CN107968264B

CN107968264B - Polygonal loop antenna, communication device, and antenna manufacturing method

Info

Publication number: CN107968264B
Application number: CN201610915923.9A
Authority: CN
Inventors: 高飞; 陆金星; 沈钢
Original assignee: Nokia Shanghai Bell Co Ltd
Current assignee: Nokia Shanghai Bell Co Ltd
Priority date: 2016-10-20
Filing date: 2016-10-20
Publication date: 2020-07-31
Anticipated expiration: 2036-10-20
Also published as: CN107968264A; WO2018073650A1

Abstract

Embodiments of the present disclosure relate to a polygonal loop antenna, and a communication device and an antenna manufacturing method. For example, a polygonal loop antenna, comprising: a radiating device including a plurality of radiating elements, each of the radiating elements constituting one side of the antenna; a plurality of capacitive devices, an even number of the capacitive devices being disposed on each side of the antenna; and a plurality of feeding elements, one feeding element being arranged between two adjacent capacitive elements on each side of the antenna. Corresponding communication devices and antenna manufacturing methods are also disclosed.

Description

Polygonal loop antenna, communication device, and antenna manufacturing method

Technical Field

Embodiments of the present disclosure relate generally to communication technology and, more particularly, relate to polygonal loop antennas and corresponding communication devices and antenna manufacturing methods.

Background

In 4G-Long term evolution (L TE) wireless communications, Multiple Input Multiple Output (MIMO) techniques have been used to provide large channel capacity in MIMO systems, wireless communication system performance is improved by using antenna diversity, such as widely used polarization diversity.

However, the effect of pattern diversity on capacity improvement is closely related to the radio environment. The effect of directional antennas on capacity improvement is less pronounced when the radio environment is poor, e.g., the signal-to-noise ratio (SNR) is low. At present, Reconfigurable Antennas (RA) with pattern diversity have received much attention in standardization work for 5G systems, but RA suitable for MIMO systems have not been designed. The use of directional patterns RA to improve the accuracy of the positioning system is also proposed for indoor positioning scenarios. However, RA used in RSS based positioning systems is typically large and difficult to integrate into MIMO antenna arrays.

Disclosure of Invention

In general, embodiments of the present disclosure propose polygonal loop antennas and corresponding communication devices and antenna manufacturing methods.

In a first aspect, embodiments of the present disclosure provide a polygonal loop antenna. The antenna includes: a radiating device including a plurality of radiating elements, each of the radiating elements constituting one side of the antenna; a plurality of capacitive devices, an even number of the capacitive devices being disposed on each side of the antenna; and a plurality of feed elements, one of said feed elements being disposed between two adjacent capacitive elements on each side of said antenna.

In a second aspect, embodiments of the present disclosure provide a communication device comprising at least one antenna according to the first aspect.

In a third aspect, embodiments of the present disclosure provide a method of manufacturing an antenna according to the first aspect.

As will be understood from the following description, a polygonal loop antenna structure is provided according to an embodiment of the present disclosure. Each side of the antenna is formed by a radiating element, an even number of capacitive elements are arranged on the side, and a feed element is arranged between two adjacent capacitive elements. Compared with the traditional antenna, the polygonal loop antenna disclosed by the embodiment of the disclosure has the advantages of smaller size and thickness, wider working bandwidth and capability of generating more radiation states. Moreover, the feed network of the polygonal loop antenna is simple and easy to manufacture.

It should be understood that the statements herein reciting aspects are not intended to limit the critical or essential features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become apparent from the following description.

Drawings

The above and other features, advantages and aspects of various embodiments of the present disclosure will become more apparent by referring to the following detailed description when taken in conjunction with the accompanying drawings. In the drawings, like or similar reference characters designate like or similar elements, and wherein:

FIG. 1 shows a perspective view of a common aperture antenna having two radiating states;

fig. 2(a), 2(b) and 2(c) show top, side and bottom views of such an antenna;

FIG. 3 shows a perspective view of a square loop antenna (S L A) loaded with a Hybrid High Impedance Surface (HHIS);

fig. 4 shows a perspective view of S L a with capacitive coupling;

fig. 5(a) and 5(b) show perspective and top views of a polygonal loop antenna according to certain other embodiments of the present disclosure;

FIG. 6 illustrates a reflection coefficient curve for an antenna according to the present disclosure;

figure 7 illustrates a three-dimensional radiation pattern of an antenna according to certain embodiments of the present disclosure;

figures 8(a) and 8(b) illustrate two-dimensional radiation patterns of antennas according to certain embodiments of the present disclosure;

figure 9 illustrates the co-polarized and cross-polarized components of the radiation patterns of an antenna according to some embodiments of the present disclosure in the vertical plane;

10(a) to 10(D) show 3D radiation patterns of an antenna according to certain embodiments of the present disclosure for four antenna configurations; and

fig. 11 illustrates a block diagram of a communication device, in accordance with certain embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numbers refer to the same or similar elements.

Detailed Description

Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While certain embodiments of the present disclosure are shown in the drawings, it is to be understood that the present disclosure may be embodied in various forms and should not be construed as limited to the embodiments set forth herein, but rather are provided for a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the disclosure are for illustration purposes only and are not intended to limit the scope of the disclosure.

The term "communication device" as used herein refers to a device having the capability to transceive radio signals in a wireless communication network. Examples of the communication device include a network device and a terminal device.

The term "network device" as used herein refers to a base station or other entity or node having a particular function in a communication network. A "base station" (BS) may represent a node B (NodeB or NB), an evolved node B (eNodeB or eNB), a Remote Radio Unit (RRU), a Radio Head (RH), a Remote Radio Head (RRH), a relay, or a low power node such as a pico base station, a femto base station, or the like. In the context of the present disclosure, the terms "network device" and "base station" may be used interchangeably for purposes of discussion convenience, and may primarily be referred to as an eNB as an example of a network device.

The term "terminal equipment" or "user equipment" (UE) as used herein refers to any terminal equipment capable of wireless communication with a base station or with each other. As an example, the terminal device may include a Mobile Terminal (MT), a Subscriber Station (SS), a Portable Subscriber Station (PSS), a Mobile Station (MS), or an Access Terminal (AT), and the above-described devices in a vehicle. In the context of the present disclosure, the terms "terminal device" and "user equipment" may be used interchangeably for purposes of discussion convenience.

The terms "include" and variations thereof as used herein are inclusive and open-ended, i.e., "including but not limited to. The term "based on" is "based, at least in part, on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment". Relevant definitions for other terms will be given in the following description.

As described above, Reconfigurable Antennas (RA) with pattern diversity have received much attention in the standardization work of 5G systems. However, existing antenna solutions have the disadvantages of low gain, narrow bandwidth, large and complex three-dimensional (3D) structure, and the like. This limits the performance of the MIMO antenna array. MIMO antennas require RA as a basic element to be small enough.

In addition, it is also proposed to use the directional diagram RA to improve the accuracy of a positioning system using Received Signal Strength (RSS) for indoor positioning scenarios. RSS based methods are more feasible than, for example, time of arrival (TOA), time difference of arrival (TDOA), and angle of arrival (AOA) based methods. On the one hand, such an approach can take advantage of existing wireless infrastructure, which can reduce capital expenditure (CAPEX). On the other hand, current standard commercial radio technologies such as Wi-Fi, ZigBee, active Radio Frequency Identification (RFID), bluetooth, etc. all provide RSS measurements, and thus the same algorithm for RSS measurements can be applied across different system platforms. However, there are complex multipath effects in unpredictable indoor environments, including shadowing (e.g., signals are blocked), reflection (e.g., radio waves bounce off objects), diffraction (e.g., radio waves spread out when encountering obstacles), and refraction (e.g., radio waves bend when passing through different media), among others. Due to these effects, the RSS measurements may decay in an unpredictable manner. The use of pattern RA can improve the accuracy of RSS based positioning systems. However, as mentioned above, RA used in RSS based positioning systems is typically large and difficult to integrate into MIMO antenna arrays. In this case, it is necessary to design an efficient antenna arrangement having a small size and thickness and a large bandwidth so as to be applicable to a MIMO system.

A method of increasing the operating bandwidth without increasing the size of the antenna has been proposed. Fig. 1, 2(a), 2(b), and 2(c) show perspective, top, side, and bottom views, respectively, of an exemplary antenna 100 designed in this way. As shown in fig. 1, antenna 100 includes a circular radiating patch 110, a ground dielectric plate 120, and a feed patch 130. In this example, the thickness H of the media sheet 120 is 3.7mm, which may be selected to be RogersRT @

5880(tm) dielectric slab. Dielectric sheet 120The electrical constant was 2.2 and the dielectric loss angle was 0.0009. Feed tab 130 is connected to feed probe 140 at a distance hl from radiating tab 110. Five support posts 150-1 to 150-5 (collectively referred to as support posts 150) are disposed around the feed tab 130 and the feed probe 140.

As shown in fig. 2(c), the support post 150-1 is grounded via two coupling capacitors 210. Support posts 150-2 through 150-5 may be grounded through PIN diodes 220, or the four support posts may not be grounded. A Direct Current (DC) control signal may be fed through the support post 150-1 after passing through the radio frequency choke 230, as shown in fig. 2 (b). Accordingly, a direct current path is formed from the support post 150-1 through the radiation sheet 110 to the remaining support posts 150-2 to 150-5. By this antenna arrangement two radiation states, a broadside radiation pattern and a cone radiation pattern, can be obtained.

In addition, for beam adaptive applications, a square loop antenna (S L a) is proposed, S L a typically has four feed points, which when sequentially excited by a single feed point, can direct the beam to four different spatial quadrants in sequence, thereby producing four radiation states, however, this antenna suffers from three major drawbacks that (a) it is too thick at a quarter wavelength, (b) it has a limited bandwidth, and (c) the radiation pattern has strong side lobes.

One approach is to load a Hybrid High Impedance Surface (HHIS) on S L A. FIG. 3 shows a perspective view of an example S L A300 with HHIS loaded As shown, S L A300 has feed

points

305, 310, 315, and 320 respectively arranged on four sides₀/13.6. However, such a design is complex to implement. For example, it may be desirable to make a plurality of holes, as shown. This wastes a lot of manpower and material costs. In addition, the size of the antenna is still large.

FIG. 4 shows another S L A400, which uses capacitive coupling, as shown, the four sides of S L A400 have a length of l_lThe length of the dielectric slab is L. one

feed

405, 410, 415 and 420 is arranged on each sideAt the

feed

405, 410, 415 or 420, a rectangular metal patch is arranged with a width l_plThickness of w_pl. Each metal patch forms a width w with the antenna_lThereby achieving capacitive coupling. In addition, an opening is disposed on each side of the antenna 400, having a width g_l. This arrangement can significantly reduce the thickness of the antenna and is relatively simple to implement. However, in such an antenna arrangement, each metal patch forms a single resonance with the corresponding antenna aperture, resulting in a certain loss of operating bandwidth.

To address these and other potential problems, embodiments of the present disclosure provide a polygonal loop antenna with each side of the antenna being formed by one radiating element. An even number of capacitive elements are arranged on each side of the antenna and a feed unit is arranged between two adjacent capacitive elements. The polygonal-loop antenna according to the embodiments of the present disclosure is smaller in size and thickness and wider in bandwidth, and is capable of forming more adaptive radiation beams, compared to a conventional antenna.

The principles and specific embodiments of the present disclosure will be described in detail below with reference to fig. 5(a) and 5(b), which show perspective and top views, respectively, of an exemplary polygonal-shaped loop antenna 500 according to some embodiments of the present disclosure.

In this example, antenna 500 is implemented as a quad loop antenna, i.e., S L A. however, it should be understood that this is for exemplary purposes only in other embodiments, antenna 500 may have any other suitable number of sides.

As shown, antenna 500 includes a radiating element 505 that includes four radiating elements 510-1, 510-2, 510-3, and 510-4 (collectively radiating elements 510). The antenna 500 may radiate the received feeding signal through the radiation device 505. As will be described further below. In this example, each radiating element 510 is implemented as a metal conductive strip for implementing the corresponding radiating function. Example lengths l of the metal conductive strips, as shown in FIG. 5(b)_a40mm, example width w_aTypically, the resonant frequency of S L a is inversely proportional to its average circumferential length, thus the average circumference of the antenna 500 in this example is 4 × (l)_a-w_a) 153.6mm, a resonant frequency of about 3.5GHz is generated, thus, the 3.4-3.6 GHz band requirement of L TE system can be satisfied.

The antenna 500 also includes a plurality of capacitive devices 520-1 through 520-8 (collectively capacitive devices 520). In this example, two capacitive devices are arranged on each side. It should be understood that this is by way of example only and not by way of limitation. Any suitable even number of capacitive devices may be arranged on each side of the antenna. For example, in some embodiments, four capacitive devices 520 may be disposed on each side.

Capacitive device 520 may be implemented as any suitable capacitive device now known or later developed in accordance with embodiments of the present disclosure. In this example, as shown in FIG. 5(b), the capacitive element 520 is an interdigital capacitor having a length l_f4mm, finger width w_f0.3mm, and a spacing g_f＝0.2mm。

The capacitive devices 520 must be arranged on each side of the antenna 500 in a manner that does not reduce the radiation efficiency, which in this embodiment should be as close as possible to the feed port. In order to further reduce the thickness of the antenna, it is possible to adjust the loading capacity and the position thereof, but at the same time the operating bandwidth or the radiation efficiency of the antenna is affected. In some embodiments, the capacitive devices 520-1 and 520-2 are embedded in corresponding conductive metal strips (i.e., the radiating element 510-1).

According to an embodiment of the present disclosure, the antenna 500 further includes a plurality of feeding elements 530-1, 530-2, 530-3, and 530-4 (collectively referred to as feeding elements 530). On each side of the antenna 500, a feed element 530 is arranged between two adjacent capacitive elements 520. In this example, each feed element 530 includes feed probes 540-1, 540-2, 540-3, and 540-4 (collectively referred to as feed probes 540). The size of the feeding probe 540 can be designed according to actual needs. In this example, the diameter of the feed probe 540 is 1.3 mm.

As shown, feed probe 540 contacts radiating element 510 at corresponding feed points 550-1, 550-2, 550-3, and 550-4 (collectively feed points 550). The feeding probe 540 is used to receive a feeding signal. Then, as described above, the feed signal is radiated by the radiation device 505.

Similar to conventional S L A, one feed probe (e.g., feed probe 540-1) may be sequentially fed while the other feed probes (e.g., feed probes 540-2, 540-3, and 540-4) are left open to control the generation of multiple tilted beams, thereby forming multiple radiation states.

To further enhance the performance of the antenna, in some embodiments, the capacitive devices 520 may be symmetrically placed on either side of the respective feed point 550. The pitch of the capacitive devices 520 may be designed according to actual needs. In this example, the spacing between two adjacent capacitive devices 520 is 4 mm.

The antenna 500 further includes a hexagonal dielectric plate 560. in this example, three layers of laminate material are used for the dielectric plate 560, for example, Taconic RF-60(tm) laminate material may be used, the total thickness of the dielectric plate 560 is 5.4mm, and the side length L is 80 mm.

According to embodiments of the present disclosure, a method of reducing the size and thickness of conventional antennas and increasing the operating bandwidth is provided. The proposed antenna may be, for example, a common aperture reconfigurable antenna, the size of which is smaller compared to a reconfigurable antenna based on the selection of individual subelements. The thickness of the film is approximately 0.063 lambda at 3.5GHz₀The thickness of the conventional antenna 300 shown in fig. 3 (e.g., 0.074 λ)₀) Thinner, as compared to the thickness of the antenna shown in FIG. 4 (0.045 λ)₀) But is slightly thicker but can achieve 3 times the bandwidth of the structure shown in figure 4. The size and thickness are closely related to the cost and compactness of the antenna. Reduction of size and thicknessEnabling MIMO antenna arrays to take advantage of this RA while still having a compact structure for the overall system. Due to small size and thickness, large bandwidth and high configurability, such antennas can be used for MIMO and positioning in 5G systems.

The Radio Frequency (RF) performance of the polygonal-loop antenna according to the embodiments of the present disclosure is explained below with reference to fig. 6 to 10. The RF performance shown is that of antenna 500 when feed point 530-1 is energized, which is based on Ansoft HFSS analysis and simulation.

Fig. 6 shows a reflection coefficient curve 600 for the antenna 500. Curve 600 is obtained using a 50 Ω internal resistance of the generator. As shown in the figure, the reflection coefficient reaches the standard of below-10 dB in the frequency band range of 3.35-3.90. Particularly, the reflection coefficient is below-15 dB in the frequency band range of 3.4-3.79 GHz. The bandwidths of these two bands account for 15.2% and 10.8% of the total band, respectively. The operating bandwidth of the antenna 500 is significantly increased compared to conventional antennas. In addition, the introduction of interdigital capacitors enables two adjacent resonance frequency points to be generated, so that the thickness of the antenna is reduced, and meanwhile, the working bandwidth of the antenna is increased.

Fig. 7, 8(a) and 8(b) show the radiation patterns of antenna 500, with fig. 7 showing 3D radiation pattern 700 and fig. 8(a) and 8(b) showing two-dimensional (2D) radiation patterns 810 and 820 of antenna 500. Patterns 700 and 800 were measured with 3.5GHz as the center frequency point.

As shown in fig. 7, the antenna 500 produces a radiation pattern that is tilted in one quadrant. When feed point 530-1 is excited while keeping the other feed points 530-2, 530-3, and 530-4 open, the radiation direction of antenna 500 is opposite to the excited feed point 530-1. The 2D pattern 810 shown in fig. 8(a) is obtained by cutting the 3D pattern 700 at 180 °. As shown, the peak point is oriented at 43 ° and 180 °. The antenna 500 has a maximum realized gain of 7.7dBi in the direction of the maximum radiation field.

Fig. 9 shows a homopolar component 910 and a cross-polar component 920 of the radiation pattern of the antenna 500 in the vertical plane. The main lobe is linearly polarized in the E θ direction due to the current in the linear direction. Because of this, the cross-polarization components have a very low magnitude as shown, and are therefore not visible when the pattern is cut vertically. The pattern exhibits cross-polarization components when cut azimuthally. The cross-polarized component is 11dB less than the co-polarized component, which is superior to conventional antennas. In addition, there are no cross-polarization side lobes in the direction of the co-polarized main lobe. The main beam has a half-power azimuth beamwidth of about 60. In the case where the antenna 500 has capacitive devices symmetrically loaded on both sides of each of the feed points 530-1 to 530-4, the resulting radiation pattern when the other feed points 530-2, 530-3, and 530-4 are excited is the same as the radiation pattern when one feed point 530-1 is excited.

Fig. 10(a) to 10(D) show the 3D radiation patterns of the antenna 500 for four antenna configurations

In the configuration shown in FIG. 10(a), θ_max＝42°，φ _max180 °; in FIG. 10(b), θ_max＝42°，φ_max270 °; in FIG. 10(c), θ_max＝42°，φ_max360 °; in FIG. 10(d), θ_max＝42°，φ_max90 ° is set. Therefore, the four configurations radiate inclined beams in different space quadrants, and the directional diagram reconfigurable antenna is realized.

Fig. 11 illustrates a block diagram of a communication device 1100 suitable for implementing embodiments of the present disclosure. As shown, the communication device 1100 includes a controller 1110. The controller 1110 controls the operation and functions of the communication device 1100. For example, in certain embodiments, the controller 1110 may perform various operations by way of instructions 1130 stored in memory 1120 coupled thereto. The memory 1120 may be of any suitable type suitable to the local technical environment and may be implemented using any suitable data storage technology, including but not limited to semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems. Although only one memory unit is shown in fig. 11, there may be multiple physically distinct memory units in the communication device 1100.

The controller 1110 may be of any suitable type suitable to the local technical environment and may include, but is not limited to, one or more of general purpose computers, special purpose computers, microcontrollers, digital signal controllers (DSPs), and controller-based multi-core controller architectures. The communication device 1100 may also include a plurality of controllers 1110. The controller 1110 is coupled to a transceiver 1140, which transceiver 1140 transmits and receives radio signals via one or more antennas 1150. All of the features described above with reference to fig. 5 and 10 apply to the antenna 1150 and are not described in detail herein.

In general, the various example embodiments of this disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Certain aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While aspects of embodiments of the disclosure have been illustrated or described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that the blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

By way of example, embodiments of the disclosure may be described in the context of machine-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various embodiments, the functionality of the program modules may be combined or divided between program modules as described. Machine-executable instructions for program modules may be executed within local or distributed devices. In a distributed facility, program modules may be located in both local and remote memory storage media.

Computer program code for implementing the methods of the present disclosure may be written in one or more programming languages. These computer program codes 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 computer or other programmable data processing apparatus, cause the functions/acts specified in the flowchart and/or block diagram block or blocks to be performed. The program code may execute entirely on the computer, partly on the computer, as a stand-alone software package, partly on the computer and partly on a remote computer or entirely on the remote computer or server.

In the context of this disclosure, a machine-readable medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. More detailed examples of a machine-readable storage medium 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 storage device, a magnetic storage device, or any suitable combination thereof.

Additionally, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In some cases, multitasking or parallel processing may be beneficial. Likewise, while the above discussion contains certain specific implementation details, this should not be construed as limiting the scope of any invention or claims, but rather as describing particular embodiments that may be directed to particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A polygonal-shaped loop antenna comprising:

a radiation device including a plurality of radiation elements, each of the radiation elements constituting one side of the radiation device;

a plurality of capacitive devices, an even number of the capacitive devices being disposed on each side of the radiating device; and

a plurality of feed elements, one of the feed elements being disposed between two adjacent capacitive elements on each side of the radiating element.

2. The antenna of claim 1, wherein the feeding unit comprises:

a feed probe for receiving a feed signal and contacting the radiating element at a feed point.

3. An antenna according to claim 2, wherein said two adjacent capacitive devices are symmetrically arranged on either side of said feed point.

4. The antenna of claim 1, further comprising:

and an included angle formed between two adjacent radiation units is opposite to one edge of the medium plate.

5. The antenna of claim 1, wherein the radiating element comprises a metal conductive strip.

6. The antenna of claim 5, wherein the capacitive device is embedded in the metal conductive strip.

7. The antenna of claim 1, wherein the capacitive device comprises an interdigital capacitor.

8. A communication device comprising at least one antenna according to any one of claims 1 to 7.