ANTENNA STRUCTURE

Abstract

An antenna structure includes a feeding radiation element, a first radiation element, a second radiation element, an extension radiation element, and a dielectric substrate. The feeding radiation element has a feeding point. The first radiation element is coupled to a ground voltage. The first radiation element is adjacent to the feeding radiation element. The second radiation element is coupled to the ground voltage. The second radiation element is adjacent to the feeding radiation element. The extension radiation element is coupled to the first radiation element. The feeding radiation element and the second radiation element are at least partially surrounded by the first radiation element. The feeding radiation element, the first radiation element, the second radiation element, and the extension radiation element are all disposed on the dielectric substrate.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority of Taiwan Patent Application No. 112213004 filed on Nov. 29, 2023, the entirety of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

Field of the Invention

The disclosure generally relates to an antenna structure, and more particularly, to a wideband antenna structure.

Description of the Related Art

With the advancements being made in mobile communication technology, mobile devices such as portable computers, mobile phones, multimedia players, and other hybrid functional portable electronic devices have become more common. To satisfy consumer demand, mobile devices can usually perform wireless communication functions. Some devices cover a large wireless communication area; these include mobile phones using 2G, 3G, and LTE (Long Term Evolution) systems and using frequency bands of 700 MHZ, 850 MHz, 900 MHz, 1800 MHZ, 1900 MHZ, 2100 MHz, 2300 MHz, and 2500 MHz. Some devices cover a small wireless communication area; these include mobile phones using Wi-Fi systems and using frequency bands of 2.4 GHz, 5.2 GHz, and 5.8 GHz.

Antennas are indispensable elements for wireless communication. If an antenna for signal reception and transmission has an insufficient operational bandwidth, it may degrade the communication quality of the relative mobile device. Accordingly, it has become a critical challenge for designers to design a small-size, wideband antenna structure.

BRIEF SUMMARY OF THE INVENTION

In an exemplary embodiment, the invention is directed to an antenna structure that includes a feeding radiation element, a first radiation element, a second radiation element, an extension radiation element, and a dielectric substrate. The feeding radiation element has a feeding point. The first radiation element is coupled to a ground voltage. The first radiation element is adjacent to the feeding radiation element. The second radiation element is coupled to the ground voltage. The second radiation element is adjacent to the feeding radiation element. The extension radiation element is coupled to the first radiation element. The feeding radiation element and the second radiation element are at least partially surrounded by the first radiation element. The feeding radiation element, the first radiation element, the second radiation element, and the extension radiation element are all disposed on the dielectric substrate.

In some embodiments, the feeding radiation element substantially has a relatively large L-shape. The first radiation element substantially has a meandering shape. The second radiation element substantially has a relatively short L-shape. The extension radiation element substantially has a rectangular shape.

In some embodiments, the feeding radiation element is disposed between the first radiation element and the second radiation element.

In some embodiments, a first coupling gap is formed between the first radiation element and the feeding radiation element. A second coupling gap is formed between the second radiation element and the feeding radiation element. The width of the second coupling gap is greater than the width of the first coupling gap.

In some embodiments, the first radiation element includes a U-shaped segment.

In some embodiments, the antenna structure covers a first frequency band, a second frequency band, and a third frequency band. The first frequency band is from 700 MHz to 800 MHz. The second frequency band is from 1710 MHz to 1920 MHz. The third frequency band is from 1920 MHz to 2170 MHz.

In some embodiments, the length of the feeding radiation element is substantially equal to 0.25 wavelength of the second frequency band.

In some embodiments, the length of the first radiation element is substantially equal to 0.25 wavelength of the first frequency band.

In some embodiments, the length of the second radiation element is substantially equal to 0.25 wavelength of the third frequency band.

In some embodiments, the length of the U-shaped segment is substantially equal to 0.5 wavelength of the third frequency band.

BRIEF DESCRIPTION OF DRAWINGS

The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:

FIG. 1 is a diagram of an antenna structure according to an embodiment of the invention; and

FIG. 2 is a diagram of VSWR (Voltage Standing Wave Ratio) of an antenna structure according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

In order to illustrate the purposes, features and advantages of the invention, the embodiments and figures of the invention are shown in detail as follows.

Certain terms are used throughout the description and following claims to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms “include” and “comprise” are used in an open-ended fashion, and thus should be interpreted to mean “include, but not limited to . . . ”. The term “substantially” means the value is within an acceptable error range. One skilled in the art can solve the technical problem within a predetermined error range and achieve the proposed technical performance. Also, the term “couple” is intended to mean either an indirect or direct electrical connection. Accordingly, if one device is coupled to another device, that connection may be through a direct electrical connection, or through an indirect electrical connection via other devices and connections.

The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

Furthermore, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

FIG. 1 is a diagram of an antenna structure 100 according to an embodiment of the invention. The antenna structure 100 may be applied to a mobile device, such as a smart phone, a tablet computer, a notebook computer, a wireless access point, a router, or any device with a communication function. Alternatively, the antenna structure 100 may be applied to an electronic device, such as any unit of IOT (Internet of Things).

In the embodiment of FIG. 1, the antenna structure 100 includes a feeding radiation element 110, a first radiation element 120, a second radiation element 130, an extension radiation element 140, and a dielectric substrate 150. The feeding radiation element 110, the first radiation element 120, the second radiation element 130, and the extension radiation element 140 may all be made of metal materials, such as copper, silver, aluminum, iron, or their alloys.

The feeding radiation element 110 may substantially have a relatively long L-shape. Specifically, the feeding radiation element 110 may have a first end 111 and a second end 112. A feeding point FP is positioned at the first end 111 of the feeding radiation element 110. The second end 112 of the feeding radiation element 120 is an open end. The feeding point FP may be further coupled to a signal source 190. For example, the signal source 190 may be an RF (Radio Frequency) module for exciting the antenna structure 100. In some embodiments, the feeding radiation element 110 is disposed between the first radiation element 120 and the second radiation element 130.

The first radiation element 120 may substantially have a meandering structure. Both of the feeding radiation element 110 and the second radiation element 130 are at least partially surrounded by the first radiation element 120. Specifically, the first radiation element 120 has a first end 121 and a second end 122. The first end 121 of the first radiation element 120 is coupled to a ground voltage VSS. The second end 122 of the first radiation element 120 is an open end. For example, the ground voltage VSS may be provided by a system ground plane (not shown) of the antenna structure 100. In addition, the second end 122 of the first radiation element 120 may be substantially aligned with the second end 112 of the feeding radiation element 110. In some embodiments, the first radiation element 120 includes a U-shaped segment 125 positioned at the second end 122. The U-shaped segment 125 has an open side 126. In some embodiments, the first radiation element 120 is adjacent to the feeding radiation element 110, such that a first coupling gap GC1 can be formed between the first radiation element 120 and the feeding radiation element 110. It should be noted that the term “adjacent” or “close” over the disclosure means that the distance (spacing) between two corresponding elements is smaller than a predetermined distance (e.g., 10 mm or the shorter), but often does not mean that the two corresponding elements directly touch each other (i.e., the aforementioned distance/spacing between them is reduced to 0).

The second radiation element 130 may substantially have a relatively short L-shape (compared with the feeding radiation element 110). Specifically, the second radiation element 130 has a first end 131 and a second end 132. The first end 131 of the second radiation element 130 is coupled to the ground voltage VSS. The second end 132 of the second radiation element 130 is an open end. The second end 132 of the second radiation element 130 and the second end 112 of the feeding radiation element 110 may substantially extend in the same direction. On the other hand, the second end 132 of the second radiation element 130 and the second end 122 of the first radiation element 120 may substantially extend in opposite directions. In some embodiments, the second radiation element 130 is adjacent to the feeding radiation element 110, such that a second coupling gap GC2 can be formed between the second radiation element 130 and the feeding radiation element 110. For example, the width of the second coupling gap GC2 may be greater than the width of the first coupling gap GC1.

The extension radiation element 140 may substantially have a rectangular shape. Specifically, the extension radiation element 140 has a first end 141 and a second end 142. The first end 141 of the extension radiation element 140 is coupled to a connection point CP on the first radiation element 120. The second end 142 of the extension radiation element 140 is an open end. For example, the second end 142 of the extension radiation element 140 and the second end 112 of the feeding radiation element 110 may substantially extend in opposite directions and away from each other. In some embodiments, the aforementioned connection point CP is adjacent to the first end 121 of the first radiation element 120.

The feeding radiation element 110, the first radiation element 120, the second radiation element 130, and the extension radiation element 140 may all be disposed on the same surface of the dielectric substrate 150. The shape and type of the dielectric substrate 150 are not limited in the invention. For example, the dielectric substrate 150 may be an FR4 (Flame Retardant 4) substrate, a PCB (Printed Circuit Board), or an FPC (Flexible Printed Circuit). In some embodiments, the antenna structure 100 is a planar antenna structure. However, in alternative embodiments, the antenna structure 100 is modified to a 3D (Three-Dimensional) antenna structure.

FIG. 2 is a diagram of VSWR (Voltage Standing Wave Ratio) of the antenna structure 100 according to an embodiment of the invention. The horizontal axis represents the operational frequency (MHz), and the vertical axis represents the VSWR. According to the measurement of FIG. 2, the antenna structure 100 can cover a first frequency band FB1, a second frequency band FB2, and a third frequency band FB3. For example, the first frequency band FB1 may be from 700 MHz to 800 MHZ, the second frequency band FB2 may be from 1710 MHz to 1920 MHz, and the third frequency band FB3 may be from 1920 MHz to 2170 MHz. Therefore, the antenna structure 100 can support at least the wideband operations of LTE (Long Term Evolution).

The operational principles of the antenna structure 100 in some embodiments are described below. The feeding radiation element 110 can be excited to generate the second frequency band FB2. The first radiation element 120 can be excited by the feeding radiation element 110 using a coupling mechanism, so as to generate the first frequency band FB1. The second radiation element 130 can be excited by the feeding radiation element 110 using another coupling mechanism, so as to generate the third frequency band FB3. According to practical measurements, the extension radiation element 140 can be configured to fine-tune the impedance matching of the second frequency band FB2, and the U-shaped segment 125 of the first radiation element 120 can be configured to increase the operational bandwidth of the third frequency band FB3.

The element sizes of the antenna structure 100 in some embodiments are as follows. The length L1 of the feeding radiation element 110 may be substantially equal to 0.25 wavelength (λ/4) of the second frequency band FB2 of the antenna structure 100. The width W1 of the feeding radiation element 110 may be from 0.5 mm to 1.5 mm. The length L2 of the first radiation element 120 may be substantially equal to 0.25 wavelength (λ/4) of the first frequency band FB1 of the antenna structure 100. The width W2 of the first radiation element 120 may be from 0.5 mm to 1.5 mm. The length L3 of the second radiation element 130 may be substantially equal to 0.25 wavelength (λ/4) of the third frequency band FB3 of the antenna structure 100. The width W3 of the second radiation element 130 may be from 0.5 mm to 1.5 mm. In the first radiation element 120, the length LA of the U-shaped segment 125 may be substantially equal to 0.5 wavelength (λ/2) of the third frequency band FB3 of the antenna structure 100, and the width W4 of the open side 126 of the U-shaped segment 125 may be from 4 mm to 6 mm. The length L5 of the extension radiation element 140 may be from 16 mm to 24 mm, such as about 20 mm. The width W5 of the extension radiation element 140 may be from 5 mm to 9 mm, such as about 7 mm. The width of the first coupling gap GC1 may be smaller than or equal to 1 mm, such as about 0.5 mm. The width of the second coupling gap GC2 may be smaller than or equal to 2 mm, such as about 0.9 mm. The above ranges of element sizes are calculated and obtained according to many experimental results, and they help to optimize the operational bandwidth and the impedance matching of the antenna structure 100.

In some embodiments, the aforementioned antenna structure 100 is applied in a POS (Point of Sale) system (not shown). Since the POS system includes the aforementioned antenna structure 100, the POS system can support the function of wireless communication. In some embodiments, the POS system further includes an RF circuit, a filter, an amplifier, a processor, and/or a housing, but it is not limited thereto.

The invention proposes a novel antenna structure. In comparison to the conventional design, the invention has at least the advantages of small size, wide bandwidth, and low manufacturing cost. Therefore, the invention is suitable for application in a variety of mobile communication devices or the IOT.

Note that the above element sizes, element shapes, and frequency ranges are not limitations of the invention. An antenna designer can fine-tune these settings or values to meet different requirements. It should be understood that the antenna structure of the invention is not limited to the configurations of FIGS. 1 and 2. The invention may merely include any one or more features of any one or more embodiments of FIGS. 1 and 2. In other words, not all of the features displayed in the figures should be implemented in the antenna structure of the invention.

Use of ordinal terms such as “first”, “second”, “third”, etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having the same name (but for use of the ordinal term) to distinguish the claim elements.

While the invention has been described by way of example and in terms of the preferred embodiments, it should be understood that the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.

Claims

1. An antenna structure, comprising: a feeding radiation element, having a feeding point;a first radiation element, coupled to a ground voltage, wherein the first radiation element is adjacent to the feeding radiation element;a second radiation element, coupled to the ground voltage, wherein the second radiation element is adjacent to the feeding radiation element;an extension radiation element, coupled to the first radiation element, wherein the feeding radiation element and the second radiation element are at least partially surrounded by the first radiation element; anda dielectric substrate, wherein the feeding radiation element, the first radiation element, the second radiation element, and the extension radiation element are disposed on the dielectric substrate.

2. The antenna structure as claimed in claim 1, wherein the feeding radiation element substantially has a relatively large L-shape, the first radiation element substantially has a meandering shape, the second radiation element substantially has a relatively short L-shape, and the extension radiation element substantially has a rectangular shape.

3. The antenna structure as claimed in claim 1, wherein the feeding radiation element is disposed between the first radiation element and the second radiation element.

4. The antenna structure as claimed in claim 1, wherein a first coupling gap is formed between the first radiation element and the feeding radiation element, a second coupling gap is formed between the second radiation element and the feeding radiation element, and a width of the second coupling gap is greater than that of the first coupling gap.

5. The antenna structure as claimed in claim 1, wherein the first radiation element comprises a U-shaped segment.

6. The antenna structure as claimed in claim 5, wherein the antenna structure covers a first frequency band, a second frequency band, and a third frequency band, the first frequency band is from 700 MHz to 800 MHz, the second frequency band is from 1710 MHz to 1920 MHz, and the third frequency band is from 1920 MHz to 2170 MHz.

7. The antenna structure as claimed in claim 6, wherein a length of the feeding radiation element is substantially equal to 0.25 wavelength of the second frequency band.

8. The antenna structure as claimed in claim 6, wherein a length of the first radiation element is substantially equal to 0.25 wavelength of the first frequency band.

9. The antenna structure as claimed in claim 6, wherein a length of the second radiation element is substantially equal to 0.25 wavelength of the third frequency band.

10. The antenna structure as claimed in claim 6, wherein a length of the U-shaped segment is substantially equal to 0.5 wavelength of the third frequency band.