A high isolation antenna between the same frequency bands and a micro base station

Abstract

The present application provides a high isolation antenna and micro base station between the same frequency bands, and the antenna includes: an antenna floor, a radiator, a feeding circuit and a coupling circuit. Among them, multiple radiators are distributed in multiple columns on the antenna floor, and multiple radiators in each column are connected to the same feeding circuit to transmit and receive electromagnetic signals of the same frequency. A total feeding port is provided on each feeding circuit. The coupling circuit is arranged between the total feeding ports corresponding to the radiators of two adjacent columns to couple the port signals at the corresponding total feeding ports, and generate an adjustment coupling signal with the same amplitude and opposite phase as the spatial coupling signal at the corresponding total feeding ports of the radiators of the adjacent columns to offset the spatial coupling signal. The antenna provided in the present application can effectively reduce the spatial coupling between the antennas of the micro base station and improve the isolation between the antennas in the same frequency band by adding a directional coupling circuit to the total feeding port, and does not increase the additional design difficulty and layout space.

Description

Technical Field

[0001] The present application relates to the field of antenna technology, and in particular to a high isolation antenna and a micro base station between the same frequency bands. Background Art

[0002] Micro base stations are network operation equipment that can cooperate with macro base stations to complete network coverage, improve the system capacity of the operator's communication network, and meet the access needs of terminals. Micro base stations can further increase the coverage area of ​​the network and directly provide network access to terminals in environments with many buildings such as cities. Therefore, the signal quality of micro base stations directly affects the network access quality of terminals.

[0003] Micro base stations generally consist of two parts: a back-end transmission circuit and a front-end antenna. In actual applications, the front-end antenna is fed by the back-end transmission circuit to realize the reception and transmission of electromagnetic signals. For micro base station antennas arranged in more than one column, the antenna band isolation can reflect the degree of mutual coupling between antennas in different columns and the purity of the received signal. In general, for two columns of antennas with the same frequency, it is very difficult for their band isolation to meet the use requirements. If the antenna band isolation is poor, it will cause crosstalk between different signals, resulting in a higher bit error rate in the micro base station, affecting the communication quality.

[0004] In order to improve the inter-band isolation of antennas, the spacing between the two antenna columns can be increased to reduce the spatial coupling between the two columns of antennas. For example, the column spacing is set to 0.8λ, where λ is the wavelength of the transmitted signal. However, due to the small size of the micro base station itself, the available space for the front-end antenna is smaller, and the array spacing is difficult to reach 0.8λ. Therefore, for two columns of the same-frequency antenna, the inter-band isolation is difficult to meet the requirements.

[0005] It is also possible to add a metal isolation strip between two adjacent columns of antennas, or, as in the solution disclosed in application number 201811031141.4, add a metal isolation strip metasurface above the antenna to block the electromagnetic signals of the two columns of antennas through the metal isolation strip, thereby reducing the spatial coupling effect. However, in micro base stations, the space is extremely limited, and when the array spacing is small, it is difficult to effectively improve the inter-band isolation by loading metal isolation strips between arrays. For the method of loading a metal isolation strip metasurface above the antenna, it is required that the height of the metal isolation strip from the floor is at least 1 / 4λ, which is also difficult to meet in micro base station antennas. Therefore, under normal circumstances, it is impossible to improve the inter-band isolation of micro base station antennas in the above manner, resulting in relatively poor inter-band isolation of micro base station antennas. Summary of the invention

[0006] The present application provides a high isolation antenna between the same frequency bands and a micro base station to solve the problem of poor isolation between the antenna bands of traditional micro base stations.

[0007] On the one hand, the present application provides a high isolation antenna between the same frequency bands, comprising an antenna floor, and a plurality of radiators and a feeding circuit arranged on the antenna floor; the plurality of radiators are distributed in a plurality of columns, and the plurality of radiators in each column are connected to the same feeding circuit to transmit and receive electromagnetic signals of the same frequency; the feeding circuit is provided with a main feeding port, and also includes a coupling circuit;

[0008] The coupling circuit is arranged between the total feed ports corresponding to two adjacent columns of the radiators to couple the port signals at the total feed ports corresponding to one column of the radiators, and generate an adjustment coupling signal with an amplitude equal to that of the spatial coupling signal and an opposite phase at the total feed ports corresponding to the adjacent column of the radiators to offset the spatial coupling signal.

[0009] Optionally, the coupling circuit includes a coupler and a coaxial line;

[0010] One end of the coupler is arranged at the position of the main feed port corresponding to a column of radiators, and the other end is connected to the main feed port corresponding to the adjacent column of radiators through the coaxial line;

[0011] The length of the coaxial line is sufficient to make the phase of the adjustment coupling signal differ from the phase of the spatial coupling signal by 180°, so that the spatial coupling signal is offset by the adjustment coupling signal.

[0012] Optionally, the coupling circuit also includes an absorption resistor; the coupler is an interdigital coupler or a coupled line coupler; the coupler includes a coupling port and an isolation port; the isolation port of the coupler is grounded through the absorption resistor; and the coupling port of the coupler is connected to the coaxial line.

[0013] Optionally, the resistance value of the absorption resistor is equal to the resistance value of the coaxial line.

[0014] Optionally, the couplers are provided at both ends of the coaxial line, and the couplers at both ends of the same coaxial line are respectively arranged at the positions of the total feeding ports corresponding to the radiators in two adjacent columns.

[0015] Optionally, the radiator is a radiator based on a single-polarization antenna, a microstrip antenna, a symmetrical dipole or a helical antenna.

[0016] Optionally, the radiator is a radiator based on a dual-polarized antenna, and each column of the radiators is connected to two feeding circuits; and two coupling circuits are provided between four main feeding ports corresponding to two adjacent columns of the radiators.

[0017] Optionally, the radiator includes two vibrator units arranged crosswise with each other; in each column of the radiators, multiple vibrator units with the same deflection direction are connected to the same feeding circuit; in two adjacent columns of the radiators, a coupling circuit is provided between the total feeding ports corresponding to the multiple vibrator units with the same deflection direction.

[0018] Optionally, the antenna further includes a dielectric plate; the dielectric plate is arranged on the antenna floor; and the radiators in the same column are arranged on the same dielectric plate.

[0019] On the other hand, the present application also provides a micro base station, which includes the above-mentioned high isolation antenna between the same frequency bands.

[0020] It can be seen from the above technical solutions that the present application provides a high isolation antenna and micro base station between the same frequency bands, and the antenna includes: an antenna floor, a radiator, a feeding circuit and a coupling circuit. Among them, multiple radiators are distributed in multiple columns on the antenna floor, and multiple radiators in each column are connected to the same feeding circuit to transmit and receive electromagnetic signals of the same frequency. A total feeding port is provided on the feeding circuit. The coupling circuit is arranged between the total feeding ports corresponding to the radiators of two adjacent columns to couple the port signals at the corresponding total feeding ports, and generate an adjustment coupling signal with an amplitude equal to that of the spatial coupling signal and an opposite phase at the total feeding ports corresponding to the radiators of the adjacent columns to offset the spatial coupling signal. The antenna provided in the present application can effectively reduce the spatial coupling between the antennas of the micro base station and improve the isolation between the antennas in the same frequency band by adding a directional coupling circuit to the total feeding port, and does not increase the additional design difficulty and layout space. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] Figure 1 This is a schematic diagram of the structure of a high isolation antenna between the same frequency bands in this application;

[0023] Figure 2 This is a schematic diagram of a top view structure of a high isolation antenna between the same frequency bands of the present application;

[0024] Figure 3 This is a schematic diagram of the coupling circuit structure of the high isolation antenna in the same frequency band of the present application;

[0025] Figure 4 This is a comparison chart of the isolation between high isolation antennas in the same frequency band of this application;

[0026] Figure 5 A schematic diagram of the antenna structure of a single-polarized dual coupler for this application;

[0027] Figure 6 This is a schematic diagram of the top view of the single-polarized dual-coupler antenna of the present application;

[0028] Figure 7A schematic diagram of the structure of a dual-polarized single coupler antenna for this application;

[0029] Figure 8 This is a schematic structural diagram of a dual-polarization dual-coupler antenna of the present application. DETAILED DESCRIPTION

[0030] The following embodiments are described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following embodiments do not represent all implementations consistent with the present application. They are only examples of systems and methods consistent with some aspects of the present application as detailed in the claims.

[0031] Inter-band isolation refers to the ability of two columns of antennas (radiating units) to maintain independent transmission and reception of electromagnetic signals. Since the electromagnetic signals emitted by two columns of antennas close to each other will produce spatial coupling, that is, the electromagnetic signal emitted by one column of antennas will propagate from the space above or to the side of the antenna to the area where the other column of antennas is located, forming a coupling effect, thereby generating a spatial coupling signal in the other column. This spatial coupling signal will affect the propagation quality of the original electromagnetic signal. Therefore, high isolation antennas between the same frequency bands can reduce the spatial coupling effect and make the electromagnetic signals emitted by the two columns of antennas relatively independent of each other. Generally, the isolation between the same frequency bands of micro base station antennas should be at least -23dB.

[0032] In order to improve the isolation of micro base station antennas, the present application provides a high isolation antenna between the same frequency bands. Figure 1 , is a schematic diagram of the structure of a high isolation antenna between the same frequency bands in this application. Figure 1 It can be seen that the high isolation antenna between the same frequency bands provided in the present application includes: an antenna floor 1, a radiator 3, a feeding circuit 4 and a coupling circuit 5. Among them, the antenna floor 1 is arranged at the bottom layer for supporting other components. The antenna floor 1 is a metal plate for grounding. In practical applications, it can have different sizes and shapes according to the number and spacing of the radiators 3 arranged thereon.

[0033] Radiator 3 is an antenna vibrator unit for transmitting and receiving electromagnetic signals, and can be a radiator based on a single-polarized antenna, a dual-polarized antenna, a microstrip antenna, a symmetrical vibrator or a helical antenna. In practical applications, the structure of radiator 3 can be selected according to different operating environments of micro base stations. Obviously, for the same micro base station, in order to ensure the antenna radiation quality, multiple radiators 3 need to have the same structure. For example, Figure 1 In the patch form shown, the multiple radiators 3 are all radiators based on single-polarized antennas; for example, Figure 3 The cross-element form shown is that the multiple radiators 3 are all radiators based on dual-polarization antennas.

[0034] The plurality of radiators 3 are distributed in a plurality of columns on the antenna floor 1, each column comprising a plurality of radiators 3, and the plurality of radiators 3 in each column are connected to the same feeding circuit 4 to transmit and receive electromagnetic signals of the same frequency. Figure 1 As shown, in an antenna, there are two columns, left and right, each column contains two radiators 3. The two radiators 3 in the left column are connected to a left feeding circuit 4; the two radiators 3 in the right column are connected to a right feeding circuit 4. It can be seen that Figure 1 The antenna shown includes four radiators 3 and two feeding circuits 4 in total.

[0035] In actual applications, the feeding circuit 4 is provided with electronic devices related to the antenna receiving and transmitting signals to generate electromagnetic signals of specific frequency and wavelength, and transmit them through the radiator 3. Since in this application, the radiators 3 in the same column are connected to the same feeding circuit 4, the electromagnetic wave signals emitted by the radiators 3 in the same column are also the same. In addition, due to the application of MIMO (multiple-in multiple-out) technology in 5G commercial networks, it is required that there must be multiple columns of radiators 3 with the same frequency in the same antenna. Therefore, in this application, the electromagnetic wave signals corresponding to the multiple columns of radiators 3 also maintain the same frequency. The feeding circuit 4 is provided with a total feeding port. Figure 1 As shown, the main feed port (a, b) can be a branch interface structure set on the feed circuit 4 of each column of radiators 3. In order to facilitate the wiring of the coupling circuit 5, the main feed port can be set in the area close to two adjacent columns.

[0036] In practical applications, the above structure can feed each column of radiators 3 through the feeding circuit 4 so that the radiators 3 can send and receive electromagnetic signals. When two adjacent columns of radiators 3 send electromagnetic signals, due to the close distance between them, the signals sent will generate spatial coupling with the other column. For example, the left and right columns of radiators 3 send electromagnetic signals of 1710-1880MHz. When the signals propagate from the left column to the right column, spatial coupling signals will be generated, thereby affecting the electromagnetic signal emission of the right column radiator 3. Similarly, the electromagnetic signals emitted by the right column radiators 3 on both sides can also affect the emission of the left column electromagnetic signals through spatial coupling.

[0037] Furthermore, the antenna further comprises a dielectric plate 2; the dielectric plate 2 is arranged on the antenna floor 1; the radiators 3 in the same column are arranged on the same dielectric plate 2. The dielectric plate 2 can be a plate-like structure made of dielectric material, such as a PCB board, etc., so as to arrange the feeding circuit 4 and other electrical components.

[0038] In order to reduce the influence of spatial coupling on the original signal, the high isolation antenna between the same frequency bands provided by the present application further includes a coupling circuit 5. The coupling circuit 5 is arranged between the main feed ports corresponding to two adjacent columns of radiators 3 to couple the port signal at the main feed port corresponding to one column of radiators 3, and generate an adjustment coupling signal with the same amplitude and opposite phase as the spatial coupling signal at the main feed port corresponding to the adjacent column of radiators 3 to offset the spatial coupling signal.

[0039] In practical applications, the coupling circuit 5 can couple an adjusted coupling signal of a certain energy from the total feed port a corresponding to the left column radiator 3, and transmit it to the total feed port b corresponding to the right column radiator 3. The energy of the coupled adjusted coupling signal is P1. Similarly, there is spatial mutual coupling between the two columns of radiators 3, which causes the electromagnetic signal of the left column radiator 3 to be spatially coupled to the right column radiator 3, and then the spatial coupling signal is transmitted to the right column total feed port b through the right column radiator 3 and the corresponding feeding circuit 4. The energy of the spatial coupling signal is P2. The size of the spatial coupling energy is equal to the square of the inter-band isolation amplitude of the two columns of radiators 3, that is:

[0040] P2=|S ba | 2 ;

[0041] Correspondingly, at the right column main feed port b, there are two coupling signals, the adjustment coupling signal P1 and the space coupling signal P2. By properly controlling the adjustment coupling signal P1 so that it has the same amplitude and opposite phase as the space coupling signal, the two signals can cancel each other out, thus improving the inter-band isolation of the two columns of radiators 3.

[0042] The inter-band isolation between the three radiators in the left and right columns is Figure 2 The feed signal at the middle left column main feed port a is coupled to the right radiator 3 through the left column radiator 3, and then transmitted to the signal transmission coefficient S at the right column main feed port b through the right radiator 3 and the feeding circuit 4. ba .

[0043] The signal at the left column main feed port a is spatially coupled to the right column main feed port b. The corresponding transmission path of the spatially coupled signal (denoted as T c o uple1 ): Left column feed circuit 4 - left column radiator 3 (represented as T ant1 )-the spatial distance from the left column to the right column (expressed as T space )-radiator 3 in the right column-feeding circuit 4 in the right column (represented as T ant2 ). According to microwave network theory, the above transmission path can be divided into three local networks, each of which can be expressed by the transmission matrix T = [ABCD], that is, the three local networks are:

[0044]

[0045]

[0046]

[0047] Then the transmission matrix of the entire path from the left main feed port a to the right main feed port b through spatial coupling can be obtained by the transmission line matrix cascade theorem:

[0048]

[0049] At the same time, the conversion relationship between the transmission coefficient matrix [S] and the transmission matrix [T] is as follows:

[0050]

[0051] From the above formula, we can see that the transmission coefficient is as follows:

[0052]

[0053] Then, the spatial coupling signal energy from the left main feeding port a to the right main feeding port b through spatial coupling can be expressed as:

[0054]

[0055] Where P a is the total input energy of the total feed port a on the left.

[0056] Specifically, the coupling circuit 5 includes a coupler 51 and a coaxial line 52. One end of the coupler 51 is arranged at the position of the total feed port corresponding to a column of radiators 3, and the other end is connected to the total feed port corresponding to the adjacent column of radiators 3 through the coaxial line 52. The length of the coaxial line 52 is sufficient to make the phase of the adjusted coupling signal differ from the phase of the spatial coupling signal by 180°, so as to offset the spatial coupling signal by the adjusted coupling signal.

[0057] like Figure 2 , Figure 3 As shown, in the technical solution provided by the present application, a directional coupler 51 is designed at the main feed port a in the left column. Through the coupler 51, the adjusted coupling energy P1 coupled from the main feed port a in the left column can be directly transmitted to the main feed port b in the right column through the coaxial line 52.

[0058] Similarly, according to the transmission line matrix theory, an intuitive analysis can be performed, from the main feed port a on the left, through the coupler 51 to the main feed port b on the right (expressed as T couple2 ): Directional coupler 51 (denoted as T coupler )-coaxial line 52 (represented by T coax), its transmission line matrix is:

[0059] T couple2 =T coupler ·T coax ;

[0060] Since the transmission coefficients of the directional coupler 51 and the coaxial line 52 can be expressed directly, there is no need to first express them in the form of a matrix T = [ABCD] and then perform reverse deduction to obtain the corresponding transmission coefficient matrix [S].

[0061] The directional coupler 51 is a 90° directional coupler, so its transmission coefficient can be expressed as:

[0062]

[0063] Among them, α1 is the coupling coefficient of the coupler;

[0064] The transmission coefficient of the coaxial line 52 is expressed as:

[0065]

[0066] Where, α2 is the attenuation coefficient of the coaxial cable; d coax is the length of the coaxial cable;

[0067] Then the adjusted coupling signal transmitted from the left main feed port a to the right main feed port b through the directional coupler is:

[0068]

[0069] Because α2 is relatively small, the coupling coefficient α1 of the coupler 51 is comparable to the spatial coupling coefficient (isolation amplitude), and by adjusting the length of the coaxial line 52 at the output end of the coupler 51, the phase in the above formula P1 is 180° different from the phase in P2. That is:

[0070]

[0071] Finally, the two coupled signals P1 and P2 at the right column main feed port b cancel each other out, thereby improving the isolation between the two columns of antenna bands with the same frequency.

[0072] The above is a method for improving the inter-band isolation from a theoretical perspective. However, in actual engineering, the length of the coaxial line 52 is generally not obtained by strict theoretical calculation, and it is difficult to obtain an accurate value for the spatial coupling distance in theoretical calculation. Therefore, the specific debugging method is: first measure the initial inter-band isolation amplitude | S ba∣, then design a directional coupler 51 with a coupling coefficient that matches it, and finally actually adjust the length of the coaxial line 52 so that the inter-band isolation is significantly improved, which means that the two coupled signals are equivalently considered to have equal amplitudes and a 180° phase difference at the right column total feed port b. The method of using the directional coupler 51 can not only significantly improve the isolation between the same frequency bands of the micro base station antenna, but also does not increase the additional design difficulty, providing a reliable guarantee for the successful realization of a high-isolation micro base station antenna.

[0073] In actual projects, Figure 4 As shown, the above method is used to improve the inter-band isolation of the micro base station co-frequency dual-row antenna with a signal frequency of 1710-1880MHz. Figure 4 The solid line in the middle is the initial band-to-band isolation without a coupler, and the dotted line is the band-to-band isolation with a coupled line coupler. Figure 4 It can be seen that after adding the coupler 51, the inter-band isolation of the micro base station antenna is improved from the initial -20dB to below -25dB, meeting the system use requirements.

[0074] It can be seen from the above technical solutions that the present application provides a high isolation antenna and micro base station between the same frequency bands, wherein the antenna includes an antenna floor 1, a radiator 3, a feeding circuit 4 and a coupling circuit 5. Among them, multiple radiators 3 are distributed in multiple columns on the antenna floor 1, and multiple radiators 3 in each column are connected to the same feeding circuit 4 to transmit and receive electromagnetic signals of the same frequency. A total feeding port (a, b) is provided on the feeding circuit 4. The coupling circuit 5 is arranged between the total feeding ports (a, b) corresponding to the radiators 4 of two adjacent columns to couple the port signals at the corresponding total feeding port a, and generate an adjustment coupling signal with an amplitude equal to that of the spatial coupling signal and an opposite phase at the corresponding total feeding port b of the radiator of the adjacent column to offset the spatial coupling signal.

[0075] The antenna provided in the present application can effectively reduce the spatial coupling between micro base station antennas and improve the isolation between antennas in the same frequency band without increasing additional design difficulty and layout space by adding a directional coupling circuit 5 between the main feeding ports (a, b).

[0076] In some embodiments of the present application, Figure 3 As shown, the coupling circuit 5 also includes an absorption resistor 53. The absorption resistor 53 can be selected in the form of a resistor according to the overall structural requirements of the antenna. For example, the absorption resistor 53 can be a chip resistor. The coupler 51 is a coupling line including a coupling port and an isolation port; the isolation port of the coupler 51 is grounded through the absorption resistor 53; and the coupling port of the coupler 51 is connected to the coaxial line 52. Further, the resistance value of the absorption resistor 53 is equal to the resistance value of the coaxial line 52.

[0077] For example, if the total resistance value of the coaxial line 52 is 50Ω, the absorption resistor 53 is a chip resistor with a resistance value of 50Ω. In practical applications, a coupling line coupler 51 is provided at the main feed port a on the left side, the coupling port at the upper end of which is connected to the coaxial line 52, and the isolation port at the lower end is connected to the 50Ω chip resistor, and the other end of the chip resistor 502 is connected to the ground to absorb excess parasitic signals.

[0078] It should be noted that in the technical solution provided in the present application, the resistance value of the absorption resistor 53 is generally equal to the resistance value of the coaxial line 52, but in actual applications, the two may not be equal, as long as the resistance value of the absorption resistor 53 and the resistance value of the coaxial line 52 can maintain the impedance matching characteristics of the entire coupling circuit 5. Obviously, it is easier to maintain impedance matching when the resistance values ​​of the two are equal.

[0079] In some embodiments of the present application, Figure 5 , Figure 6 As shown, the coupler 51 is a coupled line coupler or an interdigital coupler. The couplers 51 are disposed at both ends of the coaxial line 52, and the couplers 51 at both ends of the same coaxial line 52 are disposed at the main feed port positions corresponding to the radiators 3 in two adjacent columns.

[0080] In this embodiment, an antenna with a single polarized radiator 3 and a dual coupler 51 is provided. That is, the antenna is provided with a coupler 51 at the total feed ports (a, b) of the left and right columns. The coupler 51 may be a coupled line coupler or an interdigital coupler. If the initial spatial coupling coefficient (inter-band isolation) is between -25dB and -30dB, and the system requires an inter-band isolation of -30dB to -40dB, a dual coupled line coupler 51 may be used to improve the inter-band isolation. The two couplers 51 can realize that the coupling signal amplitude from the total feed port a on the left side to the total feed port b on the right side is approximately (-10dB to -20dB) × 2 = (-20dB to -40dB), which can match the initial spatial coupling coefficient, thereby improving the isolation between the two columns of radiators 3.

[0081] When the initial isolation is poor (e.g., about -15dB), if a dual coupler method is used, the coupler 51 uses an interdigital coupler for matching. The interdigital coupler can provide a strong coupling coefficient (greater than -6dB), so after the coupled signal passes through the dual-path coupler, the amplitude (-6dB×2=-12dB) finally reaches the total feed port b in the right column, which can match the spatial coupling coefficient, and finally achieve the purpose of anti-phase cancellation.

[0082] In some embodiments of the present application, Figure 7As shown, the radiator 3 is a radiator based on a dual-polarized antenna, and each column of radiators 3 is connected to two feeding circuits 4 ; two coupling circuits 5 are arranged between four main feeding ports corresponding to two adjacent columns of radiators 3 .

[0083] That is, in this embodiment, a dual-polarization single coupler antenna is provided. Specifically, the radiator 3 includes two dipole units arranged crosswise with each other. In each column of radiators 3, multiple dipole units with the same deflection direction are connected to the same feeding circuit 4. In two adjacent columns of radiators 3, a coupling circuit 5 is provided between the total feeding ports corresponding to the multiple dipole units with the same deflection direction.

[0084] Similarly, based on the radiator 3 of the dual-polarized antenna, two couplers 51 can be arranged on a coaxial line 52 in the coupling circuit 5 to form a dual-polarized dual-coupler antenna, such as Figure 8 shown.

[0085] The above-mentioned dual-polarization single coupler antenna form and dual-polarization dual coupler antenna form can respectively improve the isolation of the dual-polarization antenna. That is, in order to improve the inter-band isolation of the two co-polarized signals, two coupler signals need to be added. In practical applications, the appropriate coupler 51 can be designed according to the system requirements, and then the length of the coaxial line 52 can be adjusted so that the coupling signals at the total feed ports c and d of the right-hand dual-polarization antenna are equal in amplitude to the corresponding polarization spatial coupling coefficient (inter-band isolation) and have a phase difference of 180°, thereby finally improving the inter-band isolation of the entire system.

[0086] Based on the above-mentioned high isolation antenna between the same frequency bands, the present application also provides a micro base station to cooperate with the macro base station to provide mobile network connection for terminals within the coverage area. The micro base station includes the above-mentioned high isolation antenna between the same frequency bands, and may also include other modules, such as a core network module, a modulation and demodulation module, a power control module, and a power supply module.

[0087] Since the high isolation antenna between the same frequency bands provided by the present application can improve the isolation of the antenna through the coupling circuit 5, it can adapt to the narrow space in the micro base station. It can be seen that the micro base station provided by the present application does not need to follow the traditional method of improving the isolation between the same frequency bands, that is, there is no need to increase the antenna spacing, or add isolation strips, or use metasurfaces for physical decoupling, which can effectively reduce the spatial coupling between the antennas of the micro base station, thereby improving the isolation between the same frequency bands between the antennas, and does not increase additional design difficulty and layout space.

[0088] Similar parts between the embodiments provided in this application can be referenced to each other. The specific implementation methods provided above are only a few examples under the general concept of this application and do not constitute a limitation on the protection scope of this application. For those skilled in the art, any other implementation methods expanded based on the scheme of this application without creative work belong to the protection scope of this application.

Claims

1. A high isolation antenna between the same frequency bands, comprising an antenna floor (1), and a plurality of radiators (3) and a feeding circuit (4) arranged on the antenna floor (1); the plurality of radiators (3) are arranged in a plurality of columns, and the plurality of radiators (3) in each column are connected to the same feeding circuit (4) to transmit and receive electromagnetic signals of the same frequency; the feeding circuit (4) is provided with a main feeding port, characterized in that: Also includes a coupling circuit (5); The coupling circuit (5) is arranged between the main feed ports corresponding to two adjacent columns of the radiators (3) to couple the port signal at the main feed port corresponding to one column of the radiators (3), and to generate an adjustment coupling signal having an amplitude equal to that of the spatial coupling signal and an opposite phase at the main feed port corresponding to the adjacent column of the radiators (3), thereby offsetting the spatial coupling signal; The radiator (3) is a radiator based on a dual-polarized antenna, and each column of the radiators (3) is connected to two corresponding feeding circuits (4); two coupling circuits (5) are provided between the four main feeding ports corresponding to two adjacent columns of the radiators (3); The radiator (3) comprises two vibrator units arranged crosswise with each other; In each column of the radiators (3), a plurality of the vibrator units with the same deflection direction are connected to the same feeding circuit (4); and in two adjacent columns of the radiators (3), a coupling circuit (5) is provided between the main feeding ports corresponding to the plurality of the vibrator units with the same deflection direction.

2. The high isolation antenna between the same frequency bands according to claim 1, characterized in that: The coupling circuit (5) comprises a coupler (51) and a coaxial line (52); One end of the coupler (51) is arranged at the position of the main feed port corresponding to a row of radiators (3), and the other end is connected to the main feed port corresponding to the adjacent row of radiators (3) through the coaxial line (52); The length of the coaxial line (52) is sufficient to make the phase of the adjusted coupling signal differ from the phase of the spatial coupling signal by 180 degrees, so as to offset the spatial coupling signal through the adjusted coupling signal.

3. The high isolation antenna between the same frequency bands according to claim 2, characterized in that: The coupling circuit (5) further includes an absorption resistor (53); The coupler (51) is an interdigital coupler or a coupled line coupler; the coupler (51) comprises a coupling port and an isolation port; the isolation port of the coupler (51) is grounded via the absorption resistor (53); and the coupling port of the coupler (51) is connected to the coaxial line (52).

4. The high isolation antenna between the same frequency bands according to claim 3, characterized in that: The resistance value of the absorption resistor (53) is equal to the resistance value of the coaxial line (52).

5. The high isolation antenna between the same frequency bands according to claim 2, characterized in that: The couplers (51) are provided at both ends of the coaxial line (52), and the couplers (51) at both ends of the same coaxial line (52) are respectively arranged at the positions of the total feed ports corresponding to the radiators (3) in two adjacent columns.

6. The high isolation antenna between the same frequency bands according to claim 1, characterized in that: The radiator (3) is a radiator based on a single-polarization antenna, a microstrip antenna, a symmetrical dipole or a helical antenna.

7. The high isolation antenna between the same frequency bands according to claim 1, characterized in that: The antenna further comprises a dielectric plate (2); the dielectric plate (2) is arranged on the antenna floor (1); and the radiators (3) in the same column are arranged on the same dielectric plate (2).

8. A micro base station, characterized in that: The micro base station includes the high isolation antenna between the same frequency bands as described in any one of claims 1-7.

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