Method for obtaining active differential reflection coefficient of differentially excited array antenna

Abstract

The present invention discloses a method for obtaining the active differential reflection coefficient of an array antenna with differential excitation, which is applied to an array antenna with differential excitation. The array antenna includes N antenna elements arranged in an array, and each antenna element is excited by its corresponding differential port. The differential port of the m-th antenna element includes an m- port and an m+ port. The active reflection coefficient of the m-th antenna element is Among them, is the scattering parameter from the single port m+ to the single port n+, is the scattering parameter from the single port m- to the single port n-, is the scattering parameter from the single port m+ to the single port n-, and is the scattering parameter from the single port m- to the single port n+. The advantages of the present invention are as follows: The process of obtaining the active differential reflection coefficient is simple and easy to implement, which is of great significance for the matching optimization design of the array antenna with differential excitation.

Description

Technical Field

[0001] The present invention relates to the field of microwave technology, and more particularly to a method for obtaining the active differential reflection coefficient of an array antenna with differential excitation. Background Art

[0002] Integrating a traditional single-port antenna into a radio frequency front-end requires the use of a balun, and the introduction of the balun will increase the size and loss of the radio frequency front-end. At present, differential signal transmission technology is usually adopted in the radio frequency front-ends of wireless communication systems because differential technology has advantages such as suppressing common-mode signals and harmonics, promoting system miniaturization and integration, reducing losses, and improving circuit linearity, thereby improving the anti-interference ability of communication systems. There have been a large number of research reports on antenna elements with differential excitation. Differential antennas have the advantages of low cross-polarization, strong anti-interference ability, and easy integration with radio frequency front-ends. During the design process of an antenna element with differential excitation, the matching degree of the ports and the radiation degree of energy are reflected by the differential reflection coefficient of the antenna element with differential excitation. The smaller the differential reflection coefficient of the antenna element with differential excitation, the higher the port matching degree of the antenna and the higher the radiation degree of energy. During the antenna design process, the port matching effect of the antenna can be distinguished by calculating the differential reflection coefficient of the antenna element with differential excitation, thereby determining whether the antenna meets the design requirements. Therefore, obtaining the differential reflection coefficient of an antenna element with differential excitation is of great significance.

[0003] Currently, the theoretical analysis and research on the reflection coefficient of a single-port of an antenna element have been relatively extensive. However, there is less research on the active differential reflection coefficient of an array antenna with differential excitation. Chinese Patent Publication No. CN110320412A discloses a reflection coefficient test device and test method for a differentially-fed log-periodic antenna. The reflection coefficient test device can test the differential signal of the differentially-fed log-periodic antenna. By synthesizing the measured differential signals, the port reflection coefficient of the differentially-fed log-periodic antenna can be obtained. However, it is necessary to design a reflection coefficient test device for the differentially-fed log-periodic antenna and connect the device to the antenna under test to obtain the reflection coefficient. The process is complex and not easy to implement, and it is for calculating the reflection coefficient of a single antenna element and does not involve the calculation of the active differential reflection coefficient of an array antenna with differential excitation. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that the calculation of the differential reflection coefficient of a single antenna element in the prior art cannot meet the calculation of the active differential reflection coefficient of a differential array antenna.

[0005] The present invention realizes the solution to the above technical problems through the following technical means: A method for obtaining the active differential reflection coefficient of an array antenna with differential excitation, which is applied to an array antenna with differential excitation. The array antenna includes N antenna elements arranged in an array, and each antenna element is excited by its corresponding differential port. The differential port of the m-th antenna element includes an m - port and an m + port. The active differential reflection coefficient of the m-th antenna element is where is the scattering parameter from the single port m + to the single port n + ; is the scattering parameter from the single port m - to the single port n - ; is the scattering parameter from the single port m + to the single port n - ; is the scattering parameter from the single port m - to the single port n + .

[0006] The present invention calculates the active differential reflection coefficient through the scattering coefficients of each single port of the array antenna with differential excitation. The calculation method is simple, without the need to separately design an active differential reflection coefficient test device, without the need for additional wiring control of the antenna. The process of obtaining the active differential reflection coefficient is simple and easy to implement, which has important significance for the matching optimization design of the array antenna with differential excitation.

[0007] Furthermore, the feeding method of the m - port and the m + port of the m-th antenna element is equal-amplitude and anti-phase feeding.

[0008] Furthermore, the active differential reflection coefficient of the array antenna with differential excitation is negatively correlated with the port matching degree of the array antenna with differential excitation.

[0009] Furthermore, the active differential reflection coefficient of the array antenna with differential excitation is related to the energy radiation efficiency of the array antenna with differential excitation.

[0010] Furthermore, the active differential reflection coefficients of two structurally symmetric antenna elements in the array antenna are equal.

[0011] Furthermore, the array antenna includes 3 microstrip patch antenna elements, which are the first microstrip patch antenna element to the third microstrip patch antenna element respectively. The differential ports of the first microstrip patch antenna element are 1 - port and 1 +The differential ports of the first microstrip patch antenna element are 2 - port and 2 + port. The differential ports of the second microstrip patch antenna element are 3 - port and 3 + port.

[0012] Furthermore, the active differential reflection coefficient of the first microstrip patch antenna element is

[0013]

[0014] The active differential reflection coefficient of the second microstrip patch antenna element is

[0015]

[0016] The active differential reflection coefficient of the third microstrip patch antenna element is

[0017]

[0018] Furthermore, the array antenna further includes a dielectric substrate, and the 3 microstrip patch antenna elements are arranged in an array on the dielectric substrate.

[0019] Still further, the material of the dielectric substrate is FR4, and the thickness t is 3 mm.

[0020] Furthermore, the active differential reflection coefficients of the first microstrip patch antenna element and the third microstrip patch antenna element are equal.

[0021] The advantages of the present invention are as follows:

[0022] (1) The active differential reflection coefficient of the array antenna with differential excitation is calculated by the scattering coefficients of each single port of the array antenna. The calculation method is simple, and there is no need to separately design an active differential reflection coefficient test device, and there is no need to perform additional wiring control on the antenna. The process of obtaining the active differential reflection coefficient is simple and easy to implement, which has important significance for the matching optimization design of the array antenna with differential excitation.

[0023] (2) The lower the active differential reflection coefficient of the array antenna with differential excitation, the higher the port matching degree of the array antenna with differential excitation. By obtaining the active differential reflection coefficient of the array antenna with differential excitation, the port matching degree of the array antenna with differential excitation can be judged, so as to judge whether the antenna meets the design requirements.

[0024] (3) The lower the active differential reflection coefficient of the differential-excited array antenna of the present invention, the higher the energy radiation level of the differential-excited array antenna. By obtaining the active differential reflection coefficient of the differential-excited array antenna, the energy radiation level of the differential-excited array antenna can be judged, thereby judging whether the antenna meets the design requirements.

[0025] (4) Through the calculation method of the present invention, for an array antenna with a symmetric structure, it is only necessary to calculate the active differential reflection coefficient of one of the two antenna elements with a symmetric structure, and the active differential reflection coefficient of the other antenna element is equal to the active differential reflection coefficient of the calculated antenna element. Description of the Drawings

[0026] Figure 1 Schematic diagram of the structure of the array antenna in the method for obtaining the active differential reflection coefficient of a differential-excited array antenna disclosed in an embodiment of the present invention;

[0027] Figure 2 Schematic diagram of the structure of a three-element array antenna in the method for obtaining the active differential reflection coefficient of a differential-excited array antenna disclosed in an embodiment of the present invention;

[0028] Figure 3 Schematic diagram of the dimension marking of the structure of a three-element array antenna in the method for obtaining the active differential reflection coefficient of a differential-excited array antenna disclosed in an embodiment of the present invention;

[0029] Figure 4 Schematic diagram of the active differential reflection coefficient of the first microstrip patch antenna element in the method for obtaining the active differential reflection coefficient of a differential-excited array antenna disclosed in an embodiment of the present invention;

[0030] Figure 5 Schematic diagram of the active differential reflection coefficient of the second microstrip patch antenna element in the method for obtaining the active differential reflection coefficient of a differential-excited array antenna disclosed in an embodiment of the present invention;

[0031] Figure 6 Schematic diagram of the active differential reflection coefficient of the third microstrip patch antenna element in the method for obtaining the active differential reflection coefficient of a differential-excited array antenna disclosed in an embodiment of the present invention. Detailed Embodiment

[0032] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, 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 some, rather than all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] As Figure 1 shown, a method for obtaining the active differential reflection coefficient of a differentially excited array antenna is applied to a differentially excited array antenna. The array antenna includes N antenna elements 1 arranged in an array, and each antenna element 1 is excited by its corresponding differential port. The differential port of the m-th antenna element 1 includes an m - port and an m + port. The m - port and the m + port are fed with equal amplitude and opposite phase. For example, when the phase of the m - port is 0°, the phase of the m + port is 180°, and the excitation amplitudes of both are equal. The active reflection coefficient of the m-th antenna element 1 is wherein, is the scattering parameter from the single port m + to the single port n + , is the scattering parameter from the single port m - to the single port n - , is the scattering parameter from the single port m + to the single port n - , is the scattering parameter from the single port m - to the single port n + .

[0034] As a further improvement of the present invention, the active differential reflection coefficient of the differentially excited array antenna is negatively correlated with the port matching degree of the differentially excited array antenna. By obtaining the active differential reflection coefficient of the differentially excited array antenna, the port matching degree of the differentially excited array antenna can be judged, thereby judging whether the antenna meets the design requirements.

[0035] As a further improvement of the present invention, the active differential reflection coefficient of the differentially excited array antenna is negatively correlated with the energy radiation degree of the differentially excited array antenna. By obtaining the active differential reflection coefficient of the differentially excited array antenna, the energy radiation degree of the differentially excited array antenna can be judged, thereby judging whether the antenna meets the design requirements.

[0036] As a further improvement of the present invention, the active differential reflection coefficients of two structurally symmetric antenna elements 11 and 13 in the array antenna are equal. For a structurally symmetric array antenna, it is only necessary to calculate the active differential reflection coefficient of one of the two structurally symmetric antenna elements 11 and 13, i.e., antenna element 11, and the active differential reflection coefficient of the other antenna element 13 is equal to the calculated active differential reflection coefficient of antenna element 11.

[0037] As Figure 2 shown, the present invention gives a three-element array antenna structure for illustrating the calculation process of the active differential reflection coefficient of a differentially excited array antenna. The array antenna includes 3 microstrip patch antenna elements 1 and a dielectric substrate 3. The dielectric substrate 3 is made of FR4 with a thickness t of 3 mm. The microstrip patch antenna elements 1 adopt a differential feeding method. The numbers of the 3 microstrip patch antenna elements 1 are the first microstrip patch antenna element 11 to the third microstrip patch antenna element 13 respectively. The 3 microstrip patch antenna elements are arranged in an array on the dielectric substrate 3. A metal floor 2 is provided below the dielectric substrate 3. The feeding metal posts pass through the dielectric substrate 3 to form a feeding port with the metal floor 2. Two feeding ports form a differential port. For example, the m - port and the m + port are respectively a feeding port, and the m - port and the m + port together form a differential port. The differential ports of the first microstrip patch antenna element 11 are the 1 - port and the 1 + port respectively. The differential ports of the second microstrip patch antenna element 12 are the 2 - port and the 2 + port respectively. The differential ports of the third microstrip patch antenna element 13 are the 3 - port and the 3 + port respectively.

[0038] As Figure 3 shown, the dimensions of the three-element array antenna of the present invention are shown. The dimensions of the dielectric substrate 3 are a width Gx of 60 mm and a length Gy of 100 mm. The length of each microstrip patch antenna element is Py of 20 mm, and the width is Px of 20 mm. The distance between the two differential ports of each microstrip patch antenna element, i.e., the feeding point distance dx, is 8 mm. The patch gap d1 between the microstrip patch antenna elements is 5 mm. The diameter of the feeding metal post is 1 mm, and the outer diameter of the feeding port is 2 mm.

[0039] As Figure 4 shown, the active differential reflection coefficient of the first microstrip patch antenna element 11 is

[0040]

[0041] As Figure 5 shown, the active differential reflection coefficient of the second microstrip patch antenna unit 12 is

[0042]

[0043] As Figure 6 shown, the active differential reflection coefficient of the third microstrip patch antenna unit 13 is

[0044]

[0045] Figure 4 and Figure 6 are basically the same. The main reason is that the structures of the first microstrip patch antenna unit 11 and the third microstrip patch antenna unit 13 are symmetric on the three-element array antenna. Because the overall structure of the antenna is symmetric, the active differential reflection coefficients of the two are the same. In practical applications, for example, for a five-element array antenna, the structures of the first microstrip patch antenna unit and the fifth microstrip patch antenna unit are symmetric, and their active differential reflection coefficients are equal. The structures of the second microstrip patch antenna unit 12 and the fourth microstrip patch antenna unit are symmetric, and their active differential reflection coefficients are equal. Other cases will not be exemplified one by one. As long as the antenna array is centrosymmetric, the active differential reflection coefficients of the symmetric structure antenna units are theoretically the same.

[0046] Through the above technical solutions, the present invention calculates the active differential reflection coefficient from the scattering coefficients of each single port of the array antenna with differential excitation. The calculation method is simple, and there is no need to separately design an active differential reflection coefficient test device, nor to perform additional wiring control on the antenna. The process of obtaining the active differential reflection coefficient is simple and easy to implement, which has important significance for the reliability design of the array antenna with differential excitation.

[0047] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for obtaining the active differential reflection coefficient of a differentially excited array antenna, characterized in that, Applied to an array antenna for differential excitation, the array antenna includes N antenna elements arranged in an array, and each antenna element is excited by its corresponding differential port. The th antenna element's differential port includes port and port. The active differential reflection coefficient of the th antenna element is , where is the scattering parameter from single port to single port , is the scattering parameter from single port to single port , is the scattering parameter from single port to single port , is the scattering parameter from single port to single port .

2. The method for obtaining the active differential reflection coefficient of an array antenna with differential excitation according to claim 1, characterized in that The port of the antenna element and the port are fed in equal amplitude and opposite phase.

3. The method for obtaining the active differential reflection coefficient of an array antenna with differential excitation according to claim 1, characterized in that, The active differential reflection coefficient of the differentially excited array antenna is negatively correlated with the port matching degree of the differentially excited array antenna.

4. A method for obtaining the active differential reflection coefficient of an array antenna with differential excitation according to claim 1, characterized in that The active differential reflection coefficient of the differentially excited array antenna is related to the energy radiation efficiency of the differentially excited array antenna.

5. A method for obtaining the active differential reflection coefficient of an array antenna with differential excitation according to claim 1, characterized in that, The active differential reflection coefficients of two structurally symmetric antenna elements in the array antenna are equal.

6. The method for obtaining the active differential reflection coefficient of an array antenna with differential excitation according to claim 1, characterized in that The array antenna includes three microstrip patch antenna units, namely the first microstrip patch antenna unit to the third microstrip patch antenna unit. The differential ports of the first microstrip patch antenna unit are respectively port and port. The differential ports of the second microstrip patch antenna unit are respectively port and port. The differential ports of the third microstrip patch antenna unit are respectively port and port.

7. The method for obtaining the active differential reflection coefficient of an array antenna with differential excitation according to claim 6, characterized in that, The active differential reflection coefficient of the first microstrip patch antenna element is The active differential reflection coefficient of the second microstrip patch antenna element is The active differential reflection coefficient of the third microstrip patch antenna element is 。 8. A method for obtaining the active differential reflection coefficient of an array antenna with differential excitation according to claim 6, characterized in that The array antenna further includes a dielectric substrate, and three microstrip patch antenna elements are arranged in an array on the dielectric substrate.

9. The method for obtaining the active differential reflection coefficient of an array antenna with differential excitation according to claim 8, wherein The material of the dielectric substrate is FR4, and the thickness t is 3 mm.

10. A method for obtaining the active differential reflection coefficient of an array antenna with differential excitation according to claim 6, characterized in that The active differential reflection coefficients of the first microstrip patch antenna element and the third microstrip patch antenna element are equal.

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