WO2020248289A1

WO2020248289A1 - Dielectric resonator antenna and dielectric resonator antenna array

Info

Publication number: WO2020248289A1
Application number: PCT/CN2019/091420
Authority: WO
Inventors: Xin Yin; Yuzhe WEI; Huaicheng ZHAO
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy
Priority date: 2019-06-14
Filing date: 2019-06-14
Publication date: 2020-12-17
Also published as: CN114245954B; CN114245954A

Abstract

Embodiments of the present disclosure relate to a DRA and a DRA array comprising the DRA. The DRA comprises a ground layer and a dielectric resonator disposed on the ground layer. The dielectric resonator comprises at least one hole extending from a top surface of the dielectric resonator towards a bottom surface of the dielectric resonator. At least part of a wall of the hole is covered with a metallic layer. The metallic layer electrically is isolated from the ground layer.

Description

DIELECTRIC RESONATOR ANTENNA AND DIELECTRIC RESONATOR ANTENNA ARRAY

FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to a dielectric resonator antenna (DRA) and a DRA array comprising the DRA.

BACKGROUND

Massive Multi-input Multi-output (mMIMO) antenna array is one of the key components in the fifth generation (5G) mobile communication systems. DRAs have been of immense research interest because of their small size, low profile, high radiation efficiency due to the absence of surface wave losses and the ease of excitation. Thus, the DRAs may be used as antenna elements in the MIMO antenna array.

SUMMARY

In general, example embodiments of the present disclosure provide a DRA and a DRA array comprising the DRA.

In a first aspect, there is provided a DRA. The DRA comprises a ground layer and a dielectric resonator disposed on the ground layer. The dielectric resonator comprises at least one hole extending from a top surface of the dielectric resonator towards a bottom surface of the dielectric resonator. At least part of a wall of the hole is covered with a metallic layer. The metallic layer electrically is isolated from the ground layer.

In some example embodiments, the at least one hole comprises a single hole formed at a center of the top surface of the dielectric resonator.

In some example embodiments, the single hole is formed as a through-hole.

In some example embodiments, the single hole is configured to have a circumference that is in the range of forty percent of an operational wavelength.

In some example embodiments, the metallic layer has a shape of a strip.

In some example embodiments, the strip has a width that is in the range of ten to twenty percent of an operational wavelength.

In some example embodiments, the metallic layer is made from at least one of the following: copper, silver, chromium, and nickel.

In a second aspect, there is provided an antenna array. The antenna array comprises a plurality of dielectric resonator antennas according to the first aspect.

In some example embodiments, the plurality of dielectric resonator antennas at least comprise a first row of dielectric resonator antennas and a second row of dielectric resonator antennas separated by a first distance, any two dielectric resonator antennas in each of the first and second rows of dielectric resonator antennas are separated by a second distance, each of the first and second distances is in the range of forty percent of an operational wavelength.

In some example embodiments, the first distance is equal to half of the operating wavelength and the second distance is equal to seventy percent of the operational wavelength.

In a third aspect, there is provided a communication device. The communication device comprises the antenna array according to the second aspect.

It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described with reference to the accompanying drawings, where:

Fig. 1A illustrates a top view of a conventional DRA array;

Fig. 1B illustrates a perspective view of an antenna element in the conventional DRA array of Fig. 1A;

Fig. 2 illustrates an isopotential profile of electric field distribution of a sub-array of the conventional DRA array of Fig. 1A;

Fig. 3A illustrates a co-polar pattern of the antenna element in the sub-array of Fig. 2;

Fig. 3B illustrates a cross polarization ratio of the antenna element in the sub-array of Fig. 2;

Fig. 4A illustrates a perspective view of a DRA according to some example embodiments of the present disclosure;

Fig. 4B illustrates a sectional view of the DRA of Fig. 4A;

Fig. 5A illustrates a perspective view of a dielectric resonator of a DRA according to some other example embodiments of the present disclosure;

Fig. 5B illustrates a sectional view of the dielectric resonator of Fig. 5A;

Fig. 6A illustrates a perspective view of a dielectric resonator of a DRA according to still other example embodiments of the present disclosure;

Fig. 6B illustrates a sectional view of the dielectric resonator of Fig. 6A;

Fig. 7A illustrates a perspective view of a dielectric resonator of a DRA according to yet other example embodiments of the present disclosure;

Fig. 7B illustrates a sectional view of the dielectric resonator of Fig. 7A;

Fig. 8A illustrates a perspective view of a dielectric resonator of a DRA according to still other example embodiments of the present disclosure;

Fig. 8B illustrates a sectional view of the dielectric resonator of Fig. 8A;

Fig. 9A illustrates a perspective view of an example implementation of a DRA according to some example embodiments of the present disclosure;

Fig. 9B illustrates an exploded perspective view of the DRA of Fig. 9A;

Fig. 10A illustrates a top view of a DRA array according to some example embodiments of the present disclosure;

Fig. 10B illustrates a top view of a sub-array of the DRA array according to some example embodiments of the present disclosure;

Fig. 11 illustrates an isopotential profile of electric field distribution of the sub-array of Fig. 10B;

Fig. 12A illustrates a co-polar pattern of an antenna element in the sub-array of Fig. 10B;

Fig. 12B illustrates a cross polarization ratio of an antenna element in the sub-array of Fig. 10B;

Fig. 13A illustrates a performance comparison diagram in terms of co-polar patterns between an antenna element according to some example embodiments of the present disclosure and a conventional fed antenna element;

Fig. 13B illustrates a performance comparison diagram in terms of cross polarization ratios between an antenna element according to some example embodiments of the present disclosure and a conventional fed antenna element;

Fig. 14A illustrates a radiation pattern of a DRA array according to some example embodiments of the present disclosure at azimuth angle of 0 degree;

Fig. 14B illustrates a radiation pattern of a DRA array according to some example embodiments of the present disclosure at azimuth angle of 60 degree; and

Fig. 14C illustrates a radiation pattern of a DRA array according to some example embodiments of the present disclosure at azimuth angle of -60 degree.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and to help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an example embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) :

(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and

(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile device or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this 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 merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as fifth generation (5G) systems, Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the future fifth generation (5G) new radio (NR) communication protocols, and/or any other protocols either currently known or to be developed in the future. In addition, the term “communication network” may also refer to non-cellular communications network. The communications may include direct device to device communication, e.g. (a) base station node to base station node, or (b) mobile device to mobile device, without any interaction of a mobile device (in case a) or a base station (in case b) . Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

As used herein, the term “communication device” refers to a network device or a terminal device in a communication network. The term “network device” refers to a node in the communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a NR Next Generation NodeB (gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology. An RAN split architecture comprises a gNB-CU (Centralized unit, hosting RRC, SDAP and PDCP) controlling a plurality of gNB-DUs (Distributed unit, hosting RLC, MAC and PHY) .

The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a mobile device, a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , or an Access Terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (e.g., remote surgery) , an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. Although functionalities described herein can be performed, in various example embodiments, in a fixed and/or a wireless network node may, in other example embodiments, functionalities may be implemented in a user equipment apparatus (such as a cell phone or tablet computer or laptop computer or desktop computer or mobile IOT device or fixed IOT device) . This user equipment apparatus can, for example, be furnished with corresponding capabilities as described in connection with the fixed and/or the wireless network node (s) , as appropriate. The user equipment apparatus may be the user equipment and/or or a control device, such as a chipset or processor, configured to control the user equipment when installed therein. Examples of such functionalities include the bootstrapping server function and/or the home subscriber server, which may be implemented in the user equipment apparatus by providing the user equipment apparatus with software configured to cause the user equipment apparatus to perform from the point of view of these functions/nodes.

The term “mobile device” refers to a device capable of being moved from point A to point B by any means, for example and not limited to: by hand, by carrying, by vehicle (driving, flying, sailing/floating in a liquid, etc) , by being worn by a user of the mobile device.

In addition, the term “communication device” may also refer to fixed or stationary electronic communication devices, e.g. base station nodes, which are devices which are fixed in place and do not move.

As mentioned above, because DRAs have lots of advantages such as small size, low profile, and high radiation efficiency, the DRAs may be used as antenna elements in the MIMO antenna array. Fig. 1A illustrates a top view of a conventional DRA array 100. As shown, the DRA array 100 comprises a plurality of rows of antenna elements 102 separated from each other uniformly. Each of the antenna elements 102 comprises a DRA.

Fig. 1B illustrates a perspective view of an antenna element 102 in the conventional DRA array 100 of Fig. 1A. As shown, the antenna element 102 is made of an entire block of dielectric material. The dielectric material has a high dielectric constant. Examples of the dielectric material may comprise one of the following: ceramic, polymer and polymer-ceramic composites.

Fig. 2 illustrates an isopotential profile 200 of electric field distribution of a sub-array of the conventional DRA array 100 of Fig. 1A. In the example as shown in Fig. 2, it is assumed that only the antenna element 102 located at a center of the sub-array is fed with an excitation signal, and the eight antenna elements surrounding the fed antenna element 102 are not fed with the excitation signal. Hereinafter, for ease of discussion, the antenna element 102 located at the center of the sub-array is also referred to as a fed antenna element 102.

As shown, the sub-array comprises three rows of antenna elements 102. A distance between the adjacent antenna elements 102 in a single row or in different rows is small. Typically, the distance is equal to half of an operating wavelength of the excitation signal.

Because the fed antenna element 102 is made of the entire block of dielectric material, an electric field formed by the fed antenna element 102 is substantially uniformly distributed in the fed antenna element 102. In addition, because the distance between the adjacent antenna elements 102 is small, mutual coupling between the adjacent antenna elements 102 is strong. In other words, part of the energy of the electric field formed by the fed antenna element 102 may be easily coupled into the antenna elements surrounding the fed antenna element 102. As shown in Fig. 2, the antenna elements adjacent to the fed antenna element 102 have strong electric field distributions. As a result, spatial distribution of the electric field formed by the fed antenna element 102 is disturbed, and a pattern of the fed antenna element 102 is seriously deteriorated.

Fig. 3A illustrates a co-polar radiation pattern 300 of the fed antenna element 102, and Fig. 3B illustrates a cross polarization ratio 310 of the fed antenna element 102. It can be seen from a curve 305 in Fig. 3A, a gain of the central antenna element 102 has obvious falloff at azimuth angles of ±60 degrees. It can be seen from a curve 315 in Fig. 3B, a cross-polarization ratio of the fed antenna element 102 is poor. Specifically, a cross polarization ratio (CPR) of the fed antenna element 102 at an azimuth angle of ±60 degree is less than 0dB, and the CPR of the fed antenna element 102 at an azimuth angle of 0 degree is only 10dB.

To reduce mutual coupling between the adjacent antenna elements 102, the distance between the adjacent antenna elements 102 may be increased. However, as the distance is increased, a scanning range of an azimuth angle will be reduced. For example, if the distance is increased from half of the operating wavelength to seventy percent of the operating wavelength, the scanning range of the azimuth angle is only about ± 25 degrees, which is less than a scanning range of ±60 degrees required by the 5G mobile communication systems. Thus, conventional DRAs cannot be used in the 5G mobile communication systems.

In order to at least in part solve above and other potential problems, example embodiments of the present disclosure provide an improved DRA. The improved DRA comprises a dielectric resonator disposed on a ground layer. The dielectric resonator comprises at least one hole extending from a top surface of the dielectric resonator towards a bottom surface of the dielectric resonator. At least part of a wall of the hole is covered with a metallic layer. The metallic layer may function as an electric wall to gather around the metallic layer most of energy of an electric field formed by the DRA. Thus, a small amount of the energy is distributed at a periphery of the dielectric resonator. Consequently, an amount of the energy that can be coupled into adjacent DRAs is reduced. As a result, a pattern performance of the DRA may be improved.

Principle and implementations of the present disclosure will be described in detail below with reference to Figs. 4A to 14C. Fig. 4A illustrates a perspective view of a DRA 400 according to some example embodiments of the present disclosure. As shown, the DRA 400 comprises a ground layer 410 and a dielectric resonator 420 disposed on the ground layer 410. The dielectric resonator 420 comprises a hole 422 extending from a top surface of the dielectric resonator 420 towards a bottom surface of the dielectric resonator 420. When the dielectric resonator 420 is attached to the ground layer 410 that the hole 422 extends towards the ground layer 410 when starting from the top layer of the dielectric resonator 420. Part of a wall of the hole 422 is covered with a metallic layer 424.

Fig. 4B illustrates a sectional view of the DRA 400 of Fig. 4A. As shown in Fig. 4B, part of the wall of the hole 422 is covered with the metallic layer 424. In this example the metallic layer 424 is an upper portion of the wall of the hole 422, where the upper portion is adjacent the top surface of the dielectric resonator 420. In other example embodiments the metallic layer 424 may be disposed at other positions on the wall of the hole 422.

The metallic layer 424 may function as an electric wall to gather most of the energy of an electric field formed by the DRA 400 around the metallic layer 424. Thus, a small amount of the energy is distributed at a periphery of the dielectric resonator 420. Consequently, an amount of the energy that can be coupled into adjacent DRAs in a DRA array is reduced. As a result, a pattern performance of the DRAs in the DRA array may be improved, which will be described later with reference to Figs. 11, 12A, 12B, 13A, 13B, 14A and 14B.

As shown in Fig. 4B, the metallic layer 424 is electrically isolated from the ground layer 410. Thus, current generated by the DRA 400 when the DRA 400 is fed with an excitation signal will not flow to the ground layer 410 via the metallic layer 424, and the energy generated by the DRA 400 can be radiated outside. The expression “electrically isolated” means that if a Direct Current (DC) was applied to flow in the ground layer, then it would not also flow in the metallic layer 424 and vice versa. In other words there is no galvanic connection between the metallic layer and any other conductive member or component nearby.

It will be appreciated that although the dielectric resonator 420 is shown in Figs. 4A and 4B as a cylindrical shape by way of example, the dielectric resonator may have any shape that is adapted to radiate energy outside. For example, the dielectric resonator may have a shape of a cuboid or a rectangular solid, as shown in Figs. 5A and 5B. Fig. 5A illustrates a perspective view of a dielectric resonator 520 of a DRA according to some other example embodiments of the present disclosure, and Fig. 5B illustrates a sectional view of the dielectric resonator 520 of Fig. 5A. In this example, the dielectric resonator 520 has a shape of a cuboid. As shown in Figs. 5A and 5B, the dielectric resonator 520 comprises a hole 522 extending from a top surface of the dielectric resonator 520 towards the bottom surface of the dielectric resonator 520, and therefore also towards the ground layer (not shown) when the ground layer is present. Part of a wall of the hole 522 is covered with a metallic layer 524. The metallic layer 524 is electrically isolated from the ground layer.

For another example, the dielectric resonator may have a shape of a circular truncated cone, as shown in Figs. 6A and 6B. Fig. 6A illustrates a perspective view of a dielectric resonator 620 of a DRA according to some other example embodiments of the present disclosure, and Fig. 6B illustrates a sectional view of the dielectric resonator 620 of Fig. 6A. In this example, the dielectric resonator 620 has a shape of a circular truncated cone. As shown in Figs. 6A and 6B, the dielectric resonator 620 comprises a hole 622 extending from a top surface of the dielectric resonator 620 towards a bottom surface of the dielectric resonator 620, and therefore also towards the ground layer (not shown) when the ground layer is present. Part of a wall of the hole 622 is covered with a metallic layer 624. The metallic layer 624 is electrically isolated from the ground layer.

In addition, it will also be appreciated that although a cross section of the hole 422 is shown in Figs. 4A, 4B, 5A and 5B as a cylindrical shape by way of example, the cross section of the hole on the dielectric resonator may have any shape that is adapted to be covered with the metallic layer 424. For example, the cross section of the hole may have a shape of a cross, as shown in Figs. 6A and 6B.

For another example, the cross section of the hole on the dielectric resonator may have a shape of a rectangle, as shown in Figs. 7A and 7B. Fig. 7A illustrates a perspective view of a dielectric resonator 720 of a DRA according to some other example embodiments of the present disclosure, and Fig. 7B illustrates a sectional view of the dielectric resonator 720 of Fig. 7A. In this example, the dielectric resonator 720 comprises a hole 722 extending from a top surface of the dielectric resonator 720 towards a bottom surface of the dielectric resonator 720, and therefore also towards the ground layer (not shown) when the ground layer is present. A cross section of the hole 722 has a shape of a rectangle. Part of a wall of the hole 722 is covered with a metallic layer 724. The metallic layer 724 is electrically isolated from the ground layer.

Further, it will be appreciated that the

holes

422, 522, 622 and 722 are formed as through-holes by way of example. That is, the

holes

422, 522, 622 and 722 extend to bottom surfaces of the

dielectric resonators

420, 520, 620 and 720, respectively. In some other example embodiments of the present disclosure, the hole on the dielectric resonator may not extend to a bottom surface of the dielectric resonator, as shown in Figs. 8A and 8B. Fig. 8A illustrates a perspective view of a dielectric resonator 820 of a DRA according to some other example embodiments of the present disclosure, and Fig. 8B illustrates a sectional view of the dielectric resonator 820 of Fig. 8A. In this example, the dielectric resonator 820 comprises a hole 822 and an entire wall of the hole 822 is covered with a metallic layer 824. The hole 822 does not extend to a bottom surface 826 of the dielectric resonator 820.

Furthermore, it can be seen from Figs. 4A, 5A, 6A, 7A and 8A that each of the

dielectric resonators

420, 520, 620, 720 and 820 comprises a single hole formed at a center of the top surface of the respective dielectric resonator. In this way, the energy generated by each of the

dielectric resonators

420, 520, 620, 720 and 820 can be uniformly distributed around the respective metallic layer. However, in some other example embodiments of the present disclosure, the hole may be offset from the center of the top surface of the respective dielectric resonator.

Moreover, it will be appreciated that although each of the

dielectric resonators

420, 520, 620, 720 and 820 is shown to comprise a single hole, at least one of the

dielectric resonators

420, 520, 620, 720 and 820 may comprise a plurality of holes. In such example embodiments, the plurality of holes may or may not be uniformly distributed on the top surface of the respective dielectric resonator.

In example embodiments where a dielectric resonator of a DRA comprises a single hole, a circumference of the single hole may be in the range of forty percent of an operating wavelength of an excitation signal to the operating wavelength.

In some example embodiments of the present disclosure, at least one of the

metallic layers

424, 524, 624, 724 and 824 may have a shape of a strip. In some example embodiments of the present disclosure, a width of the strip may be in the range of ten to twenty percent of the operating wavelength of the excitation signal.

In some example embodiments of the present disclosure, the metallic strip which is distributed about a midway point between the top and bottom surfaces of the dielectric resonator 420 and having first and second non-metallic portions of the wall above and below the metallic strip. Equally the metallic layer or strip could be closer to the ground layer 410 than the top surface of the dielectric resonator 420.

Because the single hole has a circumference that is less than the operating wavelength of the excitation signal or the strip has a width that is less than the operating wavelength of the excitation signal, the impedance bandwidth of the DRA according to the present disclosure will be substantially the same as that of a conventional DRA.

In some example embodiments of the present disclosure, each of the

metallic layers

424, 524, 624, 724 and 824 may be made from, and not limited to, at least one of the following: copper, silver, chromium, and nickel. It will be appreciated that the

metallic layers

424, 524, 624, 724 and 824 may be formed on the wall of the

holes

422, 522, 622, 722 and 822 by using any known method. For example, in example embodiments where the metallic layer 424 is made from silver, the metallic layer 424 may be formed by coating the wall of the hole 422 with silver. Of course, coating is just one example way for forming the metallic layer without suggesting limiting the scope of the present disclosure thereto, any other appropriate method may be employed.

In some example embodiments, at least one of the

holes

422, 522, 622, 722 and 822 is completely surrounded by the dielectric material provided by the dielectric resonator. In other words, the hole is not a notch or cut-out at the edge of the dielectric resonator.

In some example embodiments, a bottom surface of at least one of the

holes

422, 522, 622, 722 and 822 may be covered with a metallic layer. Thus, the size of the hole is smaller than that of a hole which bottom surface is not covered.

Fig. 9A illustrates a perspective view of an example implementation 900 of a DRA 400 as shown in Fig. 4A. As shown in Fig. 9A, the example implementation 900 comprises the ground layer 410 and the dielectric resonator 420 disposed on the ground layer 410. The ground layer 410 is disposed on a substrate 910. A feeding structure 920 is provided on a bottom surface of the substrate 910. Fig. 9B illustrates an exploded perspective view of the example implementation 900 of Fig. 9A. In the example implementation 900, the feeding structure 920 employs a slot coupling configuration. As shown in Fig. 9B, in the slot coupling configuration,

slots

412 and 414 that cross each other are formed on the ground layer 410. The feeding structure 920 comprises a first feed port 922 and a second feed port 924. The first feed port 922 and the second feed port 924 may receive an excitation signal from an active circuit. The dielectric resonator 420 may be excited through the

slots

412 and 414 in the ground layer 410 by the excitation signal.

It will be appreciated that the slot coupling configuration for the feeding structure 920 has been described by way of example, and the feeding structure 920 may employ other configurations. For example, the feeding structure 920 may employ a microstrip feeding configuration, a coaxial feeding configuration, or a coplanar waveguide feeding configuration.

Fig. 10A illustrates a top view of a DRA array 1000 operating at a centre frequency of 5GHz according to some example embodiments of the present disclosure. As shown, the DRA array 1000 comprises a plurality of rows of antenna elements 1002 separated from each other uniformly. Each of the antenna elements 1002 may comprise a DRA as shown in Fig. 4A, 5A, 6A, 7A or 8A.

In the example as shown in Fig. 10A, a size of a substrate of each antenna element 1002 is 30x42x0.526 (mm) [length x width x height] , a size of the DRA array 1000 is 504x240x0.526 (mm) [length x width x height] . To facilitate assembly, the size of the DRA array 1000 may be increased to 524x270x0.526 (mm) .

Fig. 10B illustrates a top view of a sub-array 1010 of the DRA array 1000 according to some example embodiments of the present disclosure. As shown, the sub-array 1010 comprises three rows of antenna elements 1002. Each of the rows comprises three antenna elements 1002. Adjacent rows of antenna elements 1002 are separated by a first distance D1. Adjacent antenna elements 1002 in each of the rows are separated by a second distance D2. The first distance D1 may or may not be equal to the second distance D2. In some example embodiments of the present disclosure, the first distance D1 is in the range of forty percent of an operating wavelength of an excitation signal to the operating wavelength, and the second distance D2 is in the range of sixty percent of the operating wavelength to the operating wavelength. In some other example embodiments of the present disclosure, the first distance D1 may be equal to half of the operating wavelength of the excitation signal and the second distance D2 may be equal to seventy percent of the operating wavelength.

It will be appreciated that the values of the first and second distances have been described by way of example, the first and second distances have any appropriate values based on the deployment of the DRA array.

Fig. 11 illustrates an isopotential profile 1100 of electric field distribution of the sub-array 1010 of the DRA array 1000 of Fig. 10A. In the example as shown in Fig. 11, it is assumed that only the antenna element 1002 located at a center of the sub-array 1010 is fed with an excitation signal, and the eight antenna elements surrounding the fed antenna element 1002 are not fed with the excitation signal. Hereinafter, for ease of discussion, the antenna element 1002 located at the center of the sub-array 1010 is also referred to as a fed antenna element 1002.

The fed antenna element 1002 (and its neighbouring non-fed elements of the sub-array) can receive electromagnetic energy or signals from another source (e.g. another communications device) via the ether/air, and that the fed antenna element 1002 can transmit electromagnetic energy or signals by coupling the fed antenna element 1002 to a transmitter circuit so that the fed antenna element 1002 and its adjacent non-fed elements together form a radiation pattern for transmission. The “non-fed elements” should be understood as being indirectly fed or parasitically fed by the fed antenna element 1002 using electromagnetic coupling.

As shown in Fig. 11, most of energy of an electric field formed by the fed antenna element 1002 is gathered around the metallic layer of the fed antenna element 1002. Only a small amount of the energy is distributed at a periphery of the fed antenna element 1002. The antenna elements adjacent to the fed antenna element 1002 have weak electric field distributions. As a result, a pattern performance of the fed antenna element 1002 in the sub-array 1010 is improved.

Fig. 12A illustrates a co-polar radiation pattern 1200 of the fed antenna element 1002, and Fig. 12B illustrates a cross polarization ratio 1210 of the fed antenna element 1002. It can be seen from a curve 1205 in Fig. 12A, a gain of the fed antenna element 1002 is about 3dBi at azimuth angles of ±60 degrees. It can be seen from a curve 1215 in Fig. 12B, a CPR of the fed antenna element 1002 is good. Specifically, a CPR of the fed antenna element 1002 at an azimuth angle of ±60 degree is above 14dB and a CPR of the fed antenna element 1002 at azimuth angle of 0 degree is above 19dB.

Fig. 13A illustrates a performance comparison diagram 1300 in terms of co-polar radiation patterns between the fed antenna element 1002 according to the present disclosure and the conventional fed antenna element 102. Fig. 13B illustrates a performance comparison diagram 1310 in terms of cross polarization ratios between the fed antenna element 1002 according to the present disclosure and the conventional fed antenna element 102.

It can be seen from the curve 305 in Fig. 13A that the gain of the fed antenna element 102 has obvious falloff at azimuth angles of ±60 degrees. It can be seen from the curve 1205 in Fig. 13A that the gain of the fed antenna element 1002 is smooth at azimuth angles of ±60 degrees.

It can be seen from the

curves

315 and 1215 in Fig. 13B, the CPRs of the fed antenna element 1002 at azimuth angles of ±60 degrees and 0 degree are greater than those of the fed antenna element 102.

Fig. 14A illustrates a pattern of the DRA array 1000 at azimuth angle of 0 degree, Fig. 14B illustrates a pattern of the DRA array 1000 at azimuth angle of 60 degree, and Fig. 14C illustrates a pattern of the DRA array 1000 at azimuth angle of -60 degree. It can be seen from Figs. 14A, 14B and 14C, the pattern performance of the DRA array 1000 is excellent.

It will be noted that the embodiments of the present disclosure can be implemented in software, hardware, or a combination thereof. The hardware part can be implemented by a special logic; the software part can be stored in a memory and executed by a suitable instruction execution system such as a microprocessor or special purpose hardware. Those skilled in the art would appreciate that the above apparatus and method may be implemented with computer executable instructions and/or in processor-controlled code, and for example, such code is provided on a carrier medium such as a programmable memory or an optical or electronic signal bearer.

As an example, the embodiments of the present disclosure can be described in the context of the machine executable instruction which is included, for example, in a program module executed in a device on a target physical or virtual processor. Generally, the program module includes a routine, program, library, object, class, component, data structure and the like, which executes a particular task or implement a particular abstract data structure. In various embodiments, the functions of the program modules can be merged or split among the program modules described herein. A machine executable instruction for a program module can be executed locally or within a distributed device. In a distributed device, a program module can be located in both of a local and a remote storage medium.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of this disclosure, computer program code or related data can be carried by any appropriate carrier, such as an apparatus, device or processor can execute various processing and operations as described above. The example of the carrier includes a signal, a computer readable medium and the like. The example of the signal may include a signal broadcast electrically, optically, wirelessly, acoustically or in other forms, such as a carrier, an infrared signal and the like.

A computer readable medium may be any tangible medium that may contain, or store a program for use by or in connection with an instruction execution system, apparatus or device. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, although operations of the present methods are described in a particular order in the drawings, it does not require or imply that these operations are necessarily performed according to this particular sequence, or a desired outcome can only be achieved by performing all shown operations. On the contrary, the execution order for the steps as depicted in the flowcharts may be varied. Alternatively, or in addition, some steps may be omitted, a plurality of steps may be merged into one step, or a step may be divided into a plurality of steps for execution. It would be appreciated that features and functions of two or more devices according to the present disclosure can be implemented in combination in a single implementation. Conversely, various features and functions that are described in the context of a single implementation may also be implemented in multiple devices.

Although the present disclosure has been described with reference to various embodiments, it should be understood that the present disclosure is not limited to the disclosed example embodiments. The present disclosure is intended to cover various modifications and equivalent arrangements included in the spirit and scope of the appended claims.

Claims

A dielectric resonator antenna, comprising:

a ground layer; and

a dielectric resonator disposed on the ground layer, the dielectric resonator comprising at least one hole extending from a top surface of the dielectric resonator towards a bottom surface of the dielectric resonator, at least part of a wall of the hole covered with a metallic layer, the metallic layer electrically isolated from the ground layer.
The dielectric resonator antenna of Claim 1, wherein the at least one hole comprises a single hole formed at a center of the top surface of the dielectric resonator.
The dielectric resonator antenna of Claim 2, wherein the single hole is formed as a through-hole.
The dielectric resonator antenna of Claim 2, wherein the single hole is configured to have a circumference that is in the range of forty percent of an operational wavelength.
The dielectric resonator antenna of Claim 1, wherein the metallic layer has a shape of a strip.
The dielectric resonator antenna of Claim 5, wherein the strip has a width that is in the range of ten to twenty percent of an operational wavelength.
The dielectric resonator antenna of Claim 1, wherein the metallic layer is made from at least one of the following: copper, silver, chromium, and nickel.
A dielectric resonator antenna array, comprising:

a plurality of dielectric resonator antennas of any of Claims 1 to 7.
The dielectric resonator antenna array of Claim 8, wherein the plurality of dielectric resonator antennas at least comprise a first row of dielectric resonator antennas and a second row of dielectric resonator antennas separated by a first distance, any two dielectric resonator antennas in each of the first and second rows of dielectric resonator antennas are separated by a second distance, each of the first and second distances is in the range of forty percent of an operational wavelength of an excitation signal to the operational wavelength.
The dielectric resonator antenna array of Claim 9, wherein the first distance is equal to half of the operational wavelength and the second distance is equal to seventy percent of the operational wavelength.
A communication device, comprising the dielectric resonator antenna array of any of Claims 8 to 10.