Dual-polarization filtering antenna, antenna array and radio frequency communication equipment

Abstract

The invention belongs to the technical field of wireless communication equipment, and relates to a dual-polarization filtering antenna, an antenna array and radio frequency communication equipment, the dual-polarization filtering antenna adopts a multi-layer structure, a top radiation patch layer comprises two orthogonal cross-shaped patches, gaps on arms of the dual-polarization filtering antenna generate resonance to realize filtering, and meanwhile, polarization characteristics are optimized; the thickness of the middle dielectric layer is optimized through simulation, and a low profile is achieved; the bottom metal floor layer via hole is connected with the top layer to enhance radiation. According to the antenna array, a plurality of antenna units are arranged according to a rule and are matched with a microstrip line feed network to realize beam forming. The radio frequency communication equipment integrates an antenna array, a radio frequency front end and a baseband processing and power management unit, and information is extracted by a baseband unit after signals are subjected to antenna filtering, array transmission and front end processing.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technologies, and particularly to a dual-polarized filtering antenna, an antenna array including the antenna, and a radio frequency communication device employing the antenna array. Background Art

[0002] In modern wireless communication systems, dual-polarized antennas can simultaneously receive and transmit signals of two orthogonal polarizations, effectively improving the channel capacity and spectrum utilization rate of the communication system. However, traditional dual-polarized antennas often lack filtering functions and require additional filters to suppress out-of-band interference, which not only increases the complexity and cost of the system, but also leads to an increase in the system volume. In addition, the structural design of traditional dual-polarized antennas has certain limitations in achieving high gain, low profile, and good polarization characteristics. Therefore, it is of great practical significance to develop a dual-polarized antenna with filtering functions, a compact structure, and excellent performance. Summary of the Invention

[0003] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Simplifications or omissions may be made in this part, as well as in the abstract and title of the present application, to avoid obscuring the purpose of this part, the abstract, and the title, and such simplifications or omissions shall not be used to limit the scope of the present invention.

[0004] The purpose of the present invention is to provide a dual-polarized filtering antenna, an antenna array, and a radio frequency communication device to solve the problems in the prior art such as the lack of filtering functions, complex structure, large volume, and limited performance of dual-polarized antennas.

[0005] A dual-polarized filtering antenna includes:

[0006] A top-layer radiation patch layer, which consists of two mutually orthogonal cross-shaped patches. Each arm of the cross-shaped patch is etched with slits of specific shapes and sizes. The slits are used to generate multiple resonance modes to achieve the filtering function, and optimize the antenna polarization characteristics by changing the current distribution. Moreover, the structural parameters of the two cross-shaped patches are independent of each other;

[0007] An intermediate dielectric layer, which uses a dielectric material with appropriate dielectric constant and low-loss characteristics. Its thickness is optimized through simulation to achieve a low-profile design while ensuring the antenna performance;

[0008] A bottom-layer metal floor layer, whose size is slightly larger than that of the top-layer radiation patch layer, is used to reflect the electromagnetic waves radiated by the antenna, improve the antenna directivity and gain. Moreover, vias of specific shapes and positions are formed on the metal floor, and the vias are connected to the top-layer radiation patch layer through metallized vias to form a current path.

[0009] Preferably, the slots on the cross-shaped patch arms are used to generate multiple resonance modes, and the multiple resonance modes enable the antenna to respond at different frequencies, thereby realizing the filtering function.

[0010] Preferably, the slots on the cross-shaped patch arms optimize the polarization characteristics of the antenna in the horizontal polarization and vertical polarization directions by changing the current distribution.

[0011] Preferably, the structural parameters of the two mutually orthogonal cross-shaped patches are independent of each other, so that they can independently process horizontal polarization signals and vertical polarization signals respectively.

[0012] Preferably, the dielectric constant and thickness of the intermediate dielectric layer are optimized by simulation to achieve a low-profile design while ensuring the antenna performance.

[0013] Preferably, the vias opened on the bottom metal floor layer are connected to the top radiation patch layer through metallized vias, and the formed current path can enhance the radiation performance of the antenna.

[0014] An antenna array adopts a planar array structure, arranges a plurality of the dual-polarization filtering antenna units on the same plane according to a preset rule, the spacing between adjacent antenna units is between 0.5λ and 1λ (λ is the operating wavelength), and the specific spacing value is determined by simulation optimization to ensure that the mutual coupling between antenna units is small and meets the beamforming requirements of the array.

[0015] A radio frequency communication device includes:

[0016] The antenna array as described above;

[0017] A radio frequency front-end circuit, the signals output by the antenna array through the feeding network are connected to the input end of the low-noise amplifier (LNA) of the radio frequency front-end, and the signals amplified by the LNA enter the mixer and are mixed with the local oscillator (LO) generated local oscillator signal to convert the radio frequency signal into an intermediate frequency signal, and the impedance matching requirement is met during the connection process;

[0018] A baseband processing unit and a power management unit, which are integrated with the radio frequency front-end and the antenna array to form a complete radio frequency communication device, and can be applied to scenarios such as 5G base stations and wireless local area network (WLAN) access points.

[0019] Advantages of the present invention:

[0020] 1. The composite patch and slot structure realizes the filtering function: Traditional dual-polarization filtering antennas usually adopt complex circuits or multiple independent filtering units, while the present invention realizes the filtering function by etching slots on the radiation patch, utilizes the resonance effect generated by the slots, organically combines the radiation patch and the filtering unit, simplifies the antenna structure, and improves the integration degree.

[0021] 2. Dual polarization achieved by orthogonal cross-shaped patches: Two mutually orthogonal cross-shaped patches are used to achieve dual polarization, which has better symmetry and lower cross-polarization level compared with traditional structures. The current distribution of the cross-shaped patches is more uniform in the horizontal and vertical directions, improving the polarization purity and gain of the antenna, and it is easier to achieve impedance matching in different polarization directions.

[0022] 3. Performance optimization by multi-layer structure: The multi-layer structure design organically combines the top radiation patch layer, the middle dielectric layer and the bottom metal floor layer, giving full play to the functions of each layer, and achieving good radiation and filtering performance in the case of low profile. By adjusting the dielectric constant and thickness of the dielectric layer, as well as the size and via design of the bottom metal floor layer, the resonant frequency, bandwidth and radiation pattern of the antenna can be optimized.

[0023] 4. Through reasonable array layout and feed network design, the antenna array can provide signal transceiver functions with high gain and high isolation, and at the same time achieve beamforming, effectively improving the coverage range and communication capacity of the communication system.

[0024] 5. The radio frequency communication device of the present invention integrates an innovative dual-polarization filtering antenna array and a radio frequency front-end circuit, which has a compact structure and excellent performance, and can be widely applied to a variety of wireless communication scenarios to meet the growing communication needs. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Among them:

[0027] Figure 1 is a three-dimensional schematic diagram of the dual-polarization filtering antenna;

[0028] Figure 2 is a two-dimensional schematic diagram of the top radiation patch layer;

[0029] Figure 3 is a schematic diagram of the 4x4 antenna array layout.

[0030] In the figure: 1. Cross-shaped patch; 2. Slot; 3. Middle dielectric layer; 4. Bottom metal floor layer. Detailed Embodiments

[0031] To make the objectives, features, and advantages of the present invention more apparent and understandable, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0032] I. Embodiment of a dual-polarized filtering antenna:

[0033] Fabrication of the top-layer radiation patch layer: In this embodiment, lithography is used to operate on a metal copper foil. First, two mutually orthogonal cross-shaped patches 1 are etched. The horizontal arm length of the horizontal cross-shaped patch 1 is set to 8 mm, and the vertical arm length is also 8 mm; the parameters of the vertical cross-shaped patch 1 are the same. On the patch arms, slits 2 with specific shapes and sizes are etched. For example, the length of the slit 2 on the horizontal arm of the horizontal cross-shaped patch 1 is 4 mm, and the width is 1 mm; the parameters of the slit 2 on the vertical arm are the same, and the parameters of the slit 2 on the corresponding arm of the vertical cross-shaped patch 1 are also set in this way. These slits 2 are precisely designed to generate multiple resonance modes to achieve the filtering function and optimize the polarization characteristics at the same time. Since the structural parameters of the two cross-shaped patches 1 are independent of each other, responsible for horizontal polarization and vertical polarization respectively, through such precise parameter settings, good performance can be obtained in the corresponding polarization directions, and the resonance frequency and bandwidth can be precisely controlled, enabling the antenna to generate multiple resonance points in the target frequency band to achieve filtering.

[0034] Fabrication of the middle dielectric layer 3: Rogers RO4350B dielectric material with a dielectric constant of 3.66 and excellent low-loss characteristics is selected. According to the simulation optimization results, the thickness of the dielectric layer is determined to be 2 mm. Through high-precision cutting and processing techniques, the flatness and thickness uniformity of the dielectric layer are ensured, thereby achieving a low-profile design while ensuring the antenna performance.

[0035] Fabrication of the bottom metal floor layer 4: The bottom metal floor is made of metal copper foil, and its size is set to be 3 mm larger than the top-layer radiation patch layer in both length and width. Through holes with a diameter of 0.5 mm are drilled on the floor. The positions of the through holes are arranged, and through the metallized via process, the through holes are connected to the top-layer radiation patch layer to form a current path, thereby effectively reflecting the electromagnetic waves radiated by the antenna and improving the directivity and gain of the antenna.

[0036] Assembly: Assemble the top-layer radiation patch layer, the middle dielectric layer 3, and the bottom metal floor layer 4 in sequence, and use a high-temperature resistant and good-insulating adhesive to ensure the firm connection between the layers and ensure that the alignment accuracy between the layers is within ±0.1 mm.

[0037] II. Embodiment of an antenna array:

[0038] Arrange the fabricated dual-polarized filtering antenna elements in a 4x4 rectangular array layout. The spacing between adjacent antenna elements is determined by simulation optimization to be 0.8 times the operating wavelength (assuming the operating wavelength is 30 mm, then the spacing is 24 mm). Connect each antenna element using a microstrip feed network. The width of the microstrip line is designed to be 1.5 mm according to the signal transmission characteristics. During the assembly process, precisely control the spacing between adjacent antenna elements to ensure meeting the design requirements. The input signal is evenly distributed to each branch through a power divider, and then the phase of each element is adjusted by a phase shifter according to the beamforming requirements. The phase shift accuracy of the phase shifter can reach ±5°, to achieve precise beamforming function, ensure small mutual coupling between antenna elements and meet the beamforming requirements of the array, thereby providing high-gain and high-isolation signal transceiver functions for the communication system.

[0039] Overall operating principle (including an embodiment of a radio frequency communication device):

[0040] When a radio frequency signal arrives at the dual-polarized filtering antenna, the top radiation patch layer plays a key role. The horizontally polarized radio frequency signal mainly excites the cross-shaped patch 1 in the horizontal direction, and the vertically polarized signal excites the cross-shaped patch 1 in the vertical direction. The slots 2 on the patch arms generate different responses to signals of different frequencies according to their specific length, width, and position. Within the target frequency band, the resonance mode generated by the slots 2 enables the signals of the corresponding frequencies to pass through smoothly, while signals of other frequencies are suppressed, completing the filtering process. For example, in the 5 GHz target frequency band, through the designed slot 2 structure, signals in the 4.5 - 5.5 GHz frequency band can pass through, and signals in other frequency bands are effectively attenuated. The intermediate dielectric layer 3 supports both the top radiation patch layer and the bottom metal floor layer 4 on one hand, and on the other hand, its dielectric constant and thickness affect the electromagnetic characteristics of the antenna, ensuring good signal transmission and radiation effects inside the antenna. The bottom metal floor layer 4 reflects the electromagnetic waves radiated by the antenna, forms a good electromagnetic coupling with the top radiation patch layer, improves the directivity and gain of the antenna, and radiates the signals after filtering and polarization processing into space;

[0041] In the antenna array composed of multiple dual-polarized filtering antenna elements, the signals received by each element are transmitted through the microstrip feed network. The power divider evenly distributes the input signal to each antenna element to ensure that each element obtains an appropriate excitation amplitude. The phase shifter adjusts the signal phase of each element according to the beamforming requirements. For example, when it is necessary to direct the beam to a specific direction, the phase shifter will adjust the phase of the signals of each element, so that the electromagnetic waves radiated by each element are in-phase and superimposed in that direction, enhancing the signal strength in that direction, while canceling each other out in other directions, reducing the sidelobe level, achieving precise beamforming, and thus improving the coverage range and signal quality of the communication system;

[0042] The signal output by the antenna array enters the radio frequency front-end circuit. The signal first reaches the low-noise amplifier (LNA), which amplifies the signal to improve the signal-to-noise ratio. In this embodiment, the selected LNA has a noise figure of 1.5 dB and a gain of 20 dB, which can effectively amplify weak signals and introduce less noise. The amplified signal then enters the mixer and is mixed with the local oscillator (LO) signal to convert the radio frequency signal into an intermediate frequency signal for subsequent baseband processing. During the signal transmission process, impedance matching debugging is performed through the matching circuit to make the input and output impedances both 50 Ω, reducing signal transmission loss. After being converted into an intermediate frequency signal, the signal enters the baseband processing unit, which uses a high-performance processor to perform operations such as digital processing, demodulation, and decoding of the signal, and extracts the original information data. The power management unit uses an efficient voltage regulator chip to stably supply power to the entire device, ensuring the normal operation of each unit, and finally realizing a complete radio frequency communication function, which can be widely applied to scenarios such as 5G base stations and wireless local area network (WLAN) access points.

[0043] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of protection required by the present invention. The scope of protection required by the present invention is defined by the appended claims and their equivalents.

Claims

1. A dual-polarized filtering antenna, characterized in that, Comprising: A top-layer radiating patch layer, which consists of two cross-shaped patches (1) orthogonal to each other. Slots (2) with specific shapes and dimensions are etched on the arms of each of the cross-shaped patches (1). The slots (2) are used to generate multiple resonance modes to achieve the filtering function, and optimize the antenna polarization characteristics by changing the current distribution. Moreover, the structural parameters of the two cross-shaped patches (1) are independent of each other; An intermediate dielectric layer (3), which uses a dielectric material with appropriate dielectric constant and low-loss characteristics, and its thickness is optimized through simulation to achieve a low-profile design while ensuring the antenna performance; A bottom-layer metal ground layer (4), whose size is slightly larger than that of the top-layer radiating patch layer, is used to reflect the electromagnetic waves radiated by the antenna, improve the antenna directivity and gain. Moreover, vias with specific shapes and positions are opened on the metal ground, and the vias are connected to the top-layer radiating patch layer through metallized vias to form a current path.

2. The dual-polarized filtering antenna according to claim 1, wherein The slots (2) on the arms of the cross-shaped patch (1) are used to generate multiple resonance modes, and the multiple resonance modes can enable the antenna to generate responses at different frequencies, thereby achieving the filtering function.

3. The dual-polarized filtering antenna according to claim 1, wherein The slots (2) on the arms of the cross-shaped patch (1) optimize the polarization characteristics of the antenna in the horizontal polarization and vertical polarization directions by changing the current distribution.

4. The dual-polarization filtering antenna according to claim 1, wherein The structural parameters of the two cross-shaped patches (1) orthogonal to each other are independent of each other, enabling them to independently process horizontal polarization signals and vertical polarization signals respectively.

5. The dual-polarized filtering antenna according to claim 1, characterized in that The dielectric constant and thickness of the intermediate dielectric layer (3) are optimized through simulation to achieve a low-profile design while ensuring the antenna performance.

6. The dual-polarized filtering antenna according to claim 1, wherein The vias opened on the bottom-layer metal ground layer (4) are connected to the top-layer radiating patch layer through metallized vias, and the formed current path can enhance the radiation performance of the antenna.

7. An antenna array, characterized in that, Adopting a planar array structure, multiple dual-polarization filtering antenna units described in any one of claims 1-6 are arranged on the same plane according to a preset rule. The spacing between adjacent antenna units is between 0.5λ and 1λ (λ is the operating wavelength), and the specific spacing value is determined through simulation optimization to ensure that the mutual coupling between antenna units is small and meets the beamforming requirements of the array.

8. A radio frequency communication device, characterized in that, Comprising: The antenna array described in claim 7; A radio frequency front-end circuit. The signals output by the antenna array through the feeding network are connected to the input end of the low-noise amplifier (LNA) of the radio frequency front-end. The signals amplified by the LNA enter the mixer and are mixed with the local oscillator (LO) signals generated by the local oscillator to convert the radio frequency signals into intermediate frequency signals, and the impedance matching requirements are met during the connection process; A baseband processing unit and a power management unit, which are integrated with the radio frequency front-end and the antenna array to form a complete radio frequency communication device, and can be applied to scenarios such as 5G base stations and wireless local area network (WLAN) access points.

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