Compact modular active-passive antenna system with minimized antenna blockage

Abstract

This application provides a compact, modular active-passive antenna system with minimized antenna blockage. According to one aspect, a passive antenna module for an active-passive antenna system is provided. The passive antenna module includes a base for detachable mounting to an active antenna module. The base includes an opening or cavity that extends at least partially over the active antenna module when the base is mounted to the active antenna module. The passive antenna module includes a ground plane layer disposed within or over the opening or cavity and fixed to the base. The ground plane layer includes a metallic or metallized grid. The passive antenna module includes a first antenna array comprising one or more first antenna elements partially disposed on the base and adjacent to and partially over the opening or cavity. The base and the ground plane layer are adapted to serve as a ground plane for the first antenna array.

Description

Technical Field

[0001] Various embodiments relate generally to antennas, and more particularly to active-passive antennas. Background Art

[0002] An active-passive antenna (APA) (or equivalent APA system) is a multi-band passive antenna that integrates 5G active features. For example, APAs are used in 5G base stations. Typically, an APA is an antenna system that integrates a (5G) active massive MIMO antenna (i.e., a massive antenna array or panel integrated with radio transceiver elements to form a single unit) with a (4G or lower) passive antenna. Electronics, RF components, and bases are shared between the active and passive antennas of the APA. Such an arrangement provides a variety of benefits, such as a reduced bill of materials, reduced overall weight, and reduced overall wind loads. Some existing APA solutions adopt a modular structure, in which the passive and / or active parts of the APA form independent but electrically (and physically) connected modules that are independently detachable and replaceable even in the "field" (i.e., on the ground). However, the process of replacing the above modules of the APA is typically complex and time-consuming because it requires first removing all RF connections between the active antenna module and the passive antenna module. For example, in some solutions, the passive antenna module is not separable as a single component, but must be split into multiple smaller parts before separation. An APA solution is needed that allows simple replacement of the active and / or passive antenna modules of the APA, even in the field, while still maintaining the benefits of the compact form factor of known modular APA systems. This should be achieved so that the active and passive antenna modules do not cause significant obstruction to each other, even when beam scanning / forming is occurring.

[0003] WO 2021195040 A2 discloses a base station antenna, which includes an externally accessible active antenna module releasably coupled to a recessed section, which extends longitudinally and transversely along and across a rear portion of a base station antenna housing over a cavity in the base station antenna. The base station antenna housing has a passive antenna assembly that cooperates with the active antenna module.

[0004] EP 3886333 A1 discloses a base station antenna comprising a first antenna having a first spaced column and a second spaced column of first radiating elements, the first radiating elements being configured to operate within a first frequency band. An active antenna system (AAS) is provided, the AAS being configured to operate within a second frequency band (typically a higher frequency band). The AAS comprises a second antenna in a space between the first column and the second column of first radiating elements. The first radiating elements may comprise an inclined feed pole, the inclined feed pole supporting higher integration by enabling the first radiating elements to extend beyond at least a portion of the second antenna. Summary of the invention

[0005] According to one aspect, the subject matter of the independent claims is provided. Embodiments are defined in the dependent claims.

[0006] One or more embodiments are set forth in further detail in the drawings and the description that follows. Other features will be apparent from the description and drawings, and from the claims.

[0007] Some embodiments provide a passive antenna module for an active-passive antenna system and an active-passive antenna system. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In the following, some example embodiments will be described with reference to the accompanying drawings, in which:

[0009] Figure 1 illustrates an example of a communication system in which embodiments may be applied;

[0010] Figure 2A , Figure 2B and Figure 3 illustrates an active-passive antenna system according to an embodiment;

[0011] Figure 4 illustrates a passive antenna module of an active-passive antenna system according to an embodiment;

[0012] Figure 5 and Figure 6 An active-passive antenna system using electromagnetic coupling and a waveguide element according to an embodiment is illustrated respectively; and

[0013] Fig. 7A , Figure 7B and Figure 7C An example of a unit cell of a second antenna array of an active antenna module, an example of a unit cell of a ground plane layer and a capacitive coupling element of a passive antenna module, and two unit cells stacked on each other are illustrated respectively. DETAILED DESCRIPTION

[0014] The following embodiments are exemplary. Although the specification may refer to "one", "an" or "some" embodiments in several places, this does not necessarily mean that each such reference is to the same embodiment (s), or that the feature only applies to a single embodiment. Individual features of different embodiments may also be combined to provide other embodiments.

[0015] In the following, different exemplary embodiments will be described using a radio access architecture based on Advanced Long Term Evolution (LTE-Advanced (LTE-A)) or New Radio (NR, 5G) as an example of an access architecture to which the embodiments may be applied, without limiting the embodiments to such an architecture. It is clear to a person skilled in the art that the embodiments may also be applied to other kinds of communication networks with suitable components by appropriately adjusting the parameters and procedures. Some examples of other options suitable for the system are Universal Mobile Telecommunications System (UMTS) Radio Access Network (UTRAN or E-UTRAN), Long Term Evolution (LTE, same as E-UTRA), Wireless Local Area Network (WLAN or WiFi), Worldwide Interoperability for Microwave Access (WiMAX), Personal Communications Service (PCS), Wideband Code Division Multiple Access (WCDMA), systems using Ultra-Wideband (UWB) technology, sensor networks, Mobile Ad Hoc Networks (MANETs), and Internet Protocol Multimedia Subsystem (IMS), or any combination thereof.

[0016] Figure 1 An example of a simplified system architecture is depicted, showing only some elements and functional entities, which are all logical units, the implementation of which may differ from what is shown. Figure 1 The connections shown are logical connections; the actual physical connections may be different. It is clear to those skilled in the art that the system typically also includes Figure 1 Other functions and structures than those shown.

[0017] However, the embodiments are not limited to the systems given as examples, but a person skilled in the art may apply the solution to other communication systems having the necessary characteristics.

[0018] Figure 1 The example of FIG. 1 shows a portion of an exemplary radio access network.

[0019] Figure 1 User equipment 100 and 102 are shown, and user equipment 100 and 102 are configured to be in a wireless connection state with an access node (such as (e / g) NodeB) 104 providing the cell on one or more communication channels in the cell. The physical link from the user equipment to the (e / g) NodeB is called an uplink or reverse link, and the physical link from the (e / g) NodeB to the user equipment is called a downlink or forward link. It should be understood that the (e / g) NodeB or its functions can be implemented using any node, host, server or access point entity suitable for such purposes.

[0020] The communication system usually includes more than one (e / g)NodeB, in which case the (e / g)NodeBs may also be configured to communicate with each other via wired or wireless links designed for this purpose. These links may be used for signaling purposes. (e / g)NodeB is a computing device configured to control the radio resources of the communication system to which it is coupled. NodeB may also be referred to as a base station, an access point, an access node, or any other type of interface device including a relay station capable of operating in a wireless environment. (e / g)NodeB includes or is coupled to a transceiver. From the transceiver of the (e / g)NodeB, a connection is provided to an antenna unit, which establishes a bidirectional radio link to a user device. The antenna unit may include multiple antennas or antenna elements (possibly forming an antenna array). (e / g)NodeB is further connected to a core network 110 (CN or next generation core NGC). Depending on the system, the counterpart on the CN side may be a service gateway (S-GW, routing and forwarding user data packets), a packet data network gateway (P-GW, for providing a connection between a user equipment (UE) and an external packet data network), or a mobile management entity (MME), etc.

[0021] User equipment (also referred to as UE, user equipment, user terminal, terminal device, etc.) shows a type of device to which resources on the air interface are allocated and assigned, and therefore any features of the user equipment described herein can be implemented using a corresponding device (such as a relay node). An example of such a relay node is a layer 3 relay (self-backhaul relay) toward a base station.

[0022] A user device generally refers to a portable computing device, which includes a wireless mobile communication device with or without a subscriber identity module (SIM), including but not limited to the following types of devices: mobile stations (mobile phones), smart phones, personal digital assistants (PDAs), handheld devices, devices using wireless modems (alarms or measuring devices, etc.), laptop computers and / or touch screen computers, tablet computers, game consoles, notebooks, and multimedia devices. It should be understood that a user device can also be an almost exclusive uplink-only device, an example of which is a camera or video camera that loads images or video clips to a network. A user device can also be a device with the ability to operate in an Internet of Things (IoT) network, in which an object is provided with the ability to transmit data over a network without human-to-human or human-to-computer interaction. A user device can also use the cloud. In some applications, a user device can include a small portable device with a radio component (such as a watch, headset, or glasses), and the calculation is performed in the cloud. A user device (or in some embodiments, a layer 3 relay node) is configured to perform one or more of the user device functions. A user device may also be called a subscriber unit, a mobile station, a remote terminal, an access terminal, a user terminal, or User Equipment (UE), to mention just a few names or devices.

[0023] The various techniques described herein may also be applied to cyber-physical systems (CPS) (systems of computing elements that collaborate to control physical entities). CPS can implement and utilize a large number of interconnected ICT (information and communication technology) devices (sensors, actuators, processor microcontrollers, etc.) embedded in different locations in physical objects. Mobile cyber-physical systems, in which the physical systems in question have inherent mobility, are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robots and electronic devices transported by humans or animals.

[0024] Additionally, although the apparatus is depicted as a single entity, different units, processors and / or memory units may be implemented. Figure 1 Not all are shown).

[0025] 5G supports the use of multiple-input multiple-output (MIMO) antennas, many more base stations or nodes than LTE (the so-called small cell concept), including macro sites that collaborate with smaller base stations and adopt multiple radio technologies, depending on service requirements, use cases and / or available spectrum. 5G mobile communications support a variety of use cases and related applications, including video streaming, augmented reality, different data sharing methods and various forms of machine-type applications (such as (massive) machine-type communications (mMTC)), including vehicle safety, different sensors and real-time control. 5G is expected to have multiple radio interfaces, i.e., below 6GHz, cmWave and mmWave, and can be integrated with existing traditional radio access technologies such as LTE. Integration with LTE can be implemented as a system, at least in the early stages, in which macro coverage is provided by LTE and 5G radio interface access comes from small cells by aggregation to LTE. In other words, 5G is planned to support both inter-RAT operability (such as LTE-5G) and inter-RI operability (inter-radio interface operability, such as below 6GHz-cmWave, above 6GHz-mmWave). One of the concepts considered for use in 5G networks is network slicing, in which multiple independent and dedicated virtual subnets (network instances) can be created in the same infrastructure to run services with different requirements for latency, reliability, throughput and mobility.

[0026] The current architecture in LTE networks is completely distributed in the radio and completely centralized in the core network. Low-latency applications and services in 5G require content to be close to the radio, leading to local bursting and multi-access edge computing (MEC). 5G enables analysis and knowledge generation to be performed at the data source. This approach requires the use of resources that may not be continuously connected to the network, such as laptops, smartphones, tablets, and sensors. MEC provides a distributed computing environment for application and service hosting. It also has the ability to store and process content close to cellular subscribers to speed up response time. Edge computing covers a wide range of technologies such as wireless sensor networks, mobile data collection, mobile signature analysis, collaborative distributed peer-to-peer self-organizing networks and processing (also categorized as local cloud / fog computing and grid / mesh computing), dew computing, mobile edge computing, thin cloud, distributed data storage and retrieval, autonomous self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (massive connectivity and / or latency critical), critical communications (autonomous vehicles, traffic safety, real-time analysis, time-critical control, healthcare applications).

[0027] The communication system may also be capable of communicating with or utilizing services provided by other networks such as the public switched telephone network or the Internet 112. The communication system may also be capable of supporting the use of cloud services, for example, at least a portion of the core network operations may be provided as a cloud service (this is in the Figure 1The communication system may also include a central control entity that provides facilities for networks of different operators to cooperate, for example, in spectrum sharing.

[0028] Edge cloud can be introduced into the radio access network (RAN) by utilizing network function virtualization (NFV) and software defined networking (SDN). Using edge cloud can mean that access node operations will be performed at least partially in a server, host or node that is operatively coupled to a remote radio head or base station including the radio part. Node operations can also be distributed among multiple servers, nodes or hosts. The application of cloudRAN architecture enables RAN real-time functions to be performed on the RAN side (in the distributed unit DU 104) and non-real-time functions to be performed in a centralized manner (in the centralized unit CU 108).

[0029] It should also be understood that the work distribution between core network operations and base station operations may be different from that of LTE, or even non-existent. Some other technological advances that may be used are big data and all-IP, which may change the way networks are built and managed. 5G (or New Radio NR) networks are designed to support multiple hierarchical structures, where MEC servers can be placed between the core and the base station or nodeB (gNB). It should be understood that MEC can also be applied to 4G networks.

[0030] 5G can also make use of satellite communications to enhance or supplement the coverage of 5G services, for example by providing backhaul. Possible use cases are to provide service continuity for machine-to-machine (M2M) or Internet of Things (IoT) devices or for passengers on board, or to ensure service availability for critical communications and future rail / maritime / aeronautical communications. Satellite communications can make use of geostationary earth orbit (GEO) satellite systems, as well as low earth orbit (LEO) satellite systems, in particular mega-constellations (systems in which hundreds of (nano) satellites are deployed). Each satellite 106 in a mega-constellation can cover several satellite-enabled network entities that create a ground cell. A ground cell can be created by a ground relay node 104 or a gNB located on the ground or in a satellite.

[0031] It is obvious to a person skilled in the art that the depicted system is only an example of a part of a radio access system, and in practice the system may include multiple (e / g)NodeBs, a user equipment may access multiple radio cells, and the system may also include other devices, such as physical layer relay nodes or other network elements. At least one (e / g)NodeB may be a home (e / g)NodeB. In addition, in a geographical area of ​​the radio communication system, a plurality of different kinds of radio cells and a plurality of radio cells may be provided. The radio cells may be macro cells (or umbrella cells), which are large cells with a diameter typically up to tens of kilometers, or smaller cells such as micro, femto or pico cells. Figure 1 The (e / g)NodeB can provide any kind of these cells. A cellular radio system can be implemented as a multi-layer network comprising several cells. Typically, in a multi-layer network, one access node provides one or more cells, and thus multiple (e / g)NodeBs are required to provide such a network structure.

[0032] In order to meet the needs of improving the deployment and performance of communication systems, the concept of "plug and play" (e / g) NodeB is introduced. Usually, in addition to the home (e / g) NodeB (H(e / g)nodeB), the network that can use "plug and play" (e / g) NodeB also includes the home nodeB gateway or HNB-GW ( Figure 1 (not shown). An HNB gateway (HNB-GW) installed in a network of an operator's network can aggregate services from a large number of HNBs back to the core network.

[0033] In some embodiments, Figure 1 The system shown may be a system including one or more active-passive antenna (APA) systems. Specifically, the access node 104 may include an APA system. An APA system may be defined as an antenna system that integrates a (5G) active MIMO antenna array with a (4G or lower) passive antenna array (or a single antenna). An active antenna array is generally defined as an antenna array into which one or more active electronic components (i.e., active circuit systems) are integrated. Specifically, an active antenna array may be defined here and below as an antenna array integrated with a radio unit (radio transmitter, receiver or transceiver or parts thereof, including active and passive elements).

[0034] An APA system may specifically be an antenna system that integrates a (5G) active massive MIMO antenna array with a (4G or lower) passive antenna array (or a single antenna). The term "massive MIMO antenna array" refers to a MIMO antenna array having a large number of individual antenna elements. In a massive MIMO (mMIMO) system, the number of antenna elements in the MIMO antenna array of an access node may be assumed to be greater than the number of terminal devices served by the access node. For example, a massive MIMO antenna array may be defined here and below as a MIMO antenna array having at least 8, 16, or 32 antenna elements.

[0035] Some existing APA solutions adopt a modular structure, in which the passive and / or active parts of the APA form independent but electrically (and physically) connected modules, which can be independently detachable and replaceable even in the "field" (i.e., in the field). However, since there are usually multiple electrical connections between the active part or module and the passive part or module of the APA, the process of replacing the above modules of the APA is generally complicated and time consuming, because it requires first removing all electrical connections between the active antenna module and the passive antenna module. For example, in some solutions, the passive antenna module is not detachable as a single component, but must be split into multiple smaller parts before separation.

[0036] Embodiments seek to provide a modular APA system and modules thereof, wherein active antenna modules (also referred to as active modules) and passive antenna modules (also referred to as passive modules) are separate entities that are not electrically connected (i.e., via RF connectors) to facilitate their removal and replacement. Compared to conventional APA solutions, the active antenna module is not specifically designed for integration with the passive antenna module, and can therefore also be used separately from the passive antenna module. Unlike multiple separate modules in some conventional APA solutions, this also applies to passive antenna modules formed as a single module. By eliminating the need for an RF connector between the active antenna module and the passive antenna module, the entire APA system becomes less complex and can improve performance (e.g., in terms of gain and / or passive intermodulation). However, such an APA system according to an embodiment should still be compact (e.g., to minimize weight and wind loads) and provide good performance. In addition, the above-mentioned APA system according to an embodiment should preferably be configured so that the APA system can operate in a satisfactory manner without causing significant deterioration in its performance due to any antenna blocking caused by the passive antenna module to the active antenna module, and vice versa.

[0037] Figure 2A and Figure 2BA schematic diagram of an APA system 200 according to an embodiment is provided, the APA system 200 having a fully separable and independently operable passive antenna module 201 and an active antenna module 211. Specifically, Figure 2A A simplified cross-sectional side view of an APA system 200 is shown, and Figure 2B A top view thereof is shown. Figure 2A Corresponds to Figure 2B The APA system 200 may form a terminal device such as Figure 1 of a terminal device 100, 102) or an access node (such as Figure 1 Part of the access node 104).

[0038] It should be noted that Figure 2A and Figure 2B A very simplified view is shown with many elements of the APA system 200 omitted (eg, any power distribution elements, the radio unit, and the radome). Figure 3 A more detailed view of an exemplary APA system is provided in , which is discussed later.

[0039] refer to Figure 2A and Figure 2B , the APA system 200 includes a passive antenna module 201 and an active antenna module 211. The passive antenna module 201 includes a first antenna array 204, the first antenna array 204 includes a plurality of first antenna elements ( Figure 2A and Figure 2B , two and four first antenna elements 205 are shown respectively therein, and the active antenna module 211 includes a second antenna array 213, which includes a plurality of second antenna elements 214. The two first antenna elements 205 are specifically arranged on opposite sides of the active antenna module 211. The second antenna array 213 may be a (5G) active massive MIMO antenna array, and the first antenna array 204 may be a (4G or lower) passive antenna array (or even just a single antenna).

[0040] The passive antenna module 201 further comprises a first base 202 (or equivalent to a first frame), and the active antenna module 211 further comprises a second base 212 (or equivalent to a second frame). In fact, the first base 202 may completely or partially surround the active antenna module 211, so that a (slender) opening or cavity is provided in the first base 202, which is used to receive the active antenna module 211. The above-mentioned two first antenna elements 205 may be specifically arranged on opposite (slender) sides of the above-mentioned opening or cavity. The first base 202 may be at least partially made of metal so as to realize a (planar) metal ground plane 207. The first base 204 may be detachably attachable or mountable to the second base 212 of the active antenna module 211. However, no (wired) electrical connection may be provided (or need not be provided) between the passive antenna module 201 and the active antenna module 211. In other words, the passive antenna module 201 and the active antenna module 211 can be completely independent radio modules that are (only) mechanically connected to each other. Figure 3 Discuss in more detail.

[0041] Typically, the first antenna array 204 may be adapted to operate at a first (operating) frequency band, and the second antenna array 213 may be adapted to operate at a second (operating) frequency band that is higher than the first (operating) frequency band. The first frequency band may be a radio frequency band, such as within a super high frequency (SHF) band and / or an ultra high frequency (UHF) band, and the second frequency band may be a radio frequency band, such as within an extremely high frequency (EHF) band and / or any higher frequency band. In some embodiments, the center frequency of the second frequency band may be equal to or greater than the center frequency of the first frequency band multiplied by 2, 3, or 4. For example, the first antenna array 204 may be adapted to operate below 1 GHz (e.g., in a 694-960 MHz band), and the second antenna array 213 may be adapted to operate in a 3.3-3.8 GHz band or a 3.3-4.2 GHz band, or other frequency bands whose lowest frequency is at least 3 times the highest frequency of the first operating frequency band of the first antenna array 204.

[0042] The first antenna array 204 may be specifically a one-dimensional or two-dimensional planar array with uniform antenna spacing. The first antenna array 204 is arranged at least partially adjacent to the second antenna array 213 of the active antenna module 211. Generally, the first antenna element 205 of the first antenna array 204 may be adjacent to one (longitudinal) side of the active antenna module 211 or adjacent to two opposite (longitudinal) sides of the active antenna module 211 (the longitudinal direction is Figure 2B vertical or up / down direction). Figure 2A and Figure 2BAs shown, the first antenna element 205 partially extends over the active antenna module 211 (or similarly extends over an opening or cavity provided in the passive antenna module 201, or extends over a metal grid 221 in the above opening or cavity and a two-dimensional array 222 of metal patches arranged in the above metal grid). The plurality of first antenna elements 205 of the first antenna array 204 may be at least mostly arranged over a (planar) metal ground plane 207 of the passive antenna module 201 (different from the ground plane 215 of the active antenna module 211).

[0043] The plurality of first antenna elements 205 of the first antenna array 204 may be any conventional resonant antenna element used in an antenna array, such as a patch or cross-dipole antenna of any known design. The plurality of first antenna elements 205 may be dual-polarized antenna elements. Preferably, the (multiple) first antenna elements 205 should be designed so that the antenna blocking caused by them to the second antenna array 213 is minimized. This can usually be achieved by minimizing the metal or metallized (or generally conductive) surface area of ​​the (multiple) first antenna elements 205. For example, a cross-dipole or patch-type antenna design may be used for the first antenna element 205. In one embodiment, one or more first antenna elements 205 are cross-dipole antenna elements, wherein one or more slots are provided in each dipole arm to minimize the blocking caused to the second antenna array 213. For example, the (multiple) first antenna elements 205 may be microstrip antennas (without a ground plane), i.e., printed antennas based on a printed circuit board (PCB), or antennas formed by separate (thin) metal sheets. The above-mentioned (multiple) first antenna elements 205 may specifically be omnidirectional and / or dual-polarized antenna elements. The first antenna element(s) 205 may be at least partially made of metal or an alloy.

[0044] The plurality of first antenna elements 205 may be separated from the first ground plane 207 by free space (i.e., air) or by a substrate (on which the plurality of first antenna elements 205 may be printed, and the other side of the substrate may be metallized to form the first ground plane 207). In at least some embodiments, the first antenna array 204 may be substantially arranged at a distance of λ / 4 from the first pedestal 202 (or specifically from the first ground plane 207 formed by the first pedestal 204) serving as its ground plane, where λ is a first wavelength, and the first wavelength is a wavelength corresponding to a frequency (e.g., a center frequency) within a first operating frequency band of the first antenna array 204. The first ground plane layer 207 may serve as a primary ground plane for the first antenna array 204 (because it is at least mostly located directly below the first antenna elements 205).

[0045] The passive antenna module 201 includes a ground plane layer 220. The ground plane layer 220 may be arranged in or on the opening or cavity in the passive antenna module 201. The ground plane layer 220 may be fixed to the first base 202 of the passive antenna module 201. The ground plane layer 220 may be configured so that it can be used as a ground plane for the first antenna array 204 while allowing a (significant) portion of the (higher frequency) electromagnetic waves radiated by the second antenna array 213 to pass through it. In other words, the ground plane layer 220 may be used as a second ground plane for the first antenna array 204 and is transparent or at least semi-transparent at a frequency higher than a certain predefined frequency (a frequency higher than the operating frequency of the first antenna array 204) or at least at a second operating frequency band of the second antenna array 213 of the active antenna module 211. At least in some embodiments, the ground plane layer 220 may be substantially aligned (perpendicular) with the first ground plane 207. In other embodiments, the ground plane layer 220 may be arranged at a lower level than the first ground plane 207. In at least some embodiments, the first antenna array 204 may be disposed substantially at a distance of λ / 4 from a ground plane layer 220 that serves as its ground plane, where λ is a first wavelength, which is a wavelength corresponding to a frequency within a first operating frequency band (e.g., a center frequency) of the first antenna array 204. Due to the ground plane layer 220, the passive antenna module 201 is fully operational even in the absence of the active antenna module 211 (i.e., the first antenna array 204 does not have to rely on using the ground plane of the active antenna module 211 as its ground plane).

[0046] In the example shown, the ground plane layer 220 includes a metal or metallized grid 221 and a two-dimensional array 222 of metal patches arranged within the metal grid 221. Each metal patch of the two-dimensional array 222 can be located within a specific unit cell of the metal grid 221. In general, a unit cell of a grid can be defined as the smallest repeating unit of the grid. In some alternative embodiments, a metallized grid (i.e., a grid made of a non-metallic material but having a metallized (external) surface) can be used instead of the metal grid 221. The metal or metallized grid 221 can be electrically connected to the first ground plane 207.

[0047] The metal or metallized grid 221 (equivalently referred to as a grid) can be any type of grid. The metal or metallized grid 221 can be a regular grid or an irregular grid. For example, the metal or metallized grid 221 can be a square grid, a rectangular grid, a diamond grid, a triangular grid, or a regular or irregular polygonal grid. The metal or metallized grid 221 can have a first period along a first direction and a second period along a second direction orthogonal to the first direction.

[0048] The metal or metallized grid 221 may have one or more periods along different directions that are electrically small in view of the first antenna array 204 and its operating frequency. The maximum size of a unit cell of the metal or metallized grid 221 (or period or maximum period in the case where multiple different periods are definable) may be defined such that the metal or metallized grid 221 can be used as a ground plane for the first antenna array 204. For example, the maximum size of a unit cell of the metal or metallized grid 221 (or the period or maximum period in the case where multiple different periods are definable) can be, for example, less than a second wavelength divided by 5, 6, 7, 8, 9, 10, 11 or 12, where the above-mentioned second wavelength is a (free space) wavelength corresponding to a frequency within the first operating frequency band of the first antenna array 204 (e.g., the center frequency). Additionally or alternatively, the maximum size of a unit cell of the metal or metallized grid 221 (or the period or maximum period in the case where multiple different periods are definable) can be, for example, greater than a third wavelength divided by 5, 4, 3 or 2, where the above-mentioned third wavelength is a (free space) wavelength corresponding to a frequency within the second operating frequency band of the second antenna array 213 (e.g., the center frequency). The selected (multiple) periods of the metal or metallized grid 221 may correspond to a compromise between an effective ground plane behavior at a first operating frequency band and an effective (semi-)transparent behavior at a second operating frequency band, which may also take into account the size of the second antenna element 214 of the second antenna array 213 (assuming that the second antenna array 213 has the same period as the metal or metallized grid 221).

[0049] The metal patches of the two-dimensional array 222 may be located within (unit) cells of the metal or metallized grid 221 (with metal patches within each or most unit cells of the metal or metallized grid). The metal patches may be shaped such that they substantially fill the unit cells of the metal or metallized grid 221 or at least fill most of the unit cells of the metal or metallized grid 221. For example, the metal patches may be square patches, rectangular patches, circular patches, elliptical patches, or any patches having regular or irregular polygonal shapes.

[0050] For example, the ground plane layer 220 (or at least the two-dimensional array 222 of metal patches thereof) may be implemented as at least one printed circuit board ( Figure 2A and Figure 2B not shown).

[0051] As long as the ground plane layer 220 is arranged sufficiently close to the second antenna array 213 of the active antenna module 211 when the passive antenna module 201 and the active antenna module 211 are connected (i.e., when the first base 202 of the passive antenna module 201 is mounted on the active antenna module 211), the propagation characteristics (e.g., S11, gain and radiation pattern) of the active antenna array 213 remain relatively unchanged and thus the active antenna module 211 still functions. For example, the ground plane layer 220 can be arranged so that when the passive antenna module 201 and the active antenna module 211 are connected, the ground plane layer 220 is at least located within a (electrically) small distance from the second antenna array 213 of the active antenna module 211. Such an electrically small distance may, for example, be at least equal to or less than λ / 4, λ / 5, λ / 6, λ / 7, λ / 8, λ / 9, λ / 10, λ / 12 or λ / 15 (depending on the specific desired performance), where λ is the (free space) wavelength corresponding to a frequency within a second operating frequency band (e.g., a center frequency) of the second antenna array 213.

[0052] In some embodiments, the two-dimensional array of metal patches 222 may be omitted. In such embodiments, the ground plane layer 220 may include only a metal or metallized grid 221 (e.g., implemented as at least one PCB or implemented as a separate grid made of metal or made of a non-metallic material with a metallized surface). It is well known that even a simple metal grid can approximate a ground plane.

[0053] The plurality of first antenna elements 205 may be fed by a feeding arrangement or element 206, which may form part of a first power distribution arrangement of the passive antenna module 201, to achieve beamforming for the first antenna array 204. Further elements of the first power distribution arrangement may include one or more phase shifters, which form a first phase shifter network, for example, located inside the element 202. The above-mentioned feeding elements 206 may also be used as support elements for the plurality of first antenna elements 205 (e.g. in a microstrip line feeding, the (multiple) PCBs may provide the support), or alternatively, they may be integrated into a separate support element.

[0054] The feed can be arranged with a coaxial cable (using a balanced-to-unbalanced transformer) or a microstrip line. In some embodiments, the passive antenna module 201 may include a balanced-to-unbalanced transformer integrated into a power distribution device or forming part thereof. A balanced-to-unbalanced transformer is an electrical device that converts a balanced signal and an unbalanced signal, and vice versa. Specifically, a balanced-to-unbalanced transformer can be used here to convert an unbalanced signal of a coaxial cable into a balanced signal to feed the first antenna element 205 (e.g., a cross-dipole type antenna) in transmission and provide the opposite operation in reception. For example, the balanced-to-unbalanced transformer can be a sleeve balanced-to-unbalanced transformer configured to operate at a first frequency band (or at least configured to operate optimally at a frequency within the first frequency band).

[0055] The second antenna array 213 may specifically be a one-dimensional or two-dimensional planar array with uniform antenna spacing. The plurality of second antenna elements 214 of the second antenna array 213 may be arranged on a (planar) ground plane 215. The plurality of second antenna elements 214 may be separated from the ground plane 215 by free space (i.e., air) or by a substrate (on which a plurality of second antenna elements 214 may be printed, and the other side of the substrate may be metallized to form the ground plane 215). The plurality of second antenna elements 214 may be fed by a feeding element 216, which may form part of a second power distribution device of the active antenna module 211 (other elements are, for example, inside the element 214) to achieve beamforming for the second antenna array 213. For example, each feeding element 216 may correspond to one or more coaxial cables or other transmission lines, which are used to feed the corresponding second antenna element 214 at one or more feeding points (the outer conductor of the coaxial cable is connected to the ground 215) or one or more pairs of feeding points. The ground plane 215 may be mounted on the second base 212 of the active antenna module 211 .

[0056] All the multiple second antenna elements 214 of the second antenna array 213 have the same geometry and size. The multiple second antenna elements 214 can be any conventional resonant antenna element used in the (5G) antenna array, such as a patch or cross dipole antenna of any known design. The multiple second antenna elements 204 can be dual-polarized antenna elements. The multiple second antenna elements 214 can be microstrip antennas, i.e., printed antennas based on a printed circuit board (PCB), or antennas formed by separate (thin) metal sheets. The multiple second antenna elements 214 can specifically be omnidirectional and / or dual-polarized antenna elements. The multiple second antenna elements 214 can be made at least in part of a metal or an alloy.

[0057] The plurality of second antenna elements 214 may be assumed to be much smaller (or specifically, electrically much smaller) than any operating wavelength of the first antenna array 204, such that the plurality of second antenna elements 214 are only able to weakly interact with any electromagnetic waves transmitted by or receivable via the first antenna array 204. However, the first antenna array 204 may still cause some antenna blocking to the second antenna array 213, particularly when large beam scanning angles are employed.

[0058] although Figure 2A Although not shown in the figure, the active antenna module 211 may include a radio unit operably coupled to the second antenna array 213 for radio reception and / or transmission via the second antenna array 213 and / or other at least partially active circuit systems. The radio unit may be a radio receiver, a transmitter or a transceiver. As described above, the active antenna module 211 also includes a second power distribution device for distributing power to and from the plurality of second antenna elements 214 of the second antenna array 213. The second power distribution device may provide one or more input / output ports.

[0059] Finally, it should be noted that in the illustrated embodiment vertical metal walls 203, 217 extending vertically from the first ground plane 207 and the second ground plane 217 are provided to better isolate the first antenna array 204 and the second antenna array 213 from each other. The metal walls 203, 217 can be arranged along one direction or along two orthogonal directions (thus forming a grid of walls). When the passive antenna module 201 and the active antenna module 211 are connected (e.g. Figure 2A ), the metal wall 217 of the active antenna module 211 may be substantially aligned with the metal or metallized grid 221 of the passive antenna module 201. In other embodiments, elements 203, 217 may be omitted.

[0060] and Figure 2A and Figure 2B compared to, Figure 3 The APA system 300 including the passive antenna module 301 and the active antenna module 311 according to the embodiment is illustrated in a more detailed view. Specifically, Figure 3 The APA system 300 according to an example embodiment is shown in a perspective view when the passive antenna module 301 and the active antenna module 311 are not yet attached to each other, and the APA system 300 according to an example embodiment is shown in another perspective view when the passive antenna module 301 and the active antenna module 311 are attached to each other. In general, the APA system 300 can be used with Figure 2A and Figure 2B Corresponding to the APA system 200.

[0061] refer to Figure 3, the passive antenna module 301 includes a first base (or frame) 302, which is suitable for being detachably mounted (or detachably attached) to the active antenna module 311 of the APA system 300. The first base 302 can be made of metal or alloy at least in large part. To achieve this, the first base 302 includes a cavity 303, which is suitable for extending above the active antenna module 311 when the first base 302 is mounted on the active antenna module 311 to minimize the antenna blockage caused by the passive antenna module 301 (mainly by its first base 302). The cavity 303 can specifically pass through the first base 302 in a direction orthogonal to the plane of the first base 302 (or equi-orthogonal to the plane of the first antenna array 304). The cavity can be formed on the side of the first base 302. Figure 3 The arrow in indicates the installation direction. When the first base 302 is mounted on the active antenna module 311, the cavity 303 may in particular extend at least partially over the second antenna array of the active antenna module 311. Once mounted, the first base 302 of the passive antenna module 301 is adapted to substantially surround the active antenna module 311 (i.e., surround the active antenna module 311 from three sides, with one side remaining open). In other words, the active antenna module 311 is embedded in the first base 302 of the passive antenna module 301.

[0062] In other embodiments, an opening (or hole) may be provided in the first base 302 instead of a cavity. The difference between an opening and a cavity is that an opening is surrounded by the first base from all sides, while a cavity may be open at one side (e.g., Figure 3 303). When the first base 302 is mounted on the active antenna module 311, the above-mentioned opening can extend above the active antenna module 310 to minimize the antenna blocking caused by the passive antenna module 301 (mainly by its first base 302). When the first base 302 is mounted on the active antenna module 311, the opening 303 can in particular extend at least partially above the second antenna array of the active antenna module 311. The opening 303 can be a rectangular opening, for example. Once mounted, the first base 302 of the passive antenna module 301 is suitable for surrounding the active antenna module 311. In other words, the active antenna module 310 is embedded in the first base 302 of the passive antenna module 301.

[0063] like Figure 3 As shown, both the first base 302 and the opening or cavity 303 may have a shape elongated in the same direction. In addition, one or more first antenna elements may be specifically arranged adjacent to one or more longitudinal surfaces of the opening or cavity 302 (i.e., not necessarily adjacent to the transverse surfaces of the opening or cavity 302).

[0064] A ground plane layer may fit into the opening or cavity 303. In this particular example, the ground plane layer comprises a metal or metallized grid 321 only.

[0065] The passive antenna module 301 also includes a first antenna array 304, which includes a plurality of first antenna elements (here specifically eight) arranged on two opposite sides of the cavity 303. As described above, in this embodiment, the first antenna array 304 (and the associated feeding structure or element) can be directly mounted on the first base 302. The plurality of first antenna elements can be arranged at least partially adjacent to the cavity 303. The plurality of first antenna elements can partially overlap or extend above the cavity 303 (although they can be mainly located above the first base 302, such as Figure 3 The first antenna array 304 may be arranged substantially at a distance of λ / 4 from the first base 302 serving as its ground plane and / or from the ground plane layer (here comprising a metal or metallized grid 321), where λ is a first wavelength corresponding to a frequency (e.g., a center frequency) within a first frequency band of the first antenna array 304.

[0066] In some embodiments, in addition to the first antenna array 304, the passive antenna module 301 may further include one or more other passive antenna arrays 307, which are arranged on the first base 302 and adjacent to the cavity 303 (i.e., not above the cavity) and adjacent to the first antenna array 304. Specifically, the one or more other passive antenna arrays 307 may be arranged adjacent to the cavity 303 in the longitudinal direction of the first base 302, rather than being arranged adjacent to the cavity 303 in the transverse direction of the first base 304 like the first antenna array 304.

[0067] The passive antenna module 301 further includes a first radome 331 for protecting the passive antenna module 301 and the active antenna module 311 (when the active antenna module 311 is attached to the passive antenna module 301). The first radome 331 may be made of, for example, polycarbonate.

[0068] It should be noted that although Figure 3 The metal or metallized grid 321 is shown arranged outside the first radome 331 , but in other implementations, the metal or metallized grid 321 (or generally a ground plane layer) may be arranged inside the first radome 331 of the passive antenna module 301 .

[0069] Figure 4 A schematic diagram of a passive antenna module 401 (separated from an active antenna module) of an APA system is provided. Specifically, Figure 4 The passive antenna module 401 is shown in side view. It should be noted that Figure 4A very simplified view is shown, in which many elements of the passive antenna module 401 (e.g., any power distribution elements) are omitted. The passive antenna module 401 may form a terminal device such as Figure 1 of a terminal device 100, 102) or an access node (such as Figure 1 Part of the access node 104).

[0070] The passive antenna module 401 may largely correspond to Figure 2A and Figure 2B The passive antenna module 201 is shown as a shared reference numeral. Figure 2A and Figure 2B and / or Figure 3 Any features discussed here also apply mutatis mutandis here. Figure 4 The differences between passive antenna modules.

[0071] As in the previous embodiment, the passive antenna module 401 includes a ground plane layer 420, which here includes a metal or metallized grid 421 and a two-dimensional array 422 of metal patches. Here, the ground plane layer 420 is implemented as a printed circuit board 423. The printed circuit board 423 is arranged in an opening or cavity of the first base 202 (in some alternative embodiments, on it) and fixed to the first base 202. In this case, the metal or metallized grid 421 and the two-dimensional array 422 of metal patches correspond to the metallization pattern on the surface of the above-mentioned at least one printed circuit board 423, and the surface opposite to the above-mentioned surface is bare (i.e., not metallized). The metallization of the printed circuit board 423 can be electrically connected (e.g., via soldering) to the ground plane 207 of the first base 202. Although the metal or metallized grid 421 and the two-dimensional array 422 of metal patches are printed on the upper surface of the printed circuit board here, in other embodiments, they can be printed on the lower surface of the printed circuit board 423 or on two opposite surfaces of the above-mentioned at least one printed circuit board 423, respectively. Any conventional PCB material may be used here. PCB 423 may be thin (eg, less than 1 mm) and / or have a low dielectric constant (eg, relative dielectric constant less than 5 or less than 3) to minimize any deleterious effects of the PCB's dielectric on propagation characteristics.

[0072] also, Figure 4 The radome 430 surrounding the passive antenna module 401 is shown in dashed lines. For example, the radome 430 can be made of polycarbonate. It should be noted that there is no specific connection between the radome 430 and the PCB implementation of the ground plane layer 420, that is, a specific embodiment can implement one or both of the above features.

[0073] Although combined with Figure 2, Figure 3 and Figure 4 The APA systems discussed work adequately in many scenarios, but they suffer from several drawbacks. Since the passive antenna array partially extends over the active antenna array (e.g. Figure 2A and Figure 2B ), the scanning capability of the active antenna array may be limited due to antenna blocking. In other words, if a large scanning angle (relative to the broadside direction) is used, the beam is at least partially blocked by the passive antenna module, resulting in a deterioration in the performance of the active antenna array. Due to practical considerations related to, for example, mechanical design, it may not always be possible to adjust the active antenna module so that its ground plane is aligned with the base provided by the passive antenna module (e.g. Figure 2A and Figure 2B ) provides ground plane alignment, i.e., with Figure 2A and Figure 2B Compared to the APA system, the active antenna array may need to be arranged at a lower position than the passive antenna array. This further exacerbates the above-mentioned beam scanning problem, resulting in a serious limitation of the beam scanning capability. These problems can be overcome if the electromagnetic field radiated by the active antenna module can be transferred or guided farther from the active antenna array and then re-radiated.

[0074] Figure 5 A schematic diagram of an APA system 500 according to an embodiment is provided. Specifically, Figure 5 The APA system 500 (including the passive antenna module 501 and the active antenna module 511) is shown in a side view. It should be noted that Figure 5 A very simplified view is shown, in which many elements of the passive antenna module 501 (e.g., any power distribution elements, the radio unit, and the radome) are omitted. The APA system 500 may form a terminal device such as Figure 1 2 ) or part of an access node (such as access node 104 of FIG. 2 ).

[0075] APA System 500 can be used to a large extent with Figure 2A and Figure 2B The APA system 200 corresponds to the APA system 200, as indicated by shared reference numerals. Figure 5 The active antenna module 211 can be completely connected with Figure 2A and Figure 2B The active antenna module 211 corresponds to the active antenna module 211. Figure 2A and Figure 2B and / or Figure 3 and / or Figure 4 Any features discussed here also apply mutatis mutandis here. Figure 5 The difference between the passive antenna modules 201 and 501.

[0076] refer to Figure 5 , the passive antenna module 501 and Figure 2A and Figure 2B The passive antenna module 201 of the present invention corresponds to the passive antenna module 201 of the present invention, wherein an array (or set) 502 of electromagnetic coupling elements 503 is added, which is arranged on the ground plane layer 220 (but separated from the ground plane layer 220 by a certain distance) to couple the electromagnetic radiation received from the active antenna module to the free space when the first base 202 is mounted on the active antenna module. In other words, the coupling structure (e.g., dipole or loop) of the electromagnetic coupling element 503 captures the electromagnetic field radiated by the second antenna array 213, and then, these captured electromagnetic fields are re-radiated by the radiating structure (e.g., dipole, patch or loop) of the electromagnetic coupling element 503. The electromagnetic coupling element 503 can be configured to be excited at least at the second operating frequency band of the second antenna array 213 of the active antenna module 211 (or at least at one or more frequencies therein). Each electromagnetic coupling element 503 may include one or more resonant elements, and the one or more resonant elements have a resonant frequency within the above-mentioned second operating frequency band of the second antenna array 213.

[0077] The array 502 of electromagnetic coupling elements 503 may be substantially aligned with the openings in the metal or metallized grid 221. Additionally or alternatively, the array 502 of electromagnetic coupling elements 503 may be substantially aligned with the second antenna array 213 of the plurality of second antenna elements 214 (when the passive antenna module 201 and the active antenna module 211 are connected). The number of electromagnetic coupling elements 503 may be equal to or less than the number of the plurality of second antenna elements 214 in the second antenna array 213 (the former case is as shown in FIG. 1 ). Figure 5 shown).

[0078] exist Figure 5 In the example shown in , the electromagnetic coupling element 503 is based on capacitive coupling. The electromagnetic coupling element 503 shown may more specifically correspond to a structure in which two horizontal dipoles (parallel to the plurality of second antenna elements 214 and arranged at different distances from the plurality of second antenna elements 214) are connected to at least one vertical (metal or metallization) portion. Alternatively, the electromagnetic coupling element 503 shown may correspond to two horizontal dual-polarization dipoles (parallel to the plurality of second antenna elements 214 and arranged at different heights), which are connected to at least one vertical (metal or metallization) portion, as will be discussed below in conjunction with FIG. 7 .

[0079] The plurality of electromagnetic coupling elements 503 may generally include one or more capacitive coupling elements and / or one or more inductive coupling elements. For example, the capacitive coupling element may include one or more (connected) dipoles arranged substantially parallel to the plurality of second antenna elements 214. The inductive coupling element may include one or more (connected) loops arranged, for example, along a plane substantially parallel to the plane of the plurality of second antenna elements 214.

[0080] The distance between the array 502 of electromagnetic coupling elements 503 and the ground plane layer 220 may be (electrically) small. Such an electrically small distance may be at least equal to or less than λ / 4, λ / 5, λ / 6, λ / 7, λ / 8, λ / 9, λ / 10, λ / 12, or λ / 15, where λ is a (free space) wavelength corresponding to a frequency (e.g., a center frequency) within a second operating frequency band of the second antenna array 213 of the active antenna module 211. The array 502 of electromagnetic coupling elements 503 may be located in the near field or non-radiating near field of the second antenna array 213 at the second operating frequency band of the second antenna array 213. The array 502 of multiple electromagnetic coupling elements 503 may be spaced apart by a spacer material layer (such as a dielectric layer) ( Figure 5 ) is separated from the ground plane layer 220.

[0081] The array 502 of multiple electromagnetic coupling elements 503 may be spaced apart by a layer of a spacer material (such as a dielectric layer) ( Figure 5 ) is separated from the ground plane layer 220.

[0082] Figure 6 A schematic diagram of an APA system 600 according to an embodiment is provided. Specifically, Figure 6 The APA system 600 (including the passive antenna module 601 and the active antenna module 611) is shown in a side view. It should be noted that Figure 6 A very simplified view is shown, in which many elements of the passive antenna module 601 (e.g., any power distribution elements, the radio unit, and the radome) are omitted. The APA system 600 may form a terminal device such as Figure 1 2 ) or part of an access node (such as access node 104 of FIG. 2 ).

[0083] APA System 600 can be used to a large extent with Figure 2A and Figure 2B The APA system 200 of the present invention corresponds to the APA system 200 of the present invention, as shown by the shared reference numerals. Figure 2A and Figure 2B and / or Figure 3 and / or Figure 4 Any features discussed here also apply mutatis mutandis. Figure 6The difference between APA systems 200 and 600.

[0084] refer to Figure 6 , the passive antenna module 601 and Figure 2A and Figure 2B Corresponding to the passive antenna module 201 of the present invention, an array (or set) 602 of electromagnetic waveguide elements 603 (or an array 602 of equivalent electromagnetic waveguide elements 603) is added, which is arranged above the ground plane layer 220 (but separated by a certain distance from the ground plane layer 220) to guide the electromagnetic radiation received from the active antenna module to the free space when the first base 202 is mounted on the active antenna module. In other words, one end of the electromagnetic waveguide element 603 (for example, one end of the waveguide) captures the electromagnetic field radiated by the second antenna array 213, and these captured electromagnetic fields propagate along the electromagnetic waveguide element 603, and then are re-radiated at the other end of the electromagnetic waveguide element 603. The electromagnetic waveguide element 603 can be configured to support electromagnetic waves at least at the second operating frequency band of the second antenna array 213 of the active antenna module 611 (or at least at some frequencies therein).

[0085] As described above, the electromagnetic waveguide element 603 may be a waveguide. For example, the electromagnetic waveguide element 603 may be a hollow metal (or metallized) waveguide or a dielectric waveguide. The dielectric waveguide may be a dielectric waveguide with or without metal or metallized walls. For example, the electromagnetic waveguide element 603 may be oriented substantially perpendicular to the plane of the second antenna array 213 to direct the electromagnetic waves away from the second antenna array 213 (e.g., Figure 6 The number of electromagnetic waveguide elements 603 may be equal to or less than the number of the plurality of second antenna elements 214 in the second antenna array 213 (the former case is as shown in FIG. Figure 6 shown).

[0086] The distance between the array 602 of electromagnetic waveguide elements 603 and the ground plane layer 220 may be (electrically) small. The above distance may be at least equal to or less than λ / 4, λ / 5, λ / 6, λ / 7, λ / 8, λ / 9, λ / 10, λ / 12 or λ / 15, where λ is the (free space) wavelength corresponding to a frequency (e.g., center frequency) within the second operating frequency band of the second antenna array 213 of the active antenna module 511. In some embodiments, the array 602 of electromagnetic waveguide elements 603 may even be in contact with the ground plane layer 220.

[0087] The distance between the ground plane layer 220 and the second antenna array 213 may also be (electrically) smaller, similar to that discussed in connection with the previous embodiments.The array 602 of electromagnetic waveguide elements 603 may be located in the near field of the second antenna array 213 at least at its second operating frequency band.

[0088] The array 602 of multiple electromagnetic waveguide elements 603 may be spaced apart by layers of spacer material (such as dielectric layers) ( Figure 6 ) is separated from the ground plane layer 220.

[0089] Figure 6 The active antenna module 611 shown is connected to Figure 2A and Figure 2B The active antenna module 211 of FIG. 6 is different in that the active antenna module 611 includes an inclined (or skewed) metal wall 612 protruding from the ground plane 215 at a certain angle (i.e., a non-90° angle) instead of a metal wall orthogonal to the ground plane 215 of the second antenna array 213. The inclined metal wall 612 is specifically inclined away from the second antenna element 214 so as to form a cup-like shape (or an equivalent horn-like antenna shape) (with the ground plane 215) around the plurality of second antenna units 214 and their feeding elements 216. In other words, a set of inclined metal walls 612 formed around a particular second antenna element 214 can form an inverted right truncated cone shape (e.g., having a circular, square, or regular polygonal base), or have a shape formed by connecting a bottom base having a first shape (e.g., circular) and a (larger) top base having a second shape (e.g., square) (substantially aligned with and parallel to the bottom base). These types of shapes are used to more efficiently direct the electromagnetic field radiated by the second antenna array 213 in a desired direction (i.e., Figure 6 In other embodiments, the metal wall may be configured to protrude vertically from the ground plane 215, as in the previous embodiments.

[0090] Fig. 7A , Figure 7B and Figure 7C A practical non-limiting example of a capacitive coupling element of a passive antenna module arranged on a second antenna element 705 of a second antenna array of an active antenna module according to an embodiment is illustrated. Specifically, Fig. 7A The figure shows a unit cell structure 701 of an active antenna module. Figure 7B The capacitive coupling element 721 of the passive antenna module is shown. Figure 7C The diagram shows a combination of the unit cell structure 701 and the capacitive coupling element 721. Figure 7C In FIG. 7 , some elements related to the capacitive coupling element 721 are presented as transparent.

[0091] It should be noted that although Fig. 7A , Figure 7B and Figure 7C A relatively large empty space is shown around the unit cell structure 701, but in actual situations, the above elements 701, 721 can be arranged next to each other, such as Figure 2A and Figure 2B shown.

[0092] refer to Fig. 7A , the unit cell structure 701 of the active antenna module includes a second antenna element 705, a feeding element 704 for the second antenna element 705, and a set of metal walls 703, which protrude from the ground plane 702 of the second antenna module 705 and surround the feeding element 704 and the second antenna element 705. The second antenna element 705 is a dual-polarized cross-dipole dipole antenna, which includes a main cross-dipole antenna element 706 fed by the feeding element 704 and a parasitic cross-dipole antenna element 707 arranged on the main cross-dipole antenna element 706 (separated from it by a certain distance). The main and parasitic cross dipoles 706, 707 can be printed on different surfaces of the printed circuit board. The feeding element 704 is implemented here using a microstrip line. The shape of a set of inclined metal walls 703 formed around the feeding element 704 and the second antenna element 705 is formed by connecting a bottom base having a circular shape and a top base having a square shape aligned and parallel to the bottom base (with a narrow straight or non-inclined portion at the distal end).

[0093] refer to Figure 7B (and Figure 7C ), the capacitive coupling element 721 of the passive antenna module includes a cross-dipole type capacitive element 721 and a metal wall 722 surrounding the cross-dipole type capacitive element 721. The cross-dipole type capacitive element 721 includes a bottom cross-dipole element 723, a top cross-dipole element 725, and a portion 724 connecting the bottom and top cross-dipole elements. Each of the bottom cross-dipole element 723 and the top cross-dipole element 725 includes two dipoles that cross each other (each dipole has two different opposite and parallel dipole arms), thereby forming an "x" shape (such as the characteristics of a cross-dipole). The cross-dipole type capacitive element 721 can be made of metal or alloy. The metal wall 722 protruding vertically from the ground plane layer 733 is used to shape the electromagnetic field radiated by the cross-dipole type capacitive element 721 (that is, to shape the antenna pattern generated by the second antenna element 705). In other words, the metal wall 722 can play a similar role as the wall 703.

[0094] Layer 732 may correspond to a radome (eg, made of polycarbonate) of a passive antenna module.

[0095] The upper surface of the layer 732 may be metallized, or a separate metal sheet may be provided to form the ground plane layer 733. The ground plane layer 733 comprises a (continuous) metal or metallized layer or surface 734 having an opening (or hole) 735. The opening 735 coincides with the metal wall 722 surrounding the capacitive coupling element 721, i.e., the lower opening of the metal wall 722 facing the active antenna module corresponds to the opening 735 in the ground plane layer 733. As described above, in a practical scenario, the capacitive coupling elements 721 may be arranged in close proximity to each other (e.g. Figure 5 ), and thus the ground plane layer 733 having a plurality of openings 735 (eg, one opening 735 for each capacitive coupling element 721) forms a grid, as described above.

[0096] Figure 7C Shown are stacked Fig. 7A and Figure 7B It should be noted that for clarity, the layer 731 forming part of the active antenna module has not been previously described. Fig. 7A The above-mentioned layer 731 may correspond to the radome of the active antenna module, while the layer 732 may correspond to the radome of the passive antenna module (similar to Figure 7B ).

[0097] also, Figure 7C Also shown is an electromagnetic directional element 726 (made of metal or alloy) in the form of a rectangular metal patch arranged on top of the capacitive coupling element 721. The metal directional element 722 is used to tune the S11 parameter (i.e., reflection coefficient) of the second antenna element 705 of the active antenna module. In other embodiments, other shapes of the element 726 may be used.

[0098] For example, Fig. 7A , Figure 7B and Figure 7C The exemplary structure shown may have the following dimensions to enable operation in the 3.2 to 3.8 GHz frequency band.

[0099] • The distance between the ground plane 702 and the cross-dipole antenna element 705 is 28 mm.

[0100] The size of the opening of a set of cup-shaped walls 703 is 40 mm x 40 mm.

[0101] The lateral dimensions of the entire unit cell structure 701 (ie, the period of the second antenna array of the active antenna module in two orthogonal directions) are 42 mm x 58 mm.

[0102] The thickness of the radome layer 731 of the active antenna module is 2 mm.

[0103] The thickness of the radome layer 732 of the passive antenna module is 2 mm.

[0104] • The wall 722 surrounding the capacitive coupling element 721 has a height of 10 mm and lateral dimensions of 40 mm x 40 mm.

[0105] The electromagnetic guiding element 726 has a size of 27 mm x 27 mm and is placed at a distance of 732 mm from the radome layer of the passive antenna module.

[0106] Each dipole arm of each bottom cross-dipole element 723 of the capacitive coupling element 721 has a length of 15 mm and a maximum width of 5 mm (the width being the dimension orthogonal to the longitudinal direction of the dipole arm).

[0107] Each dipole arm of each top crossed dipole element 725 of the capacitive coupling element 721 has a length of 15 mm and a maximum width of 5 mm (the width being the dimension orthogonal to the longitudinal direction of the dipole arm).

[0108] As used in this application, the term "circuitry" may refer to one, more, or all of the following:

[0109] (a) a hardware circuit implementation only (such as an implementation using only analog and / or digital circuitry), and

[0110] (b) a combination of hardware circuitry and software such as (where applicable):

[0111] (i) a combination of analog and / or digital hardware circuits and software / firmware, and

[0112] (ii) any portion of hardware processor(s) (including digital signal processor(s)) with software, software and memory(s) that work together to cause a device such as a mobile phone or server to perform various functions), and

[0113] (c) Hardware circuit(s) and / or processor(s), such as microprocessor(s) or portion(s) of microprocessor(s), the operation of which requires software (e.g., firmware), but where the software is not required for operation, the software may be absent.

[0114] This definition of circuitry applies to all uses of the term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its accompanying software and / or firmware. The term circuitry also covers (e.g., if applicable to a particular claim element) a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or network device.

[0115] Although the present invention has been described above with reference to the examples according to the accompanying drawings, it is obvious that the present invention is not limited thereto, but can be modified in various ways within the scope of the appended claims. Therefore, all words and expressions should be interpreted broadly, and they are intended to illustrate rather than limit the embodiments. It is clear to those skilled in the art that, with the advancement of technology, the inventive concept can be implemented in various ways. In addition, it is clear to those skilled in the art that the described embodiments can but need not be combined with other embodiments in various ways.

Claims

1. A passive antenna module for an active-passive antenna system, the passive antenna module comprising: a base for detachably mounting to an active antenna module of the active-passive antenna system, wherein the base includes an opening or cavity for extending at least partially over the active antenna module when the base is mounted to the active antenna module; a ground plane layer disposed within or over the opening or cavity and secured to the base, wherein the ground plane layer comprises at least a metal or metallized grid; a first antenna array comprising one or more first antenna elements disposed partially over the base and adjacent to the opening or cavity and partially over the opening or cavity, wherein the base and the ground plane layer are adapted to function as a ground plane for the first antenna array; as well as one or more electromagnetic coupling elements, the one or more electromagnetic coupling elements being arranged above the ground plane layer and configured to couple electromagnetic radiation received from the active antenna module via the ground plane layer to free space when the base is mounted on the active antenna module; and / or One or more electromagnetic waveguide elements are arranged above the ground plane layer for guiding electromagnetic radiation received from the active antenna module via the ground plane layer to free space when the base is mounted on the active antenna module.

2. The passive antenna module of claim 1, wherein the ground plane layer further comprises a two-dimensional array of metal patches arranged within the metal or metallized grid.

3. The passive antenna module according to claim 1 or 2, wherein the base and the opening or cavity both have a shape elongated along the same direction, and the one or more first antenna elements are arranged at least partially adjacent to one or more longitudinal faces of the opening or cavity.

4. The passive antenna module according to claim 1 or 2, wherein the one or more first antenna elements are resonant antenna elements having equal geometric shapes and sizes, and / or the first antenna array is a one-dimensional planar array or a two-dimensional planar array having uniform antenna spacing.

5. The passive antenna module according to claim 1 or 2, wherein the passive antenna module is adapted so that the first antenna array is substantially arranged at a distance of a first wavelength divided by 4 from both the base and the ground plane layer, wherein the first wavelength is a wavelength corresponding to a frequency within a first operating frequency band of the first antenna array.

6. A passive antenna module according to claim 1 or 2, wherein the maximum size of the unit cell of the metal or metallized grid is less than the second wavelength divided by 8, divided by 9, divided by 10 or divided by 11, and the second wavelength is a wavelength corresponding to a frequency within the first operating band of the first antenna array.

7. The passive antenna module according to claim 1 or 2, further comprising: A printed circuit board is arranged in or over the opening or cavity and fixed to the base, wherein the ground plane layer is implemented as a metallization pattern on a surface of the at least one printed circuit board, wherein a surface opposite to the surface is exposed.

8. The passive antenna module according to claim 1 or 2, wherein the passive antenna module comprises the one or more electromagnetic coupling elements, and further comprises: one or more metal walls, the one or more metal walls surrounding at least one of the one or more electromagnetic coupling elements, for further directing the electromagnetic radiation received from the active antenna module, and / or A metal electromagnetic guiding element is arranged on the one or more electromagnetic coupling elements to reduce reflection.

9. The passive antenna module according to claim 1 or 2, wherein the passive antenna module comprises the one or more electromagnetic waveguide elements, and the one or more electromagnetic waveguide elements comprise one or more hollow metal waveguides and / or one or more dielectric waveguides.

10. An active-passive antenna system, comprising: The passive antenna module according to any one of claims 1 to 9, adapted to operate at least in a first operating frequency band; as well as An active antenna module, wherein the passive antenna module is detachably mounted on the active antenna module, wherein the active antenna module comprises: The second antenna array is adapted to operate in a second operating frequency band higher than the first operating frequency band, wherein the ground plane layer of the passive antenna module is adapted to be transparent or semi-transparent in the second operating frequency band.

11. The active-passive antenna system of claim 10, wherein the opening or cavity of the base of the passive antenna module is adapted to extend entirely over at least the second antenna array of the active antenna module, or over the active antenna module.

12. The active-passive antenna system according to any one of claims 10 to 11, wherein no wired electrical connection is provided between the passive antenna module and the active antenna module.

13. An active-passive antenna system according to any one of claims 10 to 11, wherein the second antenna array is a planar two-dimensional antenna array with uniform antenna element spacing, and / or the maximum size of the unit cell of the metal or metallized grid is greater than a third wavelength divided by 4 or 3, and the third wavelength is a wavelength corresponding to a frequency within the second operating band of the second antenna array.

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