A method for obtaining the active common-mode reflection coefficient of a ring antenna array with equal amplitude and phase excitation

Abstract

The present invention discloses a method for obtaining the active common-mode reflection coefficient of a constant-amplitude and in-phase excited ring antenna array, which is applied to a common-mode fed array antenna. The array antenna includes N antenna units arranged in a linear array, each antenna unit is fed by its corresponding common-mode port, the common-mode port of the mth antenna unit includes a ma port and an mb port, and the active common-mode reflection coefficient of the mth antenna unit is: mana is the scattering parameter from single-port ma to single-port na, S mbnb is the scattering parameter from single port mb to single port nb, S manb is the scattering parameter from single-port ma to single-port nb, S mbna It is the scattering parameter from single port mb to single port na, where N≥1, 1≤m≤N. The advantage of the present invention is that it provides a method for calculating the active common-mode reflection coefficient of a common-mode fed array antenna, which can determine the degree of port matching under common-mode excitation, thereby determining whether the antenna meets the design requirements.

Description

Technical Field

[0001] The present invention relates to the field of microwave technology, and more particularly to a method for obtaining the active common-mode reflection coefficient of a constant-amplitude and in-phase excited ring antenna array. Background Art

[0002] Differentially excited antennas have been widely studied and applied, but less research has been conducted on common-mode excited antennas, which are widely used in mobile phone terminal antennas. Currently, theoretical analysis and research on differential excitation of antenna units is quite extensive, but research on the active common-mode reflection coefficient of common-mode fed array antennas is less extensive. Calculating the active common-mode reflection coefficient of an antenna unit can be used to determine the degree of port matching under common-mode excitation, thereby determining whether the antenna meets design requirements. Therefore, research on the active common-mode reflection coefficient of antenna units has gradually become a hot topic in the industry.

[0003] Chinese patent publication number CN114361784A discloses a wideband, compact circularly polarized antenna based on common-mode and differential-mode transmission. The antenna comprises a circular metal structure printed on the upper surface of a dielectric substrate and a T-shaped metal structure on the lower surface. A T-shaped slot is etched into the circular metal structure on the upper surface of the dielectric substrate. Port a is located on the upper surface of the dielectric substrate outside the T-shaped slot, and port b is located at the end of the T-shaped metal structure. When ports a and b are fed with equal amplitude and in phase, the antenna achieves circularly polarized radiation. At a center frequency of 2.8 GHz, the antenna exhibits a common relative bandwidth of no less than 35.7%. The common bandwidth includes the bandwidth where the reflection coefficients of ports a and b are less than -10 dB, and the bandwidth where the axial ratio is less than 3 dB. This antenna combines the advantages of circular polarization antenna miniaturization with wide bandwidth, offering advantages such as wide bandwidth, small size, compact structure, stable radiation pattern, and bidirectional radiation. However, the antenna only constrains the range of the reflection coefficient and does not include its calculation. This makes it impossible to determine the degree of port matching under common-mode excitation, and therefore, to determine whether the antenna meets design requirements. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that the existing technology of the ring antenna array with equal amplitude and same phase excitation lacks a method for calculating the reflection coefficient, and there is a problem that it is impossible to determine the degree of port matching under common mode excitation and whether the antenna meets the design requirements.

[0005] The present invention solves the above technical problems through the following technical means: a method for obtaining the active common-mode reflection coefficient of a constant-amplitude and in-phase excited ring antenna array, which is applied to a common-mode fed array antenna, wherein the array antenna includes N antenna units arranged in a linear array, each antenna unit is fed by its corresponding common-mode port, the common-mode port of the mth antenna unit includes a ma port and an mb port, and the active common-mode reflection coefficient of the mth antenna unit is Among them, S manais the scattering parameter from single-port ma to single-port na, S mbnb is the scattering parameter from single port mb to single port nb, S manb is the scattering parameter from single-port ma to single-port nb, S mbna is the scattering parameter from single-port mb to single-port na, where N ≥ 1 and 1 ≤ m ≤ N.

[0006] The present invention provides a method for calculating the active common-mode reflection coefficient of a common-mode fed array antenna. By obtaining the active common-mode reflection coefficient of the common-mode fed array antenna, the port matching degree of the common-mode fed array antenna can be determined, thereby determining whether the antenna meets the design requirements. This is of great significance to the reliability design of the common-mode fed array antenna.

[0007] Furthermore, the antenna unit includes a loop antenna and parasitic strips symmetrically distributed on both sides of the loop antenna. The loop antenna is a rectangular frame structure surrounded by metal rods. A feeding port is provided at the center position of each of the two relatively parallel metal rods of the rectangular frame structure. The two feeding ports serve as common mode ports. The parasitic strip is a metal rod-shaped structure and protrusions are provided at both ends thereof perpendicular to the length direction, and the protrusions are facing the side where the loop antenna is located.

[0008] Furthermore, the port matching degree of the antenna array is adjusted by adjusting the distance between the loop antenna and the parasitic strip.

[0009] Furthermore, the beam adjustment of the antenna array is achieved by adjusting the length of the parasitic strip and / or the distance between the parasitic strip and the loop antenna.

[0010] Furthermore, the feeding mode of the ma port and the mb port of the mth antenna unit is equal-amplitude and in-phase feeding.

[0011] Furthermore, the active common-mode reflection coefficient of the common-mode fed array antenna is negatively correlated with the port matching degree of the common-mode fed array antenna.

[0012] Furthermore, the active common-mode reflection coefficient of the common-mode fed array antenna is related to the energy radiation efficiency of the common-mode fed array antenna.

[0013] Furthermore, the active common-mode reflection coefficients of the two antenna units with symmetrical structures in the array antenna are equal.

[0014] Furthermore, the array antenna includes three antenna units, which are arranged in a linear array. Each antenna unit is provided with a common mode port. The common mode port of the first antenna unit includes port 1a and port 1b, the common mode port of the second antenna unit includes port 2a and port 2b, and the common mode port of the third antenna unit includes port 3a and port 3b.

[0015] Furthermore, the active common mode reflection coefficient of the first antenna unit is

[0016] activeSc1=0.5*(S 1a1a +S 1b1b +S 1a2a +S 1a3a +S 1b2b +S 1b3b +S 1a1b +S 1b1a +S 1a2b +S 1a3b +S 1b2a +S 1b3a )

[0017] The active common mode reflection coefficient of the second antenna unit is

[0018] activeSc2=0.5*(S 2a2a +S 2b2b +S 2a1a +S 2a3a +S 2b1b +S 2b3b +S 2a2b +S 2b2a +S 2a1b +S 2a3b +S 2b1a +S 2b3a )

[0019] The active common mode reflection coefficient of the third antenna unit is

[0020] activeSc3=0.5*(S 3a3a +S 3b3b +S 3a1a +S 3a2a +S 3b1b +S 3b2b +S 3a3b +S 3b3a +S 3a1b +S 3a2b +S 3b1a +S 3b2a ).

[0021] The advantages of the present invention are:

[0022] (1) The present invention provides a method for calculating the active common-mode reflection coefficient of a common-mode fed array antenna. By obtaining the active common-mode reflection coefficient of the common-mode fed array antenna, the port matching degree of the common-mode fed array antenna can be determined, thereby determining whether the antenna meets the design requirements. This is of great significance to the reliability design of the common-mode fed array antenna.

[0023] (2) The present invention can adjust the port matching degree of the antenna array by adjusting the distance between the loop antenna and the parasitic band, and can adjust the beam of the antenna array by adjusting the length of the parasitic band and / or its distance from the loop antenna.

[0024] (3) The lower the active common-mode reflection coefficient of the common-mode-fed array antenna of the present invention, the higher the port matching degree of the common-mode-fed array antenna, so the matching degree can be determined by calculating the reflection coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the array antenna structure in a method for obtaining the active common-mode reflection coefficient of a ring antenna array with constant amplitude and in-phase excitation disclosed in an embodiment of the present invention;

[0026] Figure 2 A schematic diagram illustrating the dimensions of an array antenna in a method for obtaining the active common-mode reflection coefficient of a ring antenna array with constant amplitude and in-phase excitation disclosed in an embodiment of the present invention;

[0027] Figure 3 A schematic diagram of the active common-mode reflection coefficient of the first antenna unit in a method for obtaining the active common-mode reflection coefficient of a ring antenna array with constant amplitude and in-phase excitation disclosed in an embodiment of the present invention;

[0028] Figure 4 A schematic diagram of the active common-mode reflection coefficient of the second antenna unit in a method for obtaining the active common-mode reflection coefficient of a ring antenna array with constant amplitude and in-phase excitation disclosed in an embodiment of the present invention;

[0029] Figure 5 A schematic diagram of the active common-mode reflection coefficient of the third antenna unit in a method for obtaining the active common-mode reflection coefficient of a ring antenna array with constant amplitude and in-phase excitation disclosed in an embodiment of the present invention;

[0030] Figure 6 A schematic diagram of the radiation direction of the array antenna in a method for obtaining the active common-mode reflection coefficient of a ring antenna array with constant amplitude and in-phase excitation disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0032] like Figure 1As shown, a method for obtaining the active common-mode reflection coefficient of a constant-amplitude, in-phase excited ring antenna array is applied to a common-mode fed array antenna. The array antenna includes N antenna elements 1 arranged in a linear array. Each antenna element 1 is fed by its corresponding common-mode port. The common-mode ports of the mth antenna element 1 include an ma port and an mb port, where N ≥ 1 and 1 ≤ m ≤ N. The ma port and mb port of the mth antenna element 1 are fed by constant-amplitude, in-phase feeding.

[0033] Continue reading Figure 1 The antenna unit 1 includes a loop antenna 11 and parasitic strips 12 symmetrically distributed on either side of the loop antenna 11. The loop antenna 11 is a rectangular frame structure formed by metal rods. A feed port is provided at the center of each of the two parallel metal rods of the rectangular frame structure. The two feed ports serve as common-mode ports. The parasitic strips 12 are metal rod-shaped structures with protrusions at both ends perpendicular to their length, facing the side where the loop antenna 11 is located. The port matching degree of the antenna array is adjusted by adjusting the distance between the loop antenna 11 and the parasitic strips 12. The beam of the antenna array is adjusted by adjusting the length of the parasitic strips 12 and / or their distance from the loop antenna 11.

[0034] The active common-mode reflection coefficient of antenna unit 1 is calculated, which can be used to determine the port matching degree under common-mode excitation, thereby determining whether the antenna meets the design requirements. Therefore, the research on the active common-mode reflection coefficient of antenna unit 1 is relatively popular. The present invention provides a reflection coefficient calculation method to solve the industry hot issues. Specifically, the active common-mode reflection coefficient of the mth antenna unit 1 is

[0035]

[0036] Among them, S mana is the scattering parameter from single-port ma to single-port na, S mbnb is the scattering parameter from single port mb to single port nb, S manb is the scattering parameter from single-port ma to single-port nb, S mbna is the scattering parameter from single-port mb to single-port na.

[0037] In this embodiment, the active common-mode reflection coefficient of the common-mode fed array antenna is negatively correlated with the port matching degree of the common-mode fed array antenna. The lower the active common-mode reflection coefficient of the common-mode fed array antenna, the higher the port matching degree of the common-mode fed array antenna. Thus, the matching degree can be determined by calculating the reflection coefficient. The active common-mode reflection coefficient of the common-mode fed array antenna is also related to the energy radiation efficiency of the common-mode fed array antenna.

[0038] As a further improvement, the active common mode reflection coefficients of the two symmetrical antenna units 1 in the array antenna are equal. For example, Figure 1 The active common-mode reflection coefficient of the first antenna unit 1 is equal to the active common-mode reflection coefficient of the third antenna unit 1.

[0039] In order to more clearly understand the structure and design ideas of the present invention, the present invention is described by taking three antenna units 1 as an example. Specifically, the array antenna includes three antenna units 1, which are arranged in a linear array. Each antenna unit 1 is provided with a common mode port. The common mode port of the first antenna unit 1 includes port 1a and port 1b, the common mode port of the second antenna unit 1 includes port 2a and port 2b, and the common mode port of the third antenna unit 1 includes port 3a and port 3b. Figure 2 As shown, the line width D3 of the loop antenna 11 in the antenna unit 1 is 1 mm, the length D2 is 65 mm, the width D1 of the loop antenna 11 is 5 mm, the length L1 of the parasitic band 12 is 90.5 mm, the length L2 of the bend of the parasitic band 12 is 1.25 mm, the distance L4 between the parasitic band 12 and the loop antenna 11 is 17.25 mm, and the gap D4 between each loop antenna 11 is 35 mm.

[0040] like Figure 3 As shown, the active common mode reflection coefficient of the first antenna unit 1 is

[0041] activeSc1=0.5*(S 1a1a +S 1b1b +S 1a2a +S 1a3a +S 1b2b +S 1b3b +S 1a1b +S 1b1a +S 1a2b +S 1a3b +S 1b2a +S 1b3a )

[0042] like Figure 4 As shown, the active common mode reflection coefficient of the second antenna unit 1 is

[0043] activeSc2=0.5*(S 2a2a +S 2b2b +S 2a1a +S 2a3a +S 2b1b +S 2b3b +S 2a2b +S 2b2a +S 2a1b +S 2a3b +S 2b1a +S 2b3a )

[0044] like Figure 5 As shown, the active common mode reflection coefficient of the third antenna unit 1 is

[0045] activeSc3=0.5*(S 3a3a +S 3b3b +S 3a1a +S 3a2a +S 3b1b +S 3b2b +S 3a3b +S 3b3a +S 3a1b +S 3a2b +S 3b1a +S 3b2a ).

[0046] from Figure 3 and Figure 5 It can be seen that the active reflection coefficients of the two are substantially the same, which further proves that the active common-mode reflection coefficients of the two antenna units 1 with symmetrical structures in the array antenna of the present invention are equal.

[0047] like Figure 6 As shown in the figure, it is the radiation pattern of the common-mode fed array antenna provided by the present invention. It can be seen from the figure that the radiation pattern of the antenna array designed by the present invention has good superposition performance, and a more symmetrical pattern is obtained, which meets the design requirements.

[0048] Through the above technical solution, the present invention provides a method for calculating the active common-mode reflection coefficient of a common-mode fed array antenna. The calculation method is simple, does not require a separate design of an active common-mode reflection coefficient test device, and does not require additional wiring control of the antenna. The process of obtaining the active common-mode reflection coefficient is simple and easy to implement. By obtaining the active common-mode reflection coefficient of the common-mode fed array antenna, the port matching degree of the common-mode fed array antenna can be determined, thereby determining whether the antenna meets the design requirements. This is of great significance to the reliability design of the common-mode fed array antenna.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for obtaining the active common-mode reflection coefficient of a ring antenna array with equal amplitude and in-phase excitation, characterized in that: An array antenna for common-mode feeding, wherein the array antenna comprises N antenna units arranged in a linear array, each antenna unit being fed by its corresponding common-mode port. The common mode ports of the antenna elements include Ports and Port, The active common mode reflection coefficient of each antenna element is ,in, Is a single port To single port The scattering parameters, Is a single port To single port The scattering parameters, Is a single port To single port The scattering parameters, Is a single port To single port Scattering parameters, where N≥1, 1≤ ≤N; The antenna unit includes a loop antenna and parasitic strips symmetrically distributed on both sides of the loop antenna. The loop antenna is a rectangular frame structure surrounded by metal rods. A feeding port is provided at the center position of each of the two relatively parallel metal rods of the rectangular frame structure. The two feeding ports serve as common mode ports. The parasitic strip is a metal rod-shaped structure and has protrusions at both ends perpendicular to the length direction. The protrusions face the side where the loop antenna is located.

2. The method for obtaining the active common mode reflection coefficient of a loop antenna array with constant amplitude and in-phase excitation according to claim 1, characterized in that: The port matching degree of the array antenna is adjusted by adjusting the distance between the loop antenna and the parasitic strip.

3. The method for obtaining the active common mode reflection coefficient of a loop antenna array with constant amplitude and in-phase excitation according to claim 1, characterized in that: The beam adjustment of the array antenna is achieved by adjusting the length of the parasitic strip and / or the distance between the parasitic strip and the loop antenna.

4. The method for obtaining the active common mode reflection coefficient of a loop antenna array with constant amplitude and in-phase excitation according to claim 1, characterized in that: The said Antenna elements Ports and The port is fed in equal amplitude and in phase.

5. The method for obtaining the active common mode reflection coefficient of a loop antenna array with constant amplitude and in-phase excitation according to claim 1, characterized in that: The active common-mode reflection coefficient of the common-mode fed array antenna is negatively correlated with the port matching degree of the common-mode fed array antenna.

6. The method for obtaining the active common mode reflection coefficient of a loop antenna array with constant amplitude and in-phase excitation according to claim 1, characterized in that: The active common-mode reflection coefficient of the common-mode fed array antenna is related to the energy radiation efficiency of the common-mode fed array antenna.

7. The method for obtaining the active common mode reflection coefficient of a loop antenna array with constant amplitude and in-phase excitation according to claim 1, characterized in that: The active common-mode reflection coefficients of the two antenna units with symmetrical structures in the array antenna are equal.

8. The method for obtaining the active common mode reflection coefficient of a loop antenna array with constant amplitude and in-phase excitation according to claim 1, characterized in that: The array antenna includes three antenna units arranged in a linear array, each antenna unit is provided with a common mode port, and the common mode port of the first antenna unit includes Ports and Port, the common mode port of the second antenna unit includes Ports and Port, the common mode port of the third antenna unit includes Ports and port.

9. The method for obtaining the active common mode reflection coefficient of a loop antenna array with constant amplitude and in-phase excitation according to claim 8, characterized in that: The active common mode reflection coefficient of the first antenna unit is The active common mode reflection coefficient of the second antenna unit is The active common mode reflection coefficient of the third antenna unit is 。

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