Antenna device having a radiating loop

Abstract

An antenna device includes a first radiating structure operating in a first frequency band. The antenna device also includes a second radiating structure operating in a second frequency band. The second radiating structure includes a radiating loop formed along a closed line, wherein the radiating loop is made into a coil extending along the closed line and is electrically invisible in the first frequency band. The antenna device exhibits improved mutual electrical invisibility (or transparency), wherein even when the first radiating structure operating in the first frequency band and the second radiating structure operating in the second frequency band are placed near each other, the second radiating structure operating in the second frequency band does not affect the performance of the first radiating structure operating in the first frequency band.

Description

Technical Field

[0001] The present disclosure relates generally to the field of telecommunication devices, and more particularly to antenna devices having a radiating loop. Background Art

[0002] With the development of new wireless communication technologies, such as the fifth generation (5G) or the upcoming 6G communication technology, there is an increasing demand for the development of antenna equipment for reliable communication. One of the key technologies to achieve the new generation of mobile communications is massive multiple-input and multiple-output (m MIMO), such as below 6 gigahertz (GHz). In general, new deployments of antenna equipment in telecommunications infrastructure still face many challenges, including local regulations. For example, there are restrictions related to the size of a given antenna that can be deployed. In order to facilitate activities related to telecommunications services (such as site acquisition and / or reuse of existing mechanical support structures at the site), it is expected that the size and wind load of any newly deployed antenna should be comparable to traditional products. To address these challenges, more radiating structures or antenna arrays need to be integrated under the same radome and share the same area. Among many technical strategies, one of the key points to meet these requirements is that the radiating structures designed for two or more frequency bands, such as low-band (LB) and high-band (HB), should be electrically invisible or transparent to each other when operating in an antenna device (or array). However, conventional antenna devices have technical problems with electrical visibility, and when radiating elements of one frequency band are placed near other radiating elements of different frequency bands, the performance of at least one radiating element will be affected. For example, when a low-frequency antenna array is overlaid on a high-frequency antenna array, the radiation generated by the high-frequency antenna array tends to be distorted. In addition, the electromagnetic field will be reflected or re-radiated by the low-frequency antenna array in an unwanted manner, which reduces the directivity of the high-frequency antenna array, increases the side lobe value, reduces the front-to-back ratio, and deteriorates the cross-polar discrimination value, etc., which are all undesirable situations.

[0003] In view of this, there is a need to overcome the above-mentioned disadvantages associated with conventional antenna devices, such as dual-band or multi-band antenna devices. Summary of the invention

[0004] The present disclosure seeks to provide an antenna device having a radiating loop. The present disclosure seeks to provide a solution to the existing problem, namely, how to achieve mutual electrical invisibility or transparency of radiating structures operating in different frequency bands on a conventional antenna device without degrading performance. The purpose of the present disclosure is to provide a solution that at least partially overcomes the problems encountered in the prior art and to provide an improved antenna device compared to a conventional antenna device, wherein the electrical invisibility or mutual transparency between two radiating structures operating in at least two different frequency bands is improved.

[0005] The objects of the present disclosure are achieved by the solutions provided in the attached independent claims. Advantageous embodiments of the present disclosure are further defined in the dependent claims.

[0006] In one aspect, the present disclosure provides an antenna device. The antenna device includes a first radiating structure operating in a first frequency band and a second radiating structure operating in a second frequency band. The second radiating structure includes a radiating loop formed along a closed line, wherein the radiating loop is made into a coil extending along the closed line and electrically invisible in the first frequency band.

[0007] The antenna device of the present disclosure exhibits improved mutual invisibility (or transparency), wherein even when a first radiating structure operating in a first frequency band and a second radiating structure operating in a second frequency band are placed near each other, the second radiating structure operating in the second frequency band does not affect the performance of the first radiating structure operating in the first frequency band. Electrical invisibility between the two radiating structures is achieved due to a radiating loop. The radiating loop is made into a coil so that an inductance distributed along the radiating loop is introduced. This inductance changes the impedance of the radiating loop, thereby reducing the amount of scattered fields (for example, the scattered fields are less than -50 dB). In other words, the radiating loop maintains its characteristics at a desired frequency (i.e., in the lower second frequency band) while being transparent (i.e., not reflecting radiation or energy) to another frequency band (e.g., the higher first frequency band).

[0008] In an implementation, the radiation loop is arranged on a circumference of the second radiation structure.

[0009] Since the radiation loop is arranged on the circumference of the second radiation structure, the radiation loop occupies a larger area on the second radiation structure, thereby increasing the inductance distributed along the radiation loop on the circumference and achieving the effect of increasing the bandwidth of the second radiation structure.

[0010] In another implementation, the radiating loop is substantially square in top view.

[0011] The shape of the radiating loop determines the amount of inductance introduced, and the response of the inductance varies with frequency, which helps to reduce the amount of scattered fields, thereby improving the electrical invisibility between radiating structures. Typically, when current passes through a traditional coil, the individual turns of the wire can generate magnetic fields, which pass through the center of the coil and add (i.e., superimpose) to produce a strong field. However, in the antenna device of the present disclosure, when the coil shape is square, any potential magnetic fields are canceled by superposition.

[0012] In another implementation, the second frequency band is lower than the first frequency band.

[0013] Typically, the use of different frequency bands can directly affect the size of the radiating structure, the placement of the radiating structure, and thus the overall size and complexity of the conventional antenna device. Beneficially, the antenna device of the present disclosure exhibits improved mutual invisibility, wherein even when a first radiating structure operating in a higher frequency band and a second radiating structure operating in a lower frequency band are placed near each other, the second radiating structure operating in the lower frequency band does not affect the performance of the first radiating structure operating in the higher frequency band.

[0014] In another implementation, the second radiating structure overlaps the first radiating structure in a plan view.

[0015] Since the first radiation structure overlaps with the second radiation structure, the architecture of the antenna device is very compact.

[0016] In another implementation, the coil includes conductive tracks printed on different layers of a printed circuit board and connected to each other by vias.

[0017] By using conductive tracks printed on different layers of a printed circuit board (PCB), it is easier to etch and define the width, spacing and length of the coils that define the radiating loops.

[0018] In another implementation, the coil comprises a metal strip printed on a plastic bearing element.

[0019] By using metal strips printed on a plastic support element, manufacturing complexity, maintenance costs and overall costs of the antenna device are reduced.

[0020] In another implementation, the first radiation structure is arranged on the lower plane of the support structure at a first distance from the reflector, and the second radiation structure is arranged on the upper plane of the support structure at a second distance from the lower plane.

[0021] Arranging the first radiating structure and the second radiating structure at a first distance and a second distance from the lower plane enables the antenna device to radiate electromagnetic signals in multiple frequency bands with reduced interference, wherein the use of the radiating loop makes the interference almost negligible.

[0022] It should be noted that all devices, elements, circuits, units and modules described in this application can be implemented in software or hardware elements or any type of combination thereof. All steps performed by various entities described in this application and the functions to be performed by various entities described are intended to refer to the corresponding entities for performing the corresponding steps and functions. Although in the description of the following specific embodiments, the specific functions or steps performed by external entities are not reflected in the description of the specific detailed elements of the entity performing the specific steps or functions, it should be clear to the technician that these methods and functions can be realized by corresponding hardware or software elements or any combination thereof. It is understandable that, without departing from the scope of the present disclosure defined by the appended claims, the features of the present disclosure are easy to be combined in various combinations.

[0023] Additional aspects, advantages, features and objects of the present disclosure will become apparent from the accompanying drawings and detailed description of illustrative embodiments which are interpreted in conjunction with the following appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] When read in conjunction with the accompanying drawings, the above summary of the invention and the following specific implementation of the illustrative embodiments can be better understood. In order to illustrate the present disclosure, the exemplary structure of the present disclosure is shown in the accompanying drawings. However, the present disclosure is not limited to the specific methods and tools disclosed herein. In addition, it should be understood by those skilled in the art that the drawings are not drawn to scale. Where possible, the same elements are represented by the same numbers.

[0025] Embodiments of the present disclosure will now be described by way of example only with reference to the following drawings, in which:

[0026] Figure 1A is a side view of an exemplary arrangement of a first radiating structure relative to a second radiating structure in an antenna device according to an embodiment of the present disclosure;

[0027] Figure 1B is a top view of an exemplary arrangement of a first radiating structure relative to a second radiating structure in an antenna device according to an embodiment of the present disclosure;

[0028] Figure 1C is a diagram of a portion of an antenna device according to an embodiment of the present disclosure;

[0029] Figure 1D According to the embodiment of the present disclosure Figure 1C Illustration of a square radiating loop of an antenna device in FIG.

[0030] Figure 1E is a diagram of a portion of an antenna device having a close-up view of a radiating loop according to another embodiment of the present disclosure;

[0031] Figure 1F is a diagram of a radiating loop of a coil made with conductive tracks and through holes according to another embodiment of the present disclosure;

[0032] Figure 2A is an illustration of a radiating loop having a metal strip printed on a plastic support element according to an embodiment of the present disclosure;

[0033] Figure 2B According to another embodiment of the present disclosure Figure 2A A top view of the radiating loop in ;

[0034] Figure 2C According to another embodiment of the present disclosure Figure 2A Bottom view of the radiating loop in;

[0035] Figure 2D According to another embodiment of the present disclosure Figure 2A A side view of the radiating loop in;

[0036] Figure 3 To illustrate a graphical representation of a scattering analysis of an antenna device according to an embodiment of the present disclosure;

[0037] Figure 4 A graphical representation of a radiation pattern for describing an antenna device according to an embodiment of the present disclosure; and

[0038] Figure 5 FIG. 4 is a graphical representation of a scattered field value relative to an operating frequency for describing an antenna device according to an embodiment of the present disclosure.

[0039] In the drawings, underlined numbers are used to indicate the item in which the underlined number is located or an item adjacent to the underlined number. Non-underlined numbers are associated with the item identified by the line that associates the non-underlined number with the item. When a number is not underlined and has an associated arrow, the non-underlined number is used to identify the general item that the arrow points to. DETAILED DESCRIPTION

[0040] The following detailed description describes embodiments of the present disclosure and the manner in which these embodiments may be implemented. Although some modes of implementing the present disclosure have been disclosed, those skilled in the art will recognize that there may be other embodiments for implementing or practicing the present disclosure.

[0041] Figure 1A is a side view of an exemplary arrangement of the first radiating structure 102 and the second radiating structure 104 in the antenna device 100. Figure 1A , shows a side view of a first radiating structure 102 on a first substrate 108 and a second radiating structure 104 with a radiating loop 106 on a second substrate 110. In the shown example, a reflector 112 is arranged below the two radiating structures 102,104. Figure 1A The following is used to describe an exemplary arrangement of the second radiating structure 104 on the first radiating structure 102. Figure 1C to Figure 1F The second radiating structure 104 including the radiating loop 106 is shown and described in detail in FIG.

[0042] The antenna device 100 is used to radiate electromagnetic signals in two frequency bands in parallel. In an example, the antenna device 100 may be referred to as a dual-band antenna device or a multi-band antenna device. The antenna device 100 may be used in a wireless communication system. Such wireless communication systems may include, but are not limited to, base stations (e.g., evolved Node B (eNB) or next generation NodeB (gNB)), repeater devices, or other customized telecommunication hardware.

[0043] The first radiation structure 102 refers to a radiation element or a radiator of the antenna device 100. The first radiation structure 102 is used to work in a first frequency band. In an embodiment, the first radiation structure 102 includes a plurality of radiation elements working in the first frequency band. The first radiation structure 102 is printed on a first substrate 108.

[0044] The second radiation structure 104 includes a plurality of radiation elements and a radiation loop 106. The second radiation structure 104 is configured to operate in a second frequency band different from the first frequency band. For example, the second frequency band may be lower than the first frequency band. The second radiation structure 104 is printed on a second substrate 110.

[0045] The radiating loop 106 is a conductive element included in the second radiating structure 104 of the antenna device 100. The radiating loop 106 increases the bandwidth of the second radiating structure 104, reduces the beam width of the second radiating structure, and improves the isolation of the second radiating structure 104 from adjacent radiating elements such as the first radiating structure 102, while being electrically invisible to the first frequency band radiated by the first radiating structure 102.

[0046] The first substrate 108 is used as a substrate for the first radiating structure 102, and the second substrate 110 is used as a substrate for the second radiating structure 104. In an embodiment, the first substrate 108 and the second substrate 110 are both printed circuit boards (PCBs). The first substrate 108 or the second substrate 110 is a single-layer printed circuit board or a double-layer printed circuit board. In an embodiment, the second substrate 110 is a double-layer printed circuit board, wherein the top layer and the bottom layer of the PCB are used to etch and define the width, spacing and length of the coils that define the radiating loop 106. In an example, the first substrate 108 and the second substrate 110 may be FR4 substrates.

[0047] The reflector 112 is disposed in the antenna device 100 for reflecting and redirecting RF energy in a desired direction. The reflector 112 is arranged at a first distance from the first radiation structure 102 (i.e., closer to the first radiation structure 102), and the second radiation structure 104 is arranged at a second distance from the first radiation structure 102.

[0048] Figure 1B FIG. 1 is a top view of an exemplary arrangement of the first radiation structure 102 relative to the second radiation structure 104 in the antenna device 100 according to an embodiment of the present disclosure. Figure 1B , a second radiating structure 104 overlapping the first radiating structure 102 is shown in a top view. The second radiating structure 104 includes a plurality of radiating elements, such as a first radiating element 104A, a second radiating element 104B, a third radiating element 104C, and a fourth radiating element 104D. In the present embodiment, the second radiating structure 104 includes four radiating elements, which form two electric dipoles. Optionally, in some embodiments, the second radiating structure 104 may include one radiating element instead of a plurality of elements. It should be understood by a person of ordinary skill in the art that the number of radiating elements within the second radiating structure 104 may be increased or decreased without limiting the scope of the present disclosure. A radiating loop 106 included in the second radiating structure 104 is also shown, and the radiating loop 106 surrounds a plurality of radiating elements, such as a first radiating element 104A, a second radiating element 104B, a third radiating element 104C, and a fourth radiating element 104D.

[0049] In operation, the first radiating structure 102 is configured to operate in a first frequency band, while the second radiating structure 104 is configured to operate in a second frequency band. The second radiating structure 104 includes a radiating loop 106 formed along a closed line, wherein the radiating loop 106 is formed as a coil extending along the closed line and being electrically invisible in the first frequency band. In other words, the first radiating structure 102 radiates a radio frequency (RF) signal in a first frequency band, which is different from a second frequency band in which the second radiating structure 104 radiates RF signals. As shown in the figure, the first radiating structure 102 and the second radiating structure 104 are arranged near each other and may transmit RF signals in their respective frequency bands at the same time. Even when the two radiating structures are placed near each other, the radiating loop 106 of the second radiating structure 104 does not affect the performance of the first radiating structure 102 operating in a higher frequency band. Figure 1D An example of a radiating loop 106 formed as a continuous closed line is shown and further described in FIG. Since the radiating loop 106 is in the form of a coil, an inductance distributed along the coil is introduced during operation. This inductance may change the impedance of the radiating loop 106, thereby reducing the amount of scattered fields. In other words, the radiating loop 106 maintains its characteristics at a desired frequency (i.e., in the lower second frequency band) while being transparent (i.e., not reflecting radiation or energy) to the first frequency band (i.e., the higher frequency band).

[0050] According to an embodiment, in a top view, the second radiation structure 104 overlaps the first radiation structure 102. The second radiation structure 104 is arranged on the first radiation structure 102 (in an example, as shown in FIG. Figure 1B ), which ensures that the antenna device 100 has a compact structure. In an embodiment, the second radiating structure 104 is almost like a planar structure printed on the second substrate.

[0051] Typically, in a conventional dual-band antenna device, when a lower frequency radiating element (or a lower frequency array) covers a higher frequency radiating element (or a higher frequency array), the lower frequency radiating element (or the lower frequency array) distorts the radiation generated by the higher frequency radiating element (or the higher frequency array). In addition, the lower frequency radiating element (or the lower frequency array) reflects or re-radiates the electromagnetic field in an unwanted manner, which reduces the directivity of the higher frequency radiating element (or the higher frequency array), increases the side lobes, reduces the front-to-back ratio, deteriorates the cross-pole discrimination value, etc. In contrast to conventional dual-band antenna devices, the radiating loop 106 of the second radiating structure 104 surrounding all radiating elements of the second radiating structure 104 avoids or at least significantly reduces any radiation distortion generated by the first radiating structure 102. Therefore, to some extent, the radiating loop 106 can achieve mutual invisibility or transparency, wherein the second radiating structure 104 of one frequency band (e.g., a lower frequency band) near the first radiating structure 102 of a different frequency band (higher frequency) does not affect each other's performance. Alternatively, if the remaining elements of the second radiating structure 104 are designed to be electrically invisible in the first frequency band by any suitable known technique, the entire second radiating structure 104 including the radiating loop 106 will be electrically transparent to the first frequency band.

[0052] Figure 1C FIG. 1 is a diagram of a portion of an antenna device according to an embodiment of the present disclosure. Figure 1A and Figure 1B Component description in Figure 1C . refer to Figure 1C , shows a second radiation structure 104 of the antenna device 100. The second radiation structure 104 includes a radiation loop 106 and a plurality of radiation elements enclosed in the radiation loop 106, such as a first radiation element 104A, a second radiation element 104B and a third radiation element 104C. The second radiation structure 104 is printed on a second substrate 110, which is arranged on a support structure 114.

[0053] In this embodiment, the second radiation structure 104 includes four radiation elements (the fourth radiation element is not visible because Figure 1C Only a portion of the antenna device 100 is depicted in FIG. 1 ), the four radiating elements form two electric dipoles. The second radiating structure 104 is configured to operate in a second frequency band different from the first frequency band. For example, the second frequency band may be lower than the first frequency band.

[0054] The support structure 114 is a first substrate (eg Figure 1A The first substrate 108) and the second substrate 110 provide support and mechanical strength. In an example, the support structure 114 can be made of plastic.

[0055] According to an embodiment, the radiating loop 106 is arranged on the circumference of the second radiating structure 104. The radiating loop 106 adds an inductance distributed along the radiating loop 106 placed on the circumference (i.e., the near side) of the second radiating structure 104. In addition, the shape of the radiating loop 106 (including density, radius, number of turns per defined length, etc.) determines the amount of inductance introduced, and the frequency response varies with the first radiating structure (e.g. Figure 1A and Figure 1B The amount of inductance added by the radiating loop 106 changes with the operating frequency of the first radiating structure 102 and the second radiating structure 104. The amount of inductance added by the radiating loop 106 changes the impedance of the radiating loop 106 accordingly and makes the radiating loop electrically transparent to the first frequency band. In some embodiments, transparency can be achieved whenever the scattered field value is below -50 decibels (dB). The scattered field is a potential measure of the surface current in the first frequency band (e.g., the higher frequency band).

[0056] According to another embodiment, the radiating loop 106 is substantially square in a top view. The radiating loop 106 is arranged on the second radiating structure 104 along a closed line, and the closed line is embodied as a square. In the example, the radiating loop 106 represents a square shape in a top view, such as Figure 1D Typically, when current is passed through a conventional coil, the individual turns of the wire may generate magnetic fields that pass through the center of the coil and add (i.e., superimpose) to generate a strong magnetic field. However, in antenna device 100, when the shape of the coil defining radiating loop 106 is a square, any potential magnetic fields are canceled out by superposition. For example, in Figure 1D , Figure 1E and Figure 1F The shape and structure of the radiating loop 106 are described in further detail in .

[0057] According to an embodiment, the second frequency band is lower than the first frequency band. The second frequency band is the frequency band in which the second radiating structure 104 operates, while the first radiating structure (eg Figure 1A and Figure 1B The first radiating structure 102 of the embodiment of the present invention operates in a first frequency band. In other words, the first radiating structure is used to operate at a frequency higher than the second frequency band. For example, the first frequency band corresponds to a mid-band (e.g., 1.427 GHz to 2.2 GHz) or a high-band (e.g., 1.71 GHz to 2.69 GHz), and the second frequency band is lower than the first frequency band (e.g., a low-band such as 690 MHz to 960 MHz). In another example, the first frequency band corresponds to the "F1" band, i.e., the millimeter wave (mmWave) frequency of the 5G NR band, and the second frequency band corresponds to the "F2" band (i.e., sub-6 GHz).

[0058] According to an embodiment, the first radiating structure (eg Figure 1A and Figure 1BThe first radiation structure 102 is arranged on the lower plane of the support structure 114 and is connected to the reflector (eg Figure 1A The reflector 112 of the support structure 114 is at a first distance, and the second radiation structure 104 is arranged on the upper plane of the support structure 114 and at a second distance from the lower plane. The support structure 114 is a first substrate (e.g. Figure 1A The first substrate 108 and the second substrate 110 provide support and mechanical strength. The support structure 114 includes a lower plane and an upper plane. The first substrate (e.g. Figure 1A The first substrate 108 is arranged on the lower plane of the support structure 114, serving as the base of the first radiating structure. The second substrate 110 is arranged on the upper plane of the support structure 114, serving as the base of the second radiating structure 104. The arrangement of the first radiating structure and the second radiating structure 104 at different distances from the reflector plane enables the antenna device 100 to radiate electromagnetic signals in different frequency bands with reduced interference. In addition, the use of the radiation loop 106 in the second radiating structure 104 also makes signal interference almost negligible. In addition, a reflector is integrated in the antenna device 100 to reflect and redirect RF energy in a desired direction. The reflector (e.g. Figure 1A The reflector 112 of the support structure 114 is arranged closer to the lower plane of the support structure 114 than to the upper plane of the support structure 114. In other words, the first radiating structure arranged on the lower plane of the support structure 114 is at a first distance from the reflector (i.e., relatively closer to the reflector), while the second radiating structure 104 is at a second distance from the lower plane (i.e., a larger distance) when positioned on the upper plane of the support structure 114 and is relatively far from the reflector. The reflector increases the gain in a given direction by reflecting RF energy.

[0059] Figure 1D According to the embodiment of the present disclosure Figure 1C Illustration of the radiating loop of an antenna device in FIG. Figure 1C Component description in Figure 1D . refer to Figure 1D , showing the radiating loop (e.g. Figure 1C Configuration of the radiation loop 106 of the antenna device 100).

[0060] The radiating loop 106 is made into a coil and is arranged on the circumference of the second radiating structure 104. The radiating loop 106 adds an inductance distributed along the radiating loop 106 placed on the circumference (i.e., the near side) of the second radiating structure 104. In general, the inductance value (represented by L) of the radiating loop 106 (or coil) depends on the shape (e.g., density, radius, etc.) of the radiating loop 106 (or coil) according to the following equation (Equation 1)

[0061]

[0062] Where A represents the cross-sectional area of ​​the radiating loop 106 (or coil), l represents the length of the radiating loop 106 (or coil), and N represents the number of turns of the radiating loop 106 (or coil). For a given inductance value (i.e., L) of the radiating loop 106 (or coil), the frequency response of the radiating loop 106 varies depending on the operating frequency. This is because the impedance of the radiating loop 106 (represented by Zl) depends on the operating frequency and inductance (i.e., L) of the radiating loop 106 according to the following equation (i.e., Equation 2):

[0063] Zl=jωL(2)

[0064] Wherein, Z1 represents the impedance provided by the radiation loop 106 to the first radiation structure 102 of the antenna device 100.

[0065] For a given inductance value (i.e., L), the impedance (i.e., Zl) depends only on the operating frequency. Thus, at low frequencies, the impedance (i.e., Zl) is low, and the radiating loop 106 (or coil) acts as a short circuit and behaves as a typical coil. However, at high frequencies, the impedance (i.e., Zl) becomes high, and the radiating loop 106 (or coil) acts as an open circuit (or transparent). Thus, due to the high impedance (i.e., Zl), the coil defining the radiating loop 106 becomes transparent (i.e., an open circuit) to the first frequency band (i.e., the higher frequency band) radiated by the first radiating structure 102. In addition, the radiating loop 106 (or coil) behaves similarly to a series of unconnected bars.

[0066] For a given frequency value, the impedance (i.e., Zl) depends only on the inductance (i.e., L), which varies in direct proportion to the number of turns (i.e., N) and the cross-sectional area of ​​the radiating loop 106 (or coil). The higher the number of turns (or the higher the density), the higher the inductance value and the higher the resulting impedance (i.e., Zl). Therefore, at high density, the radiating loop 106 (or coil) acts like an open circuit. Thus, by controlling the density or by controlling the number of turns of the coil defining the radiating loop 106, the radiating loop 106 can be made transparent (i.e., an open circuit) in a first frequency band. Therefore, by using the radiating loop 106 in the second radiating structure 104, the radiation pattern ( Figure 1A and Figure 1B (in Chinese) are not affected.

[0067] The radiating loop 106 is arranged along a closed line, which is embodied as a square. Generally, when current passes through a conventional coil, the individual turns of the wire may generate magnetic fields, which pass through the center of the coil and add (i.e., superimpose) to generate a strong magnetic field. However, in the antenna device 100, when the shape of the coil defining the radiating loop 106 is a square, any potential magnetic fields are offset by superposition.

[0068] Figure 1EFIG. 1 is a diagram of a portion of an antenna device having a close-up view of a radiating loop according to another embodiment of the present disclosure. Figure 1C and Figure 1D Component description in Figure 1E . refer to Figure 1E , shows a portion of an antenna device (e.g., antenna device 100) having a close-up view of a radiating loop (e.g., radiating loop 106). Radiating loop 106 includes an upper conductive track 116 and a lower conductive track 118. Upper conductive track 116 and lower conductive track 118 are connected to each other using a plurality of vias 120.

[0069] The radiation loop 106 (or coil) includes conductive tracks printed on different layers of a printed circuit board (PCB), such as an upper conductive track 116 and a lower conductive track 118. The different layers of the PCB include a top layer and a bottom layer for etching and defining the width, spacing, and length of the radiation loop 106 (or coil). A plurality of through holes 120 are used to connect the top layer and the bottom layer of the PCB. The required plurality of through holes 120 depends on the width of the upper conductive track 116 and the lower conductive track 118. Typically, one or two through holes in the plurality of through holes 120 are sufficient to connect the upper conductive track 116 and the lower conductive track 118. However, it should be understood by those of ordinary skill in the art that the number of through holes in the plurality of through holes 120 may vary as needed without limiting the scope of the present disclosure.

[0070] The upper conductive rail 116 and the lower conductive rail 118 are square in shape (i.e., a polygon with four edges or sides) and are connected to each other through a plurality of through holes 120. The plurality of through holes 120 are arranged on the edges of the upper conductive rail 116 and the lower conductive rail 118. The plurality of through holes 120 are used to support the upper conductive rail 116 and the lower conductive rail 118.

[0071] Figure 1F FIG. 1 is a diagram of a radiating loop made as a coil with conductive tracks and through holes according to another embodiment of the present disclosure. Figure 1B , Figure 1C , Figure 1D and Figure 1E Component description in Figure 1F . refer to Figure 1F , showing a radiating loop 106 made as a coil with conductive tracks and vias (eg Figures 1A to 1D radiating loop 106).

[0072] In an embodiment, the upper conductive track 116 of the radiating loop 106 includes a plurality of upper conductive tracks, such as a first upper conductive track 116A, a second upper conductive track 116B, and a third upper conductive track 116C. Similarly, the lower conductive track 118 of the radiating loop 106 includes a plurality of lower conductive tracks, such as a first lower conductive track 118A, a second lower conductive track 118B, and a third lower conductive track 118C. The upper conductive tracks 116 and the lower conductive tracks 118 are arranged diagonally but in opposite directions. For example, the first upper conductive track 116A is connected to a previous lower conductive track (not shown here) and the first lower conductive track 118A using a plurality of through holes 120 such as a first through hole 120A, a second through hole 120B, a third through hole 120C, and a fourth through hole 120D. The second upper conductive rail 116B is connected to the first lower conductive rail 118A and to the second lower conductive rail 118B using a plurality of through holes 120, such as the fifth through hole 120E, the sixth through hole 120F, the seventh through hole 120G, and the eighth through hole 120H. Similarly, the third upper conductive rail 116C is connected to the second lower conductive rail 118B and to the third lower conductive rail 118C using a plurality of through holes 120, such as the ninth through hole 120I, the tenth through hole 120J, the eleventh through hole 120K, and the twelfth through hole 120L.

[0073] Figure 2A is an illustration of a radiating loop having a metal strip printed on a plastic support element according to an embodiment of the present disclosure. Figures 1A to 1F Component description in Figure 2A . refer to Figure 2A , a radiating loop 200 is shown. The radiating loop 200 comprises a plurality of metal strips 202 printed on a plastic support element 204.

[0074] Radiating loop 200 corresponds to Figure 1C 106 in the radiating loop 100. In an embodiment, polyethylene plastic (PEP) or similar technology is used to print (i.e., etch or deposit) a plurality of metal strips 202 on a plastic support element 204 to produce the radiating loop 200. The plurality of metal strips 202 and the plastic support element 204 have the same size over the entire circumference of the second radiating structure 104. The plurality of metal strips 202 are continuously arranged around the plastic support element 204. However, it should be understood by a person skilled in the art that another similar technology can be used to print the plurality of metal strips 202 on the plastic support element 204 without limiting the scope of the present disclosure.

[0075] Figure 2B According to another embodiment of the present disclosure Figure 2A Side view of the radiating loop in . Figure 2A Component description in Figure 2B . refer to Figure 2B , showing Figure 2AFIG. 2 is a top view of the radiating loop 200 in FIG. In the top view, the plurality of metal strips 202 of the radiating loop 200 appear to be square and are arranged diagonally on the upper surface of the plastic support element 204.

[0076] Figure 2C According to another embodiment of the present disclosure Figure 2A Bottom view of the radiating loop in . Figure 2C Combination Figure 2A The components in the reference Figure 2C , showing Figure 2A 2. In the bottom view, the plurality of metal strips 202 of the radiating loop 200 appear to be square and are arranged on the lower surface of the plastic supporting element 204.

[0077] Figure 2D According to another embodiment of the present disclosure Figure 2A Side view of the radiating loop in . Figure 2A Component description in Figure 2D . refer to Figure 2D , showing Figure 2A 2. In the side view, the plurality of metal strips 202 of the radiating loop 200 appear to be rectangular and are arranged on the side surface of the plastic supporting element 204.

[0078] Figure 3 FIG. 1 is a graphical representation of a scattering analysis of an antenna device according to an embodiment of the present disclosure. Figures 1A to 1F as well as FIG. 2A to FIG. 2D Component description in Figure 3 . refer to Figure 3 , showing an antenna device (e.g. Figure 1C 1. A graphical representation 300 of an antenna device 100 is shown. The graphical representation 300 includes an X-axis 302 representing frequency (in Gigahertz (GHz)) and a Y-axis 304 representing scattered power (in decibel (dB)).

[0079] The scattering analysis of the antenna device 100 is performed by using a high frequency structure simulator (HFSS) tool. In the graphical representation, the first line 306 represents the scattering behavior of a conventional antenna device. The second line 308 represents the scattering behavior of the antenna device 100. The graphical representation 300 also includes an elliptical area 310, which highlights the difference between the scattering behavior of the conventional antenna device and the antenna device 100 in the high frequency range (approximately 1.90 GHz–2.20 GHz). In the elliptical area 310, the antenna device 100 has a lower scattered field value (i.e., less than -50 dB) compared to the conventional antenna device. The reason is that in the conventional antenna device, a typical ring is used that is opaque in the high frequency range, and degrades the radiation pattern of any radiating structure (or antenna array) placed under the typical ring. However, in the antenna device 100, ( Figure 1C The ring in the form of the radiating loop 106 becomes transparent to the first radiating structure 102 placed below the radiating loop 106, and thus, the radiating loop 106 does not affect the radiation pattern of the first radiating structure 102. Therefore, due to the radiating loop 106, the antenna device 100 exhibits a lower scattered field value (i.e., less than -50 dB).

[0080] Figure 4 1 is a graphical representation of a radiation pattern of an antenna device according to an embodiment of the present disclosure. Figure 1C to Figure 1F , FIG. 2A to FIG. 2D and Figure 3 Component Description Figure 4 . refer to Figure 4 , showing an antenna device (eg Figure 1C 4. A graphical representation 400 of a radiation pattern of an antenna device 100 of FIG. 400 includes an X-axis 402 representing θ values ​​(unit: degree (deg)) and a Y-axis 404 representing normalized values ​​of the radiation field (unit: decibel (dB)).

[0081] In the graphical representation 400, a plurality of lines 406 represent various radiation patterns of the antenna device 100. The radiation pattern represented by the plurality of lines 406 is obtained when the radiation loop 106 of the second radiation structure 104 (or the low frequency array) is transparent (i.e., open circuit) to the first radiation structure 102 (or the high frequency array) at high frequencies. Therefore, the radiation loop 106 does not affect the radiation pattern of the first radiation structure 102. Therefore, the antenna device 100 exhibits lower scattered field values ​​compared to conventional antenna devices that exhibit relatively high scattered field values. In conventional antenna devices, a conventional antenna array that operates at a lower frequency and includes a typical loop (or a loop and a probe) is not transparent to another antenna array that operates at a higher frequency, thereby deteriorating the radiation pattern of the antenna array that operates at the higher frequency. Therefore, the conventional antenna device exhibits a higher scattered field value, which is not preferred.

[0082] Figure 5 FIG. 1 is a graphical representation of the change of the scattered field value of the antenna device with respect to the operating frequency according to an embodiment of the present disclosure. Figure 1C to Figure 1F Component Description Figure 5 . refer to Figure 5 , showing an antenna device (eg Figure 1C 1. A graphical representation 500 of a change in a scattered field value of an antenna device 100 with respect to an operating frequency. The graphical representation 500 includes an X-axis 502 representing frequency (unit: GHz) and a Y-axis 504 representing scattered field values ​​(unit: decibel (dB)).

[0083] In the graphical representation 500, the first line 506 represents the change of the scattered field value of the antenna device 100 with respect to the operating frequency. The first line 506 depicts that the scattered field value decreases as the operating frequency of the antenna device 100 increases. The first line 506 includes a first point 506A (which can also be represented as m1) and a second point 506B (which can also be represented as m2). The first point 506A (i.e., m1) has a scattered field value of -49.70 dB at a frequency of 1.7 GHz. The second point 506B (i.e., m2) has a scattered field value of -50.91 dB at a frequency of 2.2 GHz. Due to the high operating frequency, the second point 506B (i.e., m2) has a relatively low scattered field value. The reason is that by increasing the density of the radiation loop 106, the inductance (i.e., L) of the radiation loop 106 increases, which further causes the impedance (i.e., Zl) of the radiation loop 106 to increase according to equation 2. In addition to the increase in inductance (i.e., L), the operating frequency is also increased at each step, and therefore, the impedance (i.e., Zl) is further increased. The further increase in impedance (i.e., Zl) causes the scattered field value to be further reduced. The density of the radiating loop 106 (or coil) is increased by increasing the number of turns (i.e., N) of the coil.

[0084] Without departing from the scope of the present disclosure as defined by the appended claims, the embodiments of the present disclosure described above may be modified. Expressions such as "comprise", "include", "combined with", "have", "is / are" and the like used to describe and claim the present disclosure are intended to be interpreted in a non-exclusive manner, that is, to allow the existence of items, components or elements that are not explicitly described. References to the singular should also be interpreted as involving the plural. The word "exemplary" used herein means "as an example, instance or illustration". Any embodiment described as "exemplary" is not necessarily interpreted as being more preferred or more advantageous than other embodiments, and / or excluding the combination of features of other embodiments. The word "optionally" used herein means "provided in some embodiments and not provided in other embodiments". It should be understood that certain features of the present disclosure described in the context of a single plurality of embodiments for the sake of clarity may also be provided in a single embodiment by combination. Conversely, the various features of the present invention described in the context of a single embodiment for the sake of brevity may also be provided individually or in any suitable combination or as any other described embodiment of the present disclosure.

Claims

1. An antenna device (100), characterized in that: include: - a first radiating structure (102) adapted to operate in a first frequency band, and - a second radiating structure (104), the second radiating structure being configured to operate in a second frequency band, the second radiating structure (104) comprising a radiating loop (106, 200) formed along a closed line, wherein the radiating loop (106, 200) is made into a coil extending along the closed line and being electrically invisible in the first frequency band; Wherein, the radiation loop (106, 200) is arranged on the circumference of the second radiation structure (104).

2. The antenna device (100) according to claim 1, characterized in that The radiation loop (106, 200) is substantially square in a top view.

3. The antenna device (100) according to claim 1, characterized in that The second frequency band is lower than the first frequency band.

4. The antenna device (100) according to any one of claims 1 to 3, characterized in that: The second radiating structure (104) overlaps with the first radiating structure (102) in a top view.

5. The antenna device (100) according to any one of Claims 1 to 3, characterized in that: The coil comprises conductive tracks which are printed on different layers of a printed circuit board and connected to each other by vias.

6. The antenna device (100) according to any one of Claims 1 to 3, characterized in that: The coil comprises a metal strip (202) printed on a plastic support element (204).

7. The antenna device (100) according to any one of Claims 1 to 3, characterized in that: The first radiation structure (102) is arranged on a lower plane of the support structure (114) and is at a first distance from the reflector (112); and the second radiation structure (104) is arranged on an upper plane of the support structure (114) and is at a second distance from the lower plane.

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