TWI718599B - Communication device - Google Patents

Abstract

A communication device includes a ground plane, an antenna array, and an EBG (Electromagnetic Band Gap) structure. The antenna array includes a plurality of antenna elements. The EBG structure includes a plurality of EBG units. The EBG units are coupled to the ground plane. The antenna array is surrounded by the EBG structure. The EBG structure is configured to suppress the front-to-back ratio of the radiation efficiency of the antenna array.

Description

Communication device

The present invention relates to a communication device, and more particularly to a communication device that can reduce the front-to-back ratio of the radiation pattern of the antenna array.

With the development of mobile communication technology, mobile devices have become more and more common in recent years, such as portable computers, mobile phones, multimedia players and other portable electronic devices with mixed functions. In order to meet people's needs, mobile devices usually have wireless communication functions. Some cover long-distance wireless communication ranges. For example, mobile phones use 2G, 3G, LTE (Long Term Evolution) systems and their use of 700MHz, 850 MHz, 900MHz, 1800MHz, 1900MHz, 2100MHz, 2300MHz, and 2500MHz frequency bands for communication. Some cover short-distance wireless communication ranges, for example: Wi-Fi, Bluetooth systems use 2.4GHz, 5.2GHz and 5.8GHz frequency bands for communication.

Antenna is a necessary element for mobile devices to surf the Internet at a high speed. After entering the next generation of communications, 5G-supporting antenna arrays often face two major dilemmas, one is the short communication distance (Communication Distance), and the other is the poor spatial efficiency (Spatial Efficiency), both of which are caused by The isolation between the antenna elements is too low and the front-to-back ratio of the radiation pattern of the antenna array is too high. In view of this, it is necessary to propose a new solution to overcome the problems faced by the prior art.

In a preferred embodiment, the present invention provides a communication device including: a ground plane; an antenna array including a plurality of antenna elements; and an electromagnetic band gap structure including a plurality of electromagnetic band gap units, wherein the electromagnetic bands The gap units are all coupled to the ground plane; wherein the antenna array is surrounded by the electromagnetic band gap structure.

In some embodiments, the electromagnetic band gap structure is used to suppress the front-to-back ratio of the radiation pattern of the antenna array.

In some embodiments, the antenna array covers an operating frequency band between 27 GHz and 29 GHz.

In some embodiments, the antenna elements are arranged in a first symmetrical pattern.

In some embodiments, the first symmetrical pattern exhibits a square shape.

In some embodiments, each of the antenna elements is a patch antenna.

In some embodiments, the length of each of the antenna elements is approximately equal to 0.25 wavelength of the operating frequency band.

In some embodiments, the distance between any adjacent two of the antenna elements is approximately equal to 0.5 times the wavelength of the operating frequency band.

In some embodiments, the total number of the antenna elements is 16.

In some embodiments, the electromagnetic bandgap units are arranged in a second symmetrical pattern.

In some embodiments, the second symmetrical pattern presents a hollow square.

In some embodiments, the second symmetrical pattern includes a first ring and a second ring, the second ring is located inside the first ring, and the antenna elements are all located inside the second ring .

In some embodiments, each of the electromagnetic bandgap units exhibits a mushroom shape.

In some embodiments, each of the electromagnetic bandgap units includes a top metal sheet and a connecting metal pillar, and the top metal sheet is coupled to the ground plane via the connecting metal pillar.

In some embodiments, the length of each of the electromagnetic bandgap units is less than 0.1 times the wavelength of the operating frequency band.

In some embodiments, the height of each of the electromagnetic bandgap units is less than 0.1 times the wavelength of the operating frequency band.

In some embodiments, the distance between any adjacent two of the electromagnetic band gap units is less than 0.02 wavelength of the operating frequency band.

In some embodiments, the shortest distance from any one of the antenna elements to the electromagnetic band gap structure is greater than 0.25 times the wavelength of the operating frequency band.

In some embodiments, the total number of the electromagnetic band gap units is 184.

In some embodiments, the communication device further includes: a dielectric substrate disposed on the ground surface, wherein the electromagnetic band gap units all penetrate the dielectric substrate.

In order to make the purpose, features and advantages of the present invention more comprehensible, specific embodiments of the present invention are listed below, with the accompanying drawings, and detailed descriptions are as follows.

In the specification and the scope of patent application, certain words are used to refer to specific elements. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and the scope of patent application do not use differences in names as a way to distinguish elements, but use differences in functions of elements as a criterion for distinguishing. The terms "include" and "include" mentioned in the entire specification and the scope of the patent application are open-ended terms and should be interpreted as "including but not limited to". The term "approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and achieve the basic technical effect. In addition, the term "coupling" includes any direct and indirect electrical connection means in this specification. Therefore, if it is described in the text that a first device is 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 through other devices or connection means. Two devices.

FIG. 1 is a schematic diagram of a communication device 100 according to an embodiment of the invention. As shown in Figure 1, the communication device 100 includes a ground plane (Ground Plane) 110, an antenna array (Antenna Array) 120, and an electromagnetic band gap (Electromagnetic Band Gap, EBG) structure 130, all of which can be made of metal materials to make. The antenna array 120 includes a plurality of antenna elements (not shown). The shapes and types of the antenna elements are not particularly limited in the present invention. For example, each antenna element can be a patch antenna, a monopole antenna, a dipole antenna, a bowtie antenna, and a loop antenna. Antenna), a helical antenna (Helical Antenna), or a chip antenna (Chip Antenna), but it is not limited to this. The electromagnetic band gap structure 130 includes a plurality of electromagnetic band gap units (not shown), and the electromagnetic band gap units are all coupled to the ground plane 110. The shapes and types of the electromagnetic bandgap units are not particularly limited in the present invention. It must be noted that the antenna array 120 is completely surrounded by the electromagnetic band gap structure 130. Under this design, the electromagnetic band gap structure 130 can be used to suppress the front-to-back ratio of the radiation pattern of the antenna array 120, thereby effectively increasing the communication distance of the communication device 100. And Spatial Efficiency. In addition, although not shown in Figure 1, the communication device 100 may further include other components, such as a processor, a power supply module, or (and) a housing.

The following embodiments will introduce the detailed structure and specific implementation of the communication device 100. It must be understood that these drawings and descriptions are only examples and are not used to limit the scope of the present invention.

FIG. 2 is a top view of the communication device 200 according to an embodiment of the invention. In the embodiment of FIG. 2, the communication device 200 includes a ground plane 210, an antenna array 220, and an electromagnetic band gap structure 230, all of which can be made of metal materials. The antenna array 220 includes a plurality of antenna elements 240. For example, each of the antenna elements 240 can each be a patch antenna. The antenna elements 240 can be arranged into a first symmetrical pattern (Symmetrical Pattern) 250. For example, the first symmetrical pattern 250 may be approximately a square. In some embodiments, the total number of the antenna elements 240 is 16, and they can form a 4×4 square matrix. In other embodiments, the total number of the antenna elements 240 can also be adjusted according to different requirements.

The electromagnetic band gap structure 230 includes a plurality of electromagnetic band gap units 260, and the electromagnetic band gap units 260 are all coupled to the ground plane 210. For example, each of the electromagnetic band gap units 260 may each exhibit a mushroom-shape (Mushroom-Shape). The electromagnetic band gap units 260 can be arranged in a second symmetrical pattern 270. For example, the second symmetrical pattern 270 may present a hollow square. In detail, the second symmetrical pattern 270 may include a first loop 271 and a second loop 272, wherein the second loop 272 may be located inside the first loop 271, and the antenna elements 240 of the antenna array 220 are all It can be located inside the second ring 272. According to the actual measurement results, the arrangement of the double-ring electromagnetic bandgap unit 260 can be used as a Band Rejection Filter, which can effectively block surface waves in a target band (Target Band). . In some embodiments, the total number of the electromagnetic band gap units 260 is 184. In other embodiments, the total number of the electromagnetic bandgap units 260 can also be adjusted according to different requirements.

FIG. 3 shows a partial cross-sectional view of the communication device 200 according to an embodiment of the present invention (which can be along a cross-sectional line LC1 in FIG. 2). In the embodiment of FIG. 3, each of the electromagnetic bandgap units 260 includes a top metal sheet 261 and a connecting metal pillar 262, wherein the top metal sheet 261 is coupled to the connecting metal pillar 262 GND plane 210. For example, the top metal sheet 261 can be approximately a small square, which can be approximately parallel to the ground surface 210; and the connecting metal post 262 can be approximately a cylindrical shape, which can be connected to the ground surface 210 and the top metal surface 261. Roughly perpendicular to each other. However, the present invention is not limited to this. In other embodiments, the top metal sheet 261 may also have an equilateral triangle, a circle, an ellipse, or a trapezoid, and the connecting metal pillar 262 may also have a triangular pillar shape or a quadrangular pillar shape.

In some embodiments, the antenna array 220 covers an operating frequency band between 27 GHz and 29 GHz, so it can support 5G millimeter wave (Millimeter Wave) broadband operation. In terms of operating principles, the target frequency band of the band rejection filter formed by the electromagnetic band gap units 260 can be equivalent to the operating frequency band of the antenna array 220 to avoid unnecessary surface wave diffusion. Therefore, the electromagnetic band gap structure 230 can be used to suppress the front-to-back ratio of the radiation pattern of the antenna array 220, thereby effectively improving the communication distance and space efficiency of the communication device 200. According to actual measurement results, after adding the surrounding design of the electromagnetic band gap structure 230, the front-to-back ratio of the antenna array 220 will decrease by about 6dB to 8dB, which can already meet the practical application requirements of general communication devices.

In some embodiments, the component size of the communication device 200 may be as described below. The length L1 of each of the antenna elements 240 can be approximately equal to 0.25 times the wavelength (λ/4) of the operating frequency band of the antenna array 220. The distance D1 between any adjacent two of the antenna elements 240 is approximately equal to 0.5 times the wavelength (λ/2) of the operating frequency band of the antenna array 220. The length L2 of each of the electromagnetic band gap units 260 (or the length L2 of the top metal sheet 261) is less than 0.1 times the wavelength (λ/10) of the operating frequency band of the antenna array 220. The height H1 of each of the electromagnetic band gap units 260 (or the height H1 of the top metal sheet 261) is less than 0.1 times the wavelength (λ/10) of the operating frequency band of the antenna array 220. The distance D2 between any adjacent two of the electromagnetic band gap units 260 is less than 0.02 wavelength (λ/50) of the operating frequency band of the antenna array 220. The shortest distance DS from any one of the antenna elements 240 to the electromagnetic band gap structure 230 is greater than 0.25 times the wavelength (λ/4) of the operating frequency band of the antenna array 220. The range of the above distance is obtained based on the results of many experiments, which helps to minimize the front-to-back ratio of the radiation pattern of the antenna array 220 and maximize the communication distance and space efficiency of the communication device 200.

FIG. 4 is a cross-sectional view of the communication device 400 according to an embodiment of the invention. Figure 4 is similar to Figures 2 and 3. In the embodiment of FIG. 4, the communication device 400 further includes a dielectric substrate (Dielectric Substrate) 480, wherein the dielectric substrate 480 is disposed on the ground surface 210. The antenna elements 240 of the antenna array 220 can all be arranged on the dielectric substrate 480. The electromagnetic band gap units 260 of the electromagnetic band gap structure 230 can pass through the dielectric substrate 480. In some embodiments, the dielectric constant of the dielectric substrate 480 is between 2-6. It should be noted that if the dielectric substrate 480 is added, the corresponding relationship between the aforementioned element size and wavelength can be adjusted according to the dielectric constant of the dielectric substrate 480, so that the overall size of the communication device 400 can be reduced. The remaining features of the communication device 400 in Fig. 4 are similar to those of the communication device 200 in Figs. 2 and 3, so the two embodiments can achieve similar operating effects.

The present invention provides a novel communication device, which includes an electromagnetic band gap structure surrounding an antenna array. Compared with the traditional design, the present invention at least has the advantage of suppressing the front-to-back comparison of the radiation pattern of the antenna array. Therefore, the present invention is very suitable for application in various communication devices to improve their communication distance and space efficiency.

It should be noted that the above-mentioned component size, component shape, and frequency range are not the limiting conditions of the present invention. The antenna designer can adjust these settings according to different needs. The communication device of the present invention is not limited to the state shown in Figs. 1-4. The present invention may only include any one or more of the features of any one or more of the embodiments shown in FIGS. 1-4. In other words, not all the features of the figures need to be implemented in the communication device of the invention at the same time.

The ordinal numbers in this specification and the scope of the patent application, such as "first", "second", "third", etc., do not have a sequential relationship with each other, and they are only used to distinguish two having the same Different components of the name.

Although the present invention is disclosed as above in the preferred embodiment, it is not intended to limit the scope of the present invention. Anyone who is familiar with the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, The scope of protection of the present invention shall be subject to those defined by the attached patent scope.

100, 200, 400 ~ communication device; 110, 210～Grounding plane; 120, 220～antenna array; 130, 230 ~ electromagnetic band gap structure; 240～antenna element; 250～The first symmetrical pattern; 260～Electromagnetic band gap unit; 261～Top metal sheet; 262～Connect the metal column; 270~Second symmetrical pattern; 271~The first ring; 272~The second ring; 480～Dielectric substrate; D1, D2～spacing; DS～shortest distance; H1～height; L1, L2～length; LC1～hatched line; X～X axis; Y～Y axis; Z～Z axis.

Figure 1 is a schematic diagram of a communication device according to an embodiment of the invention. Figure 2 is a top view of the communication device according to an embodiment of the invention. FIG. 3 is a partial cross-sectional view of the communication device according to an embodiment of the invention. FIG. 4 is a cross-sectional view of the communication device according to an embodiment of the invention.

100～Communication device; 110～Grounding plane; 120～antenna array; 130 ~ Electromagnetic band gap structure.

Claims (17)

A communication device includes: a ground plane; an antenna array including a plurality of antenna elements; and an electromagnetic band gap structure including a plurality of electromagnetic band gap units forming a rectangle together, wherein the electromagnetic band gap units are all coupled to The ground plane; wherein the antenna array is surrounded by the electromagnetic band gap structure as a whole, wherein the electromagnetic band gap structure does not extend into any independent two of the antenna elements; wherein the antenna elements are arranged into one The first symmetrical pattern; wherein the first symmetrical pattern presents a square; wherein the shortest distance from any one of the antenna elements to the electromagnetic band gap structure is greater than 0.25 times the wavelength of an operating frequency band of the antenna array. The communication device described in the first item of the scope of patent application, wherein the electromagnetic band gap structure is used to suppress the front-to-back ratio of the radiation pattern of the antenna array. As for the communication device described in item 1 of the scope of patent application, the operating frequency band is between 27 GHz and 29 GHz. In the communication device described in the first item of the scope of patent application, each of the antenna elements is a patch antenna. For the communication device described in item 3 of the scope of patent application, the length of each of the antenna elements is approximately equal to 0.25 times the wavelength of the operating frequency band. As for the communication device described in item 3 of the scope of patent application, the distance between any adjacent two of the antenna elements is approximately equal to 05 times the wavelength of the operating frequency band. For the communication device described in item 1 of the scope of patent application, the total number of the antenna elements is 16. For the communication device described in item 1 of the scope of patent application, the electromagnetic band gap units are arranged in a second symmetrical pattern. The communication device described in item 8 of the scope of patent application, wherein the second symmetrical pattern is a hollow square. The communication device described in claim 8, wherein the second symmetrical pattern includes a first ring and a second ring, the second ring is located inside the first ring, and the antenna elements They are all located inside the second ring. In the communication device described in item 1 of the scope of patent application, each of the electromagnetic bandgap units exhibits a mushroom shape. The communication device described in claim 1, wherein each of the electromagnetic bandgap units includes a top metal sheet and a connecting metal pillar, and the top metal sheet is coupled via the connecting metal pillar Connect to this ground plane. For the communication device described in item 3 of the scope of patent application, the length of each of the electromagnetic band gap units is less than 0.1 times the wavelength of the operating frequency band. For the communication device described in item 3 of the scope of patent application, the height of each of the electromagnetic band gap units is less than 0.1 times the wavelength of the operating frequency band. For the communication device described in item 3 of the scope of patent application, the distance between any adjacent two of the electromagnetic band gap units is less than 0.02 times the wavelength of the operating frequency band. For the communication device described in item 1 of the scope of patent application, the total number of the electromagnetic bandgap units is 184. The communication device described in item 1 of the scope of the patent application further includes: a dielectric substrate disposed on the ground plane, wherein the electromagnetic band gap units all penetrate the dielectric substrate.

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