency f2 superimpose additively and therefore generate a higher signal than the remaining sidebands. This is indicated by the two different linetypes. In another - not shown - variant other frequency ratios are present, so that the signals in relation to the frequency z. B. next to each other.

In the 3 c ) is the resulting reduced received signal Rx shown again for both signal paths 21 . 22 results. It can be seen clearly the increased signal in the middle resulting from the addition of the sidebands.

The 4 shows a first implementation of the decoupling device 1 that has two antennas 100 and two signal paths 21 . 22 features. For clarity, only the components of the upper signal path are 21 provided with reference numerals. However, the reference numerals and explanations apply correspondingly to the lower signal path 22 ,

That at the transmission signal input 4 applied transmission signal Tx_f1 here comes through a hybrid (other designations are hybrid couplers or power distributors) as an embodiment of a power divider 9 to the antenna connector 3 and thus to the upper antenna 100 , In addition, passes through the power divider 9 the transmission signal Tx_f1 - In the illustrated embodiment via a power divider 84 - to the coupling output 6 from there to the lower signal path 22 to get.

The transmission signal Tx_f1 that of the power splitter 9 comes, passes through the power divider 84 to the phase adjuster 82 and the amplitude adjusting device 83 and from there to an entrance of the difference generator designed as Wilkinson divider 81 ,

To this difference generator 81 is also the received signal Rx_1 guided. The received signal Rx_1 is from the - here upper - antenna 100 received and passes through the antenna connection 3 to the power divider 9 and then to the other input of the difference generator 81 ,

At the difference generator 81 are thus the received signal Rx_1 (or - as will be explained below - more precisely: that about the over-coupling signal Tx_f2 reduced reception signal Rx_1 ) and the amplitude and phase processed transmit signal Tx_f1 in front. The transmission signal Tx_f1 is in relation to the amplitude by the amplitude adjusting device 83 matching the received signal Rx_1 be set. In addition, the transmission signal has Tx_f1 through the phasing device 82 undergo a phase change by 180 °, so that an addition of the phase-corrected signal with the received signal Rx_1 causes a difference.

Thus, the difference generator causes 81 that from the received signal Rx_1 the transmission signal Tx_f1 Will get removed.

Conversely, the upper signal path is replaced 21 over the coupling input 7 , the here also as a coupling output 6 serves, the transmission signal Tx_f2 of the lower signal path 22 as a coupling signal.

The overcoupling signal Tx_f2 passes through the - here with the transmission path 10 connected - power dividers 84 to the - with the antenna connection 3 contacted - power divider 9. The power divider 9 , which is designed in the embodiment shown as a hybrid, also serves as a difference generator 80 in particular the difference generator described above 81 is upstream and the first here, the received signal Rx_1 receives. Alternatively, the power divider can be 9 also describe as directional coupler.

The difference generator 80 , which is thus also a hybrid here, forms the difference between the received signal Rx_1 and the over-coupling signal Tx_f2 , That around the overcoupling signal Tx_f2 reduced reception signal Rx_1 then the other - alternative name would be downstream - difference generator 81 fed.

In the embodiment shown, the power divider 84 designed as a Wilkinson divider. In an alternative embodiment, not shown, it is a hybrid from which an output is terminated with a resistor.

The function is described again in other words:

The upper antenna 100 receives the received signal generated by the modulation of the RFID tag Rx_1 ,

From the received signal Rx_1 is via a first difference generator 80 the over-coupling signal Tx_f2 away. The overcoupling signal Tx_f2 is the transmission signal Tx_f2 of the lower signal path 22 and passes through a coupling output 6 of the lower signal path 22 , via a transmission path 10 and via a crossover input 7 of the considered signal path 21 - here also via a power divider 84 - to the first difference generator 80 ,

The next step is by the second or downstream difference generator 81 from the - already to the Überkoppelsignal Tx_f2 reduced - received signal Rx_1 the transmission signal Tx_f1 away. The transmission signal Tx_f1 passes through the power divider 9 and here about the optional power divider 84 to the phase adjuster 82 , which has a phase difference of 180 ° between the fed back transmission signal Tx_f1 and the transmission signal Tx_f1 as part of the received signal Rx_1 generated. The phase-corrected transmission signal Tx_f1 is then correspondingly by the amplitude adjusting device 83 attenuated or amplified so that the amplitude matches the transmitted signal component in the received signal Rx_1 is.

The second difference generator 81 then forms by adding the signals applied to its signal inputs: Rx_1 and Tx_f1 a difference, which is the reduced received signal Rx is that via the signal output 5 is issued.

Such a reduced received signal Rx is also from the lower signal path 22 via the associated received signal output 5 output.

The two reduced received signals Rx are processed accordingly by a - not shown - downstream device.

In the example shown, the overcoupling outputs fall 6 and the over-coupling inputs 7 of the two signal paths 21 . 22 together. In addition, only one transmission path 10 present over the thus the transmission signals Tx_f1 respectively. Tx_f2 each of a signal path 21 . 22 to the other signal path 22 . 21 be transmitted.

Along the transmission path 10 are still a Phaseneinstellvorrichtung 104 and an amplitude adjusting device 103 available. The adjustment of amplitude and phase refers in each case to an average value, because both signals Tx_f1 and Tx_f2 be transmitted over a connection.

The realization of the decoupling device 1 of the 5 is different from the realization of 4 with regard to the difference generator 81 , which is the difference between the transmission signal Tx_f1 and the received signal Rx_1 that in the embodiment already to the Überkoppelsignal Tx_f2 is reduced, generated.

The difference generator 81 is in the embodiment of 4 a Wilkinson divider and is in the embodiment of 5 a hybrid. One port of the hybrid is connected via the system impedance (typically 50 ohms) to ground or terminated with an ideally reflection-free impedance. On the description of the remaining components is on the description of the 4 directed.

The realization of the decoupling device 1 of the 6 is similar to the variant of 4 , The difference lies in the design of the unit of power dividers 9 and difference generator 80 in the design of the 4 is formed by a hybrid.

In the embodiment of 6 the unit is a power divider 9 and difference generator 80 a Wilkinson divider linked to another Wilkinson divider, both with three goals. In each case a single gate is opposite two gates, which are interconnected by a transverse resistance. The transverse resistance acts as insulation between the two gates. The two Wilkinson dividers are each connected so that the respective individual gates are contacted.

In one of the two Wilkinson dividers are the gates opposite the individual gate with the transmission signal input 4 or with the other difference generator 81 connected. In the other and mirror-symmetrically opposite Wilkinson divider connections exist in the direction of the coupling output 6 as well as the antenna connection 3 , Thus, both the Überkoppelsignal arrive Tx_f2 as well as the received signal Rx_1 on this Wilkinson divider, so that the difference is formed.

The realization of the 7 is similar to the design of the 6 , The unit forms a power divider 9 and difference generator 80 a Wilkinson divider that has four gates, three of which are exits. There is an output with the antenna connection 3 connected so that from the transmit signal input 4 originating and guided over the Wilkinson divider transmission signal Tx_f1 is emitted. Another output is with the coupling output 6 as well as the thus identical over-coupling input 7 connected. The third output is via the phasing device 82 and the amplitude adjusting device 83 with the other difference generator 81 connected to the transmission signal Tx_f1 to lead there.

About the middle output is therefore the transmission signal Tx_f1 to the lower signal path 22 guided. In addition, the Überkoppelsignal Tx_f2 received and from the over the upper output, which is thus also an input, incoming received signal Rx_1 deducted.

In this embodiment, therefore, is not a power divider or Wilkinson divider 84 as in the embodiments of 4 to 6 available.

The embodiments of 4 to 7 each have only one transmission path 10 between the two signal paths 21 . 22 , In the embodiment of 8th In contrast, and in accordance with the variant of 1 two transmission paths 10 present, each with its own Phaseneinstellvorrichtung 104 and a separate amplitude adjuster 103 feature. Therefore, one is more accurate adjustment of amplitude and phase of the over-coupling signals Tx_f1 . Tx_f2 for processing by the respective processing device 8th possible.

In addition, in contrast to the other embodiments in the signal path 21 . 22 only one difference generator 80 as part of the processing device 8th available.

The difference generator 80 Here is a Wilkinson divider with three outputs, over which the received signal Rx_1 , the transmission signal Tx_f1 and the over-coupling signal Tx_f2 be supplied. It is thus directly the difference between the received signal Rx_1 and the transmission signal Tx_f1 as well as the over-coupling signal Tx_f2 educated.

With the transmission signal input 4 a Wilkinson divider is also connected to three outputs, which in the embodiment shown as a power divider 9 serves. An output is connected to an output of a Wilkinson divider connected to the antenna connector 3 connected is. Another output is via a phasing device 82 and an amplitude adjusting device 83 with the difference generator 80 for transmission and adaptation in terms of amplitude and phase of the transmission signal Tx_f1 connected. The middle output leads to the coupling output 6 ,

The antenna 100 is via the antenna connection 3 connected to the output of the Wilkinson divider, so the received signal Rx_1 to an output of the difference generator 80 arrives. The middle output of the difference generator 80 is with the over-coupling input 7 for receiving the over-coupling signal Tx_f2 connected. The third output receives the amplitude adjusted and 180 ° rotated phase transmit signal Tx_f1 , The outputs are therefore also used as signal inputs.

Between the coupling output 6 of the upper signal path 21 and the over-coupling input 7 of the lower signal path 22 and vice versa between the over-coupling input 7 of the upper signal path 21 and the coupling output 6 of the lower signal path 22 there is a separate transmission path 10 , The individual phase adjusting devices 104 and amplitude adjusters 103 allow the separate adaptation of the two transmission signals Tx_f1 and Tx_f2 to transmit signals which are matched as amplitude signals and rotated by 180 ° with respect to the phase in each case to the difference generators 80 to be fed.

The embodiments shown can also be combined accordingly. The implementation of the described functionalities can be realized both digitally and analogously or as a combination of the two.

Overall, the decoupling device can be 1 also describe in such a way that it is a 6-port device (see. 9 ) each having two transmit ( Tx1 . tx2 ) and two receiving ports ( Rx1 . Rx2 ) and two antenna connections ( Ant 1 . ant2 ). The ports are numbered accordingly: P1 to P6 ,

In this case, according to the invention, a suppression of the transmission (or Tx) signals in the reception (or Rx -) paths instead. This means that the attenuation is as large as possible.

Here, the direct crosstalk, denoted by s ₁₂ and s ₄₅ , a transmission signal Tx_f1 . Tx_f2 to the directly associated received signal Rx_1 . Rx_2 suppressed. Furthermore, the overcoupling via the antenna connections - so the upper antenna Ant 1 on the lower antenna ant2 and vice versa - minimized.

A realization can be described with S-parameters. A possible internal description of the 6-gate of the 9 for two transmission frequencies shows the 10 ,

This shows individual blocks A . B and C , These can be described by means of S-parameters and can by means of 2x2 . 3x3 and 4x4 Matrices are clearly described in their function and task.

Simplify the in 10 shown topology on the assumption that a very good adaptation s _xx between the internal components is realized (ie s _xx goes to zero at the ports), one obtains the in 11 shown signal flow graphs.

The mathematical description is made by the following equation: $$\left[{\Gamma }_{6-TOr}\right]=\left[\begin{array}{llllll}{S}_{11}\hfill & S_{\mathrm{twelve}}\hfill & S_{13}\hfill & S_{14}\hfill & S_{15}\hfill & S_{16}\hfill \\ S_{21}\hfill & S_{22}\hfill & S_{23}\hfill & S_{24}\hfill & S_{25}\hfill & S_{26}\hfill \\ S_{31}\hfill & S_{32}\hfill & S_{33}\hfill & S_{34}\hfill & S_{35}\hfill & S_{36}\hfill \\ S_{41}\hfill & S_{42}\hfill & S_{43}\hfill & S_{44}\hfill & S_{45}\hfill & S_{46}\hfill \\ S_{51}\hfill & S_{52}\hfill & S_{53}\hfill & S_{54}\hfill & S_{55}\hfill & S_{56}\hfill \\ S_{61}\hfill & S_{62}\hfill & S_{63}\hfill & S_{64}\hfill & S_{65}\hfill & S_{66}\hfill \end{array}\right]=\left[\begin{array}{llllll}0\hfill & 0\hfill & 1\hfill & x\hfill & 0\hfill & x\hfill \\ x\hfill & 0\hfill & x\hfill & x\hfill & x\hfill & x\hfill \\ x\hfill & 1\hfill & 0\hfill & x\hfill & x\hfill & x\hfill \\ x\hfill & 0\hfill & x\hfill & 0\hfill & 0\hfill & 1\hfill \\ x\hfill & x\hfill & x\hfill & x\hfill & 0\hfill & x\hfill \\ x\hfill & x\hfill & x\hfill & x\hfill & 1\hfill & 0\hfill \end{array}\right]$$

The equation contains all the scattering parameters in the 10 illustrated signal flow graphs. The numerical values 1 and 0 Here are the optimal values for the transmission factors, but also any values between 0 and 1 possible.

For carrier suppression, eight parameters should be considered as a priority: s ₁₂ , s ₁₃ , s ₁₅ , s ₃₂ , s ₄₂ , s ₄₅ , s ₄₆ and s ₆₅ . The parameters marked with x are to be selected in such a way that the eight aforementioned parameters are maximized or minimized.

The parameters _s12 , s ₁₅ , s ₄₂ and s ₄₅ describe the transmission of both transmission signals Tx to the two received signals Rx , These are to be minimized for high carrier suppression.

Since the main overcoupling of Tx1 on Rx2 and vice versa via the antenna connections P3 and P6 is done and determined, for each of s ₄₂ and s ₁₅ , the isolation between the P3 and P6 to be viewed as. This can be, for example, the crosstalk of two antennas to each other.

Further, the transmission factors s ₆₅ , s ₄₆ , s ₃₂ and s _{13 are} to be maximized.

The parameters s ₆₅ and s ₃₂ are for the transmission signals to the antenna.

The parameters s ₁₃ and s ₄₆ should be maximum, so that the received signal experiences only a small attenuation.

The 6-goal off 10 and 11 can be connected to block B5 reflect.

This results in the simplified block diagram of twelve , Shown in the twelve a partial block with the gates P1 . P2 and P3 as well as with the transition point X to the lower part of the 6-gate.

The 13 shows the signal flow graph for the block diagram of twelve ,

This can be described by the following equation: $$\left[S_{4-TOr}\right]=\left[\begin{array}{cccc}{S}_{11}& S_{\mathrm{twelve}}& S_{13}& S_{1x}\\ S_{21}& S_{22}& S_{23}& S_{2x}\\ S_{31}& S_{32}& S_{33}& S_{3x}\\ S_{x1}& S_{x2}& S_{x3}& S_{xx}\end{array}\right]=\left[\begin{array}{cccc}0& 0& 1& x\\ x& 0& x& x\\ x& 1& 0& x\\ x& x& x& 0\end{array}\right]$$

The 14 shows a signal flow graph for the lower sub-block (signal path 22 ).

The following equation gives an idea of the description of the reflection factor of in 13 introduced port x from the perspective of the upper signal path. $$\left[S_{xx}\right]=\left(\frac{S_{12A3}{S}_{11B6}{S}_{23C2}{S}_{12B\mathrm{8th}}{S}_{23A4}{S}_{21B9}{S}_{23\mathrm{<figure-callout\; id="2"\; label="A"\; filenames="DE102017209614A1\_0004.png,DE102017209614A1\_0005.png"\; state="\{\{state\}\}">A</figure-callout>}2}}{1-S_{13A3}{\text{S}}_{21B6}{S}_{23C2}{S}_{12B\mathrm{8th}}{S}_{23A2}{A}_{21B9}}\right)+...$$

The embodiments described above are merely illustrative of the principles of the present invention. It will be understood that modifications and variations of the arrangements and details described herein will be apparent to others of ordinary skill in the art. Therefore, it is intended that the invention be limited only by the scope of the appended claims and not by the claims specific details presented with reference to the description and explanation of the embodiments herein.

References:

1. [1] AJ Soares Boaventura, A. Collado, A. Georgiadis, and N. Borges Carvalho, "Spatial Power Combining of Multi-Sine Signals for Wireless Power Transmission Applications," in IEEE Transactions on Microwave Theory and Techniques, vol. 62, no. 4, pp. 1022-1030, April 2014 ,
2. [2] N. Borges Carvalho et al., "Wireless Power Transmission: R & D Activities Within Europe," in IEEE Transactions on Microwave Theory and Techniques, vol. 62, no. 4, pp. 1031-1045, April 2014 ,
3. [3] A. Boaventura, D. Belo, R. Fernandes, A. Collado, A. Georgiadis, and NB Carvalho, "Boosting the Efficiency: Unconventional Waveform Design for Efficient Wireless Power Transfer," in IEEE Microwave Magazine, vol. 16, no. 3, pp. 87-96, April 2015 ,
4. [4] P. Kuhn, P. Schmidt, F. Meyer, G.V. Boegel and A. Grabmaier, "Comparison of Energy Harvesting via Modulation Schemes for Passive Sensor RFID," Smart SysTech 2016; European Conference on Smart Objects, Systems and Technologies, Duisburg, Germany, 2016, pp. 1-6 ,
5. [5] P. Kuhn, P. Schmidt, F. Meyer and A. Grabmaier, "Comparison on Powering Passive RFID Sensors via Variation of Modulation Indexes," in Eurosensors 2016; European Conference on, Budapest, Hungary, 2016 ,
6. [6] Jain, Mayank et al. "Practical, real-time, full duplex wireless." MobiCom (2011) ,
7. [7] Duarte et al. "Full-Duplex Wireless Communications Using Off-The-Shelf Radios: Feasibility and First Results.", In Asilomar 2010 ,

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 10284909 A [0008]
• KR 102013074585 A [0009]
• US 2008/0207259 A1 [0010]

Cited non-patent literature

• A. J. Soares Boaventura, A. Collado, A. Georgiadis, and N. Borges Carvalho, "Spatial Power Combining of Multi-Sine Signaling for Wireless Power Transmission Applications," in IEEE Transactions on Microwave Theory and Techniques, vol. 62, no. 4, pp. 1022-1030, April 2014 [0132]
• N. Borges Carvalho et al., "Wireless Power Transmission: R & D Activities Within Europe," in IEEE Transactions on Microwave Theory and Techniques, vol. 62, no. 4, pp. 1031-1045, April 2014 [0132]
• A. Boaventura, D. Belo, R. Fernandes, A. Collado, A. Georgiadis, and N. B. Carvalho, "Boosting the Efficiency: Unconventional Waveform Design for Efficient Wireless Power Transfer," in IEEE Microwave Magazine, vol. 16, no. 3, pp. 87-96, April 2015 [0132]
• P. Kuhn, P. Schmidt, F. Meyer, G.V. Boegel and A. Grabmaier, "Comparison of Energy Harvesting via Modulation Schemes for Passive Sensor RFID," Smart SysTech 2016; European Conference on Smart Objects, Systems and Technologies, Duisburg, Germany, 2016, pp. 1-6 [0132]
• P. Kuhn, P. Schmidt, F. Meyer and A. Grabmaier, "Comparison on Powering Passive RFID Sensors via Variation of Modulation Indexes," in Eurosensors 2016; European Conference on, Budapest, Hungary, 2016 [0132]
• Jain, Mayank et al. "Practical, real-time, full duplex wireless." MobiCom (2011) [0132]
• Duarte et al. "Full-Duplex Wireless Communications Using Off-The-Shelf Radios: Feasibility and First Results.", In Asilomar 2010 [0132]

Claims (15)

Decoupling device (1), with at least two signal paths (21, 22), each signal path (21, 22) having an antenna connection (3), a transmission signal input (4), a coupling output (6), an over-coupling input (7) and a processing device (8), wherein the transmission signal input (4) and the antenna connection (3) are coupled to one another such that a transmission signal (Tx_f1, Tx_f2) applied to the transmission signal input (4) reaches the antenna connection (3), wherein the transmit signal input (4) and the over-coupling output (6) are coupled to one another such that the transmit signal (Tx_f1, Tx_f2) present at the transmit signal input (4) reaches the coupling-over output (6), wherein the transmit signal input (4) and the processing device (8) are coupled to one another such that the transmit signal (Tx_f1, Tx_f2) present at the transmit signal input (4) reaches the processing device (8), the antenna connection (3) and the processing device (8) being coupled to one another in such a way that a receive signal (Rx_1, Rx_2) applied to the antenna connection (3) reaches the processing device (8), wherein the over-coupling input (7) and the processing device (8) are coupled to one another in such a way that a coupling-over signal (Tx_f2, Tx_f1) applied to the over-coupling input (7) reaches the processing device (8), wherein the processing device (8) is configured to process the transmission signal (Tx_f1, Tx_f2), the over-coupling signal (Tx_f2, Tx_f1) and the reception signal (Rx_1, Rx_2) in such a way that a subtraction of the transmission signal (Tx_f1, Tx_f2) and of the crossover signal (Tx_f2, Tx_f1) from the received signal (Rx_1, Rx_2), and wherein the Überkoppelausgänge (6) and the Überkoppeleingänge (7) of the two signal paths (21, 22) are each coupled together so that in each case a Überkoppelausgang (6) one of the two signal paths (21, 22) with the Überkoppeleingang (7) of each another of the two signal paths (22, 21) is coupled for transmission of signals. Decoupling device (1) according to Claim 1 in which the over-coupling outputs (6) and the over-coupling inputs (7) of the two signal paths (21, 22) are interconnected via a common transmission path (10). Decoupling device (1) according to Claim 1 in which the over-coupling outputs (6) and the over-coupling inputs (7) of the two signal paths (21, 22) are interconnected via at least two transmission paths (10). Decoupling device (1) according to Claim 3 wherein each transmission path (10) comprises at least one amplitude adjusting device (103) and / or a phase adjusting device (104). Decoupling device (1) according to one of Claims 1 to 4 wherein the processing device (8) comprises at least one difference generator (80, 81) for forming a difference between at least two signals. Decoupling device (1) according to Claim 5 wherein the processing device (8) comprises at least two difference generators (80, 81), one of the at least two difference generators (80) forming a difference between the received signal (Rx_1) and the coupling signal (Tx_f2), and wherein the other of the at least two difference generators (81) forms a difference between the received signal (Rx_1) and the transmission signal (Tx_f1). Decoupling device (1) according to Claim 5 wherein the processing device (8) comprises a difference generator (80), and wherein the difference generator (80) forms a difference between the received signal (Rx_1) and the crossover signal (Tx_f2) and the transmission signal (Tx_f1). Decoupling device (1) according to one of Claims 5 to 7 wherein the at least one difference generator (80, 81) has at least one hybrid, and / or wherein the at least one difference generator (80, 81) has at least one Wilkinson divider. Decoupling device (1) according to one of Claims 1 to 8th . wherein the processing device (8) comprises at least one amplitude adjusting device (83) for adjusting an amplitude of a signal, and / or wherein the processing device (8) comprises at least one phase adjusting device (82) for adjusting a phase of a signal. Decoupling device (1) according to one of Claims 1 to 9 , wherein each signal path (21, 22) has a power divider (9), and wherein the signal input (4) is connected to a signal input of the power divider (9). Decoupling device (1) according to Claim 10 wherein the power divider (9) comprises at least one hybrid, and / or wherein the power divider (9) comprises at least one Wilkinson divider. RFID reader, with at least one antenna (100) and a decoupling device (1), wherein the decoupling device (1) supplies the at least one antenna (100) with transmission signals (Tx_f1, Tx_f2) and generates at least one reduced received signal (Rx), wherein the decoupling device (1) has at least two signal paths (21, 22), each signal path (21, 22) having an antenna connection (3), a transmission signal input (4), a coupling output (6), an over-coupling input (7) and a processing device (8), wherein the transmission signal input (4) and the antenna connection (3) are coupled to one another such that a transmission signal (Tx_f1, Tx_f2) applied to the transmission signal input (4) reaches the antenna connection (3), wherein the transmit signal input (4) and the over-coupling output (6) are coupled to one another such that the transmit signal (Tx_f1, Tx_f2) present at the transmit signal input (4) reaches the coupling-over output (6), wherein the transmit signal input (4) and the processing device (8) are coupled to one another such that the transmit signal (Tx_f1, Tx_f2) present at the transmit signal input (4) reaches the processing device (8), the antenna connection (3) and the processing device (8) being coupled to one another in such a way that a receive signal (Rx_1, Rx_2) applied to the antenna connection (3) reaches the processing device (8), wherein the over-coupling input (7) and the processing device (8) are coupled to one another in such a way that a coupling-over signal (Tx_f2, Tx_f1) applied to the over-coupling input (7) reaches the processing device (8), wherein the processing device (8) is configured to process the transmission signal (Tx_f1, Tx_f2), the over-coupling signal (Tx_f2, Tx_f1) and the reception signal (Rx_1, Rx_2) in such a way that a subtraction of the transmission signal (Tx_f1, Tx_f2) and of the crossover signal (Tx_f2, Tx_f1) from the received signal (Rx_1, Rx_2), and wherein the Überkoppelausgänge (6) and the Überkoppeleingänge (7) of the two signal paths (21, 22) are each coupled together so that in each case a Überkoppelausgang (6) one of the two signal paths (21, 22) with the Überkoppeleingang (7) of each another of the two signal paths (22, 21) is coupled for transmission of signals. RFID reader after Claim 12 , wherein the decoupling device (1) according to one of Claims 2 to 11 is designed. RFID reader after Claim 12 or 13 , wherein the antenna terminals (3) of the signal paths (21, 22) of the decoupling device (1) are each connected to a separate antenna (100). RFID reader after Claim 12 or 13 in that the antenna connections (3) of the signal paths (21, 22) of the decoupling device (1) are connected to a common antenna (100).

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