CN102810738B - A kind of dual-band antenna and electronic equipment - Google Patents

Abstract

The invention provides a dual-frequency antenna, which includes: a dielectric substrate, a first antenna oscillator and a second antenna oscillator symmetrically arranged on the surface of the dielectric substrate, a feeding point and a grounding point; the first antenna oscillator includes A radiating arm, two radiating branches bent to both sides of the radiating arm, the radiating arm and the two radiating branches are connected by a plurality of conductive strips; the invention also provides an electronic device using the dual-frequency antenna. The dual-frequency antenna of the present invention realizes that the antenna has two working frequency bands through a simple structural design, realizes the wireless transmission and reception of electromagnetic signals in the two frequency bands, and has high gain, combined with the low-loss dielectric substrate, can further reduce the dual frequency The loss of the high-frequency antenna is improved, and its gain is increased, so that the antenna has a good effect of transmitting and receiving wireless signals, and the electronic equipment using the antenna realizes good wireless information interaction.

Description

A dual-frequency antenna and electronic equipment

technical field

The invention belongs to the field of communication equipment, and in particular relates to a dual-frequency antenna that can be used for communication such as Wi-Fi or Bluetooth and electronic equipment using the antenna.

Background technique

Wi-Fi is a technology that can wirelessly connect terminals such as personal computers and handheld devices (such as PDAs and mobile phones) to each other. Wi-Fi is more and more widely used in communication devices, such as wireless smart devices, wireless routers and home digital set-top boxes. Wi-Fi has larger coverage and higher transmission rate, so Wi-Fi devices have become a fashion trend in the mobile communication industry.

Especially now that the wireless mobile Internet based on the IEEE 802.11 protocol is developing rapidly, wireless mobile Internet equipment, systems and subsystems put forward higher technical parameters (gain value, standing wave and multi-antenna isolation parameters) requirements for antenna devices, and antennas have also become constraints. An important technical bottleneck of online mobile Internet equipment, systems and subsystems. There is therefore a need to provide improved antennas, antenna systems and applications for wireless electronic devices.

Furthermore, the dual-band antenna solution needs to consider the internal structure of existing equipment, so it is required to install the antenna inside the equipment casing while the mechanical design of the electronic device remains basically unchanged, without changing the layout of the antenna and the main board. Under this condition, a technical problem that the antenna is radiated forward as much as possible and the gain of the antenna is improved is realized.

Contents of the invention

In order to solve the problems existing in the prior art, the present invention realizes the built-in antenna by designing the antenna structure in the limited space of the electronic device, and produces the effects of high radiation efficiency and good matching. In order to achieve the above-mentioned purpose, the present invention Adopt the following technical solutions:

A dual-frequency antenna, the antenna comprising: a dielectric substrate, a first antenna oscillator and a second antenna oscillator symmetrically arranged on the surface of the dielectric substrate, a feeding point and a grounding point; the first antenna oscillator and the second antenna vibrator respectively include a strip-shaped radiation arm, two radiation branches bent to both sides of the radiation arm, the radiation arm and the two radiation branches are connected by a plurality of conductive strips, wherein the The two radiating branches are symmetrically distributed on both sides of the radiating arm, and the center line of symmetry is the longitudinal center line of the radiating arm.

Further, the radiation branch is parallel to the radiation arm.

Further, there are two conductive strips.

Further, the conductive strip is arranged vertically to the radiation part.

Further, the width of the radiation arm is 2-5 times that of the radiation branch.

Further, the two radiating branches are symmetrical about the center line of the radiating arm.

Further, the two radiation branches are arranged on the surface of the dielectric substrate in the form of a curved line, a straight line or a broken line with a width.

Further, the first antenna element and the second antenna element are made of metal material or conductive ink.

Further, opposite ends of the first antenna element and the second antenna element are feeding points and grounding points for each other.

The dielectric substrate component includes glass fiber cloth, epoxy resin and a compound that has a cross-linking reaction with the epoxy resin.

An electronic device includes a circuit board, and further includes the above-mentioned dual-frequency antenna electrically connected to the circuit board.

The dual-frequency antenna of the present invention realizes that the antenna has two working frequency bands through a simple structural design, realizes wireless transmission and reception of electromagnetic signals in the two frequency bands, and has high gain, combined with a low-loss dielectric substrate, can further reduce the dual frequency The loss of the high-frequency antenna is improved, and its gain is increased, so that the antenna has a good effect of transmitting and receiving wireless signals, and the electronic equipment using the antenna realizes good wireless information interaction.

Description of drawings

Fig. 1 is a schematic structural diagram of an embodiment of the dual-frequency antenna of the present invention;

Fig. 2 is the S11 simulation curve diagram of Fig. 1 dual frequency antenna;

Fig. 3 is a graph of the voltage standing wave ratio of the dual-frequency antenna of Fig. 1;

FIG. 4 is a Smith chart of the dual-frequency antenna in FIG. 1 .

Detailed ways

Reference will now be made in detail to the embodiments depicted in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other embodiments, well-known methods, procedures, components and circuits have not been described in detail so as not to unnecessarily obscure the embodiments.

Referring to Fig. 1 and Fig. 2, it is a schematic structural diagram of an embodiment of the dual-frequency antenna of the present invention, in which the oblique line part represents the metal layer, and the dual-frequency antenna includes a dielectric substrate 1, a first antenna element 2, a second antenna The oscillator 3, the feed point 4 and the grounding point 5, the first antenna oscillator 2 and the second antenna oscillator 3 are arranged on one surface of the dielectric substrate 1, and the first antenna oscillator 2 and the second antenna oscillator 3 are about the lateral center of the dielectric substrate 1 Line symmetry, so the shape and size of the first antenna element 2 and the second antenna element 3 are equal, so only the structure of the first antenna element 2 will be further described. The first antenna vibrator 2 includes a radiating arm 21, two radiating branches 22, 23 and two conductive strips 24, 25, the radiating arm 21 is strip-shaped, and the two radiating branches 22, 23 are linear with a certain width, and the two The radiating branches 22, 23 are parallel to the radiating arm 21, and are symmetrically distributed on both sides of the radiating arm 21 after being bent, and the center line of symmetry is the longitudinal center line of the radiating arm 21; Connect the radiation branch 22, the radiation arm 21 and the radiation branch 23; the feed point 4 and the ground point 5 are respectively set at opposite ends of the first antenna element 2 and the second antenna element 3 for input and output of signals.

The material of the first antenna vibrator and the second antenna vibrator is metal or conductive ink. The metal material can be gold, silver, copper, aluminum or iron. For the comprehensive consideration of cost and effect, copper can be selected as the first antenna vibrator and the first antenna vibrator. The material of the second antenna element.

In other embodiments, the two radiating branches may also be in the form of curved lines, straight lines or broken lines with a width on the surface of the dielectric substrate, which can change the electromagnetic wave response frequency band of the antenna vibrator.

The width of the radiation arm is greater than the width of the radiation branch, you can choose between 2 to 5, and you can also appropriately increase or reduce the width difference between the radiation arm and the radiation branch.

The number of conductive strips can change the transmission path of electrical signals in the antenna vibrator and change the radiation pattern of the antenna vibrator. In this embodiment, two conductive strips are used. In other embodiments, one or three or more.

Due to the symmetrical distribution of the first antenna element and the second antenna element, the feeding point and the grounding point can be interchangeably connected to corresponding contact points without affecting the overall performance of the antenna.

As shown in Figure 1, section ab is the radiation arm of the first antenna oscillator 2, section acf and section agj are radiation branches, section hd and section ie are conductive strips, and the length of the radiation arm and the radiation branch affects the low frequency section of the antenna. The cf section and gj section affect the high frequency section of the antenna, and the ef section and ij section affect the high frequency section more obviously. Adjusting the position of the hd section and ie section on the ab section can improve the high frequency section and increase the gain of some frequency points.

The components of the dielectric substrate 1 include glass fiber cloth, epoxy resin, and a compound that undergoes a crosslinking reaction with the epoxy resin. The dielectric substrate will be described in detail below through specific embodiments.

The first type of implementation is as follows:

In this type of embodiment, some low dielectric constant and low loss wetting solutions are used to produce and process the dielectric substrates (including single-layer or multi-layer laminates) of the present invention. The wetting solution includes: a first component, including epoxy resin; a second component, including a compound that undergoes a cross-linking reaction with the epoxy resin; and one or more solvents. Wherein the first component and the second component are configured and mixed according to a certain ratio. The above-mentioned first component, second component and the one or more solvents are formulated into the wetting solution. After the soaking solution is stirred, soak the glass fiber cloth in the soaking solution so that the first component and the second component are adsorbed in the glass fiber cloth or on the surface; then bake the glass fiber cloth to make The one or more solvents are volatilized, and the first component and the second component are chemically combined and cross-linked to form a semi-cured or cured product. The semi-cured product refers to the glass fiber cloth that absorbs the first component and the second component in a relatively low baking temperature environment. The first component contains epoxy resin and the second component contains compounds. Reactive soft mixture. The cured product refers to the glass fiber cloth that absorbs the first component and the second component in a relatively high baking temperature environment, the first component contains epoxy resin and the second component contains the compound part to undergo a chemical crosslinking reaction relatively hard mixture.

In this embodiment, the impregnated glass fiber cloth is baked at a low temperature to form a semi-cured product (in the form of a sheet), and then the semi-cured product is cut into cut pieces, and the multiple cut pieces are stacked according to the thickness. Combining the multi-layer dielectric substrates (ie multi-layer laminates or sheets) for thermal pressing. The purpose of the heat-pressing process is to make the epoxy resin contained in the first component and the compound contained in the second component undergo a chemical cross-linking reaction.

Of course, it can also be understood that the soaked glass fiber cloth is directly baked at a high temperature to form a cured product, that is, the single-layer dielectric substrate (ie, single-layer laminate or sheet) of the present invention.

In a specific embodiment, the compound of the second component may include a copolymer composed of a polar polymer and a non-polar polymer, such as a styrene-maleic anhydride copolymer. It can be understood that any copolymer that can undergo a chemical crosslinking reaction with the epoxy resin can be used in the formulation components of this embodiment. Wherein the styrene maleic anhydride copolymer of present embodiment, its molecular formula is as follows:

Four styrenes are contained in the molecular formula of the above-mentioned styrene-maleic anhydride copolymer. In other embodiments, the corresponding molecular weight can be selected, for example, the molecular formula of the styrene-maleic anhydride copolymer contains 6, 8 or any number of styrenes. Epoxy resins generally refer to organic polymer compounds containing two or more epoxy groups in the molecule.

In other embodiments, the compound of the second component may also be a cyanate ester prepolymer or a mixture of styrene maleic anhydride copolymer and cyanate prepolymer in any proportion.

In a specific embodiment, the epoxy resin and styrene-maleic anhydride copolymer are prepared according to the ratio of functional values, and then a certain amount of solvent is added to form a solution. Described epoxy resin and styrene maleic anhydride copolymer mixing process adopt conventional equipment to process, make epoxy resin and styrene maleic anhydride copolymer homogeneously mix as common mixing tank and reactor, thereby make the in described solution After the epoxy resin and the styrene-maleic anhydride copolymer are uniformly mixed, the soaking solution of the present invention is obtained.

In a specific embodiment, the gelation of the above-mentioned infiltration solution is promoted within 200-400 seconds by adding a certain accelerator (the gelling environment temperature is selected to be 171° C.), wherein the gelation time of the above-mentioned infiltration solution is accelerated to about 260 seconds (such as 258-260 seconds). seconds, or 250-270 seconds, etc.) the effect is better. The accelerator can be selected to include but not limited to any one of tertiary amines, imidazoles and boron trifluoride monoethylamine or a mixture thereof.

The one or more solvents can be selected including but not limited to acetone, methyl ethyl ketone, N,N-dimethylformamide, ethylene glycol methyl ether, toluene or a mixture of two or more of the above solvents to form mixed solvents.

In another embodiment, the wetting solution includes: a first component including an epoxy resin; a second component including a compound that undergoes a cross-linking reaction with the epoxy resin; and one or more solvents. The compound of the second component is selected from a mixture of styrene maleic anhydride copolymer and cyanate prepolymer in any proportion. Wherein the concentration of the cyanate prepolymer is 75%. Accelerator selects dimethyl imidazole for use; Described solvent selects butanone for use. The concrete formula of this embodiment infiltration solution is as follows:

Styrene maleic anhydride copolymer and cyanate ester prepolymer are added to the above formula at the same time, both of which can undergo chemical crosslinking reaction with epoxy resin.

The second type of implementation is as follows:

In the second type of embodiment of the present invention, some low dielectric constants of the dielectric substrates (including single-layer or multi-layer laminates, copper-clad substrates, PCB boards, chip carrier parts or similar application parts, etc.) of the present invention are produced. A low-loss composition (also called a composite or a composite material), the composition comprising glass fiber cloth, a first component and a second component, the first component comprising epoxy resin; the second component comprising A compound that undergoes a crosslinking reaction with the epoxy resin. Wherein the composition operates at a frequency of 1 GHz, has a nominal dielectric constant of ≤ 4.0 and an electrical loss tangent of ≤ 0.01. Wherein in this embodiment, the composition operates at a frequency of 1 GHz and has an electrical loss tangent of ≤0.005.

The composition manufacturing process also includes the following processes:

Firstly, the second component contains a compound that reacts with the epoxy resin to cross-link with the epoxy resin according to the ratio of functional value, and then a certain amount of solvent is added to form a solution. In a specific embodiment, the compound comprises a copolymer of a polar polymer and a non-polar polymer, and the copolymer of a preferred embodiment may be a styrene maleic anhydride copolymer. The epoxy resin and styrene maleic anhydride copolymer mixing process adopts conventional equipment for processing, such as common mixing tanks and reaction kettles to uniformly mix the epoxy resin and styrene maleic anhydride copolymer. Wherein the styrene maleic anhydride copolymer of present embodiment, its molecular formula is as follows:

Four styrenes are contained in the molecular formula of the above-mentioned styrene-maleic anhydride copolymer. In other embodiments, the corresponding molecular weight can be selected, for example, the molecular formula of the styrene-maleic anhydride copolymer contains 6 or 8 styrenes. Epoxy resins generally refer to organic polymer compounds containing two or more epoxy groups in the molecule.

In other embodiments, the compound of the second component may also be a cyanate ester prepolymer or a mixture of styrene maleic anhydride copolymer and cyanate prepolymer in any proportion.

In a specific embodiment, the epoxy resin in the solution and the styrene-maleic anhydride copolymer can carry out a chemical cross-linking reaction under certain conditions, and then attach to the glass fiber cloth after the chemical cross-linking reaction occurs, thereby A dielectric substrate of the present invention is formed.

The one or more solvents may be selected including but not limited to any one of acetone, butanone, N,N-dimethylformamide, ethylene glycol methyl ether, toluene or a mixed solvent among the above.

Described solution one concrete embodiment various component ratios are as follows table:

The above solution formula includes epoxy resin, styrene maleic anhydride copolymer, cyanate ester prepolymer, accelerator dimethylimidazole and a solvent butanone. Styrene maleic anhydride copolymer and cyanate ester prepolymer are added to the above formula at the same time, both of which can chemically crosslink with epoxy resin.

Then, extract the small amount of test samples from the above solution, test the gel time of the solution in a certain temperature environment, and adjust the gel time of the solution in the constant temperature environment by adding an accelerator. The above-mentioned solution can be gelled within 200-400 seconds by adding one or more accelerators, wherein the certain specific temperature environment can be a single temperature value or a selected specific temperature range. In this embodiment , by setting the gelation time at 171 degrees centigrade, the gelation time of the above solution is about 260 seconds (such as 258-260 seconds, or 250-270 seconds, etc.). The accelerator can be selected including but not limited to any one of tertiary amines, imidazoles and boron trifluoride monoethylamine or a mixture thereof.

In the third step, when the test sample is gelled within 200-400 seconds, the glass fiber cloth is soaked in the solution and then taken out and dried to form a composition. In this specific step, the glass fiber cloth is immersed in the solution and fully soaked to ensure that the epoxy resin and styrene-maleic anhydride copolymer are adsorbed in the glass fiber cloth or on the surface, and then the glass cloth immersed in the solution is passed by hanging on the air blower. Baking in a drying oven at 180°C for about 5 minutes, the purpose is to fully volatilize the solvent methyl ethyl ketone, and make the epoxy resin and styrene maleic anhydride copolymer chemically cross-linking, and the glass cloth react with the chemically cross-linking The product produces a semi-cured composition. It can be understood that a cured composition can be formed by prolonging the baking time and/or increasing the baking temperature. Generally, a large amount of industrial production is completed in the dipping subsystem and the oven subsystem of the vertical gluing machine.

Finally, the dried chemical composition is laminated with the conductive foil. In this specific step, the dried compound (prepreg or prepreg) is pressed together with the conductive foil in a vacuum heat press. The conductive foil is selected from conductive materials made of copper, silver, gold, aluminum or alloys of the above materials. Since the price of copper material is relatively low, the conductive foil made of copper is suitable for industrialization.

At the same time, in order to meet the requirements of some performance parameters of the antenna system or electronic equipment, multiple prepregs or prepregs are laminated to form a multilayer laminate. The application of these laminates can effectively reduce the antenna recombination loss, thereby ensuring the antenna radiation gain value.

Using the above composition, single-layer prepreg or prepreg, and multi-layer laminate to process antenna substrates, PCB boards, copper-clad substrates, chip carrier parts or similar application parts, by introducing polar and non-polar polymer copolymers form to reduce the dielectric constant and dielectric loss of the above-mentioned parts (antenna substrates, PCB boards, copper-clad substrates, chip carriers or similar application parts, single-layer or multi-layer laminated sheets), so as to meet their requirements in electronic equipment application requirements.

As shown in Figure 1 again, the ab section in the first antenna vibrator 2 is 23mm long, 8mm wide, and the ij section is 3.4mm long, as shown in Figure 2, Figure 3 and Figure 4 are the S11 simulation curves of the dual-frequency antenna shown in Figure 1 Graph, VSWR graph and Smith chart, in which the specific frequency points selected on the S11 simulation graph are marked in the following table:

Frequency/GHz Loss/dB 2.4 -17.743 2.44 -18.287 2.48 -17.288 4.9 -9.3779 5.3 -16.18 5.725 -14.924 5.75 -14.126 5.85 -11.466

Select a specific frequency point on the voltage standing wave ratio graph and mark it in the following table:

Frequency/GHz VSWR

2.4 1.29 2.44 1.24 2.48 1.26 4.9 2.24 5.3 1.61 5.725 1.31 5.75 1.33 5.85 1.47

Combined with the above table and the Smith chart shown in Figure 4, the return loss of the electronic equipment in the two electromagnetic bands of 2.4-2.48GHz and 4.9-5.85GHz is small, and the voltage standing wave ratio is mostly between 1.2-1.6, reflecting The antenna has a small return loss and a good matching effect in the above electromagnetic band.

The dual-frequency antenna of the present invention can be directly electrically connected to the circuit board of the electronic device, and a wifi communication module or a bluetooth communication module, etc. can be set on the circuit board to meet the corresponding communication requirements of the electronic device. The electronic device in the present invention includes but is not limited to a PDA , mobile phones, laptops, TVs, etc.

The preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific embodiments. Those of ordinary skill in the art, under the inspiration of the present invention, will not depart from the purpose of the present invention and the claims All those made under the protected scope are within the protection of the present invention.

Claims (6)

1. a dual-band antenna, is characterized in that, described antenna comprises: a medium substrate, the first day linear oscillator being arranged at described medium substrate surface symmetrically and the second antenna oscillator, a distributing point and an earth point; Described first day linear oscillator and described second antenna oscillator comprise banded radiation arm respectively, are bent to two radiation branches of described radiation arm both sides, and described radiation arm is connected by two buss with described two radiation branches,

Wherein, described two radiation branches are parallel with described radiation arm, and described two buss are vertical with described radiation arm arranges;

Described two radiation branches are distributed in the both sides of described radiation arm symmetrically, and symmetrical center line is the longitudinal centre line of described radiation arm;

The end of the radiation arm of described first day linear oscillator and described second antenna oscillator toward each other, and distributing point and earth point each other.

2. dual-band antenna according to claim 1, is characterized in that, the width of described radiation arm is 2 ~ 5 times of described radiation branch.

3. dual-band antenna according to claim 1, is characterized in that, described two radiation branches are arranged in having the curve of width, straight line or broken line on the surface at described medium substrate.

4. dual-band antenna according to claim 1, is characterized in that, described first day linear oscillator and described second antenna oscillator material are metal material or electrically conductive ink.

5. dual-band antenna according to claim 1, is characterized in that, described medium substrate component comprises glass-fiber-fabric, epoxy resin and comprises the compound with described epoxy resin generation cross-linking reaction.

6. an electronic equipment, comprises circuit board, it is characterized in that, also comprises the dual-band antenna as described in any one of claim 1-5 be electrically connected with described circuit board.