EP4415175A1 - Electronically controllable reflector and system - Google Patents

Abstract

Electronically controllable reflector (RIS), comprising at least one reflector element (RE), each having at least one first antenna element (AE-RX), which is designed to receive a reception signal (DS-TX) as an input signal (S-RX) with a first polarization (POL1), and an amplifier device (AMP, UNI-AMP, Bi-AMP), which is designed to electronically amplify the input signal (S-RX) and output it as an output signal (S-TX), and at least one second antenna element (AE-TX), which is designed to send the output signal (S-TX) with a second polarization (POL2) as a transmission signal (DS-RX), and a control device (CRTL), which is designed to control the output signal (S-TX) in magnitude and/or phase with electronic control means in order to form a controllable antenna characteristic of the reflector, and that the second polarization (POL2) of the first polarization (POL1).

Description

Regardless of the grammatical gender of a particular term, persons with male, female or other gender identity are included.

The invention relates to an electronically controllable reflector and a system with an electronically controllable reflector.

An electronically controllable reflector (reflective intelligent surface, or RIS) can be used to improve radio communication at higher frequencies, such as 20 GHz and above, and with obstacles between a transmitter and a receiver. A RIS usually consists of several antenna elements, the size and geometry of which are generally the same. The antenna elements are arranged geometrically on the surface of a carrier, generally following special rules. For example, round antenna elements are arranged in a hexagonal shape with a spacing of 0.8 wavelengths, for example.

An antenna element receives the incoming power wave from the transmitter with a certain gain according to the respective antenna properties. This energy is reflected by electronics in the element and changed in amplitude and/or phase. The control of the electronics in the individual elements is chosen so that the sum of the individual reflections of the antenna elements constructively overlap at the receiver.

By using an electronically controllable reflector, communication between transmitter and receiver can be ensured even in the case of a concealed connection (non-line of sight). The range of radio communication is determined, for example, by the level plan, ie the sum of power losses from the transmitter to the receiver and taking into account the transmission power, the receiver sensitivity and the noise power. In a level plan, the reflection losses of the electronically controllable reflector are also taken into account.

The technical goal is to keep the reflection losses of the electronically controllable reflector as small as possible and, if possible, to realize a reflection gain.

• Einsatz einer großen RIS-Fläche mit vielen einzelnen Antennen-Elementen,
• Verwendung von einzelnen Antennen-Elementen mit hoher Effizienz, beispielsweise mit geringen ohmschen Verlusten, und einem großen Antennengewinn,
• Einsatz einer Ansteuerelektronik der einzelnen Antennen-Elemente mit wenig Reflextionsverlusten oder sogar Verstärkung.
• Gemeinsame Optimierung der Ansteuerungseinstellungen der einzelnen Antennen-Elemente, um eine bestmögliche Feldstärkenüberlagerung der Reflexionen von den Antenneneinzelelementen am Ort des Empfängers zu erreichen.

In the state of the art, there are several technical possibilities to keep the losses of an electronically controllable reflector small and to increase the reflector reflection gain:

• Use of a large RIS area with many individual antenna elements,
• Use of individual antenna elements with high efficiency, for example with low ohmic losses, and a high antenna gain,
• Use of control electronics for the individual antenna elements with little reflection losses or even amplification.
• Joint optimization of the control settings of the individual antenna elements in order to achieve the best possible field strength superposition of the reflections from the individual antenna elements at the location of the receiver.

The problem is that all of these points are subject to limitations and restrictions and further improvements are sought.

In state-of-the-art systems, there is a latent tendency to self-oscillations due to the amplification in the RIS control electronics. Up to now, the amplification often had to be reduced to such an extent that there was no longer any tendency to oscillate. The result was that the losses in the RIS were compensated, but beyond that only very small reinforcements could be chosen.

This resulted in limitations such as transmit-receive isolation, which determines the ratio between the signal sent into the radiating element and the signal reflected back by the radiating element. In this context, directional couplers, isolators and the like are also assigned to the radiating element.

Furthermore, the inter-element isolation, which represents the isolation from the neighboring RIS antenna elements, is limited.

The achievable insulation is low and depends heavily on the immediate environment. Particularly at frequencies in the millimeter wave range above 20 GHz, manufacturing and component tolerances also have a significant influence on the insulation.

It is therefore an object of the invention to overcome the disadvantages of the prior art by a simple and efficient solution.

• zumindest ein erstes Antennen-Element, welches dazu eingerichtet ist, ein Empfangssignal als Eingangssignal mit einer ersten Polarisation zu empfangen, und
• eine Verstärker-Vorrichtung, welche dazu eingerichtet ist, das Eingangssignal elektronisch zu verstärken und als Ausgangssignal auszugeben, und
• zumindest ein zweites Antennen-Element, welches dazu eingerichtet ist, das Ausgangssignal mit einer zweiten Polarisation als Sendesignal zu senden, und
• eine Steuer-Vorrichtung, welche dazu eingerichtet ist, das Ausgangssignal in Betrag und/oder Phase mit elektronischen Steuer-Mitteln zu steuern, um eine steuerbare Antennencharakteristik des Reflektors auszubilden, und dass sich die zweite Polarisation von der ersten Polarisation unterscheidet.

The object is achieved by an electronically controllable reflector, comprising at least one reflector element, each of which includes:

• at least one first antenna element which is configured to receive a received signal as an input signal with a first polarization, and
• an amplifier device which is arranged to electronically amplify the input signal and output it as an output signal, and
• at least one second antenna element which is configured to transmit the output signal with a second polarization as a transmission signal, and
• a control device which is arranged to control the output signal in magnitude and/or phase with electronic control means in order to form a controllable antenna characteristic of the reflector, and that the second polarization differs from the first polarization.

This allows a significantly higher level of isolation to be achieved, which in turn makes it possible to significantly increase the gain in the RIS elements compared to the state of the art.

The second polarization is preferably orthogonal to the first polarization, i.e. preferably rotated by 90° in the case of linear polarization or rotating in the other direction in the case of circular polarization, for example counterclockwise for the first polarization and clockwise for the second polarization or vice versa. This advantageously decouples the input channel and the output channel of the antenna element.

As long as the gain is smaller than the isolation, stability of the RIS, i.e. oscillation-free operation, can be achieved. This applies to both the transmit-receive isolation and the inter-element isolation.

The transmitted and received signals have different polarizations. However, it is clear in the present context that in general the polarizations of the signals can also be undesirably influenced by various effects during signal transmission, such as reflections. These undesirable effects are not taken into account separately in the present context and the aforementioned difference in the polarization of both signals is not applicable to the inventive feature in which the signal with the second polarization differs from the signal with the first polarization in the method.

The RIS can also be designed to design the antenna characteristics of the reflector in such a way that the attenuation of the radio signals between transmitter, reflector and receiver is as low as possible, which can be achieved by a targeted selection of individual antenna elements and their correspondingly adapted control in terms of magnitude and/or phase.

The electronically controllable reflector can have a large number of reflector elements, for example 10, 50, 100, or even more.

The antenna elements can be realized in different arrangements.

For example, the antenna elements for receiving and transmitting can be arranged alternately to form the reflector.

Alternatively, two reflectors can be arranged next to each other. One of these reflectors with antenna elements serves as a receiver with a first polarization, and the other reflector as a transmitter with a second polarization, or the other reflector can be mounted rotated by 90° relative to the receiver with linear polarization.

The solution enables high gain and stable operation while avoiding amplifier oscillation.

Furthermore, the number of antenna elements can be reduced while maintaining the same reflector effect. For example, a gain of 3 dB halves the number of elements required, or halves the area required by the RIS.

Due to the smaller number of elements required, the beam width of the RIS's directional characteristic in the direction of the receiver is increased. This means that less precise "aiming" is required, or movements in the scenario have less impact and finding radio participants, such as by scanning in two spatial angles, requires fewer iterations and is therefore faster.

The solution is also beneficial for optimizing energy consumption.

Electronic control means for controlling signals in magnitude and/or phase are known in the art, for example electronic phase shifters, voltage dividers or electronic amplifiers in digital or analogue design, whereby, for example, in the case of digital phase shifters, two or more states can be controlled.

In a further development of the invention, it is provided that the reflector is designed to operate at an operating frequency of at least 20 GHz.

Especially at operating frequencies of a RIS of over 20 GHz, a sufficiently high number of antenna elements can be realized.

In a further development of the invention, it is provided that the at least one first antenna element and the at least one second antenna element are formed by a common antenna structure, and the amplifier device comprises a bidirectional signal amplifier which can amplify signals either in the receiving direction or the transmitting direction.

By using bidirectional amplifiers instead of unidirectional amplifiers, which are used in alternating RIS elements, the RIS can receive horizontally and reflect vertically at one time and with reverse polarization at another time using a time control. The advantage of this is that if the RIS knows which polarization is currently used as the input signal, occurs, additional elements configured accordingly in the polarization can contribute to the amplification.

From the point of view of the radio system, there is no noticeable difference in the channel properties for uplink and downlink. There are no restrictions on the radio system used.

In addition, from the point of view of the radio system, the use of a specific polarization is advantageous, because simple terminal devices often only support one polarization, or there are environmental conditions that favor or weaken a polarization. Accordingly, the bidirectionally amplifying RIS enables the use of the best connection in each case.

A further extension is provided by control electronics, which can on the one hand act purely passively, and on the other hand can also work in an amplifying manner (uni- and/or bidirectional).

The advantage of this solution is that you can choose whether amplification and thus more supply energy is required or not. The RIS can be set up and operated in an energy-optimized manner with sufficient performance. This feature is particularly relevant for applications with high availability, i.e. 24/365 operation.

This allows the reflector to be pre-adjusted to a preferred polarization plane and reception losses can be reduced.

Electronic means for adjusting the polarization are known in the art, such as the use of separate feed points on a corresponding antenna, such as a patch antenna, or the use of orthogonally arranged dipole antennas.

The object is achieved by a system comprising a radio transmitter for transmitting a data transmission signal with electronic means for controlling the polarization of the data signal, an electronically controllable reflector according to one of the preceding claims for reflecting the data transmission signal, a radio receiver for receiving the reflected data signal and a system control device connected to the radio transmitter with a communication means, wherein the radio transmitter is designed to set a predetermined polarization with its electronic means and to transmit information about this polarization to the system control device using the communication means, and the system control device is designed to set the polarization on the reflector when receiving the data signal using the respective electronic means for setting the polarization.

This allows the reflector to be pre-adjusted to a preferred polarization and reception losses can be reduced.

In a further development of the invention, it is provided that the system comprises a first radio transmitter according to the system according to the invention and a second radio transmitter, as well as a first radio receiver according to the system according to the invention and a second radio receiver, wherein the first radio transmitter and the first radio receiver form a first transceiver, and the second radio transmitter and the second radio receiver form a second transceiver, and a controllable reflector according to the system according to the invention, which is designed to connect the first transceiver to the second transceiver by means of a radio connection via the reflector, and the first radio transmitter is designed to transmit a first data signal with a first polarization at a first time, and the second radio transmitter is designed to is to send a second data signal with a second polarization, which is different from the first polarization, at a subsequent second time.

The reflector can be configured so that the first transceiver transmits and receives on the first polarization and the second transceiver transmits and receives on the second polarization.

This means that when the radio system is expanded with a RIS, no changes or adjustments to the existing transmission technology between the transceivers are necessary. These can continue to use the same antennas for sending and receiving, and thus also the same polarizations.

Fig. 1

Ein Symbolische Darstellung für einen elektronisch steuerbaren Reflektor,

Fig. 2

ein Blockschalbild des elektronisch steuerbaren Reflektors,

Fig. 3

eine Darstellung für ein Antennen-Element nach dem Stand der Technik,

Fig. 4

ein Ausführungsbeispiel für ein Antennen-Element mit eingefügtem unidirektionalem Verstärker und zwei Antennen-Anschlüssen für unterschiedliche Polarisationen,

Fig. 5

ein Ausführungsbeispiel für zwei Antennen-Elemente mit jeweils eingefügtem unidirektionalem Verstärker und zwei Antennen-Anschlüssen für unterschiedliche Polarisationen,

Fig. 6

ein Ausführungsbeispiel für ein Antennen-Element mit eingefügtem bidirektionalem Verstärker und zwei Antennen-Anschlüssen für unterschiedliche Polarisationen.

The invention is explained in more detail below using an embodiment shown in the accompanying drawings. In the drawings:

Fig.1

A symbolic representation for an electronically controllable reflector,

Fig.2

a block diagram of the electronically controllable reflector,

Fig.3

a representation of an antenna element according to the state of the art,

Fig.4

an embodiment of an antenna element with an inserted unidirectional amplifier and two antenna connections for different polarizations,

Fig.5

an embodiment of two antenna elements, each with an inserted unidirectional amplifier and two antenna connections for different polarizations,

Fig.6

an embodiment of an antenna element with inserted bidirectional amplifier and two antenna connections for different polarizations.

Fig.1 shows symbolically an example of an electronically controllable reflector RIS with a large number of round antenna elements AE, which are arranged on a planar circuit carrier with a hexagonal contour.

Fig.2 shows a block diagram of the electronically controllable reflector RIS and a radio communication system.

The electronically controllable reflector RIS comprises a plurality of reflector elements RE, each of which has a receiving antenna element AE-RX and a transmitting antenna element AE-TX. A reflector RIS can comprise a plurality of reflector elements RE.

Each reflector element RE has a first antenna element AE-RX, which is configured to receive a signal DS-TX transmitted by a transmitter TX as a received signal with a first polarization POL1 as an input signal S-RX.

Furthermore, an amplifier device AMP is provided, which is designed to electronically amplify the input signal S-RX and to output it as an output signal S-TX to the transmitting antenna element AE-TX.

Each reflector element RE has a second antenna element AE-TX, which is configured to transmit the output signal S-TX with a second polarization POL2 as a transmission signal DS-RX to a receiver RX.

Furthermore, a control device CRTL is provided, which is designed to control the output signal S-TX in magnitude and/or phase with electronic control means in order to form a controllable antenna characteristic of the reflector and that the second polarization POL2, for example a vertical polarization, differs from the first polarization POL1, for example a horizontal polarization.

The amplifier device AMP can be included by a reflector element RE.

The reflector RIS is preferably dimensioned to operate at an operating frequency of at least 20 GHz.

The first antenna element AE-RX and the second antenna element AE-TX are optionally formed by a common antenna structure AE, which together with the amplifier device AMP forms the reflector element RE.

The amplifier device AMP may comprise a bidirectional signal amplifier.

In a special embodiment, the amplifier device AMP is controlled so that the antenna element AE-RX or AE-TX, which ensures the better transmission quality of the signal DS-TX with polarization POL1, is used as the receiving element. At the same time, the other antenna element AE-TX or AE-RX is used to send the signal DS-RX with polarization POL2. The setting or control is optionally carried out using a control signal POL-C, which is transmitted by the transmitter TX. The control POL-C of the system control device CTRL is shown in the figure separately from the data transmission signal DS-TX. This representation is only a logical representation, because the data transmission signal DS-TX and the signal for controlling the polarization POL-C can optionally be transmitted via the same radio channel, but alternatively also via separate transmission channels.

In a further embodiment, a system comprises a radio transmitter TX for transmitting a data transmission signal DS-TX with electronic means for controlling the polarization POL1 of the data signal, an electronically controllable Reflector RIS for reflecting the data transmission signal DS-TX, a radio receiver RX for receiving the reflected data signal DS-RX and a system control device CTRL.

The system control device CTRL is designed to adjust the polarization POL2 when transmitting the data signal DS-RX at the reflector RIS by means of the respective electronic means for adjusting the polarization.

Electronic means for adjusting the polarization are known in the art, such as the use of separate feed points on a corresponding antenna, such as a patch antenna, or the use of orthogonally arranged dipole antennas.

The radio transmitter TX can further be configured to transmit a first data signal with a first polarization at a first point in time and to transmit a second data signal with a second polarization, which differs from the first polarization, at a subsequent second point in time.

The controllable reflector can be configured to reflect the first and second data signals to the radio receiver, which receives the two signals.

The system shown only represents a unidirectional signal path from the transmitter TX via the reflector RIS to the receiver RX. However, it is clear that the system can also work bidirectionally, and the transmitter TX and the receiver RX can each be formed by a transceiver which can send and receive data. It also implies that a system control device CTRL is controlled by the transmitter of the transceiver, which includes the receiver RX, in the corresponding transmission mode. In other words, the system control device CTRL can optionally be connected to the transceiver of the transmitter TX as well as to the transceiver of the receiver RX. However, for the sake of clarity, this functionality is not shown.

It is also advantageous if the RIS is only connected to one of the transceivers, namely if the transceiver is part of a "base station". In the base station, all data on transmission and reception times as well as the transmission directions (uplink/downlink) of all participants are known.

In a specific embodiment, a system is provided, comprising a radio transmitter TX for transmitting a data transmission signal DS-TX with electronic means for controlling the polarization POL1 of the data signal, an electronically controllable reflector RIS for reflecting the data transmission signal DS-TX, a radio receiver RX for receiving the reflected data signal DS-RX and a system control device CTRL connected to the radio transmitter TX with a communication means.

The radio transmitter TX is designed to set a predetermined polarization POL1 using its electronic means and to transmit information about this polarization POL1 to the system control device CTRL using the communication means.

A predetermined polarization POL1 is set on the radio transmitter TX using its electronic means.

This polarization POL1 is transmitted to the system control device CTRL using the communication medium.

The system control device CTRL is designed to adjust the polarization POL1 on the reflector RIS upon receiving the data signal DS-TX by means of the respective electronic means for adjusting the polarization.

In a further specific embodiment, a system is provided comprising a first radio transmitter TX and a second radio transmitter, as well as a first radio receiver RX and a second radio receiver.

The first radio transmitter TX and the first radio receiver RX form a first transceiver.

The second radio transmitter and the second radio receiver form a second transceiver.

A controllable reflector RIS is designed to connect the first transceiver with the second transceiver using a radio link and the reflector RIS.

The first radio transmitter TX is configured to transmit a first data signal with a first polarization at a first time.

The second radio transmitter is configured to transmit a second data signal with a second polarization that differs from the first polarization at a subsequent second point in time.

In Fig.3 an antenna element according to the state of the art is shown.

An antenna element AE receives a signal, feeds the signal to a divider circuit DIV, amplifies the received signal with a unidirectional amplifier UNI-AMP, and feeds the amplified signal back to the antenna element AE via the divider DIV for radiation.

If the gain of the UNI-AMP amplifier is set too high, this can lead to undesirable oscillation of the arrangement.

Fig.4 represents an embodiment of an antenna element with an inserted unidirectional amplifier and two antenna connections for different polarizations.

An antenna element AE receives a signal via a first feed port, which has only a vertical polarization plane VER detects and amplifies the received signal with a unidirectional amplifier UNI-AMP, and feeds the amplified signal back to the antenna element AE for transmission, but via a second feed connection with a different horizontal polarization plane HOR compared to the polarization plane VER of the first feed connection.

The vertical polarization plane VER corresponds to the first polarization POL1 according to the previous figures, and the horizontal polarization plane HOR corresponds to the second polarization POL2 according to the previous figures, which is different from the first polarization POL1.

Fig.5 shows an embodiment of two antenna elements, each with an inserted unidirectional amplifier and two antenna connections for different polarizations HOR and VER.

The arrangement corresponds to a duplicate arrangement according to the previous figure, but a separate signal path is provided for two different polarization planes HOR and VER.

Fig.6 represents an embodiment of an antenna element with an inserted bidirectional amplifier BI-AMP and two antenna connections for different polarizations, wherein the bidirectional amplifier BI-AMP provides a single signal path for both feed connections for a horizontal and vertical polarization plane HOR and VER.

List of reference symbols:

AE, AE-RX, AE-TX

Antenna element

DIV

Directional coupler

DS-RX

signal sent to a receiver, transmission signal of the reflector

DS-TX

signal sent by a transmitter TX, received signal of the reflector

HOR

horizontal polarization

POL1, POL2

polarization

RIS

electronically controllable reflector

AMP, UNI-AMP, BI-AMP

amplifier

RE

Reflector element

RX

Recipient

TX

Sender

VER

vertical polarization

Claims (6)

Electronically controllable reflector (RIS), comprising a plurality of reflector elements (RE), each characterized by a first antenna element (AE-RX) which is configured to receive a reception signal (DS-TX) as an input signal (S-RX) with a first polarization (POL1), and an amplifier device (AMP, UNI-AMP, BI-AMP) which is designed to electronically amplify the input signal (S-RX) and output it as an output signal (S-TX), and a second antenna element (AE-TX) which is arranged to transmit the output signal (S-TX) with a second polarization (POL2) as a transmission signal (DS-RX), and a control device (CRTL) which is arranged to to control the output signal (S-TX) in magnitude and/or phase with electronic control means in order to form a controllable antenna characteristic of the reflector, and that the second polarization (POL2) differs from the first polarization (POL1). Reflector (RIS) according to one of the preceding claims, wherein the reflector (RIS) is adapted to operate at an operating frequency of at least 20 GHz. Reflector (RIS) according to one of the preceding claims, wherein the at least one first antenna element (AE-RX) and the at least one second antenna element (AE-TX) are formed by a common antenna structure (AE). Reflector (RIS) according to one of the preceding claims, wherein the amplifier device (AMP) comprises a bidirectional signal amplifier (BI-AMP) which is adapted to be controlled by the control device (CRTL) in its direction, and in magnitude and/or in phase. System comprising a radio transmitter (TX) for transmitting a data transmission signal (DS-TX) with electronic means for controlling the polarization (POL1) of the data signal, an electronically controllable reflector (RIS) according to one of the preceding claims for reflecting the data transmission signal (DS-TX), a radio receiver (RX) for receiving the reflected data signal (DS-RX) and a system control device (CTRL) connected to the radio transmitter (TX) with a communication means, wherein the radio transmitter (TX) is designed to set a predetermined polarization (POL1) with its electronic means and to transmit information about this polarization (POL1) to the system control device (CTRL) using the communication means, and the system control device (CTRL) is designed to set the polarization (POL1) on the reflector (RIS) when receiving the data signal (DS-TX) using the respective electronic means for setting the polarization. System according to the preceding claim, comprising a first radio transmitter (TX) according to the system of the preceding claim and a second radio transmitter, as well as a first radio receiver (RX) according to the system of the preceding claim and a second radio receiver, wherein the first radio transmitter (TX) and the first radio receiver (RX) form a first transceiver, and the second radio transmitter and the second radio receiver form a second transceiver, and a controllable reflector (RIS) according to the system of the preceding claim, which is designed to connect the first transceiver to the second transceiver by means of a radio connection and the reflector (RIS), and the first radio transmitter (TX) is designed to send a first data signal with a first polarization at a first time, and the second radio transmitter is designed to send a second data signal at a subsequent second time. to transmit with a second polarization that is different from the first polarization.

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