Computer-implemented method for designing a reconfigurable passive radiating element of an antenna device

Abstract

The present disclosure relates to a computer-implemented method for designing a reconfigurable passive radiating element of an antenna device that comprises a polarized active radiating element for radiating radio waves of one or more polarizations, the reconfigurable passive radiating element and a control circuit. The reconfigurable passive radiating element comprises, on a substrate, multiple conductive elements, multiple switches for electrically connecting a respective pair of adjacent conductive elements of the multiple conductive elements with each other, and feeding lines for feeding control signals from the control circuit to the multiple switches. The reconfigurable passive radiating element is arranged in a main direction of radiation of the polarized active radiating element in front of the polarized active radiating element. Further, such an antenna device is disclosed. The antenna device may be used in a Fiber-to-the-Room (FTTR) system.

Description

[0001] COMPUTER-IMPLEMENTED METHOD FOR DESIGNING A RECONFIGURABLE

[0002] PASSIVE RADIATING ELEMENT OF AN ANTENNA DEVICE

[0003] TECHNICAL FIELD

[0004] The present disclosure relates to a computer-implemented method for designing a reconfigurable passive radiating element of an antenna device that comprises a polarized active radiating element for radiating radio waves of one or more polarizations, the reconfigurable passive radiating element and a control circuit. The present disclosure further relates to such an antenna device.

[0005] BACKGROUND

[0006] Multiple wireless access points systems, such as Wi-Fi networks (e.g. indoor Wi-Fi networks), make use of access point devices (may be referred to as access points) to provide wireless communication, such as an internet connection, to terminals.

[0007] SUMMARY

[0008] Introducing several co-existing access points improves the possibilities to achieve a robust connection. During operation, access points may be subject to environmental noise and electromagnetic (EM) interferences, such as from other access points in the system. A connection quality, measurable in speed and robustness by key performance indicators (KPIs), such as data rate, may be degraded by the aforementioned noise and interferences.

[0009] Reconfigurable antennas may be a possible technical solution in order to adapt the radiation to the environment and enhance the performance in real time. The reconfigurability feature may be implemented by switching devices, which may require a DC biasing and control. Such DC feeding and control may interfere with the emitted and received radio-frequency (RF) signals, i.e. with the radiated radio waves. In other words, there may be a DC-to-RF interference, which is a drawback for the radio wave radiation by the reconfigurable antenna. In view of the above, this disclosure aims to provide a computer-implemented method for designing an improved reconfigurable passive radiating element of an antenna device. An objective of this disclosure may be to provide such a method for designing a reconfigurable passive radiating element of an antenna device that is improved with regard to enhancing a DC-to-RF interference rejection.

[0010] These and other objectives are achieved by the solution of this disclosure as described in the independent claims. Advantageous implementations are further defined in the dependent claims.

[0011] A first aspect of this disclosure provides a computer-implemented method for designing a reconfigurable passive radiating element of an antenna device that comprises a polarized active radiating element for radiating radio waves of one or more polarizations, the reconfigurable passive radiating element and a control circuit. The reconfigurable passive radiating element comprises, on a substrate, multiple conductive elements, multiple switches for electrically connecting a respective pair of adjacent conductive elements of the multiple conductive elements with each other, and feeding lines for feeding control signals from the control circuit to the multiple switches. The reconfigurable passive radiating element is arranged in a main direction of radiation of the polarized active radiating element in front of the polarized active radiating element. The method comprises at least one of: minimizing, with regard to a maximum number of switches, the number of the multiple switches according to a list of different radiation patterns that the antenna device should be able to radiate, the maximum number of switches being present when each pair of adjacent conductive elements of the multiple conductive elements is electrically connected by a switch; arranging, on the substrate, the feeding lines by slanting at least a part of the feeding lines with regard to a first direction and second direction of the substrate, the first direction and the second direction being perpendicular to each other; arranging the multiple conductive elements and multiple switches on the substrate such that each of the multiple conductive elements and multiple switches is positioned by at least a minimum distance away from a position of the substrate, at which the control circuit is electrically connected to the feeding lines; and inhomogeneously distributing the feeding lines on the substrate in a region of the substrate where a near electric field of radio waves radiated by the polarized active radiating element is smaller than a threshold for the near electric field.

[0012] Any of the above described features with regard to designing the reconfigurable passive radiating element of the antenna device allows enhancing the DC-to-RF inference rejection. Namely, minimizing the number of the multiple switches minimizes the number of feeding lines for providing control signals, e.g. in the form of DC voltages, to the respective switch and, thus, reduces an impact of the DC control of the switches on the radio frequency (RF) signals radiated in the form of radio waves from the polarized active radiating element towards the reconfigurable passive radiating element. This allows enhancing the DC-to-RF interference rejection of the antenna device.

[0013] Slanting at least a part of the feeding lines with regard to a first direction and second direction of the substrate allows reducing an impact of the DC control of the switches via the part of the feeding lines on the radio frequency (RF) signals radiated in the form of radio waves from the polarized active radiating element towards the reconfigurable passive radiating element. This allows enhancing the DC-to-RF interference rejection of the antenna device.

[0014] Arranging the multiple conductive elements and multiple switches on the substrate such that each of the multiple conductive elements and multiple switches is positioned by at least a minimum distance away from a position of the substrate, at which the control circuit is electrically connected to the feeding lines reduces an impact of the DC control by the control circuit on the RF signals radiated in the form of radio waves from the polarized active radiating element towards the multiple conductive elements of the antenna device. This allows enhancing the DC- to-RF interference rejection of the antenna device. In other words, displacing the radiating structure (i.e. the multiple conductive elements and multiple switches) of the reconfigurable passive radiating element by at least the minimum distance away from the position of the substrate, at which the control circuit is electrically connected to the feeding lines allows minimizing the impact of mutual coupling and benefits primary beams, i.e. the radiation pattern, of the antenna device.

[0015] Inhomogeneously distributing the feeding lines on the substrate in a region of the substrate where a near electric field of radio waves radiated by the polarized active radiating element is smaller than a threshold for the near electric field allows reducing an impact of the DC control of the switches via the feeding lines on the radio frequency (RF) signals radiated in the form of radio waves from the polarized active radiating element towards the reconfigurable passive radiating element. This allows enhancing the DC-to-RF interference rejection of the antenna device.

[0016] Herein, a region of the substrate where a near electric field of radio waves radiated by the polarized active radiating element is smaller than a threshold for the near electric field may mean that every location in the region is subject to a power level at least 10 dB lower than a maximum value of the near electric field distribution over the complete substrate. With other words, the method may optionally comprise inhomogenously distributing the feeding lines on the substrate in a region of the substrate, wherein every location in the region is subject to a power level at least 10 dB lower than a maximum value of the near electric field distribution over the complete substrate.

[0017] Enhancing the DC-to-RF interference rejection of the antenna device allows optimizing the radiation of the antenna device on the entire frequency band of the antenna device. Designing the position of the multiple switches and multiple conductive elements on the substrate allows enhancing the DC-to-RF interference rejection of the antenna device and, thus, optimizing the radiation of the antenna device on the entire frequency band of the antenna device. Designing a routing of the feeding lines, e.g. slanting at least a part of the feeding lines and / or arranging the feeding lines as outlined above, allows enhancing the DC-to-RF interference rejection of the antenna device and, thus, optimizing the radiation of the antenna device on the entire frequency band of the antenna device.

[0018] Herein, enhancing the DC-to-RF interference rejection of the antenna device may be understood as reducing mutual interference between radio frequency (RF) fields, which determine the radiation patterns of the antenna device, and a DC signaling in the form of control signals for controlling the multiple switches.

[0019] Each switch of the multiple switches is provided for electrically connecting a different pair of two adjacent conductive elements. In other words, the multiple switches electrically connect a respective pair of two adjacent conductive elements. That is, the control circuit may be configured to control the multiple switches for controlling a conducting path between a respective pair of conductive elements of the multiple conductive elements of the passive radiating element. The multiple switches may be configured to be in the conducting state (i.e. activated) and / or in the non-conducting state (i.e. deactivated). This allows generating different radiation patterns of the antenna device. For example, in case a switch connecting a pair of two conductive elements is in the conducting state, then there is a conducting path between the two conductive elements. In case the switch connecting the pair of two conductive elements is in the non-conducting state, then there no conducting path between the two conductive elements.

[0020] The control circuit may be configured to control the multiple switches for reconfiguring the reconfigurable passive radiating element. That is, depending on which of the multiple switches are in the conducting state or in then non-conducting state a radiating structure of the reconfigurable passive radiating element may be different. Therefore, controlling the multiple switches allows configuring the radiating structure of the reconfigurable passive radiating element and, thus, reconfiguring the reconfigurable passive radiating element.

[0021] The multiple conductive elements are or form a radiating structure (i.e. passive radiating structure) of the passive radiating element. The multiple switches allow controlling interconnections between the multiple conductive elements and, thus, allow controlling the radiating structure of the passive radiating element.

[0022] The control circuit may be arranged at least partly on the substrate of the reconfigurable passive radiating element. The control circuit may be arranged at least partly on the substrate of the reconfigurable passive radiating element such that it is arranged on an surface of the substrate on which the multiple conductive elements, the multiple switches and the feeding lines are arranged, or on a second surface of the substrate that is opposite to the aforementioned surface of the substrate.

[0023] The passage “at least a part of the feeding lines” may mean a part of the feeding lines or all feeding lines. Optionally, at least a part of the feeding lines may be all feeding lines expect of at least one feeding line of the feeding lines. At least a part of the feeding lines may be slanted with regard to the first direction and second direction of the substrate such that the feeding lines are slanted whenever possible on the substrate. For example, the multiple switches may be positive intrinsic negative (PIN) diodes. In this case, the control signals provided by the control circuit to the PIN diodes may bias the respective PIN diode so that the PIN diode is in the conducting state (forward biased) or in the non-conducting state (reversed biased). The feeding lines may be referred to as “biasing lines”.

[0024] The polarized active radiating element may be a single-polarized active radiating element or a dual-polarized active radiating element. The polarized active radiating element may be configured to radiate polarized (e.g. single or dual-polarized) radio waves. The dual-polarization active radiating element may be configured to generate electric fields whose vectors are orthogonal to each other at least in the main propagation directions. The dual polarization active radiating element may be configured to radiate with horizontal and vertical polarizations.

[0025] Since the reconfigurable passive radiating element is arranged in a main direction of radiation of the polarized active radiating element in front of the polarized active radiating element electromagnetic coupling occurs between the multiple rhombic conductive elements and the dualpolarized active radiating element when the dual-polarized active radiating element radiates radio waves. The passive radiating element being arranged in the main direction of radiation of the polarized active radiating element in front of the polarized active radiating element means that the radio waves radiated by the polarized active radiating element in the main direction of radiation are radiated towards the passive radiating element.

[0026] The feeding lines for feeding the control signals from the control circuit to the switches may be referred to as “control feeding lines” or “control lines.

[0027] A pair of adjacent conductive elements of the multiple conductive elements are two conductive elements, where one of the two conductive elements immediately precedes or follows the other one of the two conductive elements.

[0028] The polarized active radiating element may be configured to be fed (i.e. driven) with one or more radio frequency (RF) signals and radiate radio waves in response to being fed (i.e. driven) with the one or more RF signals. For this, the polarized active radiating element may be electrically connected with one or more RF signal feeding lines. The reconfigurable passive radiating element is not connected to one or more RF signal feeding lines, i.e. it is not fed (i.e. driven) with one or more RF signals. The multiple conductive elements of the passive radiating elements are configured to change a radiation pattern of the polarized active radiating element when the polarized active radiating elements radiates radio waves. Optionally, the control circuit may be configured to control the polarized active radiating element and, thus, radiation by the polarized active radiating element. For this, the control circuit may be configured to control radio frequency (RF) signals provided to the polarized active radiating element.

[0029] The control circuit may comprise or be at least one of a controller, a microcontroller, a processor, a microprocessor, an application specific integrated circuit (ASIC), field programmable gate array (FPGA), etc.

[0030] Optionally at least a part of the feeding lines may comprise frequent choke inductors (e g. every tenth of a wavelength of radio waves radiated by the antenna device). This allows reducing or avoiding a RF coupling to the feeding lines. The aforementioned wavelength may be a midwavelength in a range of wavelengths that are emittable by the antenna device.

[0031] In an implementation form of the first aspect, minimizing, with regard to the maximum number of switches, the number of the multiple switches according to the list of different radiation patterns that the antenna device should be able to radiate comprises replacing a switch of the multiple switches by a short circuit or open circuit in case the switch is switched on or switched off, respectively, for achieving the different radiation patterns.

[0032] In other words, a potential switch may be replaced by a short circuit or open circuit in case the potential switch would be always switched on or switched off, respectively, for achieving all the different radiation patterns. “Switched on” means switched to the conducting state, i.e. the switch is in the conducting state; and “switched off’ means switched to the non-conducting state, i.e. the switch is in the non-conducting state.

[0033] In an implementation form of the first aspect, minimizing, with regard to the maximum number of switches, the number of the multiple switches according to the list of different radiation patterns that the antenna device should be able to radiate comprises computing a number of switches by taking the logarithm of the number of different radiation patterns to the base of two and rounding the computed result up to an integer, and providing at least the computed number of switches as the multiple switches on the substrate. For example, in case the number of different radiation patterns equals to eight, then the base of two and rounding the computed result up to an integer equals to three. In the aforementioned example, at least three switches may be provided as the multiple switches on the substrate. Relaxing the radiation pattern specification of the antenna device may allow reducing the number of the multiple switches. That is, the design method allows reducing a ratio given by the number of switches divided by the number of different radiation patterns while still allowing to fulfill technical specifications imposed to the radiation patterns.

[0034] In an implementation form of the first aspect, minimizing with regard to the maximum number of switches, the number of the multiple switches according to the list of different radiation patterns that the antenna device should be able to radiate comprises reducing an area edge coverage of the antenna device, and minimizing the multiple switches according to the reduced area edge coverage of the antenna device.

[0035] The area edge coverage of the antenna device is the edge of the area in front of the antenna device, in which the antenna device provides coverage with an acceptable wireless radiation quality, e.g. acceptable signal-to-noise-ratio (SNR), such as an acceptable Wi-Fi SNR.

[0036] In an implementation form of the first aspect, the method comprises distributing, on the substrate, the minimized number of the multiple switches according to the number and / or position of the multiple conductive elements.

[0037] In other words, the number (i.e. amount) and / or position of the multiple conductive elements may condition the distribution of the minimized number of the multiple switches.

[0038] In an implementation form of the first aspect, the method comprises using multiple rhombic conductive elements as the multiple conductive elements. The method may comprise arranging the multiple rhombic conductive elements on the substrate such that: at least one vertex of each rhombic conductive element of the multiple rhombic conductive elements is aligned with a vertex of another rhombic conductive element of the multiple rhombic conductive elements, a vertex of a first pair of facing vertexes of each rhombic conductive element faces in the first direction of the substrate, and a vertex of a second pair of facing vertexes of each rhombic conductive element faces in the second direction of the substrate.

[0039] The term “diamond-shaped” may be used as a synonym for the term “rhombic”. The term “rhombic” may be understood as a quadrilateral with four sides of the same length, and vertexes on top, bottom, left and right.

[0040] In an implementation form of the first aspect, the method comprises slanting at least a part of the feeding lines by an angle of 45 degrees with regard to the first direction and second direction of the substrate.

[0041] For example, the polarized active radiating element may be a dual-polarized active radiating element configured to radiate a horizontal polarization and a vertical polarization. The first direction and the second direction may be the horizontal and vertical direction, respectively. Thus, the 45 degrees slanting allows as much angular difference with regard to the polarizations with a trade-off between the horizontal and vertical polarization.

[0042] In an implementation form of the first aspect, the method comprises determining a region of low-power near-field distribution of electromagnetic energy on the substrate by performing a full-wave simulation of the antenna device, and arranging the control circuit at a border of the substrate where the region of low-power near-field distribution of electromagnetic energy is determined.

[0043] This allows arranging the control circuit of the antenna device with a reduced or minimum impact on the total radiation pattern of the antenna device. The region of low-power near-field distribution of electromagnetic energy on the substrate may be referred to as cold region on the substrate.

[0044] In an implementation form of the first aspect, the method comprises determining a region of low-power near-field distribution of electromagnetic energy on the substrate by performing a full-wave simulation of the antenna device, and arranging the feeding lines on the substrate in the determined region of low-power near-field distribution of electromagnetic energy. This allows arranging the feeding lines on the substrate with a reduced or minimum impact on the total radiation pattern of the antenna device.

[0045] In an implementation form of the first aspect, the method comprises determining one or more radiation patterns of the different radiation patterns that radiate in a preferred main direction, and arranging the control circuit at a border of the substrate where the control circuit has a lower interference on the determined one or more radiation patterns compared to another border of the substrate.

[0046] For example, the control circuit may be arranged at a border of the substrate where the control circuit has a minimum interference on the determined one or more radiation patters. The control circuit may be arranged at least partly on the substrate.

[0047] For example, the different radiation patterns of the antenna device may have different main radiation directions (main beams of such radiation patterns may point in different directions), wherein some of the different radiation patterns are more important with regard to a wireless communication system, e g. Wi-Fi network, in which the antenna device may be used, than others. Determining one or more radiation patterns of the different radiation patterns that radiate in a preferred main direction allows considering this. For example, in the case of a wireless communication system, such as a Wi-Fig network, in which the antenna device may be used determining the one or more radiation patterns of the different radiation patterns that radiate in a preferred main direction may comprise considering main and secondary coverage regions provided by the system. Primary regions may cover areas where the chance to have a wireless communication user, such as a Wi-Fi user, is higher compared to secondary regions. Such primary regions may correspond to areas with higher statistical chance to have users, where it may be aimed to improve the quality of the wireless communication service, e.g. Wi-Fi service, with a higher signal-to-interference-plus-noise ratio (SINR). This may lead to a higher throughput level and lower latency. Giving priority to those primary coverage regions, allows creating stronger and independent channels for wireless communication and for localization purposes.

[0048] In an implementation form of the first aspect, the method comprises determining one or more radiation patterns of the different radiation patterns that radiate in a preferred main direction, and arranging, on the substrate, more than 50% of the feeding lines in a region of the substrate where they have a lower interference on the determined one or more radiation patterns compared to a rest of the substrate.

[0049] For example, more than 50% of the feeding lines may be arranged in a region of the substrate where they have a minimum interference on the determined one or more radiation patterns. In other words, this allows arranging a larger part of the feeding lines, i.e. the control network (may be referred to as biasing network), at a side of the substrate where the control network (i.e. the feeding lines) have a lower interference on the one or more radiation patterns in the preferred main direction.

[0050] In an implementation form of the first aspect, the method comprises using multiple rhombic conductive elements as the multiple conductive elements. In addition or alternatively, the method may comprise using multiple positive intrinsic negative (PIN) diodes as the multiple switches.

[0051] In other words, the multiple conductive elements may be multiple rhombic conductive elements. In addition or alternatively, the multiple switches may be multiple PIN diodes. Optionally, the switches may be semiconductor switches. Optionally, the switches may be transistors.

[0052] In order to achieve the computer-implemented method according to the first aspect of this disclosure, some or all of the implementation forms and optional features of the first aspect, as described above, may be combined with each other.

[0053] A second aspect of this disclosure provides an antenna device that comprises a polarized active radiating element for radiating radio waves of one or more polarizations, a reconfigurable passive radiating element and a control circuit. The reconfigurable passive radiating element comprises, on a substrate, multiple conductive elements, multiple switches for electrically connecting a respective pair of adjacent conductive elements of the multiple conductive elements with each other, and feeding lines for feeding control signals from the control circuit to the multiple switches. The reconfigurable passive radiating element is arranged in a main direction of radiation of the polarized active radiating element in front of the polarized active radiating element. At least one of the following is true: the number of the multiple switches is minimized, with regard to a maximum number of switches, according to a list of different radiation patterns that the antenna device is configured to radiate, the maximum number of switches being present when each pair of adjacent conductive elements of the multiple conductive elements is electrically connected by a switch; the feeding lines are arranged on the substrate such that at least a part of the feeding lines is slanted with regard to a first direction and second direction of the substrate, the first direction and the second direction being perpendicular to each other; the multiple conductive elements and multiple switches are arranged on the substrate such that each of the multiple conductive elements and multiple switches is positioned by at least a minimum distance away from a position of the substrate, at which the control circuit is electrically connected to the feeding lines; and the feeding lines are inhomogeneously distributed on the substrate in a region of the substrate where a near electric field of radio waves radiated by the polarized active radiating element is smaller than a threshold for the near electric field.

[0054] The above description of the method according to the first aspect of this disclosure is correspondingly valid for the antenna device of the second aspect of this disclosure. In other words, the antenna device of the second aspect may be implemented according to the description of the method of the first aspect. The antenna device of the second aspect may be designed by the method of the first aspect. The description of the antenna device according to the second aspect is correspondingly valid for the method of the first aspect, especially the antenna device that may be designed using the method of the first aspect.

[0055] The antenna device may be an antenna device for an access point of a multiple wireless access point system. The antenna device may be a multiple-input multiple-output (MIMO) antenna device. For example, the antenna device is a 2x2 MIMO antenna device. This is only by way of example and, thus, the antenna device may be a MIMO antenna device of higher number.

[0056] The multiple wireless access point system may be a wireless local access network (WLAN) network. Thus, the antenna device may be an antenna device for a wireless local access network (WLAN) access point. The WLAN network may be a WLAN network according to IEEE 802.11. The antenna device may be configured to be used for a Wi-Fi access point. For example, the antenna device is configured to operate at a frequency range according to Wi-Fi 6 (e.g. between 5170 and 5835 MHz). That is, the antenna device may be suitable for a Wi-Fi 6 access point. In addition or alternatively the antenna device may be configured to operate at a frequency range according to Wi-Fi6E, Wi-Fi 7 etc. That is, the antenna device may be suitable for a Wi-Fi6E access point, a Wi-Fi 7 access point etc. For example, the antenna device is configured to operate with 5.2-5.8 GHz bands (IEEE 802.1 l.a / n / ac / ax). For example, the antenna device may have a height smaller than 1 cm (low profile). For example, a surface of the antenna device may fit in 10 x 10 cm.

[0057] An access point of a multiple wireless access point system is an access point that is configured for a multiple wireless access point system. That is, such an access point may be used in a multi access point (multi- AP) architecture.

[0058] The antenna device may be configured to be used in a multi-AP architecture such as P2MP (Point to Multi Point). The access points may backhaul with wireless, coaxial, ethernet, or fiber to a main access point, wherein a backhaul with a fiber is called FTTR (Fiber-to-the-Room) technology. The antenna device may be configured to be used in a FTTR system. A FTTR device, such as a FTTR main fiber-optic unit (MFU) or sub FTTR unit (SFU), may comprise the antenna device.

[0059] FTTR is an in-premises networking technology based on optical fiber. With benefit of optical fiber, FTTR provides high-bandwidth and reliable communications, with topologies and functionalities depending on the use cases. First set of use cases enabled by the Fifth Generation Fixed Network (F5G) includes services to consumers and enterprises with assist of wireless technologies mainly by Wi-Fi. It focuses on optical elements up to connections serving locations of users in home or offices. FTTR allows fiber connection and backhauling for in-premises access networking with a main fiber-optic unit (MFU) connected over fiber to several sub FTTR units (SFUs), e.g. via splitter, by default with one SFU per each room or multiple SFUs in a room. Such solution particularly improves Wi-Fi coverage and throughput in rooms in comparison with legacy Wi-Fi systems, over 5.2-5.8 GHz bands (802.1 l.a / n / ac / ax) where path loss is greater than that of 2.4 GHz. An SFU has advantages of simple and small form which allow its easy installations on any fiber-connected location on the wall (similar to the power outlets), or on the desk. It can easily create point to multi-point networks toward multiple SFUs in a house thanks to a fiber splitter unit. The antenna device may be used in an SFU.

[0060] For example, the antenna device may be used in an optical network terminal (ONT), such as a secondary Wi-Fi ONT. Such ONT may be mounted for example to a wall, a desk, a ceiling etc Herein, an antenna device is described as a transmission (not reception) device. However, it can also be operated as a reception device. That is, the antenna device may reciprocally be operated as a reception device.

[0061] The antenna device of the second aspect and its implementation forms and optional features achieve the same advantages as the method of the first aspect and its respective implementation forms and respective optional features.

[0062] In an implementation form of the second aspect, the number of the multiple switches is minimized in that a switch of the multiple switches is replaced by a short circuit or open circuit in case the switch is switched on or switched off, respectively, for achieving the different radiation patterns.

[0063] In an implementation form of the second aspect, the number of the multiple switches is minimized in that the multiple switches on the substrate are a number of switches that is computed by taking the logarithm of the number of different radiation patterns to the base of two and rounding the computed result up to an integer.

[0064] In an implementation form of the second aspect, the number of the multiple switches is minimized according to a reduced area edge coverage of the antenna device.

[0065] In an implementation form of the second aspect, the minimized number of the multiple switches are distributed on the substrate according to the number and / or position of the multiple conductive elements.

[0066] In an implementation form of the second aspect, the multiple conductive elements are multiple rhombic conductive elements. The multiple rhombic conductive elements may be arranged on the substrate such that: at least one vertex of each rhombic conductive element of the multiple rhombic conductive elements is aligned with a vertex of another rhombic conductive element of the multiple rhombic conductive elements, a vertex of a first pair of facing vertexes of each rhombic conductive element faces in the first direction of the substrate, and a vertex of a second pair of facing vertexes of each rhombic conductive element faces in the second direction of the substrate.

[0067] In an implementation form of the second aspect, the feeding lines are arranged on the substrate such that at least a part of the feeding lines is slanted by an angle of 45 degrees with regard to the first direction and second direction of the substrate.

[0068] In an implementation form of the second aspect, the control circuit is arranged at a border of the substrate where a region of low-power near-field distribution of electromagnetic energy of the antenna device is present.

[0069] In an implementation form of the second aspect, the feeding lines are arranged on the substrate in a region of low-power near-field distribution of electromagnetic energy of the antenna device.

[0070] In an implementation form of the second aspect, the control circuit is arranged at a border of the substrate where the control circuit has a lower interference on one or more radiation patterns radiating in a preferred main direction compared to another border of the substrate.

[0071] In an implementation form of the second aspect, more than 50% of the feeding lines are arranged on the substrate in a region of the substrate where they have a lower interference on one or more radiation patterns radiating in a preferred main direction compared to a rest of the substrate.

[0072] In an implementation form of the second aspect, the multiple conductive elements are multiple rhombic conductive elements. In addition or alternatively, the multiple switches may be multiple positive intrinsic negative (PIN) diodes.

[0073] In order to achieve the antenna device according to the second aspect of this disclosure, some or all of the implementation forms and optional features of the second aspect, as described above, may be combined with each other. A third aspect of this disclosure provides a computer program comprising instructions which, when the program is executed by a computer, cause the computer to perform the method according to the first aspect of this disclosure.

[0074] A fourth aspect of this disclosure provides a storage medium storing executable program code which, when executed by a processor, causes the method according to the first aspect of this disclosure to be performed.

[0075] The computer program according to the third aspect of this disclosure and the storage medium according to the fourth aspect of this disclosure achieve the same advantages as the method of the first aspect of this disclosure.

[0076] It has to be noted that all devices, elements, units and means described in the present application could be implemented in software or hardware elements or any kind of combination thereof. All steps which are performed by the various entities described in the present application as well as the functionalities described to be performed by the various entities are intended to mean that the respective entity is adapted to or configured to perform the respective steps and functionalities. Even if, in the following description of specific embodiments, a specific functionality or step to be performed by external entities is not reflected in the description of a specific detailed element of that entity which performs that specific step or functionality, it should be clear for a skilled person that these methods and functionalities can be implemented in respective software or hardware elements, or any kind of combination thereof.

[0077] BRIEF DESCRIPTION OF DRAWINGS

[0078] The above described aspects and implementation forms will be explained in the following description of specific embodiments in relation to the enclosed drawings, in which

[0079] FIG. 1 shows an example of a computer-implemented method for designing a reconfigurable passive radiating element of an antenna device according to an embodiment of this disclosure.

[0080] FIG. 2 (a) shows an example of an implementation form of a minimizing step of the method of FIG. 1. FIG. 2 (b) shows an example of an implementation form of a minimizing step of the method of FIG. 1.

[0081] FIG. 2 (c) shows an example of an implementation form of a minimizing step of the method of FIG. 1.

[0082] FIG. 3 shows an example of an antenna device according to an embodiment of this disclosure.

[0083] FIG. 4 shows an example of an implementation form of the antenna device of FIG. 3.

[0084] FIG. 5 shows a top view of the reconfigurable passive radiating element of the antenna device of FIG. 4.

[0085] FIG. 6 shows an example of a near-field distribution of electromagnetic energy at the reconfigurable passive radiating element of FIG. 5 when the antenna device radiates radio waves.

[0086] Same elements shown in the Figures (FIGs) are labeled with the same reference sign, and may be implemented likewise.

[0087] DETAILED DESCRIPTION OF EMBODIMENTS

[0088] FIG. 1 shows an example of a computer-implemented method for designing a reconfigurable passive radiating element of an antenna device according to an embodiment of this disclosure. The method 100 of FIG. 1 is an example of the method according to the first aspect of this disclosure. Thus, the description of the method of the first aspect is correspondingly valid for the method 100 of FIG. 1.

[0089] The method 100 of FIG. 1 is a computer-implemented method for designing a reconfigurable passive radiating element of an antenna device that comprises a polarized active radiating element for radiating radio waves of one or more polarizations, the reconfigurable passive radiating element and a control circuit. The reconfigurable passive radiating element comprises, on a substrate, multiple conductive elements, multiple switches for electrically connecting a respective pair of adjacent conductive elements of the multiple conductive elements with each other, and feeding lines for feeding control signals from the control circuit to the multiple switches. The reconfigurable passive radiating element is arranged in a main direction of radiation of the polarized active radiating element in front of the polarized active radiating element. Examples of such an antenna device are shown in FIGs 3 to 5.

[0090] As shown in FIG. 1, the method 100 comprises at least one of the following steps: a step SI 00 of minimizing, with regard to a maximum number of switches, the number of the multiple switches according to a list of different radiation patterns that the antenna device should be able to radiate, the maximum number of switches being present when each pair of adjacent conductive elements of the multiple conductive elements is electrically connected by a switch; a step S200 of arranging, on the substrate, the feeding lines by slanting at least a part of the feeding lines with regard to a first direction and second direction of the substrate, the first direction and the second direction being perpendicular to each other; a step S300 of arranging the multiple conductive elements and multiple switches on the substrate such that each of the multiple conductive elements and multiple switches is positioned by at least a minimum distance away from a position of the substrate, at which the control circuit is electrically connected to the feeding lines; and a step S400 of inhomogeneously distributing the feeding lines on the substrate in a region of the substrate where a near electric field of radio waves radiated by the polarized active radiating element is smaller than a threshold for the near electric field.

[0091] For further information on the method 100 of FIG. 1, reference is made to the method according to the first aspect of this disclosure and to the description of FIGs 2 to 6.

[0092] FIG. 2 (a) shows an example of an implementation form of a minimizing step of the method of FIG. 1. The description of the method of FIG. 1 is correspondingly valid. As shown in FIG. 2 (a) the minimizing step SI 00 of the method 100 of FIG. 1 may comprise a step S101 of replacing a switch of the multiple switches by a short circuit or open circuit in case the switch is switched on or switched off, respectively, for achieving the different radiation patterns.

[0093] FIG. 2 (b) shows an example of an implementation form of a minimizing step of the method of FIG. 1. The description of the method of FIG. 1 is correspondingly valid.

[0094] As shown in FIG. 2 (b) the minimizing step SI 00 of the method 100 of FIG. 1 may comprise a step SI 02 of computing a number of switches by taking the logarithm of the number of different radiation patterns to the base of two and rounding the computed result up to an integer, and providing at least the computed number of switches as the multiple switches on the substrate.

[0095] FIG. 2 (c) shows an example of an implementation form of a minimizing step of the method of FIG. 1. The description of the method of FIG. 1 is correspondingly valid.

[0096] As shown in FIG. 2 (c) the minimizing step SI 00 of the method 100 of FIG. 1 may comprise a step S103 of reducing an area edge coverage of the antenna device, and minimizing the multiple switches according to the reduced area edge coverage of the antenna device.

[0097] The minimizing step S100 of the method 100 of FIG. 1 may comprise any combination of the steps S101, SI 02 and SI 03 of FIGs 2 (a), 2 (b) and 2 (c), respectively.

[0098] FIG. 3 shows an example of an antenna device according to an embodiment of this disclosure. The antenna device of FIG. 3 is an example of the antenna device according to the second aspect of this disclosure. Thus, the description of the antenna device according to the second aspect of this disclosure is correspondingly valid for the antenna device of FIG. 3.

[0099] As shown on the left side of FIG. 3, the antenna device 1 comprises a polarized active radiating element 2 for radiating radio waves of one or more polarizations, a reconfigurable passive radiating element 3 and a control circuit 4. As shown on the right side of FIG. 3, which shows a top view of an example of the reconfigurable passive radiating element 3, the reconfigurable passive radiating element 3 comprises, on a substrate 34, multiple conductive elements 31, and multiple switches 32 for electrically connecting a respective pair of adjacent conductive elements of the multiple conductive elements 31 with each other. According to FIG. 3, the conductive elements 31 are rhombic conductive elements. This is by way of example and, thus, the conductive elements 31 may have a different form. According to FIG. 3, the number of conductive elements 31 is sixteen. This is by way of example and may be different. According to FIG. 3, the number of switches 32 is twenty. This is by way of example and may be different.

[0100] Further, as indicated on the left side of FIG. 3 and shown in FIGs 4 and 5, the reconfigurable passive radiating element 3 comprises feeding lines 33 for feeding control signals from the control circuit 4 to the multiple switches 32. The reconfigurable passive radiating element 3 is arranged in a main direction of radiation (indicated by the arrow on the left side of FIG. 3) of the polarized active radiating element 2 in front of the polarized active radiating element 2.

[0101] For the antenna device 1 at least one of the following is true: as shown in FIG. 3, the number of the multiple switches 32 may be minimized, with regard to a maximum number of switches, according to a list of different radiation patterns that the antenna device 1 is configured to radiate, the maximum number of switches being present when each pair of adjacent conductive elements of the multiple conductive elements 31 is electrically connected by a switch 32; as shown in FIGs 4 and 5, the feeding lines 33 may be arranged on the substrate 34 such that at least a part of the feeding lines 33 is slanted with regard to a first direction dl and second direction d2 of the substrate 34, the first direction dl and the second direction d2 being perpendicular to each other; as shown in FIGs 4 and 5, the multiple conductive elements 31 and multiple switches 32 may be arranged on the substrate 34 such that each of the multiple conductive elements 31 and multiple switches 32 is positioned by at least a minimum distance d3 away from a position of the substrate 34, at which the control circuit is electrically connected to the feeding lines 33; and as shown in FIG. 5, the feeding lines 33 may be inhomogeneously distributed on the substrate 34 in a region 6 of the substrate 34 where a near electric field of radio waves radiated by the polarized active radiating element 2 is smaller than a threshold for the near electric field.

[0102] In case of the example of sixteen conductive elements 31 of the reconfigurable passive radiating element (shown in FIG. 3), the maximum number of switches 32 would be twenty-four switches. As shown in Figure 3, the switches 32 may be minimized for example to twenty switches 32. This is only by way of example and may be different. On the right side of Figure 3 an example of a control of the switches 31 by the control circuit 4 is shown, wherein “on” means that the respective switch 32 is in the conducting-state and “off’ means that the respective switch 32 is in the non-conducting state. The switching states of the switches 32 exemplarily shown in FIG. 3 will generate a specific radiation pattern of the antenna device 1. By changing the switching states of one or more of the switches 32, the radiation structure of the reconfigurable passive radiating element 3 may be changed (i.e. reconfigured). This allows generating a different radiation pattern.

[0103] Optionally, the multiple switches 32 may be multiple PIN diodes (not shown in FIG. 3).

[0104] For further information on the antenna device 1 of FIG. 3 reference is made to the description of the antenna device according to the second aspect of this disclosure and to the description of FIGs 4, 5 and 6.

[0105] FIG. 4 shows an example of an implementation form of the antenna device of FIG. 3. FIG. 5 shows a top view of the reconfigurable passive radiating element of the antenna device of FIG. 4.

[0106] The description of the antenna device 1 of FIG. 3 is correspondingly valid for the antenna device 1 of FIGs 4 and 5.

[0107] As shown in FIGs 4 and 5, a connector 35 may be arranged on the substrate 34 for electrically connecting the feeding lines 33 to the control circuit 4. The control circuit 4 may be arranged at the side of the reconfigurable passive radiating element 3, at which the connector 35 is arranged (not shown in FIGs 4 and 5). The control circuit 4 may optionally be arranged at least partly on the substrate 34. In this case the control circuit 4 may comprise the connector 35 or be connected to the feeding lines 33 without the connector 35 (i.e. the connector 35 may be omitted), which is not shown in FIGs 4 and 5. Optionally, the control circuit 4 may be arranged at least partly on the substrate 34 of the reconfigurable passive radiating element 3 such that it is arranged on a surface of the substrate 34, on which the multiple conductive elements 31, the multiple switches 32 and the feeding lines 33 are arranged, or on a second surface of the substrate 34 that is opposite to the aforementioned surface of the substrate 34. According to the example of FIGs 4 and 5, the conductive elements 31 of the reconfigurable passive radiating element 3 may be rhombic conductive elements. This is only by way of example and, thus, the conductive elements 31 may have a different form. In the following, it is assumed that the conductive elements 31 are rhombic conductive elements. The following is description is correspondingly valid in case of a different type of conductive elements 31, e.g. with a different form.

[0108] As shown in FIGs 4 and 5, the multiple rhombic conductive elements 31 may be arranged on the substrate 34 such that at least one vertex of each rhombic conductive element of the multiple rhombic conductive elements 31 is aligned with a vertex of another rhombic conductive element of the multiple rhombic conductive elements 31, a vertex of a first pair of facing vertexes of each rhombic conductive element faces in the first direction dl of the substrate 34, and a vertex of a second pair of facing vertexes of each rhombic conductive element faces in the second direction d2 of the substrate 34. This is exemplarily shown on the right side of FIG. 5 for one of the multiple rhombic conductive elements 31. Namely, as shown on the right side of FIG. 5, the rhombic conductive element 31 is arranged on the substrate 34 such that at least one vertex 3 Id of the rhombic conductive element 31 is aligned (indicated by the dotted line) with a vertex 31’ of another rhombic conductive element 31’, a vertex 31b of a first pair of facing vertexes 3 la and 3 lb of the rhombic conductive element 31 faces in the first direction dl of the substrate 34, and a vertex 3 Id of a second pair of facing vertexes 31c and 3 Id of the rhombic conductive element 31 faces in the second direction d2 of the substrate 34.

[0109] Therefore, the method 100 of FIG. 1 may optionally comprise using multiple rhombic conductive elements as the multiple conductive elements and arranging the multiple rhombic conductive elements on the substrate such that: at least one vertex of each rhombic conductive element of the multiple rhombic conductive elements is aligned with a vertex of another rhombic conductive element of the multiple rhombic conductive elements, a vertex of a first pair of facing vertexes of each rhombic conductive element faces in the first direction of the substrate, and a vertex of a second pair of facing vertexes of each rhombic conductive element faces in the second direction of the substrate. As shown in FIGs 4 and 5, at least a part of the feeding lines 33 may be slanted with regard to the first direction dl and the second direction d2 of the substrate 34. Optionally, at least a part of the feeding lines 33 may be slanted by an angle of 45 degrees with regard to the first direction dl and second direction d2 of the substrate. Thus, the method 100 of FIG. 1 may optionally comprise slanting at least a part of the feeding lines by an angle of 45 degrees with regard to the first direction and second direction of the substrate.

[0110] As shown in FIG. 5, at least a part of the feeding lines 33 may comprise frequent choke inductors 33a. This allows reducing or avoiding a RF coupling to the feeding lines 33.

[0111] As shown in FIGs 4 and 5, the conductive elements 31 may be multiple patches (e.g. rhombic patches). The substrate 34 may be a dielectric substrate, e.g. a printed circuit board (PCB) substrate. The multiple patches 31 may be implemented as metallization on the dielectric substrate 34. The multiple patches are passive patches.

[0112] As shown in FIG. 4, the polarized active radiating element 2 may optionally be a dual-polarized active radiating element 2. This is only by way of example and the polarized active radiating element may radiate radio waves of one or more polarizations. In the following, it is assumed that the polarized active radiating element 2 is a dual-polarized active radiating element for radiating radio waves of two polarizations. The description is correspondingly valid for a different type of polarized active radiating element 2.

[0113] As shown in Figure 4, the dual-polarized radiating element 2 may comprise a planar element 22 on which a patch 21 is arranged, and the patch 21 is configured to radiate radio waves of the two polarizations. The planar element 22 may be a dielectric substrate, e g. a printed circuit board (PCB) substrate. The patch 21 may be a rectangular patch, as shown in FIG. 4. The antenna device 1 may comprise a first radio frequency (RF) signal feeding line 23a, optionally a first microstrip line, accessing one side 21a of the rectangular patch 21. The first RF signal feeding line 23 a may feed a first polarization of the two polarization. The antenna device 1 may comprise a second and third RF signal feeding line 23b, 23c, optional a second and third microstrip line, accessing at two sides 21b of the rectangular patch 21 that are adjacent to the aforementioned side 21a and opposite to each other. The second and third RF signal feeding lines 23b, 23c may feed a second polarization of the two polarizations in a differential way. The patch 21 may be implemented as metallization on a dielectric substrate 22 The patch 21 is or forms a radiating structure (i.e. active radiating structure) of the dual-polarized active radiating element 2.

[0114] Alternatively or additionally, the dual-polarized active radiating element 2 may comprise an antenna array configured to radiate radio waves of the two polarizations (not shown in FIG. 4). In case the polarized active radiating element 2 is configured to radiate radio waves of one polarization or more than two polarizations, the antenna array may be configured to radiate such radio waves. The antenna array is or forms a radiating structure (i.e. active radiating structure) of the polarized active radiating element 2. The antenna array may be arranged on the planar element 22 of the polarized active radiating element 2. The antenna array may comprise multiple patches. The multiple patches may be arranged on the planar element 22 of the dual-polarized active radiating element 2.

[0115] The implementation of the polarized active radiating element 2 shown in FIG. 4 is only by way of example and may be different. That is, the polarized active radiating element 2 may be differently implemented. The description of the FIGs, especially FIGs 4, 5 and 6, is correspondingly valid when the polarized active radiating element 2 is differently implemented. The implementation of the reconfigurable passive radiating element 3 shown in FIG. 4 is also valid in case the polarized active radiating element 2 is differently implemented. This means, the implementation of the reconfigurable passive radiating element 3 does not depend on a specific implementation of the polarized active radiating element 2, such as the example of an implementation of the polarized active radiating element 2 shown in FIG. 4.

[0116] As may be derived from FIGs 3 and 4, the polarized active radiating element 2 may be arranged in a first plane, and the reconfigurable passive radiating element 3 may be arranged in a second plane. The first plane and the second plane may be parallel to each other.

[0117] FIG. 6 shows an example of a near-field distribution of electromagnetic energy at the reconfigurable passive radiating element of FIG. 5 when the antenna device radiates radio waves. The description of FIGs 3 to 5 is correspondingly valid for the reconfigurable passive radiating element of FIG. 6. The antenna device 1 may radiate radio waves as a result of the polarized active radiating element radiating radio waves in the direction of the reconfigurable passive radiating element 3. In FIG. 6, the lines 5 show electric fields of electromagnetic energy. The closer such lines 5 are the greater the power of the near-field distribution of electromagnetic energy and vice versa.

[0118] Thus, the dashed rectangle 6 represents a region of low-power near-field distribution of electromagnetic energy on the substrate 34 of the reconfigurable passive radiating element 3 and the border 6a of the substrate 34 is a border of the substrate 34 where the region 6 of the low low-power near-field distribution of electromagnetic energy is present on the substrate 34.

[0119] As shown in FIGs 5 and 6, the control circuit may be arranged at the border 6a of the substrate 34 where the region 6 of low-power near-field distribution of electromagnetic energy is present. This is especially indicated in Figure 5 by the connector 35 for connecting the control circuit 4 to the feeding lines 33 that is arranged at the border 6a of the substrate 34. The control circuit 4 may be arranged external to the reconfigurable passive radiating element 3 or at least partly on the substrate 34 of the reconfigurable passive radiating element 3.

[0120] Thus, the method 100 of FIG. 1 may comprise determining a region 6 of low-power near-field distribution of electromagnetic energy on the substrate 34 by performing a full-wave simulation of the antenna device 1, and arranging the control circuit 4 at a border 6a of the substrate 34 where the region of low-power near-field distribution of electromagnetic energy is determined.

[0121] As shown in FIGs 5 and 6, the feeding lines 33 may be arranged on the substrate 34 in the region 6 of low-power near-field distribution of electromagnetic energy. Thus, the method 100 of FIG. 1 may comprise determining a region 6 of low-power near-field distribution of electromagnetic energy on the substrate 34 by performing a full- wave simulation of the antenna device 1, and arranging the feeding lines 33 on the substrate 34 in the determined region 6 of low- power near-field distribution of electromagnetic energy.

[0122] For describing with regard to FIGs 5 and 6 optional features of the antenna device 1 and the method for designing an antenna device according to this disclosure, it may be assumed that one or more radiation patterns of the different radiation patterns of the antenna device 1 that radiate in a preferred main direction cause a near-field distribution of electromagnetic energy at the reconfigurable passive radiating element 3 as shown in FIG. 6. In this case, as shown in FIGs 5 and 6, the control circuit 4 may be arranged at the border 6a of the substrate where the control circuit 4 has a lower interference on the one or more radiation patterns radiating in the preferred main direction compared to another border of the substrate 34. This is especially indicated in Figure 5 by the connector 35 for connecting the control circuit 4 to the feeding lines 33 that is arranged at the border 6a of the substrate 34. The control circuit 4 may be arranged external to the reconfigurable passive radiating element 3 or at least partly on the substrate 34 of the reconfigurable passive radiating element 3.

[0123] Thus, the method 100 of FIG. 1 may comprise determining one or more radiation patterns of the different radiation patterns that radiate in a preferred main direction, and arranging the control circuit 4 at a border 6a of the substrate 34 where the control circuit 4 has a lower interference on the determined one or more radiation patterns compared to another border of the substrate 34.

[0124] As shown in FIGs 5 and 6, more than 50 % of the feeding lines 33, i.e. a majority of the feeding lines 33, may be arranged on the substrate 34 in a region 6 of the substrate where they have a lower interference on the one or more radiation patterns radiating in the preferred main direction compared to a rest of the substrate.

[0125] Thus, the method 100 of FIG. 1 may comprise determining one or more radiation patterns of the different radiation patterns that radiate in a preferred main direction, and arranging, on the substrate 34, more than 50% of the feeding lines 33 in a region 6 of the substrate 34 where they have a lower interference on the determined one or more radiation patterns compared to a rest of the substrate.

[0126] For further information on the method of FIGs 1 and 2, and the antenna device 1 of FIGs 3 to 6 reference is made to the description of the method according to the first aspect and the antenna device according to the second aspect of this disclosure.

[0127] The antenna device of this disclosure may be configured to be used in a multi- AP architecture such as P2MP (Point to Multi Point). The access points may backhaul with wireless, coaxial, ethemet, or fiber to a main access point, wherein a backhaul with a fiber is called FTTR (Fiber- to-the-Room) technology. The antenna device of this disclosure may be configured to be used in a FTTR system A FTTR device may comprise the antenna device of this disclosure. Optionally, the antenna device of this disclosure may be used in an optical network terminal (ONT), such as a secondary Wi-Fi ONT. Such ONT may be mounted for example to a wall, a desk, a ceiling etc. The present disclosure has been described in conjunction with various embodiments as examples as well as implementations. However, other variations can be understood and effected by those persons skilled in the art and practicing the claimed matter, from the studies of the drawings, this disclosure and the independent claims. In the claims as well as in the description the word “comprising” does not exclude other elements or steps and the indefinite article “a” or “an” does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in the mutual different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation.

Claims

CLAIMS1. A computer-implemented method for designing a reconfigurable passive radiating element (3) of an antenna device (1) that comprises a polarized active radiating element (2) for radiating radio waves of one or more polarizations, the reconfigurable passive radiating element (3) and a control circuit (4); wherein the reconfigurable passive radiating element (3) comprises, on a substrate (33), multiple conductive elements (31), multiple switches (32) for electrically connecting a respective pair of adjacent conductive elements of the multiple conductive elements (31) with each other, and feeding lines (33) for feeding control signals from the control circuit (4) to the multiple switches (32), and the reconfigurable passive radiating element (3) is arranged in a main direction of radiation of the polarized active radiating element (2) in front of the polarized active radiating element (2); wherein the method (100) comprises at least one of: minimizing (SI 00), with regard to a maximum number of switches, the number of the multiple switches according to a list of different radiation patterns that the antenna device should be able to radiate, the maximum number of switches being present when each pair of adjacent conductive elements of the multiple conductive elements is electrically connected by a switch; arranging (S200), on the substrate (34), the feeding lines (33) by slanting at least a part of the feeding lines (33) with regard to a first direction (dl) and second direction (d2) of the substrate (34), the first direction (dl) and the second direction (d2) being perpendicular to each other; arranging (S300) the multiple conductive elements (31) and multiple switches (32) on the substrate (34) such that each of the multiple conductive elements (31) and multiple switches (32) is positioned by at least a minimum distance away from a position of the substrate (34), at which the control circuit (4) is electrically connected to the feeding lines (33); and inhomogeneously distributing (S400) the feeding lines (33) on the substrate (34) in a region (6) of the substrate (34) where a near electric field (5) of radio waves radiated by the polarized active radiating element (2) is smaller than a threshold for the near electric field.

2. The computer-implemented method according to claim 1, wherein minimizing (SI 00), with regard to the maximum number of switches, the number of the multiple switches (32) according to the list of different radiation patterns that the antenna device (1) should be able to radiate comprises: replacing (S 101) a switch of the multiple switches (32) by a short circuit or open circuit in case the switch is switched on or switched off, respectively, for achieving the different radiation patterns.

3. The computer-implemented method according to claim 1 or 2, wherein minimizing (SI 00), with regard to the maximum number of switches, the number of the multiple switches according to the list of different radiation patterns that the antenna device should be able to radiate comprises: computing (SI 02) a number of switches by taking the logarithm of the number of different radiation patterns to the base of two and rounding the computed result up to an integer, and providing at least the computed number of switches as the multiple switches (32) on the substrate (34).

4. The computer-implemented method according to any one of the previous claims, wherein minimizing (SI 00) with regard to the maximum number of switches, the number of the multiple switches (32) according to the list of different radiation patterns that the antenna device (1) should be able to radiate comprises: reducing an area edge coverage of the antenna device (1), and minimizing the multiple switches (32) according to the reduced area edge coverage of the antenna device (1).

5. The computer-implemented method according to any one of the previous claims, wherein the method comprises: distributing, on the substrate (34), the minimized number of the multiple switches (32) according to the number and / or position of the multiple conductive elements6. The computer-implemented method according to any one of the previous claims, wherein the method comprises: using multiple rhombic conductive elements as the multiple conductive elements (31), and arranging the multiple rhombic conductive elements (31) on the substrate (34) such that at least one vertex of each rhombic conductive element of the multiple rhombic conductive elements (31) is aligned with a vertex of another rhombic conductive element of the multiple rhombic conductive elements (31), a vertex of a first pair of facing vertexes of each rhombic conductive element faces in the first direction (dl) of the substrate (34), and a vertex of a second pair of facing vertexes of each rhombic conductive element faces in the second direction (d2) of the substrate (34).

7. The computer-implemented method according to any one of the previous claims, wherein the method comprises: slanting at least a part of the feeding lines (33) by an angle of 45 degrees with regard to the first direction (dl) and second direction (d2) of the substrate (34).

8. The computer-implemented method according to any one of the previous claims, wherein the method comprises: determining a region (6) of low-power near-field distribution of electromagnetic energy on the substrate (34) by performing a full-wave simulation of the antenna device (1), and arranging the control circuit at a border (6a) of the substrate (34) where the region (6) of low-power near-field distribution of electromagnetic energy is determined.

9. The computer-implemented method according to any one of the previous claims, wherein the method comprises: determining a region (6) of low-power near-field distribution of electromagnetic energy on the substrate (34) by performing a full-wave simulation of the antenna device (1), and arranging the feeding lines (33) on the substrate (34) in the determined region (6) of low-power near-field distribution of electromagnetic energy.

10. The computer-implemented method according to any one of the previous claims, wherein the method comprises: determining one or more radiation patterns of the different radiation patterns that radiate in a preferred main direction, and arranging the control circuit (4) at a border of the substrate (34) where the control circuit (4) has a lower interference on the determined one or more radiation patterns compared to another border of the substrate (34).

11. The computer-implemented method according to any one of the previous claims, wherein the method comprises: determining one or more radiation patterns of the different radiation patterns that radiate in a preferred main direction, and arranging, on the substrate (34), more than 50% of the feeding lines (33) in a region of the substrate (34) where they have a lower interference on the determined one or more radiation patterns compared to a rest of the substrate (34).

12. The computer-implemented method according to any one of the previous claims, wherein the method comprises: using multiple rhombic conductive elements as the multiple conductive elements (31); and / or using multiple positive intrinsic negative, PIN, diodes as the multiple switches (32).

13. An antenna device (1) that comprises a polarized active radiating element (2) for radiating radio waves of one or more polarizations, a reconfigurable passive radiating element (3) and a control circuit (4); wherein the reconfigurable passive radiating element (3) comprises, on a substrate (34), multiple conductive elements (31), multiple switches (32) for electrically connecting a respective pair of adjacent conductive elements of the multiple conductive elements (31) with each other, and feeding lines (33) for feeding control signals from the control circuit (4) to the multiple switches (32), and the reconfigurable passive radiating element (3) is arranged in a main direction of radiation of the polarized active radiating element (2) in front of the polarized active radiating element (2); whereinat least one of the following is true: the number of the multiple switches (32) is minimized, with regard to a maximum number of switches, according to a list of different radiation patterns that the antenna device (1) is configured to radiate, the maximum number of switches being present when each pair of adjacent conductive elements of the multiple conductive elements (31) is electrically connected by a switch; the feeding lines (33) are arranged on the substrate (34) such that at least a part of the feeding lines (33) is slanted with regard to a first direction (dl) and second direction (d2) of the substrate (34), the first direction (dl) and the second direction (d2) being perpendicular to each other; the multiple conductive elements (31) and multiple switches (32) are arranged on the substrate (34) such that each of the multiple conductive elements (31) and multiple switches (32) is positioned by at least a minimum distance away from a position of the substrate (34), at which the control circuit (4) is electrically connected to the feeding lines (33); and the feeding lines (33) are inhomogeneously distributed on the substrate (34) in a region (6) of the substrate (34) where a near electric field of radio waves radiated by the polarized active radiating element (2) is smaller than a threshold for the near electric field.

14. A computer program comprising instructions which, when the program is executed by a computer, cause the computer to perform the method according to any one of claims 1 to 12.

15. A storage medium storing executable program code which, when executed by a processor, causes the method according to any one of claims 1 to 12 to be performed.

Images