Antenna structure

Abstract

The present invention discloses an antenna structure, comprising: a grounding element, a first radiating portion, a second radiating portion, a dielectric substrate, a first feeding portion, a second feeding portion, a third feeding portion, and a fourth feeding portion. The dielectric substrate has a first surface and a second surface opposite to each other, wherein the first radiating portion is arranged on the first surface, and the grounding element is arranged on the second surface. The second radiating portion is adjacent to the first radiating portion and separated from the first radiating portion. The first feeding portion has a first feeding port and is coupled to the first radiating portion. The second feeding portion has a second feeding port and is coupled to the first radiating portion. The third feeding portion has a third feeding port and is coupled to the first radiating portion. The fourth feeding portion has a fourth feeding port and is coupled to the first radiating portion.

Description

Technical Field

[0001] The present invention relates to an antenna structure, and in particular to a multi-feed antenna structure. Background Art

[0002] With the advancement of mobile communication technology, mobile devices have become increasingly common in recent years. Common examples include laptop computers, mobile phones, multimedia players, and other hybrid portable electronic devices. To meet people's needs, mobile devices typically include wireless communication capabilities. Some cover long-range wireless communication, such as mobile phones using 2G, 3G, and LTE (Long Term Evolution) systems and the 700MHz, 850MHz, 900MHz, 1800MHz, 1900MHz, 2100MHz, 2300MHz, and 2500MHz frequency bands for communication. Others cover short-range wireless communication, such as Wi-Fi and Bluetooth systems using the 2.4GHz, 5.2GHz, and 5.8GHz frequency bands for communication.

[0003] Wireless access points (WAPs) are essential components for enabling high-speed indoor internet access for mobile devices. However, because indoor environments are plagued by signal reflections and multipath fading, wireless access points must be able to simultaneously process signals from all directions and polarizations. Therefore, designing a wideband, multi-polarization antenna within the limited space of a wireless access point has become a major challenge for designers. Summary of the Invention

[0004] In a preferred embodiment, the present invention provides an antenna structure, comprising: a ground element; a first radiating portion; a dielectric substrate having a first surface and a second surface opposite to each other, wherein the first radiating portion is arranged on the first surface and the ground element is arranged on the second surface; a second radiating portion is adjacent to the first radiating portion and separated from the first radiating portion; a first feeding portion having a first feeding port and coupled to the first radiating portion; a second feeding portion having a second feeding port and coupled to the first radiating portion; a third feeding portion having a third feeding port and coupled to the first radiating portion; and a fourth feeding portion having a fourth feeding port and coupled to the first radiating portion; wherein the antenna structure covers an operating frequency band.

[0005] In some embodiments, the operating frequency band is between 2400 MHz and 2500 MHz.

[0006] In some embodiments, the first radiating portion is circular.

[0007] In some embodiments, the radius of the first radiating portion is approximately equal to 0.25 times the guided wavelength of the operating frequency band.

[0008] In some embodiments, the first radiating portion is a regular octagon.

[0009] In some embodiments, the first radiating portion further has a first notch, a second notch, a third notch, and a fourth notch, corresponding to the first feeding portion, the second feeding portion, the third feeding portion, and the fourth feeding portion, respectively.

[0010] In some embodiments, the second radiation portion has another circular shape, and an area of the second radiation portion is larger than an area of the first radiation portion.

[0011] In some embodiments, the radius of the second radiating portion is approximately equal to 0.25 times the free space wavelength of the operating frequency band.

[0012] In some embodiments, the second radiating portion is substantially parallel to the first radiating portion, and a coupling gap is formed between the second radiating portion and the first radiating portion.

[0013] In some embodiments, the width of the coupling gap is approximately equal to 0.05 free-space wavelengths of the operating frequency band.

[0014] In some embodiments, the lengths of the first feeding portion, the second feeding portion, the third feeding portion, and the fourth feeding portion are substantially equal.

[0015] In some embodiments, the first feeding portion includes a first narrower portion and a first wider portion, and the first feeding port is coupled to a first connection point on the first radiating portion via the first narrower portion and the first wider portion. The second feeding portion includes a second narrower portion and a second wider portion, and the second feeding port is coupled to a second connection point on the first radiating portion via the second narrower portion and the second wider portion. The third feeding portion includes a third narrower portion and a third wider portion, and the third feeding port is coupled to a third connection point on the first radiating portion via the third narrower portion and the third wider portion. The fourth feeding portion includes a fourth narrower portion and a fourth wider portion, and the fourth feeding port is coupled to a fourth connection point on the first radiating portion via the fourth narrower portion and the fourth wider portion.

[0016] In some embodiments, a first angle is formed between the second wider portion and the first wider portion, a second angle is formed between the third wider portion and the second wider portion, and a third angle is formed between the fourth wider portion and the third wider portion.

[0017] In some embodiments, the first feed portion is coupled to a first connection point on the first radiating portion, the second feed portion is coupled to a second connection point on the first radiating portion, the third feed portion is coupled to a third connection point on the first radiating portion, the fourth feed portion is coupled to a fourth connection point on the first radiating portion, a first angle is defined between the second connection point and the first connection point, a second angle is defined between the third connection point and the second connection point, and a third angle is defined between the fourth connection point and the third connection point, wherein the first angle, the second angle, and the third angle are all approximately equal to 45 degrees.

[0018] In some embodiments, the antenna structure also includes: a first conductive through-element, coupled between the first feed portion and a first connection point on the first radiating portion; a second conductive through-element, coupled between the second feed portion and a second connection point on the first radiating portion; a third conductive through-element, coupled between the third feed portion and a third connection point on the first radiating portion; and a fourth conductive through-element, coupled between the fourth feed portion and a fourth connection point on the first radiating portion.

[0019] In some embodiments, the first conductive through-hole via, the second conductive through-hole via, the third conductive through-hole via, and the fourth conductive through-hole via at least partially penetrate the dielectric substrate.

[0020] In some embodiments, the first feeding portion, the second feeding portion, the third feeding portion, and the fourth feeding portion are all located between the first radiating portion and the ground element.

[0021] In some embodiments, the antenna structure operates in a first mode or a second mode to provide different polarization directions.

[0022] In some embodiments, in the first mode, the first feeding port and the third feeding port are enabled, the second feeding port and the fourth feeding port are disabled, and there is a first feeding phase difference between the first feeding port and the third feeding port.

[0023] In some embodiments, in the second mode, the second feeding port and the fourth feeding port are enabled, the first feeding port and the third feeding port are disabled, and there is a second feeding phase difference between the second feeding port and the fourth feeding port. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A three-dimensional diagram of an antenna structure according to an embodiment of the present invention;

[0025] Figure 2 A perspective view of an antenna structure according to an embodiment of the present invention;

[0026] Figure 3 is a cross-sectional view of an antenna structure according to an embodiment of the present invention;

[0027] Figure 4 A perspective view of an antenna structure according to an embodiment of the present invention;

[0028] Figure 5 A perspective view of an antenna structure according to an embodiment of the present invention;

[0029] Figure 6 A three-dimensional diagram of an antenna structure according to an embodiment of the present invention;

[0030] Figure 7 A side view of an antenna structure according to an embodiment of the present invention.

[0031] Explanation of symbols

[0032] 100,400,500,600: Antenna structure

[0033] 110: Grounding element

[0034] 120,420,520: First radiation part

[0035] 130: Second radiation part

[0036] 140,640: Dielectric substrate

[0037] 150,650: First feed section

[0038] 151: first end of the first feeding portion

[0039] 152: Second end of the first feeding portion

[0040] 154: first narrow part

[0041] 155: first wider part

[0042] 160,660: Second feed part

[0043] 161: first end of the second feed-in portion

[0044] 162: Second end of the second feeding portion

[0045] 164: Second narrower part

[0046] 165: second wider part

[0047] 170,670: Third feed-in unit

[0048] 171: first end of the third feeding portion

[0049] 172: Second end of the third feeding portion

[0050] 174: The third narrow part

[0051] 175: The third widest part

[0052] 180,680: Fourth feed part

[0053] 181: First end of the fourth feeding portion

[0054] 182: Second end of the fourth feed portion

[0055] 184: The fourth narrower part

[0056] 185: Fourth wider part

[0057] 521: First Gap

[0058] 522: Second Gap

[0059] 523: The third gap

[0060] 524: The Fourth Gap

[0061] 641: Upper layer of dielectric substrate

[0062] 642: Middle layer of dielectric substrate

[0063] 643: Lower layer of dielectric substrate

[0064] 691: first conductive through-element

[0065] 692: Second conductive through-element

[0066] 693: Third conductive through-element

[0067] 694: Fourth conductive through-element

[0068] CC: Center axis

[0069] CP1: First connection point

[0070] CP2: Second connection point

[0071] CP3: Third connection point

[0072] CP4: Fourth connection point

[0073] E1: The first surface of the dielectric substrate

[0074] E2: The second surface of the dielectric substrate

[0075] FP1: First feed port

[0076] FP2: Second feed port

[0077] FP3: third feed port

[0078] FP4: Fourth feed port

[0079] GC1: coupling gap

[0080] H1: thickness of dielectric substrate

[0081] LC1: hatching

[0082] R1, R2: radius

[0083] θ1: first angle

[0084] θ2: second angle

[0085] θ3: the third angle DETAILED DESCRIPTION

[0086] In order to make the objects, features and advantages of the present invention more clearly understood, specific embodiments of the present invention are given below and described in detail with reference to the accompanying drawings.

[0087] Certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different terms to refer to the same component. This specification and claims do not distinguish components by name, but rather by functional differences. The words "include" and "comprising" mentioned throughout the specification and claims are open-ended terms and should be interpreted as "including but not limited to". The word "substantially" means that within an acceptable error range, those skilled in the art can solve the technical problem and achieve the basic technical effect within a certain error range. In addition, the word "coupled" in this specification includes any direct and indirect electrical connection means. Therefore, if the text describes a first device coupled to a second device, it means that the first device can be directly electrically connected to the second device, or indirectly electrically connected to the second device via other devices or connection means.

[0088] The following disclosure provides many different embodiments or examples for implementing the different features of the present invention. The following disclosure describes specific examples of various components and their arrangements to simplify the description. Of course, these specific examples are not intended to be limiting. For example, if this disclosure describes a first feature formed on or above a second feature, it means that it may include an embodiment in which the first feature and the second feature are in direct contact, and may also include an embodiment in which an additional feature is formed between the first feature and the second feature, so that the first feature and the second feature may not be in direct contact. In addition, the same reference symbols or (and) marks may be reused in different examples of the following disclosure. These repetitions are for the purpose of simplicity and clarity, and are not intended to limit the specific relationship between the different embodiments or (and) structures discussed.

[0089] In addition, spatially relative terms such as "below," "beneath," "lower," "above," "upper," and similar terms are used to facilitate describing the relationship between one element or feature and another element or feature in a diagram. These spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. The device may be rotated 90 degrees or in other orientations, and the spatially relative terms used herein should be interpreted accordingly.

[0090] Figure 1 A perspective view of an antenna system 100 according to an embodiment of the present invention is shown. For example, the antenna system 100 can be applied to a wireless access point, but is not limited thereto. Figure 1 As shown, the antenna structure 100 includes a ground element 110, a first radiating element 120, a second radiating element 130, a dielectric substrate 140, a first feeding element 150, a second feeding element 160, a third feeding element 170, and a fourth feeding element 180. The ground element 110, the first radiating element 120, the second radiating element 130, the first feeding element 150, the second feeding element 160, the third feeding element 170, and the fourth feeding element 180 can be made of metal materials, such as copper, silver, aluminum, iron, or alloys thereof. Figure 2 A perspective view of an antenna structure 100 according to an embodiment of the present invention is shown (to simplify the drawing, the ground element 110 and the dielectric substrate 140 are omitted). Figure 3 A cross-sectional view (along the Figure 1Please refer to the section line LC1). Figure 1 、 Figure 2 、 Figure 3 To understand the present invention.

[0091] The grounding element 110 can provide a ground voltage. The first radiating portion 120 can be generally circular. The dielectric substrate 140 can be an FR4 (Flame Retardant 4) substrate, a printed circuit board (PCB), or a flexible printed circuit board (FPC). The dielectric substrate 140 has a first surface E1 and a second surface E2 opposite to each other. The first radiating portion 120 is disposed on the first surface E1 of the dielectric substrate 140, and the grounding element 110 is disposed on the second surface E2 of the dielectric substrate 140. The area of the grounding element 110 can be much larger than the area of the first radiating portion 120.

[0092] The second radiating portion 130 can have another circular shape (a larger circle), wherein the area of the second radiating portion 130 can be larger than that of the first radiating portion 120. The second radiating portion 130 and the first radiating portion 120 can share a common central axis CC, which can be substantially perpendicular to the first surface E1 of the dielectric substrate 140. That is, the center of the second radiating portion 130 can overlap with the center of the first radiating portion 120, and the central axis CC can pass through both centers. The second radiating portion 130 is adjacent to the first radiating portion 120 and completely separated from it. In other words, the second radiating portion 130 can be floating. It should be noted that the terms "adjacent" or "adjacent" in this specification can refer to a situation where the distance between two corresponding elements is less than a predetermined distance (e.g., 5 mm or less), but generally do not include a situation where the two corresponding elements are in direct contact with each other (i.e., where the distance is reduced to zero). In some embodiments, the second radiating portion 130 is substantially parallel to the first radiating portion 120, wherein a coupling gap GC1 is formed between the second radiating portion 130 and the first radiating portion 120. Furthermore, if the second radiating portion 130 has a vertical projection on the first surface E1 of the dielectric substrate 140, the first radiating portion 120 is completely located within the vertical projection of the second radiating portion 130.

[0093] The first feeding portion 150, the second feeding portion 160, the third feeding portion 170, and the fourth feeding portion 180 can all be disposed on the first surface E1 of the dielectric substrate 140 and can be coplanar with the first radiating portion 120. For example, each of the first feeding portion 150, the second feeding portion 160, the third feeding portion 170, and the fourth feeding portion 180 can generally have a zigzag shape, a straight bar shape, or a meandering shape, but is not limited thereto.

[0094] The first feeding portion 150 has a first end 151 and a second end 152, wherein a first feeding port FP1 is located at the first end 151 of the first feeding portion 150, and the second end 152 of the first feeding portion 150 is coupled to a first connection point CP1 on the first radiating portion 120. The second feeding portion 160 has a first end 161 and a second end 162, wherein a second feeding port FP2 is located at the first end 161 of the second feeding portion 160, and the second end 162 of the second feeding portion 160 is coupled to a second connection point CP2 on the first radiating portion 120. The third feeding portion 170 has a first end 171 and a second end 172, wherein a third feeding port FP3 is located at the first end 171 of the third feeding portion 170, and the second end 172 of the third feeding portion 170 is coupled to a third connection point CP3 on the first radiating portion 120. The fourth feeding portion 180 has a first end 181 and a second end 182. A fourth feeding port FP4 is located at the first end 181 of the fourth feeding portion 180, and the second end 182 of the fourth feeding portion 180 is coupled to a fourth connection point CP4 on the first radiating portion 120. The first connection point CP1, the second connection point CP2, the third connection point CP3, and the fourth connection point CP4 can be different from each other and can all be located on the circumference of the first radiating portion 120. In some embodiments, the lengths of the first feeding portion 150, the second feeding portion 160, the third feeding portion 170, and the fourth feeding portion 180 are substantially equal to provide substantially the same phase delay.

[0095] In some embodiments, the first feeding section 150, the second feeding section 160, the third feeding section 170, and the fourth feeding section 180 all have variable-width structures. Specifically, the first feeding section 150 includes a first narrow portion 154 and a first wide portion 155, wherein the first feeding port FP1 is coupled to the first connection point CP1 via the first narrow portion 154 and the first wide portion 155. The second feeding section 160 includes a second narrow portion 164 and a second wide portion 165, wherein the second feeding port FP2 is coupled to the second connection point CP2 via the second narrow portion 164 and the second wide portion 165. The third feeding section 170 includes a third narrow portion 174 and a third wide portion 175, wherein the third feeding port FP3 is coupled to the third connection point CP3 via the third narrow portion 174 and the third wide portion 175. The fourth feed section 180 includes a fourth narrow portion 184 and a fourth wide portion 185, wherein the fourth feed port FP4 is coupled to the fourth connection point CP4 via the fourth narrow portion 184 and the fourth wide portion 185. According to actual measurement results, this unequal-width design can be used to fine-tune the feeding impedance of the antenna structure 100. However, the present invention is not limited to this. In other embodiments, the first feed section 150, the second feed section 160, the third feed section 170, and the fourth feed section 180 can all be configured as equal-width structures. In still other embodiments, the first feed section 150, the second feed section 160, the third feed section 170, and the fourth feed section 180 can be configured as a multi-segment structure (e.g., having more than two segments, each segment being non-parallel to one another) or a structure with a gradually varying width.

[0096] A first angle θ1 may be formed between the second wider portion 165 of the second feed portion 160 and the first wider portion 155 of the first feed portion 150. A second angle θ2 may be formed between the third wider portion 175 of the third feed portion 170 and the second wider portion 165 of the second feed portion 160. A third angle θ3 may be formed between the fourth wider portion 185 of the fourth feed portion 180 and the third wider portion 175 of the third feed portion 170. For example, an extension line of each of the first wider portion 155, the second wider portion 165, the third wider portion 175, and the fourth wider portion 185 may pass through the central axis CC. In some embodiments, the first angle θ1, the second angle θ2, and the third angle θ3 are substantially equal. In other embodiments, the first angle θ1 is defined between the second connection point CP2 and the first connection point CP1, the second angle θ2 is defined between the third connection point CP3 and the second connection point CP2, and the third angle θ3 is defined between the fourth connection point CP4 and the third connection point CP3. For example, by connecting any two adjacent connection points to the central axis CC, two sides of the corresponding angle can be defined, but this is not limited to this.

[0097] In some embodiments, the antenna structure 100 can cover an operating frequency band between 2400 MHz and 2500 MHz, and the principle behind this operation can be described as follows. Feeding energy from a signal source (not shown) can enter through any two of the first feeding port FP1, the second feeding port FP2, the third feeding port FP3, and the fourth feeding port FP4 to excite the antenna structure 100. The second radiating element 130 can be coupled and excited by the first radiating element 120 to enhance the radiation pattern of the antenna structure 100. With this design, the antenna structure 100 can support at least 2.4 GHz wideband operation for WLAN (Wireless Local Area Network).

[0098] In some embodiments, the antenna structure 100 can operate in either a first mode or a second mode to provide different polarization directions. In the first mode, the first feed port FP1 and the third feed port FP3 are both enabled (or in use), while the second feed port FP2 and the fourth feed port FP4 are disabled (or unused). A first feeding phase difference can exist between the first feed port FP1 and the third feed port FP3. In the second mode, the second feed port FP2 and the fourth feed port FP4 are both enabled, while the first feed port FP1 and the third feed port FP3 are both disabled. A second feeding phase difference can exist between the second feed port FP2 and the fourth feed port FP4. For example, the first feeding phase difference and the second feeding phase difference can each be equal to, but are not limited to, 0 degrees, 45 degrees, 90 degrees, 135 degrees, or 180 degrees. By selecting appropriate feeding ports and adjusting the feeding phase difference between them, the antenna structure 100 can provide various polarization directions.

[0099] In some embodiments, the dimensions of the antenna structure 100 can be as follows. The radius R1 of the first radiating portion 120 can be approximately equal to 0.25 times the guided wavelength (i.e., λg / 4, where the guided wavelength λg is defined in the dielectric substrate 140 and is adjusted based on the dielectric constant of the dielectric substrate 140) of the operating frequency band of the antenna structure 100. The radius R2 of the second radiating portion 130 can be approximately equal to 0.25 times the free-space wavelength (i.e., λf / 4, where the free-space wavelength λf is defined in free space) of the operating frequency band of the antenna structure 100. For example, the radius R2 of the second radiating portion 130 can be approximately twice the radius R1 of the first radiating portion 120. The width of the coupling gap GC1 between the second radiating portion 130 and the first radiating portion 120 can be approximately equal to 0.05 times the free-space wavelength (λf / 20) of the operating frequency band of the antenna structure 100. The thickness H1 of the dielectric substrate 140 can be between 0.4 mm and 1.6 mm. The dielectric constant of the dielectric substrate 140 may be between 2 and 16. The first angle θ1 between the second wider portion 165 of the second feed portion 160 and the first wider portion 155 of the first feed portion 150 may be approximately 45 degrees. The second angle θ2 between the third wider portion 175 of the third feed portion 170 and the second wider portion 165 of the second feed portion 160 may be approximately 45 degrees. The third angle θ3 between the fourth wider portion 185 of the fourth feed portion 180 and the third wider portion 175 of the third feed portion 170 may be approximately 45 degrees. The above ranges of component dimensions are derived based on multiple experimental results and help optimize the tunable polarization, operational bandwidth, and impedance matching of the antenna structure 100.

[0100] Figure 4 A perspective view of an antenna structure 400 according to an embodiment of the present invention is shown (to simplify the drawing, the ground element 110 and the dielectric substrate 140 are omitted). Figure 4 and Figure 2 Similar. Figure 4 In the embodiment, a first radiating portion 420 of the antenna structure 400 is substantially a regular octagon. In other embodiments, the first radiating portion 420 may be modified to be a regular N-gon, where N may be a multiple of 8 or any integer greater than or equal to 16. Based on actual measurement results, different shapes of the first radiating portion 420 can be used to fine-tune the impedance matching of the antenna structure 400. Figure 4 The remaining features of the antenna structure 400 are similar to Figure 1 、 Figure 2 、 Figure 3The antenna structure 100 is similar, so both embodiments can achieve similar operating effects.

[0101] Figure 5 A perspective view of an antenna structure 500 according to an embodiment of the present invention is shown (to simplify the drawing, the ground element 110 and the dielectric substrate 140 are omitted). Figure 5 and Figure 2 Similar. Figure 5 In the embodiment, a first radiating portion 520 of the antenna structure 500 further has a first notch 521, a second notch 522, a third notch 523, and a fourth notch 524, which correspond to the first feeding portion 150, the second feeding portion 160, the third feeding portion 170, and the fourth feeding portion 180, respectively. For example, each of the first notch 521, the second notch 522, the third notch 523, and the fourth notch 524 can be roughly triangular in shape, but is not limited to this. According to actual measurement results, the addition of the first notch 521, the second notch 522, the third notch 523, and the fourth notch 524 can be used to fine-tune the impedance matching of the antenna structure 500. Figure 5 The remaining features of the antenna structure 500 are similar to Figure 1 、 Figure 2 、 Figure 3 The antenna structure 100 is similar, so both embodiments can achieve similar operating effects.

[0102] Figure 6 A perspective view of an antenna structure 600 according to an embodiment of the present invention is shown. Figure 7 A side view of an antenna structure 600 according to an embodiment of the present invention is shown. Figure 6 、 Figure 7 and Figure 1 、 Figure 3 Similar. Figure 6 、 Figure 7In the embodiment, a dielectric substrate 640 of the antenna structure 600 is a three-layer circuit board having an upper layer 641, a middle layer 642, and a lower layer 643. The antenna structure 600 also includes a first conductive via element (CVE) 691, a second conductive via element 692, a third conductive via element 693, and a fourth conductive via element 694. The first CVE 691, the second CVE 692, the third CVE 693, and the fourth CVE 694 at least partially penetrate the dielectric substrate 640. Furthermore, a first feeding portion 650, a second feeding portion 660, a third feeding portion 670, and a fourth feeding portion 680 of the antenna structure 600 are all disposed within the middle layer 642 of the dielectric substrate 640 and may be located between the first radiating portion 120 and the ground element 110. The first conductive via 691 is coupled between the first feed portion 650 and a first connection point CP1 on the first radiating portion 120. The second conductive via 692 is coupled between the second feed portion 660 and a second connection point CP2 on the first radiating portion 120. The third conductive via 693 is coupled between the third feed portion 670 and a third connection point CP3 on the first radiating portion 120. The fourth conductive via 694 is coupled between the fourth feed portion 680 and a fourth connection point CP4 on the first radiating portion 120. This design, in which all feed portions and conductive vias are embedded in the dielectric substrate 640, increases the integration and manufacturing flexibility of the antenna structure 600. Figure 6 、 Figure 7 The remaining features of the antenna structure 600 are similar to Figure 1 、 Figure 2 、 Figure 3 The antenna structure 100 is similar, so both embodiments can achieve similar operating effects.

[0103] The present invention proposes a novel antenna structure. Compared with the prior art, the present invention has at least the advantages of multi-polarization, small size, wide bandwidth, and low manufacturing cost, and is therefore very suitable for application in various communication devices.

[0104] It is worth noting that the above-mentioned element size, element shape, and frequency range are not limiting conditions of the present invention. Antenna designers can adjust these settings according to different needs. The antenna structure of the present invention is not limited to Figures 1 to 7 The present invention may only include Figures 1 to 7 In other words, not all of the features shown in the figures need to be implemented in the antenna structure of the present invention at the same time.

[0105] In this specification and claims, ordinal numbers, such as "first," "second," "third," etc., have no sequential relationship with each other and are only used to distinguish two different components with the same name.

[0106] Although the present invention is disclosed in conjunction with the above preferred embodiments, they are not intended to limit the scope of the invention. Anyone familiar with this technology may make slight changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be based on the definition of the attached claims.

Claims

1. An antenna structure, comprising: Grounding elements; first radiation portion; A dielectric substrate having a first surface and a second surface opposite to each other, wherein the first radiating portion is disposed on the first surface, and the grounding element is disposed on the second surface; a second radiating portion, adjacent to the first radiating portion and separated from the first radiating portion; A first feeding portion having a first feeding port located at a first free end and coupled to the first radiating portion; A second feeding portion has a second feeding port located at a second free end and coupled to the first radiating portion; a third feeding portion having a third feeding port located at a third free end and coupled to the first radiating portion; as well as a fourth feeding portion having a fourth feeding port located at a fourth free end and coupled to the first radiating portion; The antenna structure covers the operating frequency band, The first feed portion is coupled to the first connection point on the first radiating portion, the second feed portion is coupled to the second connection point on the first radiating portion, the third feed portion is coupled to the third connection point on the first radiating portion, and the fourth feed portion is coupled to the fourth connection point on the first radiating portion. The first angle is defined between the second connection point and the first connection point, the second angle is defined between the third connection point and the second connection point, and the third angle is defined between the fourth connection point and the third connection point. The corresponding angles are defined by connecting any two adjacent connection points to the same central axis shared by the second radiating portion and the first radiating portion, and the first angle, the second angle and the third angle are all approximately equal to 45 degrees. 2 . The antenna structure as claimed in claim 1 , wherein the operating frequency band is between 2400 MHz and 2500 MHz. The antenna structure as claimed in claim 1 , wherein the first radiating portion has a circular shape. 4 . The antenna structure as claimed in claim 3 , wherein a radius of the first radiating portion is substantially equal to 0.25 times the guided wavelength of the operating frequency band.

5. The antenna structure as claimed in claim 1, wherein the first radiating portion further has a first notch, a second notch, a third notch and a fourth notch, corresponding to the first feeding portion, the second feeding portion, the third feeding portion and the fourth feeding portion respectively. 6 . The antenna structure as claimed in claim 1 , wherein the second radiating portion has another circular shape, and an area of the second radiating portion is larger than an area of the first radiating portion. 7 . The antenna structure as claimed in claim 6 , wherein a radius of the second radiating portion is substantially equal to 0.25 times the free space wavelength of the operating frequency band. 8 . The antenna structure as claimed in claim 1 , wherein the second radiating portion is substantially parallel to the first radiating portion, and a coupling gap is formed between the second radiating portion and the first radiating portion. 9 . The antenna structure of claim 8 , wherein a width of the coupling gap is substantially equal to 0.05 times the free space wavelength of the operating frequency band. 10 . The antenna structure as claimed in claim 1 , wherein the first feeding portion, the second feeding portion, the third feeding portion, and the fourth feeding portion are substantially equal in length.

11. The antenna structure according to claim 1, wherein the first feeding portion includes a first narrower portion and a first wider portion, the first feeding port is coupled to the first connection point on the first radiating portion via the first narrower portion and the first wider portion, the second feeding portion includes a second narrower portion and a second wider portion, the second feeding port is coupled to the second connection point on the first radiating portion via the second narrower portion and the second wider portion, the third feeding portion includes a third narrower portion and a third wider portion, the third feeding port is coupled to the third connection point on the first radiating portion via the third narrower portion and the third wider portion, the fourth feeding portion includes a fourth narrower portion and a fourth wider portion, and the fourth feeding port is coupled to the fourth connection point on the first radiating portion via the fourth narrower portion and the fourth wider portion.

12. The antenna structure as claimed in claim 11, wherein a first angle is formed between the second wider portion and the first wider portion, a second angle is formed between the third wider portion and the second wider portion, and a third angle is formed between the fourth wider portion and the third wider portion.

13. The antenna structure according to claim 1, further comprising: A first conductive through-hole element is coupled between the first feeding portion and a first connection point on the first radiating portion; a second conductive through-hole element coupled between the second feeding portion and a second connection point on the first radiating portion; a third conductive through-hole element coupled between the third feeding portion and a third connection point on the first radiating portion; and A fourth conductive through-hole element is coupled between the fourth feeding portion and a fourth connection point on the first radiating portion. 14 . The antenna structure of claim 13 , wherein the first conductive through-hole element, the second conductive through-hole element, the third conductive through-hole element, and the fourth conductive through-hole element at least partially penetrate the dielectric substrate. 15 . The antenna structure as claimed in claim 13 , wherein the first feeding portion, the second feeding portion, the third feeding portion, and the fourth feeding portion are all located between the first radiating portion and the ground element. 16 . The antenna structure as claimed in claim 1 , wherein the antenna structure operates in a first mode or a second mode to provide different polarization directions. 17 . The antenna structure of claim 16 , wherein in the first mode, the first feed port and the third feed port are enabled, the second feed port and the fourth feed port are disabled, and a first feed phase difference exists between the first feed port and the third feed port.

18. The antenna structure of claim 16, wherein in the second mode, the second feed port and the fourth feed port are enabled, the first feed port and the third feed port are disabled, and there is a second feed phase difference between the second feed port and the fourth feed port.

Images