A high frequency vibrator and base station antenna

Abstract

The present application provides a high-frequency vibrator and a base station antenna, which relate to the field of antenna technology. The high-frequency vibrator includes: a balun seat, four vibrator arms, two feeding plates, and a parasitic patch. The four vibrator arms are all installed on the balun seat; the two feeding plates are orthogonally coupled and built-in on the balun seat, the feeding plate includes a horizontal branch, a first vertical branch, a second vertical branch, and a matching branch. The length of the first vertical branch is greater than the length of the second vertical branch. One end of the first vertical branch and one end of the second vertical branch are respectively installed at two ends of the horizontal branch, and the matching branch is connected to the other end of the first vertical branch; the parasitic patch is arranged above the four vibrator arms through a fixing member. The high-frequency vibrator can effectively adjust the resonance characteristics of the antenna, reduce energy loss, and widen the signal coverage range.

Description

Technical Field

[0001] The present application relates to the field of antenna technology, and in particular to a high-frequency oscillator and a base station antenna. Background Art

[0002] With the rapid development of mobile communication technology, base station antennas, as a key component of mobile communication systems, have a direct impact on the capacity and quality of communication systems. Designing antennas that cover a wider frequency band has become a major trend in the development of mobile communications.

[0003] At present, the operating frequency of common high-frequency oscillators is generally 1.71~2.17GHz, with low radiation efficiency and small bandwidth range. In some existing technologies, in order to improve the bandwidth, a loading plate is set at the connection between the oscillator arm and the balun seat in the high-frequency oscillator to improve the radiation efficiency of the antenna. However, the effective operating frequency of such high-frequency oscillators only supports 1.71~2.69GHz, the radiation efficiency is still low, and the bandwidth range is still small. Summary of the invention

[0004] The main purpose of the embodiments of the present application is to solve at least one of the technical problems existing in the prior art, and to propose a high-frequency vibrator and a base station antenna that can effectively adjust the resonance characteristics of the antenna, reduce energy loss, and widen the signal coverage range.

[0005] To achieve the above-mentioned objectives, in the first aspect, an embodiment of the present invention application proposes a high-frequency oscillator, comprising: a balun seat, four oscillator arms, two feeding plates, and a parasitic patch, wherein the four oscillator arms are all mounted on the balun seat; the two feeding plates are orthogonally coupled and built into the balun seat, the feeding plate comprises a horizontal branch, a first vertical branch, a second vertical branch, and a matching branch, the length of the first vertical branch is greater than the length of the second vertical branch, one end of the first vertical branch and one end of the second vertical branch are respectively mounted at the two ends of the horizontal branch, and the matching branch is connected to the other end of the first vertical branch; the parasitic patch is arranged above the four oscillator arms through a fixing member.

[0006] A high-frequency oscillator provided according to an embodiment of the present invention has at least the following beneficial effects: first, in the feed sheet, the connection between the first vertical branch and the horizontal branch and the connection between the second vertical branch and the horizontal branch are both bent portions, and the area formed by the two bent portions is a bent portion, wherein the bent portion forms an inductor, and the inductance value can be adjusted by adjusting the thickness of the bent portion. In addition, the first vertical branch and the second vertical branch are both inserted into the cavity of the balun seat, and the matching branch is connected to the other end of the first vertical branch, and a capacitor can be formed between the matching branch and the cavity wall, and the capacitance value can be adjusted by adjusting the thickness of the matching branch, thereby effectively adjusting the capacitance value. The resonant characteristics of the antenna are improved, thereby expanding the operating frequency range of the antenna; secondly, in the feed plate, a matching branch is set at the other end of the first vertical branch, and the matching branch can eliminate the high-order modes generated by the coaxial cable feeding, ensuring that only the TEM mode is transmitted, avoiding the reduction of energy efficiency and signal distortion, thereby improving the gain of the antenna. In addition, the matching branch is located at the end of the feed plate and connected to the coaxial cable, which can also more effectively reduce the energy loss; finally, the parasitic patch is set above the four dipole arms through a fixing part, which can not only better improve the overall inductive reactance characteristics of the antenna and increase the gain, but also improve the standing wave effect.

[0007] In some embodiments, the connection between the first vertical branch and the horizontal branch is a first bend with a chamfer, and the connection between the second vertical branch and the horizontal branch is a second bend with a chamfer.

[0008] In some embodiments, the vibrator arm includes a first frame and a support bar, the support bar is connected to the inner end of the first frame through a mounting hole, and the mounting hole is used to fix the fixing member.

[0009] In some embodiments, a parasitic branch extending downward is provided at the outer end of each of the first frames, and two adjacent corners of the outer end are chamfered.

[0010] In some embodiments, the fixing member includes a second frame, a support column and four clips, the four clips are all arranged at the bottom of the second frame, the clips are connected to the mounting holes, the support column is arranged at the top of the second frame, and the support column is used to support the parasitic patch.

[0011] In some embodiments, the parasitic patch is an octagonal structure.

[0012] In some embodiments, the balun seat and the four vibrator arms are integrally formed.

[0013] In some embodiments, the inner end of the first frame is in an arc shape, and the inner end of the vibrator arm is adapted to the cavity of the balun seat.

[0014] In some embodiments, a reflection frame is also included, which includes a quadrilateral bottom plate and four side plates, the four side plates are respectively arranged on four sides of the quadrilateral bottom plate, and two through holes are arranged in the quadrilateral bottom plate, and the through holes are used to connect the balun seat.

[0015] In a second aspect, an embodiment of the present invention provides a base station antenna, comprising a high-frequency oscillator as described in any embodiment of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0017] The present invention is further described below in conjunction with the accompanying drawings and embodiments; Figure 1 It is a structural schematic diagram of a high-frequency oscillator provided by the present invention; Figure 2 It is a structural schematic diagram of a feeding plate in a high-frequency vibrator provided by the present invention; Figure 3 It is a structural schematic diagram of another high-frequency oscillator provided by the present invention; Figure 4 It is a schematic diagram of the structure of a balun seat in a high-frequency vibrator provided by the present invention; Figure 5 This is a simulation analysis diagram of the standing wave ratio of a high-frequency oscillator provided by the present invention; Figure 6 This is an S parameter simulation analysis diagram of a high-frequency oscillator provided by the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0019] It should be noted that the terms "first", "second", etc. in the specification, claims and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0021] With the rapid development of mobile communication technology, base station antennas, as a key component of mobile communication systems, have a direct impact on the capacity and quality of communication systems. Designing antennas that cover a wider frequency band has become a major trend in the development of mobile communications.

[0022] At present, the operating frequency of common high-frequency oscillators is generally 1.71~2.17GHz, with low radiation efficiency and small bandwidth range. In some existing technologies, in order to improve the bandwidth, a loading plate is set at the connection between the oscillator arm and the balun seat in the high-frequency oscillator to improve the radiation efficiency of the antenna. However, the effective operating frequency of such high-frequency oscillators only supports 1.71~2.69GHz, the radiation efficiency is still low, and the bandwidth range is still small.

[0023] Based on this, an embodiment of the present invention provides a high-frequency vibrator and a base station antenna, which can effectively adjust the resonance characteristics of the antenna, reduce energy loss, and widen the signal coverage range.

[0024] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0025] First, refer to Figure 1-3 The embodiment of the present invention application proposes a high-frequency oscillator, including: a balun seat 100, four oscillator arms 300, two feeding plates 200, and a parasitic patch 500. The four oscillator arms 300 are all installed on the balun seat; the two feeding plates 200 are orthogonally coupled and built into the balun seat 100, and the feeding plates 200 include a horizontal branch 210, a first vertical branch 220, a second vertical branch 230 and a matching branch 240. The length of the first vertical branch 220 is greater than the length of the second vertical branch 230. One end of the first vertical branch 220 and one end of the second vertical branch 230 are respectively installed at two ends of the horizontal branch 210, and the matching branch 240 is connected to the other end of the first vertical branch 220; the parasitic patch 500 is arranged above the four oscillator arms 300 through a fixing member 400.

[0026] According to a high-frequency oscillator provided by an embodiment of the present invention, first, in the feeding sheet 200, the connection between the first vertical branch 220 and the horizontal branch 210 and the connection between the second vertical branch 230 and the horizontal branch 210 are both bent portions, and the area formed by the two bent portions is a bent portion, wherein the bent portion forms an inductor, and the inductance value can be adjusted by adjusting the thickness of the bent portion. In addition, the first vertical branch 220 and the second vertical branch 230 are both inserted into the cavity of the balun seat, and the matching branch 240 is connected to the other end of the first vertical branch 220, and a capacitor can be formed between the matching branch 240 and the cavity wall, and the capacitance value can be adjusted by adjusting the thickness of the matching branch, thereby effectively adjusting the resonance characteristics of the antenna. Secondly, in the feeding sheet 200, by setting a matching branch 240 at the other end of the first vertical branch 220, the matching branch 240 can remove the high-order modes generated by the feeding of the coaxial cable 700, ensuring that only the TEM mode is transmitted, avoiding the reduction of energy efficiency and signal distortion, thereby improving the gain of the antenna. In addition, the matching branch 240 is located at the end of the feeding sheet 200 and connected to the coaxial cable 700, which can also more effectively reduce the energy loss; finally, the parasitic patch 500 is set above the four dipole arms 300 through the fixing part 400, which can not only better improve the overall inductive reactance characteristics of the antenna and increase the gain, but also improve the standing wave effect.

[0027] It should be noted that the four dipole arms 300 are located in the same plane, symmetrically installed on the top of the balun seat 100 with the center of the balun seat 100 as the axis, and the four dipole arms 300 are arranged opposite to each other in pairs, and the two opposite dipole arms 300 constitute a dipole, and the two dipoles are arranged orthogonally; in addition, the feeding plate 200 and the inner wall of the cavity of the balun seat 100 arranged around it constitute a feeding structure, and the feeding structure is used as a balun, and the two baluns correspond to the two dipoles respectively; secondly, a groove is provided in the middle of the horizontal branch 210, and the grooves arranged on the horizontal branches 210 of the two feeding plates 200 are concave in opposite directions, so that there is a certain interval between the two feeding plates 200.

[0028] Preferably, the first vertical branch 220 is composed of 5 branches with different widths, and the second vertical branch 230 is composed of 3 branches with different widths.

[0029] It should be noted that since the inductance value depends on the geometry of the magnetic circuit and the magnetic permeability of the material, by designing two bends, the length of the current path can be increased, thereby increasing the length and density of the magnetic field lines, which is similar to introducing an inductor element. The inductance value of the spiral inductor can be calculated by the following formula:

[0030] Where L1 is the inductance value, is the magnetic permeability in vacuum (approximately equal to 4π×10^-7 H / m), is the relative magnetic permeability of the conductor material, N is the number of coil turns, A is the effective area, is the total length of the coil. In a feed sheet 200, the curved portion can be regarded as a spiral inductor with 1 turn. Therefore, the above spiral inductor formula can be simplified to the following formula:

[0031] Among them, A1 is the effective area framed by the two bending parts, is the total length of the bending part, such as Figure 2 As shown, the area A1 surrounded by the two feeding plates 200 marked with d can be approximated as d^2. =2d+D / 2, approximately 3d, then the inductance L2 formed by the bent part can be calculated according to the following formula:

[0032] Furthermore, the coaxial cable 700 is disposed below the vibrator, and the coaxial cable 700 is connected to the matching branch 240. The capacitance C of the coaxial cable 700 can be calculated by the following formula:

[0033] Wherein, a and b are the inner conductor diameter and the outer conductor diameter of the coaxial cable 700, respectively, and ε is the relative dielectric constant. By analogy with the capacitance calculation formula of the coaxial cable 700, the capacitance formed between the matching branch 240 and the cavity wall of the balun seat 100 can be calculated. The balun seat 100 has four cylindrical cavities 110 symmetrically arranged along the central axis. Figure 4 , the diameter of the cylindrical cavity 110 can be regarded as the outer conductor diameter of the coaxial cable 700, and the width of the matching branch 240 can be regarded as the inner conductor diameter of the coaxial cable 700. Finally, the combination of the inductor and the capacitor forms an LC resonant circuit, and the resonant frequency f can be calculated according to the following formula:

[0034] The resonant frequency is determined by the values ​​of inductance and capacitance. By changing the inductance and capacitance, that is, changing the thickness of the bending branch and the thickness of the matching branch 240, the balun can resonate at different frequencies, thereby expanding the bandwidth of the antenna.

[0035] It should be noted that the main mode generated by the coaxial cable 700 feeding is the TEM mode. For a closed resonant cavity of the coaxial cable 700, the resonant frequency fo of the TEM mode can be calculated by the following formula:

[0036] Where n is the half-wave number of the electromagnetic field formed in the resonant cavity, is the length of the resonant cavity, εr is the relative dielectric constant of the medium inside the coaxial cable 700, and c is the speed of light.

[0037] Furthermore, in addition to supporting the propagation of TEM mode, the coaxial cable 700 also supports the propagation of TE and TM modes. The superposition of propagation modes with different propagation constants may have a harmful effect, so the propagation of higher-order modes needs to be avoided. Among them, the lowest-order waveguide mode is the most basic waveguide fundamental mode of the coaxial line, that is, the TE11 mode. In practice, an approximate solution commonly used for the cutoff wave number kc of the TE11 mode is:

[0038] Wherein, a and b are the inner conductor diameter and the outer conductor diameter of the coaxial cable 700, respectively. The resonant frequency f1 of the TE11 mode can be calculated based on the relationship between the cutoff wave number and the wavelength, as shown in the following formula:

[0039] It can be understood that after solving the resonant frequency of the TEM mode and the resonant frequency of the TE11 mode, the inductance-capacitance characteristics of the above-mentioned balun are used to adjust the length and width of the matching branch 240, so that the resonant frequency of the matching branch 240 meets the resonance condition of the TEM mode but does not meet the resonance condition of the TE11 mode. The main mode resonates under the action of the matching branch 240 and passes through the matching branch 240 with a lower loss, while the high-order mode has a large transmission loss through the matching branch 240 due to the detuning, thereby achieving the effect of a filter that passes the main mode and suppresses the high-order mode, thereby avoiding the influence of the high-order mode.

[0040] Preferably, the diameter of the cylindrical cavity in the balun seat 100 is 5-6 mm, and the diameter of the cylindrical cavity can be adjusted according to the frequency range that the high-frequency vibrator is required to adapt to.

[0041] Preferably, the width of the matching branch 240 is 2-3 mm, and the width and length of the matching branch 240 can be adaptively adjusted according to the frequency range that the high-frequency oscillator is required to adapt to and the requirement of meeting the main mode propagation.

[0042] It should be noted that, with the cooperation of the bending part, the matching branch 240 and the parasitic patch 500, the operating frequency of the high-frequency oscillator can meet the communication requirements of two frequency bands, namely 1710-2675MHz and 3300-3600MHz, with a bandwidth of up to 71.2%, which is far greater than the bandwidth of a general base station antenna. In addition, due to the addition of the parasitic patch 500, the gain of the antenna can reach 10.9dBi, and the standing wave ratio of the antenna is below 1.4. Figure 5As shown; and the S parameters of the two ports of the antenna are improved within the required frequency band, such as S11 and S22 are both less than -15dB, S21 is less than -25dB, the antenna has lower reflection and better isolation effect, such as Figure 6 As shown, Figure 6 The two upper line segments in the figure refer to S11 and S22 respectively, and the lower line segment refers to S21.

[0043] In some embodiments, reference Figure 2 The connection between the first vertical branch 220 and the horizontal branch 210 is a first bend portion 10 with a chamfer, and the connection between the second vertical branch 230 and the horizontal branch 210 is a second bend portion 20 with a chamfer.

[0044] It can be understood that, compared with setting the first bending portion 10 and the second bending portion 20 as a right angle structure, setting chamfers in the first bending portion 10 and the second bending portion 20 can allow the current to pass through the bending portion more stably, so that the impedance of the feeding part is relatively consistent, and prevent the increase in return loss due to energy reflection caused by impedance changes.

[0045] In some embodiments, reference Figure 1 , Figure 3 , Figure 4 The vibrator arm 300 includes a first frame body 310 and a support bar 330 . The support bar 330 is connected to the inner end of the first frame body 310 through a mounting hole 340 . The mounting hole 340 is used to fix the fixing member 400 .

[0046] It should be noted that the four vibrator arms 300 are surrounded by four first frames 310 to form a square structure. In addition, by setting a mounting hole 340 in the first frame 310 and using the mounting hole 340 to fix the fixing part 400, it is possible to avoid the additional installation of other components for fixing the fixing part 400, thereby simplifying the complexity of the overall structure, making the production and assembly process more efficient, and saving production costs.

[0047] In some embodiments, reference Figure 3 The outer end of each first frame body 310 is provided with a parasitic branch 320 extending downward, and two adjacent corners of the outer end are chamfered.

[0048] It should be noted that the outer end of the dipole arm 300 refers to the end away from the center of the balun seat 100. The setting of the parasitic branch 320 allows the current at the end of the dipole arm 300 to continue to flow along the parasitic branch 320, thereby reducing the projected area and thus reducing the size of the antenna. In addition, the two adjacent corners of the outer end are both chamfered, which reduces the current path length and forms a certain capacitance, generates coupled inductance resonance with the two adjacent dipole arms 300, and thus broadens the bandwidth. At the same time, the distance from the two adjacent dipole arms 300 becomes farther, thereby improving the isolation effect.

[0049] In some embodiments, reference Figure 4 The inner end of the first frame 310 is in an arc shape, and the inner end of the vibrator arm 300 is adapted to the cavity of the balun seat 100 .

[0050] It should be noted that the inner end portion and the outer end portion of the vibrator arm 300 are arranged opposite to each other.

[0051] In some embodiments, the balun seat 100 and the four dipole arms 300 are integrally formed.

[0052] In some embodiments, reference Figure 1 , Figure 3 The fixing member 400 includes a second frame body 410, a support column 420 and four buckles 430. The four buckles 430 are all arranged at the bottom of the second frame body 410. The buckles 430 are connected to the mounting holes 340. The support column 420 is arranged at the top of the second frame body 410. The support column 420 is used to support the parasitic patch 500.

[0053] Preferably, the second frame 410 is a quadrangular pyramid structure. The design of the quadrangular pyramid structure can more effectively utilize space, so that the fixing member 400 provides a larger supporting area and a more uniform force distribution within a limited space.

[0054] In some embodiments, reference Figure 1 , Figure 3 , the parasitic patch 500 is an octagonal structure.

[0055] It should be noted that the Yagi antenna uses the principle that a wire slightly longer than an integer multiple of λ / 4 is inductive, and a wire slightly shorter than an integer multiple of λ / 4 is capacitive. A high gain effect can be achieved by using several directional antennas, and setting the parasitic patch 500 to an octagonal structure can utilize its characteristic of changing the overall inductive reactance similar to that of the Yagi antenna to achieve the effect of increasing gain and improving standing waves. Specifically, the side length of the octagonal parasitic patch 500 is set to be slightly less than a quarter of the working wavelength. The parasitic patch 500 can be regarded as a capacitive element, and the parasitic patch 500 is placed above the vibrator at a quarter of the working wavelength. The signal passes through the parasitic patch 500 and generates an induced electromotive force ε1 and an induced voltage. The current I1, after traveling a distance of λ / 4, the electromagnetic wave reaches the vibrator arm 300, generating an induced electromotive force ε2 and an induced current I2. Due to the spatial difference of λ / 4, ε2 lags behind ε1 by 90°. Since the parasitic patch 500 is capacitive, ε1 lags behind I1 by 90°, so ε2 lags behind I1 by 180°. The induced current I1 of the parasitic patch 500 generates radiation that reaches the vibrator arm 300, forming a magnetic field H1 that lags behind I1 by 90°. According to the law of electromagnetic induction, the induced electromotive force ε2' generated by H1 on the main vibrator lags behind H1 by 90°, so ε2' lags behind I1 by 180°. Finally, ε2' and ε2 have the same phase, so the signal superposition achieves the effect of increasing the gain.

[0056] It should be noted that setting the parasitic patch 500 to an octagonal structure can achieve the effect of extending the bandwidth while ensuring the stability of the directional pattern.

[0057] In some embodiments, reference Figure 1 , and also includes a reflection frame 600, which includes a quadrilateral bottom plate 610 and four side plates 620, the four side plates 620 are respectively arranged on the four sides of the quadrilateral bottom plate 610, and two through holes 630 are arranged in the quadrilateral bottom plate 610, and the through holes 630 are used to connect the balun seat 100.

[0058] In a second aspect, an embodiment of the present invention provides a base station antenna, comprising a high-frequency oscillator as in any embodiment of the first aspect.

[0059] Obviously, the embodiments described above are only some embodiments of the present application, rather than all embodiments. The preferred embodiments of the present application are given in the accompanying drawings, but they do not limit the scope of protection of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. Although the present application is described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific implementation methods, or to replace some of the technical features therein with equivalents. Any equivalent structure made using the contents of the specification and drawings of this application, directly or indirectly used in other related technical fields, is similarly within the scope of patent protection of this application.

Claims

1. A high frequency oscillator, characterized in that: include: Barron's seat; Four vibrator arms, each of which is mounted on the balun seat; Two feeding plates, the two feeding plates are orthogonally coupled and built in the balun seat, the feeding plate comprises a horizontal branch, a first vertical branch, a second vertical branch and a matching branch, the length of the first vertical branch is greater than the length of the second vertical branch, one end of the first vertical branch and one end of the second vertical branch are respectively installed at two ends of the horizontal branch, and the matching branch is connected to the other end of the first vertical branch; A parasitic patch is arranged above the four vibrator arms through a fixing member.

2. The high frequency oscillator according to claim 1, characterized in that: The connection between the first vertical branch and the horizontal branch is a first bend with a chamfer, and the connection between the second vertical branch and the horizontal branch is a second bend with a chamfer.

3. The high frequency oscillator according to claim 1, characterized in that: The vibrator arm includes a first frame and a support bar. The support bar is connected to the inner end of the first frame through a mounting hole. The mounting hole is used to fix the fixing member.

4. The high frequency oscillator according to claim 3, characterized in that: The outer end of each first frame body is provided with a parasitic branch extending downward, and two adjacent corners of the outer end are chamfered.

5. The high frequency oscillator according to claim 3, characterized in that: The fixing member includes a second frame, a support column and four buckles, the four buckles are all arranged at the bottom of the second frame, the buckles are connected to the mounting holes, the support column is arranged at the top of the second frame, and the support column is used to support the parasitic patch.

6. The high frequency oscillator according to claim 1, characterized in that: The parasitic patch has an octagonal structure.

7. The high frequency oscillator according to claim 1, characterized in that: The balun seat and the four vibrator arms are integrally formed.

8. The high frequency oscillator according to claim 3, characterized in that: The inner end of the first frame is in an arc shape, and the inner end of the vibrator arm is matched with the cavity of the balun seat.

9. The high frequency oscillator according to claim 1, characterized in that: It also includes a reflection frame, which includes a quadrilateral bottom plate and four side plates. The four side plates are respectively arranged on four sides of the quadrilateral bottom plate. Two through holes are arranged in the quadrilateral bottom plate, and the through holes are used to connect the balun seat.

10. A base station antenna, characterized in that: It comprises the high-frequency vibrator as described in any one of claims 1 to 9.

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