EP4740268A1

EP4740268A1 - An aperture coupled antenna

Info

Publication number: EP4740268A1
Application number: EP24839075.9A
Authority: EP
Inventors: Vijay Verma; Aayush Bhatnagar; Pradeep Kumar Bhatnagar; Praveen Penta; Shubham Kumar Gupta
Original assignee: Jio Platforms Ltd
Current assignee: Jio Platforms Ltd
Priority date: 2023-07-09
Filing date: 2024-06-21
Publication date: 2026-05-13
Also published as: WO2025012959A1

Abstract

The present invention describes an aperture coupled antenna [100]. In one example, the aperture coupled antenna [100] may include at least one of a plurality of patch layers, a feed network and ground later, and a reflector layer. The patch layer may include a radiating patch element, and the feed network and ground layer may include an aperture with a cutout. The aperture coupled antenna [100] may further include a top metallic cage structure [102] and a bottom metallic cage structure [104]. The top metallic cage structure [102] may surround the radiating patch element and the bottom metallic cage structure [104] may be on a bottom side of the feed network and ground layer.

Description

AN APERTURE COUPLED ANTENNA

FIELD OF THE INVENTION

[0001] The present invention generally relates to technologies for enhancing functioning of an antenna module of a wireless communication system. More particularly, embodiments of the present disclosure relate to an aperture coupled antenna.

BACKGROUND OF THE INVENTION

[0002] The following description of related art is intended to provide background information pertaining to the field of the invention. This section may include certain aspects of the art that may be related to various features of the present invention. However, it should be appreciated that this section be used only to enhance the understanding of the reader with respect to the present invention, and not as admissions of prior art.

[0003] Wireless communication technology has rapidly evolved over the past few decades, with each generation bringing significant improvements and advancements. The first generation of wireless communication technology was based on analog technology and offered only voice services. However, with the advent of the second-generation (2G) technology, digital communication and data services became possible, and text messaging was introduced. The third generation (3G) technology marked the introduction of high-speed internet access, mobile video calling, and location-based services. The fourth generation (4G) technology revolutionized wireless communication with faster data speeds, better network coverage, and improved security. Currently, the fifth generation (5G) technology is being deployed, promising even faster data speeds, low latency, and the ability to connect multiple devices simultaneously. With each generation, wireless communication technology has become more advanced, sophisticated, and capable of delivering more services to its users.

[0004] Small cells use low-power and short-range wireless transmission systems (or base stations). A small geographical area or small-proximity indoor and outdoor space is covered by the small cells in the 5G networks. Also, 5G new radio (NR) outdoor small cell (ODSC) is medium power gNB which operates in micro class (typically 6.25 W or 38dBm per antenna port). It complements macro-level wide-area solutions for coverage and capacity and is particularly useful in hot zone/hot spot areas with high traffic and quality of service (QoS) demands. [0005] While a Macro gNB can offer satisfactory coverage and capacity in many situations, dense urban environments with tall buildings may experience intermittent mobile coverage issues. Simply adding more radios becomes impractical. Similarly, meeting the high capacity demands of numerous mobile users in commercial hubs such as malls, hotels, office blocks, and transportation hubs poses significant challenges. In such scenarios, deploying 5G Outdoor small cell (ODSC) solutions in hotspot locations becomes essential to enhance coverage and capacity, complementing the capabilities of 4G/5G gNB. In addition to this, there could be geographical areas outdoor where the coverage of Macros is not present.

[0006] This efficiently addresses the increased traffic demands in these areas. This necessitates an efficient antenna design which has broadband band constant radiation characteristics and Aperture Coupled design technology is a design approach. However, there are limitations that when the single aperture coupled element structure is extended to array design (e.g. 4T4R), the Port-to-port Isolation, Bandwidth and XPD parameters are degraded. There is a requirement in the state of the art to provide as solution for port-to-port isolation, cross polarization ratio (XPD) and band width improvement when the single aperture coupled patch element is extended to antenna array structure.

OBJECTS OF THE INVENTION

[0007] Some of the objects of the present invention, which at least one embodiment disclosed herein satisfies are listed herein below.

[0008] It is an object of the present disclosure to provide methods and systems for improving performance of an aperture coupled antenna array.

[0009] It is another object of the present disclosure to provide a solution that can provide port-to- port isolation, cross polarization ratio (XPD) and band width improvement in Aperture Coupled Patch antenna array.

[0010] It is another object of the present disclosure to provide a solution that can provide improved port to port isolation by using a bottom metallic cage structure. [0011] It is another object of the present disclosure to provide a solution that can improve XPD by using a top metallic cage structure such that the top metallic structure also benefits in controlling the horizontal beam width.

[0012] It is yet another object of the present disclosure to provide a solution that can provide an improved antenna band width by incorporating a slot of square (or circle or diamond) in the X- shaped aperture.

SUMMARY

[0013] This section is provided to introduce certain implementations of the present invention in a simplified form that are further described below in the detailed description. This summary is not intended to identify the key features or the scope of the claimed subject matter.

[0014] In an aspect of the present invention, an aperture coupled antenna comprises at least one of a plurality of patch layers, a feed network and ground layer, and a reflector layer. The patch layer comprises a radiating patch element and the feed network and ground layer comprises an aperture with a cutout. The aperture coupled antenna further includes a top metallic cage structure surrounding the radiating patch element; and a bottom metallic cage structure on a bottom side of the feed network and ground layer.

[0015] In an aspect of the present invention, at least one of the plurality of patch layers are arranged in a stack, the stack comprising the at least one of the plurality of patch layers placed above each other.

[0016] In an aspect of the present invention, the top metallic cage structure comprises a plurality of electrically conductive walls.

[0017] In an aspect of the present invention, the aperture coupled antenna further comprises a first substrate and a second substrate. The second substrate is arranged over the first substrate, wherein, the patch layer is attached to a bottom portion of the second substrate; a feed network of the feed network and ground layer, is printed on a bottom portion of the first substrate, and a ground layer of the feed network and ground layer is printed on a top portion of the first substrate; and the reflector layer is arranged below the bottom portion of the first substrate. [0018] In an aspect of the present invention, the aperture of the feed network and ground layer further is a cross-shaped aperture.

[0019] In an aspect of the present invention, the cross-shaped aperture is configured to provide electromagnetic coupling between the feed network and ground layer and the radiating patch element.

[0020] In an aspect of the present invention, the cutout of the aperture of the feed network and ground layer is one of a square-shaped, a circle-shaped, and a diamond-shaped cutout.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[0021] The accompanying drawings, which are incorporated herein, and constitute a part of this invention, illustrate exemplary embodiments of the disclosed methods and systems in which like reference numerals refer to the same parts throughout the different drawings. Components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Some drawings may indicate the components using block diagrams and may not represent the internal circuitry of each component. It will be appreciated by those skilled in the art that invention of such drawings includes invention of electrical components, electronic components or circuitry commonly used to implement such components.

[0022] FIG. 1 illustrates an exemplary diagram of an aperture coupled antenna, in accordance with exemplary embodiments of the present disclosure.

[0023] FIG. 2 illustrates exemplary an aperture coupled antenna array with a top and a bottom metallic cage, in accordance with exemplary embodiments of the present disclosure.

[0024] FIG. 3 illustrates exemplary diagrams of a top metallic cage and a bottom metallic cage, in accordance with exemplary embodiments of the present disclosure.

[0025] FIG. 4 illustrates an exemplary diagram of X-shaped aperture with Square shaped cut-out, in accordance with exemplary embodiments of the present disclosure.

[0026] FIG. 5 illustrates an exemplary diagram of an integrated antenna with patch, PCB and reflector plate, in accordance with exemplary embodiments of the present disclosure. [0027] The foregoing shall be more apparent from the following more detailed description of the disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0028] In the following description, for the purposes of explanation, various specific details are set forth to provide a thorough understanding of embodiments of the present disclosure. It will be apparent, however, that embodiments of the present disclosure may be practiced without these specific details. Several features described hereafter may each be used independently of one another or with any combination of other features. An individual feature may not address any of the problems discussed above or might address only some of the problems discussed above.

[0029] The ensuing description provides exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an exemplary embodiment. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the disclosure as set forth.

[0030] Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits, systems, processes, and other components may be shown as components in block diagram form in order not to obscure the embodiments in unnecessary detail.

[0031] The word “exemplary” and/or “demonstrative” is used herein to mean serving as an example, instance, or illustration. For the avoidance of doubt, the subject matter disclosed herein is not limited by such examples. In addition, any aspect or design described herein as “exemplary” and/or “demonstrative” is not necessarily to be construed as preferred or advantageous over other aspects or designs, nor is it meant to preclude equivalent exemplary structures and techniques known to those of ordinary skill in the art. Furthermore, to the extent that the terms “includes,” “has,” “contains,” and other similar words are used in either the detailed description or the claims, such terms are intended to be inclusive — in a manner similar to the term “comprising” as an open transition word — without precluding any additional or other elements. [0032] As discussed in the background section, the current known solutions have several shortcomings and there is a requirement to provide isolation, cross polarization ratio (XPD) and band width improvement in aperture coupled patch antenna structures.

[0033] Referring to FIG. 1, an exemplary diagram of an aperture coupled antenna [100] in accordance with exemplary embodiments of the present disclosure, is illustrated.

[0034] The aperture coupled antenna [100] comprises at least one of a plurality of patch layers, a feed network and ground layer, and a reflector layer, wherein the patch layer comprises a radiating patch element and the feed network and ground layer comprises an aperture with a cutout. The present disclosure encompasses the aperture-coupled antenna is a type of antenna where the radiating element (patch) is excited through an aperture (opening) in a ground plane. In the aperture-coupled configuration, the signal is coupled from the microstrip line feed to the radiating patch through an electrically small aperture or slot cut in the ground plane instead of directly feeding to the patch. The patch is a radiating element, which can be realized on PCB substrate or using a metallic sheet and the patch layer of the antenna that contains the radiating patch element. This patch is responsible for emitting and receiving electromagnetic waves, the feed network is typically located below the ground layer and is responsible for delivering the signal to the radiating patch through the aperture. In one example, the plurality of patch layers may be arranged in a stack, such that the stack may include the plurality of patch layers placed above each other. As would be appreciated, placing a plurality of patch layers above each other in a stack may aid in achieving broadband performance. The feed network is printed on a bottom side of the PCB and the Ground layer is printed on a top side of the PCB. Cross-slots are etched on the ground to couple the signal from feed to patch. The ground layer has an aperture through which the feed network couples electromagnetic energy to the radiating patch. The reflector layer placed behind the ground layer reflects electromagnetic waves and directs them in a desired direction, The reflector layer is used to avoid the signal leakage on back side and also to provide the structural support to overall antenna design. The radiating patch element is in the patch layer that radiates the electromagnetic energy into space or receives electromagnetic energy from space. The aperture of the feed network and ground layer further is a cross-shaped aperture. The cross-shaped aperture is configured to provide electromagnetic coupling between the feed network and ground layer and the radiating patch element. The cutout of the aperture of the feed network and ground layer is one of a squareshaped, a circle-shaped, and a diamond- shaped cutout. The electromagnetic coupling is transfer of electromagnetic energy from one component (feed network) to another (radiating patch) through the aperture without direct electrical connection.

[0035] The aperture coupled antenna [100] further comprises a top metallic cage structure [102] surrounding the radiating patch element; wherein the top metallic cage [102] structure comprises a plurality of electrically conductive walls and a bottom metallic cage structure [104] on a bottom side of the feed network and ground layer. The present disclosure encompasses the top metallic cage structure [102] is positioned around the radiating patch element. The top metallic cage structure [102] includes multiple electrically conductive walls, which serve to enclose and shield the patch element. Additionally, the bottom metallic cage structure [104] is located on the underside of the feed network and ground layer, providing further enclosure and potentially additional shielding or structural support.

[0036] Furthermore, the aperture coupled antenna [100] includes a first substrate and a second substrate, the second substrate being arranged over the first substrate, wherein, the patch layer is attached to a bottom portion of the second substrate; a feed network of the feed network and ground layer, is printed on a bottom portion of the first substrate, and a ground layer of the feed network and ground layer is printed on a top portion of the first substrate; and the reflector layer is arranged below the bottom portion of the first substrate. The present disclosure encompasses the first substrate and a second substrate, with the second substrate positioned above the first. The patch layer, which includes the radiating patch element, is attached to the bottom portion of the second substrate. The feed network, part of the feed network and ground layer, is printed on the bottom portion of the first substrate, while the ground layer is printed on the top portion of the first substrate. Below the bottom portion of the first substrate is the reflector layer, which enhances the antenna's performance by reflecting electromagnetic waves.

[0037] The antenna is extended to an array of 4T4R configuration however the disclosure is not limited thereto. Based on the desired performance metrics, such as, Gain, Vertical beam width and Sidelobe levels requirements, a plurality of antennas may be arranged vertically in a column. Multiple columns may be arranged thereafter for formation of the array antennas. For good MIMO performance, in array antennas, the spacing between two columns is generally used as 0.8-1.2k

[0038] When the single element structure is extended to 4T4R array design, the Port-to-port Isolation and XPD parameters are degraded. Also, the Horizontal beam width become narrow in the array structure. [0039] As would be appreciated, the proposed structure of aperture coupled antenna [100] may provide a number of technical advancements, and may be efficient over the conventional solutions.

[0040] Improved Port to Port Isolation: The structure incorporates advanced isolation techniques, including the use of additional isolation walls and strategic placement of elements. These measures effectively minimize coupling between ports, thereby maintaining high isolation levels even in a dense array configuration.

[0041] Enhanced XPD Parameters: To address the degradation of XPD parameters, the antenna design employs cross polarization suppression techniques. This includes optimizing the geometry and orientation of the elements to reduce unwanted polarization components.

[0042] Wider Horizontal Beam Width: The narrowing of the horizontal beam width in a 4T4R array is mitigated by utilizing a specially designed element arrangement that promotes broader beam patterns.

[0043] Referring to FIG. 2, an exemplary aperture coupled antenna array with a top and a bottom metallic cage, in accordance with exemplary embodiments of the present disclosure, is illustrated.

[0044] The described system showcases an aperture-coupled antenna array that incorporates metallic cages for enhanced performance. These metallic cages are placed around the radiating patch element as well as on the bottom side of the array, in line with the exemplary embodiments provided. The primary function of the metallic cage surrounding the radiating patch element is to improve the Cross Polarization Ratio (XPD). This means the antenna can better differentiate between various polarization states of incoming and outgoing signals, leading to clearer and more reliable communication. Additionally, this metallic cage helps in widening the horizontal beam width of the antenna's radiation pattern, ensuring a broader coverage area, which can be necessary for certain applications. Moreover, the top metallic structure controlling the horizontal beam width, providing precise management over the direction and spread of the emitted signals.

[0045] Referring to FIG. 3, exemplary diagrams of a top metallic cage [102] and a bottom metallic cage [104], in accordance with exemplary embodiments of the present disclosure, are illustrated.

[0046] The invention includes a metallic cage located on the bottom side of the feed network printed circuit board (PCB). This bottom-side metallic cage structure strategically covers only the middle two aperture coupling feeds. The primary function of this cage is to improve the isolation between ports. By increasing isolation, the metallic cage effectively reduces interference between signals at different ports, which can lead to improved performance of the antenna system. This isolation is important for maintaining signal integrity and ensuring that the antenna operates efficiently without crosstalk or signal degradation. The use of these metallic cages is an innovative approach to optimize the antenna's performance by addressing port isolation and improving signal clarity.

[0047] FIG. 4 illustrates an exemplary diagram of X-shaped aperture with Square shaped cut-out, in accordance with exemplary embodiments of the present disclosure. This configuration is designed to enhance the bandwidth of the antenna. By incorporating a square (or alternatively, a circle or diamond) shaped cutout within the X-shaped aperture, the antenna's bandwidth is significantly improved. The X-shaped aperture itself is structured to facilitate efficient electromagnetic coupling between the feed network and the radiating patch element. The addition of the geometric cutout further optimizes this coupling process, thereby expanding the range of frequencies over which the antenna can operate effectively.

[0048] FIG. 5 illustrates an exemplary diagram of an integrated antenna with patch, PCB and reflector plate, in accordance with exemplary embodiments of the present disclosure.

[0049] Partition Walls: These walls are used to improve the cross-polarization discrimination (XPD) and half-power beamwidth (HPBW). They help in isolating the individual patch elements to reduce interference and improve the antenna's performance.

[0050] Metal Patch Element: This is the primary radiating element of the antenna. The metal patches are typically designed to resonate at specific frequencies, allowing them to transmit and receive electromagnetic waves efficiently.

[0051] Feed Network PCB (Printed Circuit Board): This is the circuit board that distributes the signal to the individual metal patch elements. It ensures that each patch receives the correct signal with the appropriate phase and amplitude to create the desired radiation pattern.

[0052] Reflector Plate: The reflector plate is located behind the patch elements. Its primary function is to reflect the electromagnetic waves forward, enhancing the gain and directivity of the antenna. It helps in preventing the back radiation and directing the signal towards the intended direction. [0053] As is evident from the above description, the present disclosure overcomes the limitations of the existing solutions by providing technically advanced aperture coupled antenna that provides enhancement in the port-to-port isolation, cross polarization ration (XPD) and the bandwidth in the aperture coupled patch antenna array. Further the present solution provides an improved port to port isolation by using a bottom metallic cage structure. Additionally, the present solution provides an enhanced XPD by using top metallic cage structure such that the top metallic structure also benefits in controlling the horizontal beam width. Furthermore, the present solution also provides an improved antenna band width by incorporating a slot of square (or circle or diamond) in the X-shaped aperture. Therefore, the present disclosure provides various technical advancements and technical effects.

[0054] While considerable emphasis has been placed herein on the disclosed implementations, it will be appreciated that many implementations can be made and that many changes can be made to the implementations without departing from the principles of the present disclosure. These and other changes in the implementations of the present disclosure will be apparent to those skilled in the art, whereby it is to be understood that the foregoing descriptive matter to be implemented is illustrative and non-limiting.

Claims

We Claim:

1. An aperture coupled antenna [100] comprising: at least one of a plurality of patch layers, a feed network and ground layer, and a reflector layer, wherein the patch layer comprises a radiating patch element and the feed network and ground layer comprises an aperture with a cutout; a top metallic cage structure [102] surrounding the radiating patch element; and a bottom metallic cage structure [104] on a bottom side of the feed network and ground layer.

2. The aperture coupled antenna [100] as claimed in claim 1, wherein at least one of the plurality of patch layers are arranged in a stack, the stack comprising the at least one of the plurality of patch layers placed above each other.

3. The aperture coupled antenna [100] as claimed in claim 1, wherein the top metallic cage structure [102] comprises a plurality of electrically conductive walls.

4. The aperture coupled antenna [100] as claimed in claim 1, further comprising a first substrate and a second substrate, the second substrate being arranged over the first substrate, wherein, the patch layer is attached to a bottom portion of the second substrate; a feed network of the feed network and ground layer, is printed on a bottom portion of the first substrate, and a ground layer of the feed network and ground layer is printed on a top portion of the first substrate; and the reflector layer is arranged below the bottom portion of the first substrate.

5. The aperture coupled antenna [100] as claimed in claim 1, wherein the aperture of the feed network and ground layer further is a cross-shaped aperture.

6. The aperture coupled antenna [100] as claimed in claim 5, wherein the cross-shaped aperture is configured to provide electromagnetic coupling between the feed network and ground layer and the radiating patch element.

7. The aperture coupled antenna [100] as claimed in claim 1, wherein the cutout of the aperture of the feed network and ground layer is one of a square-shaped, a circle-shaped, and a diamond-shaped cutout.