TWI750924B - Multi-frequency antenna structure - Google Patents

Abstract

A multi-frequency antenna structure is composed of a substrate, and the substrate has a first surface and a second surface opposite to each other, and the substrate is provided with at least one unit antenna between the first and second surfaces, and each unit antenna is A first radiating portion and a second radiating portion are formed on the first and second surfaces of the substrate respectively, which are opposite and coupled to each other, so that the radiation mechanism of the high-frequency operating frequency band is the first radiating portion of the ground plane of the first surface of the substrate. The low frequency working frequency band is radiated by the second radiating part of the ground plane of the second surface of the substrate. Therefore, through the design of dual frequency and coupling effect, the broadband matching of the input impedance can be obtained to increase the working frequency bandwidth to cover the The use of all 5G IF bands does not need to be redesigned for different regions or countries.

Description

Multi-frequency antenna structure

The present invention belongs to the technical field of a mobile phone antenna, in particular to a multi-frequency antenna structure with multiple inputs and multiple outputs.

Press, with the rapid development of communication technology, communication technology has gradually shifted from wired communication to wireless communication, and the transmission medium of signals has changed from the previous tangible metal lines (such as coaxial cables) to air as the transmission medium The medium of wireless communication, and the communication bandwidth and speed have also developed from the early analog mobile phone (1G) to the recent fifth-generation mobile communication technology (English: 5th generation mobile networks or 5th generation wireless systems, referred to as 5G). However, with the rapid development of the Internet of Things (IoT) and new applications such as smart cities, many countries have begun to plan the use of spectrum for 5G mobile communication systems. The spectrum of the 5G mobile communication system can be roughly divided into three parts: the low frequency band with frequencies below 1 GHz, the intermediate frequency band with frequencies between 1 GHz and 6 GHz, and the high frequency band with frequencies above 24 GHz.

As countries differ according to the technical development conditions of their communication associations, the spectrum planning systems of major countries are shown in Table 1 below;

Table I nation low frequency band IF band high frequency band Taiwan - 3.5GHz 28GHz South Korea - 3.42-3.7GHz 28GHz China - 3.4-3.5/4.8-4.9GHz 27/37GHz Japan - 3.6-4.1/4.5-4.6GHz 28GHz America 600M 2.5/3.7-4.2GHz 28GHz/37GHz France 700M 3.4-3.8GHz 26GHz Germany 700M 2.0/3.4-3.7GHz 26GHz/28GHz

At present, the communication frequency band of 5G mobile communication is mainly used in the intermediate frequency frequency band, and the development is relatively mature. In the existing 5G mobile communication, the medium used to send and receive signals to and from wireless communication devices is the antenna. It can be seen from the above that the design of the antenna will affect the call quality of the wireless communication equipment, and due to the reduction in the size of the mobile phone and the increase in functions in recent years, the antenna design is also subject to considerable restrictions, so that it can only be applied to local frequency bands, making 5G antennas cannot meet the requirements of Multi-Input Multi-Output (MIMO for short), so manufacturers need to redesign antennas for different regions and countries according to their frequency bands, which invisibly increases the difficulty and cost of antenna design.

Therefore, integrating various communication frequency bands by using a multi-frequency antenna is more important to the development of wireless communication, and has become an urgent problem to be solved by the present invention. In view of this, the inventor of the present invention has concentrated on the research and application of the theory in view of the above-mentioned problems faced by the existing ones, adhering to the design, development and implementation experience in the related industry for many years, and improved the existing structure for the shortcomings, and finally successfully developed a A multi-frequency antenna structure is provided to overcome the trouble and inconvenience caused by the inability of the existing antenna to cover the use of the intermediate frequency band.

The main purpose of the present invention is to provide a multi-band antenna structure, which can improve the communication quality of the antenna through the MIMO technology, and can meet the trend of mobile devices gradually developing towards miniaturization, high function and multi-band.

The second main purpose of the present invention is to provide a multi-frequency antenna structure using a multi-frequency antenna structure, the operating frequency of which can cover the use of all 5G intermediate frequency bands, and there is no need to redesign the antenna due to different regions and different frequency bands.

Another main objective of the present invention is to provide a multi-frequency antenna structure using the multi-frequency antenna structure, which can effectively simplify the structure and reduce the cost.

Therefore, in order to achieve the aforementioned purpose, the present invention provides a multi-frequency antenna structure, which is composed of a substrate, the substrate has a first surface and a second surface opposite to each other, and the substrate is located between the first and second surfaces. There is at least one unit antenna between the two surfaces, and each unit antenna is formed with a first radiating part and a second radiating part opposite and coupled to each other on the first and second surfaces of the substrate respectively, so that the high-frequency operating frequency band The radiation mechanism is radiated by the first radiation part of the ground plane of the first surface of the substrate, and the low frequency operating frequency band is radiated by the second radiation part of the ground plane of the second surface of the substrate; the first radiation part of each unit antenna has A straight body abutting against the edge of the first surface of the base plate, and one side of the straight body is connected with an orthogonal body, wherein the orthogonal body includes a crossbar segment and a vertical connection to the crossbar segment corresponding to one end of the straight body The straight rod segment of the bottom edge, and the straight rod segment is connected with the aforementioned straight body to form an approximately inverted F-shaped structure, and the free end edge of the cross rod segment is connected with the ground plane of the first surface of the base plate; each The second radiating portion of the unit antenna is formed by a straight body abutting against the edge of the second surface of the substrate, and a top edge of the straight body and the second surface of the substrate are connected with a ground plane.

In this way, through the specific implementation of the above technical means, the present invention can utilize the first radiating portion and the second radiating portion of each element antenna coupled with each other on the substrate to achieve the purpose of broadband, and through the design of dual frequency and coupling effect, to Obtain wide-band matching of input impedance to increase its operating bandwidth to cover the use of all 5G IF frequency bands, no need to redesign due to different regions or countries, and can simplify the structure, while reducing design and manufacturing costs, thereby increasing the number of products added value and improve its economic efficiency.

And the present invention utilizes the following technical means to further achieve the aforementioned purposes and effects; such as:.

The substrate is a fiberglass board with a flame retardant grade of FR-4, a relative permittivity of 4.4, and a loss tangent of 0.02.

The length of the substrate is 130mm, the width is 70mm, and its thickness is about 0.8mm, and the substrate has four opposite unit antennas on both edges of the substrate, and the distance between the edge of the substrate and the top edge of the uppermost unit antenna is 2mm, the width of each unit antenna is 4mm, the length is 16mm, the distance between the bottom edge and the top edge of the adjacent unit antenna is 17mm, and the distance between the bottom edge of the lowermost unit antenna and the bottom edge of the substrate is 13mm.

The width of the straight body and the orthogonal body of the first radiating part of the unit antenna is 1mm, and the length of the straight body of the first radiating part is 7 mm, and the straight rod section of the orthogonal body of the first radiating part is connected and overlapped with the straight body The length of the straight body of the first radiating part is 2.5mm, the length of the straight body of the first radiating part is 4.5 mm, the length of the cross-bar segment of the orthogonal body is 4.5 mm, and the width of the straight body of the second radiating part is 1.4 mm, And the length of the straight body of the second radiating part is 9.3 mm, and the distance from the top edge of the straight body of the second radiating part to the top edge of the cross bar section of the orthogonal body of the first radiating part is 7 mm.

In order to enable your examiners to further understand the structure, features and other purposes of the present invention, the following are some preferred embodiments of the present invention, which are described in detail below with the accompanying drawings, and at the same time, those who are familiar with the technical field can implement them in detail. .

The present invention is a multi-frequency antenna structure. In the specific embodiment of the present invention and its components illustrated in the accompanying drawings, all references to front and rear, left and right, top and bottom, upper and lower, and horizontal and vertical, It is only used for convenience of description and is not intended to limit the present invention, nor to limit its components to any position or spatial orientation. The dimensions specified in the drawings and the description can be changed according to the design and requirements of the present invention without departing from the scope of the patent application of the present invention.

The structure of the multi-frequency antenna structure of the present invention is as disclosed in FIG. 1 and FIG. 2 , the antenna structure is composed of a substrate (10), the substrate (10) is a glass fiber board, and the substrate (10) has Opposite a first surface (11) and a second surface (12), and the length (L) of the substrate (10) is 130mm, the width (W) is 70mm, the thickness is about 0.8mm, and the flame retardant material grade It is FR-4, the relative permittivity is 4.4, the loss tangent is 0.02, and the substrate (10) is provided with at least one element antenna (20) between the first and second surfaces (11, 12), in this embodiment , the substrate (10) is respectively formed with four opposite unit antennas (20) by printed circuits on the edges of both sides, wherein each unit antenna (20) is respectively on the first and second surfaces (10) of the substrate (10). 11, 12) A first radiating portion (30) and a second radiating portion (40) that can be coupled to each other are formed, and the distance (A) between the edge of the substrate (10) and the top edge of the uppermost unit antenna (20) ) is 2mm, the width (S2) of each unit antenna (20) is 4mm, the length (S1) is 16mm, and the distance (B) between the bottom edge and the top edge of the adjacent unit antenna (20) is 17mm, And the distance (C) between the bottom edge of the lowermost unit antenna (20) and the bottom edge of the substrate (10) is 13 mm, so that the unit antenna (20) can be used to send and receive signals whose frequencies are located in the intermediate frequency band, so as to achieve coverage of all The purpose of using the 5G intermediate frequency band; for the detailed structure of the unit antenna (20), please refer to Fig. 2 and Fig. 2 (A), (B), wherein the radiation mechanism of the high frequency working band is the substrate ( 10) the first surface (11) is radiated by the first radiating part (30) of the ground plane, and the low frequency operating frequency band is radiated by the second radiating part (40) of the second surface (12) ground plane of the substrate (10), And wherein the first radiation part (30) located on the first surface (11) of the substrate (10) is as shown in FIG. 3, the first radiation part (30) has a first surface ( 11) A straight body (31) on the edge, and one side of the straight body (31) is connected with an orthogonal body (35), wherein the orthogonal body (35) includes a crossbar segment (351) and a vertical connection to the crossbar. The rod section (351) corresponds to the straight rod section (352) at the bottom edge of one end of the straight body (31), and the straight rod section (352) is connected with the aforementioned straight body (31), and the straight rod (31) is perpendicular to the The width of the body (35) is 1mm, the length of the straight body (31) is 7mm, and the length of the straight rod segment (352) of the orthogonal body (35) and the straight body (31) is 2.5mm. , so that the protruding length of the straight body (31) is 4.5mm, and the length of the crossbar segment (351) of the orthogonal body (35) is 4.5mm, forming an approximate inverted F-shaped structure, and the crossbar segment (351) The free end edge of the base plate (10) is connected to the ground plane of the first surface (11) of the substrate (10); furthermore , the second radiating portion (40) of the unit antenna (20) located on the second surface (12) of the substrate (10) is shown in FIG. 4, and the second radiating portion (40) has a 10) Formed by a straight body (41) at the edge of the second surface (12), and there is a connection between the top edge of the straight body (41) and the second surface (12) of the substrate (10) for grounding, the straight body The width of (41) is 1.4 mm, and the length of the straight body (41) is 9.3 mm, and the top edge of the straight body (41) of the second radiating portion (40) is perpendicular to the aforementioned first radiating portion (30) The distance from the top edge of the cross bar section (351) of (35) is 7 mm;

Thereby, each unit antenna (20) is made to pass through the first radiating part (30) and the second radiating part (40) coupled with each other on the first and second surfaces (11, 12) of the substrate (10), so as to increase the radiating part (40). The working bandwidth is to cover the use of all 5G IF frequency bands, and there is no need to redesign due to the different frequency bands used by regions or countries, and a multi-frequency antenna structure with simple structure and multiple input and multiple output is formed.

When the multi-frequency antenna structure of the present invention is actually simulated and tested, as shown in FIG. 5 , it can be found that the simulation results of the input impedance bandwidth ( S11 ) of the eight broadband unit antennas ( 20 ) designed on the substrate ( 10 ) , it can be seen from the results that the individual unit antennas (20) can meet the operating frequency in the range of 3.3GHz to 5.0GHz, and from the surface current simulation results of the 8 unit antennas (20) shown in Figures 6 and 7, It can be seen from the results that the radiation mechanism of the low frequency 3.5GHz is radiated by the second radiation part (40) connected to the ground plane by the second surface (12) of the substrate (10) (as shown in Figure 6), while the high frequency 4.9 The radiation mechanism of GHz is the radiation of the first radiation part (30) of the first surface (11) of the substrate (10) (as shown in FIG. 7). Also shown in FIG. 8 , the experimental and simulation results of the eight broadband unit antennas (20) designed for the substrate (10) are compared. Although there are some gaps, the experimental results are still consistent with the simulation results, and they also meet the designed bandwidth requirements.

Through the aforementioned design and description, the multi-frequency antenna structure of the present invention utilizes each element antenna (20) to pass through the first radiating portion (30) coupled to each other on the first and second surfaces (11, 12) of the substrate (10). With the second radiating part (40), for the purpose of broadband, and through the design of dual frequency and coupling effect, the broadband matching of the input impedance can be obtained to increase its operating bandwidth, so as to cover all 5G intermediate frequency bands. It can be redesigned for different regions or countries using different frequency bands, and can simplify the structure, reduce design and manufacturing costs, and greatly improve its practicability.

From this, it can be understood that the present invention is an excellent creation, in addition to effectively solving the problems faced by the prior art, it also greatly improves the efficacy, and there is no identical or similar product creation or public use in the same technical field. , and at the same time has the enhancement of efficacy, so the present invention has met the requirements of "novelty" and "progressiveness" of the invention patent, and the application for the invention patent is filed in accordance with the law.

10: Substrate 11: The first surface 12: Second surface 20: unit antenna 30: First Radiation Department 31: Straight body 35: Orthogonal 351: Crossbar Section 352: Straight rod section 40: Second Radiation Department 41: Straight body

FIG. 1 is a schematic diagram of a plane structure of the present invention arranged on a substrate.

FIG. 2 is a schematic diagram of the three-dimensional structure of the present invention, wherein (A) is the relational state of the first field type, and (B) is the relational state of the second field type.

FIG. 3 is a schematic view of the size of the first radiation part in the present invention.

FIG. 4 is a schematic view of the size of the second radiating portion in the present invention.

FIG. 5 is a schematic diagram showing the simulation results of the input impedance bandwidth (S11) of eight broadband frequencies of the present invention.

FIG. 6 is a schematic diagram of the surface current simulation results of eight broadband mobile phone antennas according to the present invention when the operating frequency is 3.5 GHz.

FIG. 7 is a schematic diagram of the surface current simulation results of eight broadband mobile phone antennas according to the present invention when the operating frequency is 3.5 GHz.

FIG. 8 is a schematic diagram showing the comparison of experimental and simulation results of eight broadband mobile phone antennas of the present invention.

10: Substrate

11: The first surface

20: unit antenna

30: First Radiation Department

40: Second Radiation Department

Claims (2)

A multi-frequency antenna structure is composed of a substrate, the substrate has a first surface and a second surface opposite to each other, and the substrate is provided with at least one element antenna between the first and second surfaces, and each of the The unit antenna is formed on the first and second surfaces of the substrate with a first radiating portion and a second radiating portion that are opposite and coupled with each other, so that the radiation mechanism of the high-frequency operating frequency band is the first radiating portion of the ground plane of the first surface of the substrate. A radiating part is radiated, and the low frequency operating frequency band is radiated by the second radiating part of the ground plane of the second surface of the substrate. The length of the substrate is 130mm, the width is 70mm, and the thickness is about 0.8mm, and the substrate is on both sides. There are four opposite element antennas on the edge respectively, and the distance between the edge of the substrate and the top edge of the uppermost element antenna is 2mm, and the distance between the bottom edge and the top edge of the adjacent element antenna is 17mm, and the bottom of the lowermost element antenna is 17mm. The distance between the edge and the bottom edge of the substrate is 13mm; the first radiating portion of each unit antenna has a straight body abutting on the edge of the first surface of the substrate, and one side of the straight body is connected with an orthogonal body, wherein the orthogonal The body includes a crossbar segment and a straight bar segment vertically connected to the crossbar segment corresponding to the bottom edge of one end of the straight body, and the straight bar segment is connected with the aforementioned straight body to form an approximately inverted F-shaped structure, and the The free end edge of the crossbar segment is connected with the ground plane of the first surface of the substrate; the second radiating portion of each unit antenna is formed by a straight body abutting against the edge of the second surface of the substrate, and the straight body tops There is a ground connection between the edge and the second surface of the substrate; the width of the straight body and the orthogonal body of the first radiating part of the unit antenna is 1 mm, and the length of the straight body of the first radiating part is 7 mm, and the The length of the straight rod section of the orthogonal body of the first radiating part and the straight body connecting and overlapping is 2.5mm, so that the length of the straight body of the first radiating part protruding is 4.5mm, and the length of the cross rod section of the orthogonal body is 4.5mm, the width of the straight body of the second radiating part is 1.4mm, and the length of the straight body of the second radiating part is 9.3mm, and the top edge of the straight body of the second radiating part is perpendicular to the first radiating part The distance between the top edge of the crossbar section of the body is 7mm. The multi-frequency antenna structure as claimed in claim 1, wherein the substrate is a glass fiber board, the flame-resistant material grade is FR-4, the relative permittivity is 4.4, and the loss tangent is 0.02.

Images