An antenna system for enabling beamforming and directional communication, an antenna device, and a related communication system

Abstract

An antenna system is provided. The antenna system comprises a waveguide configured to enable propagation of signals along a structure of the waveguide. The antenna system comprises a plurality of antennas located at respective positions along the structure of the waveguide. The plurality of antennas are configured to transmit signals propagated by the waveguide. The plurality of antennas comprise at least a first antenna and a second antenna. The antenna system comprises a plurality of coverage enhancing devices, CEDs. The plurality of CEDs comprise a first CED configured to retransmit the signals of the first antenna and a second CED configured to retransmit the signals of the second antenna.

Description

[0001] AN ANTENNA SYSTEM FOR ENABLING BEAMFORMING AND DIRECTIONAL COMMUNICATION, AN ANTENNA DEVICE, AND A RELATED COMMUNICATION SYSTEM

[0002] The present disclosure pertains to the field of wireless communications. The present disclosure relates to an antenna system for enabling beamforming and directional communication, an antenna device, and a related communication system.

[0003] BACKGROUND

[0004] Millimetre wave, mm-wave, communications, such as terahertz, THz, communications, e.g., sub-THz communications, have been envisioned as an enabling technology for 6G networks and beyond, providing superior data transfer rates and low latency for a wide range of applications.

[0005] For example, indoor communication and sensing is important for enabling a variety of applications, from smart buildings and homes to virtual and augmented reality, that rely on high- bandwidth, low-latency, and accurate sensing capabilities.

[0006] For example, Virtual Reality, VR, Extended Reality, XR, 3D remote reality, and flexible indoor entertainment are technologies that provide immersive experiences and enable interactive and personalized services within indoor environments, offering new opportunities for entertainment, education, and communication.

[0007] For example, mobile robotics in workshop and factory settings require high data transfer rates and low latency for effective communication and control, making THz technology a promising solution for enabling fast and reliable communication between robots and their controllers.

[0008] SUMMARY

[0009] However, THz technology may face several challenges for indoor communication due to its susceptibility to signal attenuation, such as blockage by objects or human bodies, and interference from interfering sources. Such factors may significantly reduce quality and reliability of THz signals. For example, in sub-THz band, blockage can cause a severe signal loss (such as, a loss greater than 40dB).

[0010] Accordingly, there is a need for antenna systems and communication systems, which may mitigate, alleviate or address the shortcomings existing and may provide for a more directional communication with less loss.

[0011] An antenna system is provided. The antenna system comprises a waveguide configured to enable propagation of signals along a structure of the waveguide. The antenna system comprises a plurality of antennas located at respective positions along the structure of the waveguide. The plurality of antennas are configured to transmit signals propagated by the waveguide. The plurality of antennas comprise at least a first antenna and a second antenna. The antenna system comprises a plurality of coverage enhancing devices, CEDs. The plurality of CEDs comprise a first CED configured to retransmit the signals of the first antenna and a second CED configured to retransmit the signals of the second antenna.

[0012] It is an advantage of the present disclosure that the disclosed antenna system may allow generation of directional beams, providing a more directional communication between one or more nodes, which in turn reduces the loss that otherwise would occur with THz technology. The disclosed antenna system may enable efficient beam steering and directionality in realtime, which may reduce impact of interference and improve communication reliability. In other words, the disclosed antenna system may improve signal strength towards one or more nodes and corresponding throughput, thereby enhancing spectral efficiency and coverage. The disclosed antenna system may be power efficient as the signals propagated by the waveguide do not suffer detrimental losses in power. The disclosed antenna system may be power efficient as it allows for an accurate power management and control of the signals propagated by the waveguide. The disclosed antenna system may be seamlessly and readily integrated into existing building infrastructure owing to its compact and efficient design.

[0013] A communication system is provided. The communication system comprises an antenna system and a network node.

[0014] It is an advantage of the present disclosure that the disclosed communication system may allow generation of directional beams, providing a more directional communication between one or more nodes, which in turn reduces the loss that otherwise would occur with THz technology. The disclosed communication system may enable efficient beam steering and directionality in real-time, which may reduce impact of interference and improve communication reliability. In other words, the disclosed communication system may improve signal strength towards one or more nodes and corresponding throughput, thereby enhancing spectral efficiency and coverage. The disclosed communication system may be power efficient as the signals propagated by the waveguide do not suffer detrimental losses in power. The disclosed communication system may be power efficient as it allows for an accurate power management and control of the signals propagated by the waveguide. The disclosed communication system may be seamlessly and readily integrated into existing building infrastructure owing to its compact and efficient design. The disclosed communication system may enable that an improved quality of service is achieved at a receiving node, such as a node intended to receive the signals propagated by the waveguide. The disclosed communication system may allow improved reception of signals at one or more receiving nodes.

[0015] An antenna device is provided. The antenna device comprises a CED and an antenna as disclosed herein.

[0016] It is an advantage of the present disclosure that the disclosed antenna device may allow generation of directional beams, providing a more directional communication between one or more nodes, which in turn reduces the loss that otherwise would occur with THz technology. The disclosed antenna device may enable efficient beam steering and directionality in real-time, which may reduce impact of interference and improve communication reliability. In other words, the disclosed antenna device may improve signal strength towards one or more nodes and corresponding throughput, thereby enhancing spectral efficiency and coverage. The disclosed antenna device may be power efficient as the signals propagated by the waveguide do not suffer detrimental losses in power. The disclosed antenna device may be power efficient as it allows for an accurate power management and control of the signals propagated by the waveguide. The disclosed antenna device may be seamlessly and readily integrated into existing building infrastructure owing to its compact and efficient design.

[0017] BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other features and advantages of the present disclosure will become readily apparent to those skilled in the art by the following detailed description of examples thereof with reference to the attached drawings, in which:

[0019] Fig. 1 is a diagram illustrating an example wireless and wired communication system according to this disclosure comprising an example network node, an example antenna device, and an example wireless device according to this disclosure,

[0020] Figs. 2A-2B schematically illustrate an example communication system according to this disclosure,

[0021] Fig. 3 schematically illustrates an example part of an antenna system according to this disclosure,

[0022] Fig. 4 schematically illustrates an example antenna system according to this disclosure, Figs. 5A-5B schematically illustrate an example part of an antenna system according to this disclosure,

[0023] Fig. 6 schematically illustrates an example communication system according to this disclosure, and

[0024] Fig. 7 is a block diagram illustrating an example antenna device according to this disclosure. DETAILED DESCRIPTION

[0025] Various examples and details are described hereinafter, with reference to the figures when relevant. It should be noted that the figures may or may not be drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the examples. They are not intended as an exhaustive description of the disclosure or as a limitation on the scope of the disclosure. In addition, an illustrated example needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular example is not necessarily limited to that example and can be practiced in any other examples even if not so illustrated, or if not so explicitly described.

[0026] The figures are schematic and simplified for clarity, and they merely show details which aid understanding the disclosure, while other details have been left out. Throughout, the same reference numerals are used for identical or corresponding parts.

[0027] Fig. 1 is a diagram illustrating an example communication system 1 according to this disclosure. The communication system 1 comprises an example network node 400 and an example wireless device 300 according to this disclosure and a core network (CN) node 600.

[0028] As discussed in detail herein, the present disclosure relates to a communication system 1 comprising a cellular system, for example, a 3GPP wireless communication system. The communication system 1 comprises one or more of: an antenna device 700, a wireless device 300, and a network node 400.

[0029] A network node disclosed herein refers to a radio access network, RAN, node operating in the radio access network, such as one or more of: a base station, BS, an evolved Node B, eNB, a Next Generation base station, gNB, in New Radio, NR, an access point, AP, and a small cell, SC. In one or more examples, the RAN node is a functional unit which may be distributed in several physical units. A core network, CN, node disclosed herein refers to a network node operating in the core network, such as in the Evolved Packet Core Network, EPC, and / or a 5G Core Network, 5GC. Examples of CN nodes in EPC include a Mobility Management Entity, MME.

[0030] In one or more examples, the CN node is a functional unit which may be distributed in several physical units.

[0031] A wireless device may refer to one or more of: a mobile device and a user equipment, UE. The wireless device 300 may be configured to communicate with the antenna system 700 via a wireless link (or radio access link) 10A.

[0032] The antenna device 700 may be configured to communicate with the network node 400 using a waveguide 10 (such as, via a wired link), such as a waveguide as disclosed herein.

[0033] Figs. 2A-2B schematically illustrate an example communication system 2 according to this disclosure. Fig. 2A illustrates the example communication system 2 in three dimensions, 3D, whereas Fig. 2B illustrates the example communication system 2 in two dimensions, 2D.

[0034] The communication system 2 comprises an antenna system and a network node 400. The antenna system comprises one or more of: a waveguide 10 and antenna devices 700. Each of the antenna devices 700 may comprise one or more of: a CED and an antenna.

[0035] A network node disclosed herein refers to a radio access network (RAN) node operating in the radio access network, such as a base station, an evolved Node B, eNBs, a global Node B, gNBs in NR, and / or a transmission and reception point (TRP). In one or more examples, the RAN node is a functional unit which may be distributed in several physical units.

[0036] The CED may be one or more of a smart repeater, a reflective intelligent surface (RIS), a network controlled repeater (NCR), and / or another wireless device (WD). The CED may provide coverage enhancement for devices using 5G and beyond. The disclosed CEDs can be one of a number of several types of devices, which can be used interchangeably herein. For example, the CEDs can be one or more of: reconfigurable intelligent surfaces, RISs, large intelligent surfaces, LISs, network configured repeaters, repeater nodes, repeater type devices, repeaters (such as, regenerative and / or non-regenerative), intelligent surfaces and reconfigurable reflective devices, RRDs. The CEDs can have one or more antennas, such as one or more of: antenna panels, antenna elements, antenna inputs, antenna outputs and unit cells for metasurfaces. The CEDs can have one or more receivers, for example low-power receivers. The CEDs can have one or more transmitters, such as an active component that provides amplification to a signal.

[0037] In one or more example wireless communication systems, the signals disclosed herein can be one or more of: energy, wave energy, FR1 and FR2 signals, 5G signals, 6G signals, sub-6 GHz, 5 sub-THz, THz, electromagnetic energy, waves, electromagnetic plane waves, electromagnetic signals, plane signals, spherical waves, spherical signals, cylindrical waves, and cylindrical signals. As disclosed herein, waves and signals can be used interchangeably. Signals may include signals with any polarization properties. The particular type of signal is not limiting. The CEDs can be used for network management. The coverage enhancing devices can be used for beam management, panel management or both beam management and panel management. The coverage enhancing devices can be used for far-field propagation, near-field propagation or both far-field propagation and near-field propagation. The coverage enhancing devices can utilize one or more of: passive array panels, active array panels and intelligent surfaces to improve coverage and beamforming of signals.

[0038] The CED may be configurable by the network node 400 and / or the CN node 600, and may be used to improve signal coverage in a wireless communication system, such as communication system 1 , 2. The CED may be used to retransmit, such as forward, signals, such as data and / or control signals, between the network node 400, the antenna, and the WD 300. Components of the disclosed CEDs, such as the active components and passive components, can be advantageous to redirect signals. As disclosed herein, redirecting can include one or more of: transmitting, reflecting, forwarding, scattering, regenerating, re-radiating, directing, retransmitting a signal, and allowing a signal to pass through. Redirecting, transmitting, and retransmitting may be used interchangeably. The redirecting may include altering direction, polarisation or both direction and polarisation of a signal. The redirecting may include one or more of: amplification, attenuation, termination, phase shifting, delaying and spatial manipulation of a signal. Spatial manipulation may be, for instance, splitting into multiple components, widening or in general applying any spatial filtering.

[0039] For example, the CEDs may redirect an incoming signal from a given incoming direction to a given outgoing direction. Components of the CEDs can be used to redirect signals in the mm- wave spectrum, in the sub-7 GHz spectrum, in the sub-6 GHz spectrum or in any other spectrum which may be used. Further, the components of the CEDs can be configured to make redirections of signals which appear in-phase in one or more of: a direction, an area, and a volume.

[0040] The retransmission can be advantageous when the WD 300 is located at hard-to-reach locations, such as at a border of a coverage area of the network node 400 and / or when a direct link between the network node 400 and the WD 300 is obstructed. It may be appreciated that the CED can also be used to increase the multiple components and / or channel rank to support MIMO communication between the network node 400 and the WD 300, even in a well-covered area. The CED may comprise a plurality of antenna elements that can be configured with a respective phase shift. By controlling the phase shifts, such as jointly controlling the phase shifts, an incoming and / or outgoing angle of a signal received and / or transmitted by the CED can be controlled and / or adapted. In one or more example systems, the angle of incoming and outgoing signals can be controlled by controlling the relative phase between antenna elements of the CED. The phase shift may be a capacitor-based phase shift and / or a true time delay line, such as a time domain shift, between antenna elements of the CED. The WD 300 may be configured to communicate with the network node 400 directly via a wireless link (or radio access link) and / or via the CED via wireless link 10A. The wireless link 10A may herein be referred to as a reflected, such as retransmitted, wireless link. The CED may be controlled by one or more network nodes, such as the network node 400, or one or more wireless devices, such as the WD 300. In one or more example systems, the communication system 2 comprises a separate CED controlling node configured to control the CED. In one or more example systems, the CED may be controlled by the network node via the antenna. For example, the CED may comprise an antenna for communication with the antenna. The antenna of the CED may be seen as an active element, e.g., configured to change to broadband, BB, signaling to control the CED. The CED may be configured to receive, from the network node, one or more codebooks, e.g., via a BB signal. In one or more example systems, the CED may be controlled by the network node via the waveguide, e.g., the antenna forwarding one or more control signals to the CED from the network node. The one or more network nodes or wireless devices controlling the CED may herein be referred to as coverage enhancing device controlling nodes. In one or more example systems, the coverage enhancing device controlling node can be a CN node, such as the CN node 600 in Fig 1 . In one or more example systems, the CED controlling node can be a node in an external network that can access the CED, for example through the internet via a gateway function and / or via a wireless control channel.

[0041] According to the current disclosure, the CED may be configured, for example by the node 400 as disclosed herein, to retransmit signals of an antenna as disclosed herein.

[0042] The waveguide 10 may operationally and / or operatively connect the antenna devices 700 to the network node 400. In other words, the communication system 2 may be seen as a distributed antenna array (such as, antenna devices 700) operationally connected to the network node 400 through the waveguide 10. In one or more example systems, the waveguide 10 may be configured to power the antenna devices, e.g., to power the antennas and / or the CEDs. The communication system 2 may be particularly beneficial for millimetre wave, mm-wave, frequency range communications (such as, in the range of 30GHz to 300GHz) and / or terahertz, THz, frequency range communications (such as, in the range of 300GHz to 3THz) and / or sub- THz frequency range communications (such as, in the range of 90GHz to 300GHz). The communication system 2 may be at least partly installed at a ceiling 26 of a room, such as used in indoor environments. The room may comprise walls 24, 25, 28, 29, a floor 27, and the ceiling 26.

[0043] The communication system 2 comprises an antenna system, such as an antenna system as disclosed herein, and a network node, such as network node 400. The network node 400 may be one or more of: a millimetre wave, mm-wave, network node, a THz network node, and a sub- THz network node. The communication system 2 comprises a plurality of antenna devices, such as a first antenna device 700A, a second antenna device 700B, a third antenna device 700C, a fourth antenna device 700D, a fifth antenna device 700E, a sixth antenna device 700F, and a seventh antenna device 700G. The antennas devices may be connected to the network node 400 via the waveguide 10. The antennas devices may be seen as interconnected, e.g., to form the communication system 2, via the waveguide 10.

[0044] In one or more example communication systems, the network node is configured for multipleinput multiple-output, MIMO, communication. In one or more example communication systems, the network node comprises a plurality of ports. In one or more examples communication systems, each port of the plurality of ports is configured to connect to the antenna system. This may be illustrated in Fig. 6.

[0045] Fig. 3 schematically illustrates an example part of an antenna system according to this disclosure. The antenna system comprises an antenna device 700 according to this disclosure. The antenna device 700 comprises a first CED 40 and a first antenna 30. The first antenna 30 may be a leaky wave antenna (such as, a leaky radiator element).

[0046] The first antenna 30 may be mounted on a waveguide 10. The waveguide 10 is configured to enable propagation of signals along a structure of the waveguide 10. The first antenna 30 may be configured to transmit a signal propagated by the waveguide 10. In other words, the first antenna 30 may be configured to receive a signal, such as a first power output, via the waveguide 10. The first antenna 30 may transmit the received signal to the CED 40 based on a radiation pattern 42 (such as, an antenna pattern).

[0047] The first CED 40 is configured to retransmit (such as, redirect and / or reflect) the signal of the first antenna 30. For example, the first CED 40 is configured to generate one or more beams based on the signal, such as a first beam 45, a second beam 46, and / or a third beam 47. The first CED 40 may control the signal received from the first antenna 30 by retransmitting the signal in a desired direction, such as with a desired beam pattern (such as, a desired beam shape). It may be appreciated that the first antenna 30 and the first CED 40 are configured such that they are facing each other. The first antenna 30 is configured to transmit signals propagated by the waveguide 10 in the radiation pattern 42 towards the first CED 40. The first CED 40 may be configured to generate directional beams towards a receiver device, such as a wireless device, such as WD 300. This may translate into interference mitigation. For example, combining the first antenna 30 with the first CED 40 may provide for improved communication throughput, reliability, and latency.

[0048] In one or more example systems, the first CED 40 is positioned at a distance D in the range of 1 / 3 to 1 / 2 of a surface size A of the first CED 40 from the first antenna 30.

[0049] Fig. 4 schematically illustrates an example antenna system 800 according to this disclosure. Fig. 4 shows a transmission of a signal from the antenna system 800 to a wireless device 300. The antenna system 800 may be configured to transmit a signal to a wireless device 300 such that an improved quality of service is achieved at the wireless device 300, such as a satisfactory signal-to-noise ratio, SNR. Fig. 4 may illustrate a distributed multiple-input multiple-output, MIMO, communication between the antenna system 800 and the wireless device 300. Fig. 4 may illustrate the antenna system 800 performing focal forming with a distributed antenna array, e.g., distributed over a first antenna device 700A, a second antenna device 700B, and a third antenna device 700C. The antenna system 800 may comprise a plurality of antenna devices, such as a first antenna device, a second antenna device, a third antenna device, a fourth antenna device, a fifth antenna device, a sixth antenna device, and a seventh antenna device. In other words, the antenna system 800 comprises a plurality of interconnected antennas devices, e.g., interconnected via the waveguide 10.

[0050] The antenna system 800 comprises a waveguide 10 and one or more antenna devices, such as the first antenna device 700A, the second antenna device 700B, and the third antenna device 700C. Each antenna device (such as, antenna device 700 of Fig. 3) comprise a CED and an antenna (such as, a leaky wave antenna). In one or more examples, the first antenna device 700A comprises a first CED and a first antenna. In one or more examples, the second antenna device 700B comprises a second CED and a second antenna. In one or more examples, the third antenna device 700C comprises a third CED and a third antenna.

[0051] The first antenna, second antenna, and third antenna may be configured to transmit a first signal, a second signal, and a third signal propagated by the waveguide 10, respectively. The first CED may be configured to retransmit (such as, redirect and / or reflect) the first signal towards the wireless device 300 based on a first directional beam pattern 51. The second CED may be configured to retransmit (such as, redirect and / or reflect) the second signal towards the wireless device 300 based on a second directional beam pattern 52. The third CED may be configured to retransmit (such as, redirect and / or reflect) the third signal towards the wireless device 300 based on a third directional beam pattern 53.

[0052] The present disclosure provides an antenna system allowing for efficient beam control, thus improving communication directivity between entities (such as, network nodes and / or wireless devices). The present disclosure provides an antenna system capable of performing multi-user MIMO communications and / or single-user MIMO communications. The present disclosure may be particularly suitable for multi-user indoor scenarios.

[0053] The antenna system 800 may be particularly beneficial for millimetre wave, mm-wave, frequency range communications and / or terahertz, THz, frequency range communications.

[0054] The antenna system 800 comprises a waveguide (such as, waveguide 10) configured to enable propagation of signals (such as, electromagnetic signals and / or optical signals) along a structure of the waveguide. The antenna system 800 comprises a plurality of antennas (such as, plurality of antennas 700A, 700B, 700C, 700D, 700E, 700F of Figs. 2A, 2B, and 4) located at respective positions along the structure of the waveguide. In one or more examples, the waveguide 10 is configured to supply power and to operationally and / or operatively connect the plurality of antennas to a network node (such as network node 400 as disclosed herein). The plurality of antennas may be positioned at a plurality of different positions along the structure of the waveguide. As may be seen in Fig. 4, the first antenna device 700A is positioned at a first position, the second antenna device 700B is positioned at a second position, and the third antenna device 700C is positioned at a third position. For example, the antenna system 800 comprises the plurality of antennas in series along the structure of the waveguide. In other words, the plurality of antennas may be connected in series along the waveguide. The plurality of antennas are configured to transmit signals propagated by the waveguide. The plurality of antennas comprise at least a first antenna and a second antenna.

[0055] The antenna system, such as antenna system 800, comprises a plurality of CEDs. The plurality of CEDs comprises a first CED (such as, first CED 40 of Fig. 3) configured to retransmit (such as, redirect and / or transmit) the signals of the first antenna. In other words, the first antenna device 700A comprises the first CED. The plurality of CEDs comprises a second CED configured to retransmit the signals of the second antenna. In other words, the second antenna device 700B comprises the second CED. The plurality of CEDs comprises the first CED and the second CED. In one or more example systems, the antenna system comprises a third antenna system 700C comprising a third antenna device comprising a third CED configured to retransmit the signals of a third antenna.

[0056] In one or more example antenna systems, the waveguide is a dielectric waveguide and / or an optical waveguide. In one or more examples, the waveguide can be one or more of: a circular waveguide, an elliptical waveguide, a rectangular waveguide, a single-ridge waveguide, a double-ridge waveguide, a slab (such as, a planar) waveguide, a multilayer waveguide, and any other suitable type of waveguide. For example, dielectric waveguides operating at sub-THz frequency range may offer low power loss, low dispersion and high power handling capabilities, e.g., in comparison with wireless transmission, such as over the air transmission with free space transmission (for example air transmission without obstacles). For example, the dielectric waveguides can be relatively easy to manufacture and readily integrated into existing building infrastructure. In other words, the present disclosure may provide a cost-effective antenna system for high-bandwidth, low-latency indoor communication.

[0057] In one or more example antenna systems, the plurality of antennas are positioned at a distance in the range of 0.2 m to 5 m from each other. In one or more examples, the plurality of antennas are positioned such that there is a portion of the waveguide without antennas between each pair of antennas. For example, the first antenna and the second antenna have an antenna spacing in the range of 0.2 m to 5 meters from each other. For example, the distance between each antenna of the plurality of antennas is at least 20A, e.g., to avoid interference between antenna devices.

[0058] In one or more example antenna systems, the waveguide comprises a splitter (such as, splitter 60 of Figs. 5A-5B) configured to split (such as, distribute) a power output of the waveguide into a first output (such as, first output 63 of Fig. 5A) having a first power output and a second output (such as, first output 64 of Fig. 5A) having a second power output. In one or more examples, the splitter divides the power output into the first output and the second output. In one or more examples, the splitter can divide the power output into two or more power outputs. In one or more examples, the power output is indicative of a power of a signal propagated by the waveguide. For example, the waveguide can comprise an input port and two or more output ports, such as a first output port and a second output port. The splitter may split the power output into the first output and the second output on a first output port and a second output port, respectively. In one or more examples, the first power output is a part of (such as, one or more of: less than half, half, and more than half) the power output of the waveguide, such as the total power output of the waveguide. In one or more examples, the second power output is a part (such as, one or more of: less than half, half, and more than half) of the power output of the waveguide, such as the total power output of the waveguide. It may be appreciated that the splitter may control the power input to an antenna. For example, the splitter may tune the power input to an antenna and / or activate or deactivate an antenna. In one or more example systems, the splitter may split the waveguide in two or more branches, such as split a main branch of the waveguide into a first branch and a second branch. It may be appreciated that the first antenna may be positioned on the first branch and the first output may be propagated via the first branch. The second output may be propagated via the second branch. In one or more example systems, the waveguide comprises a combiner to recombine the first output and the second output after the first antenna. The combiner may recombine the first branch and the second branch into the main branch again after the first antenna.

[0059] In one or more example antenna systems, the first antenna is configured to receive the first power output as input. In one or more examples, the second output is configured to proceed in the waveguide, e.g., to the next antenna on the waveguide. The second output may combined with the first output after the first antenna, e.g., to recombine the original output. The waveguide may comprise a next splitter configured to split the output into a third output and a fourth output and / or received by a following antenna of the plurality of antennas (such as, by a second antenna). For example, a next splitter, such as a second splitter of a second antenna, can split the output into a third output having a third power output and a fourth output having a fourth power output. The third output and the fourth output may be based on the second output and the first output. The third output and the fourth output may be parts of the power output of the waveguide. The second output may be recombined with the first output to an original power output. In other words, the third output may be seen as the output. A second antenna may be configured to receive the third output. The fourth output may proceed in the waveguide to be combined with the third output after the second antenna. The recombined output may then be split into a fifth output and a sixth output and / or received by a following antenna of the plurality of antennas (such as, by a third antenna). In other words, a power output may be split multiple times along the waveguide. For example, a power output may be split before each antenna and combined after each antenna. The power output may be split based on the plurality of antennas comprised in the antenna system, such as based on a number of antennas of the plurality of antennas activated for receiving a resulting split power (such as, the first output and / or the third output).

[0060] In one or more examples, a splitter can be integrated into the waveguide structure for controlling amplitude of signals (such as, the power output and / or the second output, the fourth output) at different points along the structure of the waveguide. The present disclosure may allow for an accurate and precise power management and control of a signal, such as of the power output. Stated differently, power control in waveguides (such as, dielectric waveguides) may be achieved by using a splitter, which may distribute and regulate a power of mm-wave and / or THz signals provided to an antenna. The present disclosure may provide for improved mm-wave and / or THz communication systems advantageously suitable for indoor sensing, imaging, and high-speed data transfer.

[0061] In one or more example antenna systems, the splitter comprises a tunable dielectric material, such as the splitter comprising a liquid crystal, LC. For example, a tunable dielectric material, such as a LC, may comprise a material and / or substance exhibiting liquid crystalline properties, such as properties of both liquids and solid crystals. A splitter comprising a tunable dielectric material, such as comprising a LC, may be seen as a LC waveguide splitter. A LC may be referred as a folded LC and / or a LC core.

[0062] In one or more example antenna systems, the first antenna (such as, first antenna 30 of Fig. 3) comprises a controller (such as a first controller) for controlling the power output of the first antenna. In other words, the controller may control the power input to the first antenna. In one or more example antenna systems, the second antenna comprises a second controller for controlling the power output of the second antenna. Optionally, the waveguide can comprise the controller for controlling the power output of the first antenna. The waveguide may comprise the first controller and / or the second controller for controlling the power output of the first antenna and / or the second antenna. A controller may allow to control whether an antenna should be active or not and to control an available power for transmitting signals with an antenna.

[0063] In one or more example antenna systems, the first antenna is a leaky wave antenna, LWA (such as, a fast-wave antenna). In other words, the antenna system may comprise a plurality of leaky wave antennas. In one or more examples, waveguides (such as, dielectric waveguides) can be used for constructing leaky wave antennas, which can offer advantages for THz communication, including tunability, polarization diversity, and low profile. In one or more examples, the first antenna can be integrated in the waveguide structure, allowing for compact and efficient antenna designs that can be easily integrated in indoor environments. In one or more examples, the first antenna can be used in phased array configurations to enable beamforming and directional communication, enhancing capabilities of THz communication systems. In one or more example antenna systems, the first antenna comprises one or more of: a patch antenna, a metal strip antenna, an array antenna, a dielectric resonator antenna, DRA, and a lens antenna. In other words, the antenna system may comprise one or more of: a patch antenna, a metal strip antenna, an array antenna, a dielectric resonator antenna, DRA, and a lens antenna. In one or more examples, the first antenna (such as, a leaky wave antenna) can be combined with a first CED for enabling beamforming for THz communications. The first CED may be placed near to the first antenna and act as a phase shifter to control direction of the signals (such as, THz electromagnetic signals and / or waves). The combination of the first antenna and the first CED may allow generation of directional beams that can be steered to one or more locations within an indoor environment. The combination of the first antenna and the first CED may enhance performance of THz communication systems by enabling beamforming, directionality, and in turn high-speed, low-latency, and improved communication reliability. In one or more example antenna systems, the first CED is positioned at a distance in the range of 1 / 3 to 1 / 2 of a surface size A of the first CED from the first antenna. In one or more example antenna systems, a second CED is positioned at a distance ranging from 1 / 3 to 1 / 2 of a surface size A of the second CED from a second antenna. For example, the distance between the first CED and the first antenna is of 5A, such as 15mm, when the surface size of the first CED is 10A at 100GHz. For example, a larger CED, such as an increased surface size of the CED (such as, the first CED and / or the second CED), may imply a larger distance between the CED and an antenna (such as the first antenna and / or the second antenna).

[0064] In one or more example antenna systems, the retransmission of the signals comprises the first CED being configured to generate one or more beams (such as, one or more beams 45, 46, 47 of Fig. 3) based on the signals. In other words, the retransmission of the signals comprises the first CED being configured to generate one or more beams based on the signals from the first antenna. For example, a CED, such as the first CED, having a surface size of 10x10A (such as, 4x4cm), the CED can generate one or more beams with a beamwidth of approximately 8 degrees, which may translate into performance gains of at least 20-30dB, e.g., compared with a scenario where only an antenna is used without CED.

[0065] In one or more example antenna systems, the first CED comprises a controller for controlling the retransmission of the signals. In one or more examples, the first CED is controlled and / or configured by the controller to adjust phase and amplitude of the signals (such as, THz signals). The controller may enable beam steering and directionality in real-time. Optionally, the first CED can be controlled by a network node via the waveguide and / or a control wire to the network node. For example, the first CED can be controlled through a wire (such as, the control wire) connecting the network node and a CED controller. For example, the first CED can be controlled via a wireless link, such as through a wireless connection between the network node and the CED controller. The first CED may be controlled by a Bluetooth node (such as, a beacon and / or an access point).

[0066] In one or more example antenna systems, the first CED is a liquid crystal, LC, CED. In one or more example antenna systems, the first CED comprises a liquid crystal, LC, CED. In one or more example antenna systems, the first CED comprises other meta-materials than LC, such as graphene and / or ferromagnetic materials. It may be appreciated that the CED may be controlled by tuning the cell phase of the LC. In one or more examples, a LC CED operating at sub THz frequency range can provide performance gains for indoor communication due to its high tunability, low power consumption, and ability to operate over a wide range of frequencies. By using a LC CED, it may be possible to use voltage to control the phase of the CED, and thereby save power. The first CED may be capable of performing adaptative beam selection and / or scanning, thus improving beam management. In other words, the first CED may retransmit the signals in specific directions by generating narrow beams (such as, pencil beams) in one or more specific directions for covering specific spatial areas, thereby improving coverage performance.

[0067] In one or more example antenna systems, the antenna system is configured for terahertz, THz, range communication. In one or more example antenna systems, the plurality of antennas are configured to transmit signals in the THz range (such as, between 100GHz and 10THz) and / or sub-THz range (such as, between 90GHz and 300GHz).

[0068] Figs. 5A-5B schematically illustrate an example part 800A of an antenna system 800 according to this disclosure. In one or more examples, Figs. 5A-5B illustrate a waveguide 10 comprising a splitter 60, such as a dielectric waveguide splitter. The splitter 60 may comprise a tunable dielectric material, such as a liquid crystal, LC.

[0069] The splitter 60 may be configured to split a power output 61 of the waveguide, such as a power output of the network node into the waveguide 10, into a first output having a first power output 63 and a second output a second power output 64. A first antenna 30 may be configured to receive the first power output 63 (such as, an output connected to the first antenna 30). In one or more example systems, the second power output 64 is configured to proceed in the waveguide, such as to be split by a next splitter on the waveguide into a third output and a fourth output and / or received by a following antenna of a plurality of antennas, such as by a second antenna. In one or more example systems, the splitter 68 may split the waveguide 10 in two or more branches, such as split a main branch of the waveguide into a first branch 10A and a second branch 10B. It may be appreciated that the first antenna 30 may be positioned on the first branch 10A and the first output 63 may be propagated via the first branch 10A. The second output 64 may be propagated via the second branch 10B. In one or more example systems, the waveguide 10 comprises a combiner to recombine the first output 63 and the second output 64 after the first antenna 30. The combiner may recombine the first branch 10A and the second branch 10B into the main branch again after the first antenna 30.

[0070] Fig. 6 schematically illustrates an example communication system 1000 according to this disclosure. In one or more examples, the communication system 1000 comprises a network node 400 and an antenna system as disclosed herein. In the example of Fig. 6, the communication system 1000 comprises a network node 400 and a plurality of antenna systems.

[0071] The communication system 1000 comprises a first antenna system 800A comprising a first primary antenna device 1000A, a first secondary antenna device 1000B, and a first tertiary antenna device 1000C. The first antenna system 800A comprises a first waveguide 10A (such as, waveguide 10 of Figs. 1 , 2A-2B, 3, and 4) configured to enable propagation of signals from the network node 400 to the first antenna system 800A.

[0072] The communication system 1000 comprises a second antenna system 800B comprising a second primary antenna device 1000D, a second secondary antenna device 1000E, and a second tertiary antenna device WOOF. The second antenna system 800B comprises a second waveguide 10B (such as, waveguide 10 of Figs. 1 , 2A-2B, 3, and 4) configured to enable propagation of signals from the network node 400 to the second antenna system 800B.

[0073] The communication system WOO comprises a third antenna system 800C comprising a third primary antenna device 1000G, a third secondary antenna device 1000H, and a third tertiary antenna device WOOL The third antenna system 800C comprises a third waveguide 10C (such as, waveguide 10 of Figs. 1 , 2A-2B, 3, and 4) configured to enable propagation of signals from the network node 400 to the third antenna system 800C.

[0074] The communication system WOO comprises a fourth antenna system 800D comprising a fourth primary antenna device 1000J, a fourth secondary antenna device WOOL, and a fourth tertiary antenna device WOOK. The fourth antenna system 800D comprises a fourth waveguide 10D (such as, waveguide 10 of Figs. 1 , 2A-2B, 3, and 4) configured to enable propagation of signals from the network node 400 to the third antenna system 800D.

[0075] Each of the plurality of antenna systems (such as, the first antenna system 800A, the second antenna system 800B, the third antenna system 800C, and the fourth antenna system 800D) comprises at least two CEDs (such as the first CED 40 of Fig. 3 and the second CED as disclosed herein) and at least two antennas (such as the first antenna 30 of Fig. 3 and the second antenna as disclosed herein).

[0076] In other words, each of the plurality of antenna systems (such as, the first antenna system 800A, the second antenna system 800B, the third antenna system 800C, and the fourth antenna system 800D) comprises two or more antenna devices, where each antenna device comprises a CED (such as, first CED 40 of Fig. 3) and an antenna (such as, first antenna 30 of Fig. 3).

[0077] The network node 400 may be configured to perform MIMO communications. The network node may comprise a plurality of ports, such as a plurality of radio frequency, RF, chains, for communicating with each of the plurality of antenna systems, such as the first antenna system 800A, the second antenna system 800B, the third antenna system 800C, and / or the fourth antenna system 800D. In other words, the network node 400 may comprise a plurality of antennas for communicating with each of the plurality of antenna systems. The plurality of ports may be connected to a controllable leaky wave distributed antenna system, where each antenna is equipped with a respective CED, such as first antenna system 800A, second antenna system 800B, third antenna system 800C, fourth antenna system 800D. In other words, each port of the plurality of ports may be connected to an antenna system via a waveguide. For example, a first port of the network node 400 may be connected to the first antenna system 800A via the first waveguide 10A, a second port of the network node 400 may be connected to the second antenna system 800B via the second waveguide 10B, a third port of the network node 400 may be connected to the third antenna system 800C via the third waveguide 10C, and / or a fourth port of the network node 400 may be connected to the fourth antenna system 800D via the fourth waveguide 10D.

[0078] For example, the network node 400 may be configured to transmit, to each of the plurality of antenna systems (such as first antenna system 800A, second antenna system 800B, third antenna system 800C, fourth antenna system 800D), a signal via a respective waveguide, such as via the first waveguide 10A, the second waveguide 10B, the third waveguide 10C, and / or the fourth waveguide 10D. For example, the network node 400 is configured to transmit a first signal to the first antenna system 800A via the first waveguide 10A. For example, the network node 400 is configured to transmit a second signal to the second antenna system 800B via the second waveguide 10B. For example, the network node 400 is configured to transmit a third signal to the third antenna system 800C via the third waveguide 10C. For example, the network node 400 is configured to transmit a fourth signal to the fourth antenna system 800D via the fourth waveguide 10D. In one or more example systems, the first signal, the second signal, the third signal, and the fourth signal are different signals. In one or more example systems, the first signal, the second signal, the third signal, and the fourth signal are the same signal.

[0079] The first signal may be intended to a first receiver node (such as, a first wireless device). The second signal may be intended to a second receiver node, such as a second wireless device. The third signal may be intended to a third receiver node, such as a third wireless device. The fourth signal may be intended to a fourth receiver node, such as a fourth wireless device. Each antenna system, such as first antenna system 800A, second antenna system 800B, third antenna system 800C, and fourth antenna system 800D, may enable the network node 400 to serve a corresponding a receiver node (such as, the first receiver node, the second receiver node, the third receiver node, the fourth receiver node), such as to perform a MIMO transmission.

[0080] The first signal may be propagated by the first waveguide 10A to serve more than one receiver node. In other words, each antenna system (such as first antenna system 800A, second antenna system 800B, third antenna system 800C, and fourth antenna system 800D) may allow the network node 400 to serve a plurality of receiver nodes. For example, the first antenna system 800A may enable the network node 400 to serve a first primary receiver node and a first secondary receiver node. For example, the second antenna system 800B may enable the network node 400 to serve a second primary receiver node and a second secondary receiver node. For example, the third antenna system 800C may enable the network node 400 to serve a third primary receiver node and a third secondary receiver node. For example, the fourth antenna system 800D may enable the network node 400 to serve a fourth primary receiver node and a fourth secondary receiver node. The particular number of receiver nodes is not limiting.

[0081] In one or more example systems, several antenna systems may allow the network node 400 to serve the same receiver node, such as the same wireless device. For example, the first antenna system 800A and the second antenna system 800B may serve the same receiver node.

[0082] Fig. 7 shows a block diagram of an example antenna device 700 according to the disclosure. The antenna device 700 may comprise an antenna 710 and a CED 720. The antenna 710 comprises memory circuitry 710A, processor circuitry 710B, and an interface 710C. The interface 710C of the antenna 710 may be configured to interface the antenna 710 with a waveguide as disclosed herein. The interface 710C may comprise a wired and / or a wireless interface. The CED 720 comprises memory circuitry 720A, processor circuitry 720B, and an interface 720C. The interface 720C may comprise a wired and / or a wireless interface. The antenna device 700 may be configured to perform any of the operations as disclosed herein. The antenna device 700 may be configured to be connected to a network node, such as the network node 400, via a waveguide.

[0083] The antenna device 700 is configured to communicate with a network node, such as network node 400 as disclosed herein, e.g., via a waveguide. In one or more example antenna devices and / or antenna systems, the antenna device 700 is configured to communicate with another antenna device of the antenna system, e.g., via a waveguide. The antenna device 700 is configured to communicate with one or more wireless devices as disclosed herein, e.g., via the CED 720.

[0084] The antenna 710 is configured to communicate with the CED 720, such as wirelessly communicate with, via the interface 710C and the CED interface 720C.

[0085] The antenna device 700 is configured to transmit, e.g., via the antenna 710 and / or the CED 720, signals propagated by a waveguide. The antenna device 700 is configured to retransmit, e.g., via the CED 720, the signals transmitted by the antenna 710, e.g., to one or more WDs.

[0086] The interfaces 710C, 720C may be configured for wireless communications via a wireless communication system, such as a 3GPP system, such as a 3GPP system supporting one or more of: New Radio, NR, Long Term Evolution, LTE, Narrow-band loT, NB-loT, and Long Term Evolution - enhanced Machine Type Communication, LTE-M, and 3GPP system operated in licensed bands or unlicensed bands.

[0087] The operations of the antenna device 700 may be embodied in the form of executable logic routines (for example, lines of code, software programs, etc.) that are stored on a non-transitory computer readable medium (for example, memory circuitry 710A and / or 720A) and are executed by processor circuitry 710B and / or 720A).

[0088] Furthermore, the operations of the antenna device 700 may be considered a method that the antenna device 700 is configured to carry out. Also, while the described functions and operations may be implemented in software, such functionality may also be carried out via dedicated hardware or firmware, or some combination of hardware, firmware and / or software. Memory circuitries 710A, 720A may be one or more of: a buffer, a flash memory, a hard drive, a removable media, a volatile memory, a non-volatile memory, a random access memory (RAM), and any other suitable device. In a typical arrangement, memory circuitries 710A, 720A may include a non-volatile memory for long term data storage and a volatile memory that functions as system memory for processor circuitry 710C, 720C. Memory circuitries 710A, 720A may exchange data with processor circuitries 710C, 720C respectively, over a data bus. Control lines and an address bus between memory circuitries 710A, 720A and processor circuitries 71 OB, 720B respectively, also may be present (not shown in Fig. 7). Memory circuitries 710A, 720A are considered non-transitory computer readable mediums.

[0089] Memory circuitries 710A, 720A may be configured to store information (such as information indicative of antenna configurations and / or CED configurations respectively second set of paging resources) in a part of the memory.

[0090] Examples of methods and products (antenna system and communication system) according to the disclosure are set out in the following items:

[0091] Item 1. An antenna system comprising:

[0092] - a waveguide configured to enable propagation of signals along a structure of the waveguide;

[0093] - a plurality of antennas located at respective positions along the structure of the waveguide, wherein the plurality of antennas are configured to transmit signals propagated by the waveguide, and wherein the plurality of antennas comprise at least a first antenna and a second antenna; and

[0094] - a plurality of coverage enhancing devices, CEDs, comprising a first CED configured to retransmit the signals of the first antenna and a second CED configured to retransmit the signals of the second antenna.

[0095] Item 2. The antenna system according to item 1 , wherein the waveguide is a dielectric waveguide and / or an optical waveguide.

[0096] Item 3. The antenna system according to any of the previous items, wherein the plurality of antennas are positioned at a distance in the range of 0.2 m to 5 m from each other.

[0097] Item 4. The antenna system according to any of the previous items, wherein the waveguide comprises a splitter configured to split a power output of the waveguide into a first output having a first power output and a second output having a second power output, and wherein the first antenna is configured to receive the first power output as input.

[0098] Item 5. The antenna system according to item 4, wherein the splitter comprises a tunable dielectric material. Item 6. The antenna system according to any of the previous items, wherein the first antenna comprises a controller for controlling the power output of the first antenna.

[0099] Item 7. The antenna system according to any of the previous items, wherein the first antenna is a leaky wave antenna.

[0100] Item 8. The antenna system according to any of the previous items, wherein the first antenna comprises one or more of: a patch antenna, metal strip antenna, an array antenna, a dielectric resonator, DRA, antenna, and a lens antenna.

[0101] Item 9. The antenna system according to any of the previous items, wherein the first CED is positioned at a distance in the range of 1 / 3 to 1 / 2 of a surface size A of the first CED from the first antenna.

[0102] Item 10. The antenna system according to any of the previous items, wherein the retransmission of the signals comprises the first CED being configured to generate one or more beams based on the signals.

[0103] Item 11 . The antenna system according to any of the previous items, wherein the first CED comprises a controller for controlling the retransmission of the signals.

[0104] Item 12. The antenna system according to any of the previous items, wherein the first CED is a liquid crystal CED.

[0105] Item 13. The antenna system according to any of the previous items, wherein the antenna system is configured for terahertz, THz, range communication, and wherein the plurality of antennas are configured to transmit signals in the THz range.

[0106] Item 14. A communication system comprising an antenna system according to any of items 1- 13 and a network node.

[0107] Item 15. The communication system according to item 14, wherein the network node is configured for multiple input, multiple output, MIMO, communication, and wherein the network node comprises a plurality of ports, where each port of the plurality of ports is configured to connect to an antenna system according to any of items 1-13. Item 16. An antenna device comprising an antenna and a coverage enhancing device, CED, wherein the antenna device is configured to transmit, via the antenna, signals propagated by a waveguide, and to retransmit, via the CED, the signals transmitted by the antenna.

[0108] The use of the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. does not imply any particular order, but are included to identify individual elements. Moreover, the use of the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. does not denote any order or importance, but rather the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. are used to distinguish one element from another. Note that the words “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. are used here and elsewhere for labelling purposes only and are not intended to denote any specific spatial or temporal ordering. Furthermore, the labelling of a first element does not imply the presence of a second element and vice versa.

[0109] It may be appreciated that the figures comprise some circuitries or operations which are illustrated with a solid line and some circuitries, components, features, or operations which are illustrated with a dashed line. Circuitries or operations which are comprised in a solid line are circuitries, components, features or operations which are comprised in the broadest example. Circuitries, components, features, or operations which are comprised in a dashed line are examples which may be comprised in, or a part of, or are further circuitries, components, features, or operations which may be taken in addition to circuitries, components, features, or operations of the solid line examples. It should be appreciated that these operations need not be performed in order presented. Furthermore, it should be appreciated that not all of the operations need to be performed. The example operations may be performed in any order and in any combination. It should be appreciated that these operations need not be performed in order presented. Circuitries, components, features, or operations which are comprised in a dashed line may be considered optional.

[0110] Other operations that are not described herein can be incorporated in the example operations. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the described operations.

[0111] Certain features discussed above as separate implementations can also be implemented in combination as a single implementation. Conversely, features described as a single implementation can also be implemented in multiple implementations separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations, one or more features from a claimed combination can, in some cases, be excised from the combination, and the combination may be claimed as any sub-combination or variation of any sub-combination.

[0112] It is to be noted that the word "comprising" does not necessarily exclude the presence of other elements or steps than those listed. It is to be noted that the words "a" or "an" preceding an element do not exclude the presence of a plurality of such elements.

[0113] It should further be noted that any reference signs do not limit the scope of the claims, that the examples may be implemented at least in part by means of both hardware and software, and that several "means", "units" or "devices" may be represented by the same item of hardware.

[0114] The various example methods, devices, nodes, and systems described herein are described in the general context of method steps or processes, which may be implemented in one aspect by a computer program product, embodied in a computer-readable medium, including computerexecutable instructions, such as program code, executed by computers in networked environments. A computer-readable medium may include removable and non-removable storage devices including, but not limited to, Read Only Memory, ROM, Random Access Memory, RAM, compact discs, CDs, digital versatile discs, DVDs, etc. Generally, program circuitries may include routines, programs, objects, components, data structures, etc. that perform specified tasks or implement specific abstract data types. Computer-executable instructions, associated data structures, and program circuitries represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.

[0115] Although features have been shown and described, it will be understood that they are not intended to limit the claimed disclosure, and it will be made obvious to those skilled in the art that various changes and modifications may be made without departing from the scope of the claimed disclosure. The specification and drawings are, accordingly, to be regarded in an illustrative rather than restrictive sense. The claimed disclosure is intended to cover all alternatives, modifications, and equivalents.

Claims

CLAIMS1 . An antenna system comprising:- a waveguide configured to enable propagation of signals along a structure of the waveguide;- a plurality of antennas located at respective positions along the structure of the waveguide, wherein the plurality of antennas are configured to transmit signals propagated by the waveguide, and wherein the plurality of antennas comprise at least a first antenna and a second antenna; and- a plurality of coverage enhancing devices, CEDs, comprising a first CED configured to retransmit the signals of the first antenna and a second CED configured to retransmit the signals of the second antenna.

2. The antenna system according to claim 1 , wherein the waveguide is a dielectric waveguide and / or an optical waveguide.

3. The antenna system according to any of the previous claims, wherein the plurality of antennas are positioned at a distance in the range of 0.2 m to 5 m from each other.

4. The antenna system according to any of the previous claims, wherein the waveguide comprises a splitter configured to split a power output of the waveguide into a first output having a first power output and a second output having a second power output, and wherein the first antenna is configured to receive the first power output as input.

5. The antenna system according to claim 4, wherein the splitter comprises a tunable dielectric material.

6. The antenna system according to any of the previous claims, wherein the first antenna comprises a controller for controlling the power output of the first antenna.

7. The antenna system according to any of the previous claims, wherein the first antenna is a leaky wave antenna.

8. The antenna system according to any of the previous claims, wherein the first antenna comprises one or more of: a patch antenna, metal strip antenna, an array antenna, a dielectric resonator, DRA, antenna, and a lens antenna.

9. The antenna system according to any of the previous claims, wherein the first CED is positioned at a distance in the range of 1 / 3 to 1 / 2 of a surface size A of the first CED from the first antenna.

10. The antenna system according to any of the previous claims, wherein the retransmission of the signals comprises the first CED being configured to generate one or more beams based on the signals.

11. The antenna system according to any of the previous claims, wherein the first CED comprises a controller for controlling the retransmission of the signals.

12. The antenna system according to any of the previous claims, wherein the first CED is a liquid crystal CED.

13. The antenna system according to any of the previous claims, wherein the antenna system is configured for terahertz, THz, range communication, and wherein the plurality of antennas are configured to transmit signals in the THz range.

14. A communication system comprising an antenna system according to any of claims 1-13 and a network node.

15. The communication system according to claim 9, wherein the network node is configured for multiple input, multiple output, MIMO, communication, and wherein the network node comprises a plurality of ports, where each port of the plurality of ports is configured to connect to an antenna system according to any of claims 1-13.

16. An antenna device comprising an antenna and a coverage enhancing device, CED, wherein the antenna device is configured to transmit, via the antenna, signals propagated by a waveguide, and to retransmit, via the CED, the signals transmitted by the antenna.

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