Radiating antenna and radiating unit thereof

Abstract

One embodiment of the present invention provides a radiating element of an antenna, the radiating element comprising: a dipole radiating circuit board on which a pair of dipole radiating arms are printed; a pair of dipole balun circuit boards for supporting the dipole radiating circuit boards, on which a dipole balun is printed, the pair of dipole balun circuit boards being perpendicularly intersected to form dipoles in two mutually perpendicular polarization directions; each of the dipole baluns having two slots extending in the horizontal direction, the two slots being arranged in parallel and spaced apart in the height direction to form a loading branch extending in the horizontal direction between the two slots; the loading branches of the pair of dipole balun circuit boards being short-circuited to improve polarization isolation. The purpose of the present invention is to provide a low-profile radiating antenna and a radiating element thereof, which form polarization isolation by short-circuiting the double-slit parallel loading branches, thereby reducing the size while maintaining the bandwidth and performance of the radiating element.

Description

Technical Field

[0001] The present invention relates to the field of antenna equipment, and in particular to a radiating antenna and a radiating unit thereof. Background Art

[0002] Antenna elements are the most widely used antenna type in base station applications, accounting for over 80% of base station antennas. Existing antenna elements primarily include patch element arrays, dipole elements, differential patch antennas, and slot antennas. The radiator (also called the "element") used in the radiating element of an existing dipole antenna consists of an arm, a feed network, and a balun. The theoretical height of the balun is typically set to a quarter wavelength, resulting in a relatively large element.

[0003] Patch antennas are small and easy to mold, but their size leads to poor radiation efficiency and isolation. This requires the addition of reflectors, differential feed networks, or boundary conditions to improve isolation and radiation efficiency, increasing assembly steps and costs. Differential patch antennas improve isolation through differential feed networks, eliminating isolation boundaries. However, this reduces antenna bandwidth and tracking index, and increases losses.

[0004] The overall performance of the dipole antenna is relatively good, but the performance of the antenna is greatly affected by its size. When the size is reduced, the inherent bandwidth and performance are often unable to be maintained.

[0005] Slot antennas have the advantages of low profile and small size of patch antennas, but their bandwidth is very narrow and their radiation efficiency is relatively low, so they are rarely used in base station antennas.

[0006] It can be seen that the various existing antenna elements cannot simultaneously solve the problems of large size, narrow bandwidth and poor isolation, and thus cannot meet the requirements of 5G-MIMO (fifth generation mobile communication technology - multiple input multiple output antenna). Summary of the Invention

[0007] In view of this, the object of the present invention is to provide a radiating antenna and a radiating unit thereof, which improves the bandwidth and polarization isolation by opening / shorting the double-slit parallel loading branches of the balun design, thereby maintaining the bandwidth and performance of the radiating unit while reducing the size.

[0008] An embodiment of the present invention provides a radiating unit of an antenna, characterized in that the radiating unit includes:

[0009] A vibrator radiation circuit board with paired vibrator radiation arms printed thereon;

[0010] A pair of oscillator balun circuit boards, used to support the oscillator radiation circuit board, on which the oscillator balun is printed, and the pair of oscillator balun circuit boards are perpendicularly crossed to form oscillators with two mutually perpendicular polarization directions;

[0011] Each of the oscillator baluns has two slots extending in the horizontal direction, and the two slots are arranged in parallel and spaced apart in the height direction to form a loading branch extending in the horizontal direction between the two slots;

[0012] The loading branches of a pair of oscillator balun circuit boards are short-circuited to form polarization isolation.

[0013] In one embodiment, each of the loading branches includes a first loading branch and a second loading branch, the first loading branch and the second loading branch respectively extending horizontally from two ends of the vibrator balun circuit board toward the center line of the vibrator balun circuit board, and the ends of the first loading branch and the second loading branch are spaced apart;

[0014] The ends of the first loading branches of a pair of vibrator balun circuit boards are short-circuited.

[0015] In one embodiment, ends of the second loading branches of a pair of oscillator balun circuit boards are open-circuited and connected in parallel.

[0016] In one embodiment, the length of the second loading branch is 1 / 8 wavelength.

[0017] In one embodiment, each of the oscillator baluns further comprises:

[0018] Feed circuit;

[0019] A parasitic feed circuit is adjacent to at least a portion of the feed circuit to couple with the feed circuit.

[0020] In one embodiment, the parasitic feeding circuit includes a first parasitic branch and a second parasitic branch arranged parallel to each other. The first parasitic branch and the second parasitic branch are arranged along the height direction of the vibrator balun circuit board, and the top ends are connected as a whole.

[0021] In one embodiment, the bottom ends of the first parasitic branch and the second parasitic branch share a common ground with the oscillator balun circuit board;

[0022] At least one of the first parasitic stub and the second parasitic stub is grounded via a bottom end thereof.

[0023] In one embodiment, the feeding circuit includes a first feeding branch arranged along the height direction of the vibrator balun circuit board and a second feeding branch bent inward from the top end of the first feeding branch.

[0024] The parasitic feeding circuit is arranged outside the first feeding branch.

[0025] Another embodiment of the present invention further provides a radiating antenna, comprising a plurality of radiating units as described above, wherein the radiating units are arranged on a substrate at intervals, and no isolation walls are provided between the radiating units.

[0026] It can be seen from the above technical solution that in this embodiment, by forming two slots extending in the horizontal direction on the oscillator balun, this double-slit loading structure can form a loading branch extending in the horizontal direction between the two slots, and the loading branches on the two oscillator baluns (two polarization directions) are connected in parallel to each other. In this embodiment, the two parallel loading branches are short-circuited to form a high impedance equivalent to a quarter wavelength, thereby curbing the scattering field caused by low-profile mismatch, so as to achieve the purpose of improving the antenna polarization isolation.

[0027] The radiating elements of this embodiment combine slots with shorted loading stubs, using parallel loading and polarization shorting to address the bandwidth and performance degradation caused by size reduction. In this embodiment, polarization isolation is achieved through shorted loading stubs, eliminating the need for separate isolation walls and reflectors between adjacent radiating elements. This reduces process and material costs, eases mold development, and improves consistency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The following drawings are only used to schematically illustrate and explain the present invention and are not intended to limit the scope of the present invention.

[0029] Figure 1 It is a structural schematic diagram of a first embodiment of a radiation unit of the present invention.

[0030] Figure 2 yes Figure 1 Schematic diagram of the structure of an oscillator balun circuit board.

[0031] Figure 3 yes Figure 1 and Figure 2 Comparison of isolation curves of the radiating element antenna with the loaded branch section short-circuited or not.

[0032] Figure 4 and Figure 5 It is a structural schematic diagram of a second embodiment of a radiation unit of the present invention.

[0033] Figure 6 yes Figure 4 Schematic diagram of the structure of an oscillator balun circuit board.

[0034] Figure 7 yes Figure 4 and Figure 5Comparison chart of the antenna return loss S11 curve and insertion loss S21 curve of the radiating unit.

[0035] Figure 8 It is a structural schematic diagram of a balun circuit board of a radiator in the third embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to have a clearer understanding of the technical features, purposes and effects of the invention, specific embodiments of the present invention are now described with reference to the accompanying drawings, in which the same reference numerals represent the same parts.

[0037] In this document, “illustrative” means “serving as an example, instance or illustration”, and any diagram or implementation described in this document as “illustrative” should not be interpreted as a more preferred or more advantageous technical solution.

[0038] To simplify the drawings, only the parts relevant to the present invention are schematically shown in each figure and do not represent the actual structure of the product. In addition, to simplify the drawings and facilitate understanding, in some figures, only one of the components with the same structure or function is schematically depicted or labeled.

[0039] The object of the present invention is to provide a radiating antenna and a radiating unit thereof, which form polarization isolation by short-circuiting parallel loaded branches, thereby reducing the size while maintaining the bandwidth and performance of the radiating unit.

[0040] Figure 1 It is a structural schematic diagram of a first embodiment of a radiation unit of the present invention. Figure 2 yes Figure 1 The schematic diagram of the structure of a vibrator balun circuit board. Figure 1 and Figure 2 As shown, the present invention provides a radiating unit of an antenna, comprising:

[0041] A vibrator radiation circuit board 1, on which a pair of vibrator radiation arms 11 are printed;

[0042] A pair of oscillator balun circuit boards 2 are used to support the oscillator radiation circuit board 1, on which the oscillator balun is printed. The pair of oscillator balun circuit boards 2 are perpendicular to each other and cross each other to form oscillators with two mutually perpendicular polarization directions;

[0043] Each oscillator balun has two slots 21 extending in the horizontal direction. The two slots 21 are arranged in parallel and spaced apart in the height direction to form a loading branch 22 extending in the horizontal direction between the two slots 21.

[0044] The loading branches 22 of a pair of oscillator balun circuit boards 2 are short-circuited to improve the isolation between different polarizations.

[0045] The radiator of the radiating unit includes a dipole radiating arm 11 and a dipole balun, wherein the dipole radiating arm 11 is arranged in pairs and is printed on a dipole radiating circuit board 1, and the dipole balun is printed on a dipole balun circuit board 2. The dipole balun circuit board 2 is vertically arranged below the dipole radiating circuit board 1 to support the dipole radiating circuit board 1 to extend in the horizontal direction.

[0046] like Figure 1 As shown, there may be multiple dipole radiating arms 11, each made of a metal sheet, and the multiple dipole radiating arms 11 are located in the same plane. The dipole radiating arms 11 are arranged in pairs. In this embodiment, the dipole radiating arms 11 are arranged in two pairs, and the two pairs of dipole radiating arms are perpendicular to each other. The so-called paired arrangement means that the dipole radiating arms 11 of each pair are symmetrically distributed.

[0047] The oscillator balun circuit board 2 where the oscillator balun is located supports the oscillator radiation circuit board 1 where the oscillator radiation arm 11 is located, corresponding to the case where the oscillator radiation arm 11 is provided in two pairs, such as Figure 1 As shown, this embodiment has two oscillator balun circuit boards 2, and the two oscillator balun circuit boards 2 are arranged perpendicularly to each other to form a stable cross support structure, wherein each oscillator balun circuit board 2 correspondingly supports a pair of oscillator radiation arms 11, and the extension direction of each oscillator balun circuit board 2 corresponds to the polarization direction of the pair of oscillator radiation arms 11, therefore, the polarization directions of the two oscillator balun circuit boards 2 are perpendicular to each other.

[0048] Optionally, the two vibrator balun circuit boards 2 have the same shape, but the structures of the vibrator baluns printed thereon can be selected to be the same or different.

[0049] In this embodiment, by forming two slots 21 extending in the horizontal direction on the oscillator balun, this double-slit loading structure can form a loading branch 22 extending in the horizontal direction between the two slots 21. The loading branches 22 on the two oscillator baluns (two polarization directions) are connected in parallel with each other. In this embodiment, the two parallel loading branches 22 are short-circuited to form a high impedance equivalent to a quarter wavelength, thereby curbing the scattering field caused by size reduction and low-profile mismatch, so as to achieve the purpose of improving the antenna polarization isolation.

[0050] The radiation unit of this embodiment combines the slot 21 with the short-circuited loading branch 22, and solves the problem of bandwidth and performance degradation caused by size reduction through parallel loading and polarization short circuit. Figure 3As shown, when the loading section is short-circuited, the isolation of the radiating elements of this embodiment can be increased from 18dB to 26dB. In this embodiment, the antenna's polarization isolation is achieved by short-circuiting the loading section, eliminating the need for additional isolation walls and reflectors between adjacent radiating elements. This reduces process and material costs, eases mold development, and improves consistency.

[0051] Figures 4 to 6 FIG. 1 is a schematic structural diagram of a second embodiment of a radiation unit of the present invention. Figure 6 As shown, each loading branch 22 includes a first loading branch 221 and a second loading branch 222. The first loading branch 221 and the second loading branch 222 extend horizontally from the two ends of the vibrator balun circuit board 2 toward the center line of the vibrator balun circuit board 2, and the ends of the first loading branch 221 and the second loading branch 222 are spaced apart.

[0052] Among them, such as Figure 4 As shown, the ends of the first loading branches 221 of a pair of vibrator balun circuit boards 2 are short-circuited. Figure 5 As shown, the ends of the second loading branches 222 of a pair of oscillator balun circuit boards 2 are open-circuited and connected in parallel.

[0053] The end of the second loading branch 222 is suspended to form an open circuit effect. The open second loading branch 222 is used to realize an L-shaped loading equivalent LC (inductance-capacitance) circuit to load reactance through the LC circuit, thereby achieving the effect of widening bandwidth.

[0054] In this embodiment, two loading stubs are formed between the two slots 21, and the two loading stubs are connected in different ways. The two first loading stubs 221 are short-circuited to form a high impedance equivalent to a quarter wavelength, thereby suppressing the scattered fields caused by size reduction and low-profile mismatch, thereby improving the antenna's polarization isolation. The two second loading stubs 222 are open-circuited to load reactance through an equivalent LC circuit, further broadening the bandwidth while improving isolation.

[0055] The radiating unit of this embodiment is reduced in size. Two loading branches are formed by simply setting two parallel and spaced slots on the oscillator balun. The purpose of improving polarization isolation and widening bandwidth is achieved by combining different connection methods of the two parallel loading branches. The radiating unit of this embodiment can achieve the same or even better bandwidth and performance while reducing the size of the radiating oscillator.

[0056] Figure 7 yes Figure 4 and Figure 5 The comparison of the antenna return loss S11 curve and insertion loss S21 curve of the radiating unit in FIG. Figure 7 As shown, a bandwidth of 700Mhz can be achieved at a current level of less than 15dB.

[0057] Among them, Figure 4 and Figure 5 In the second embodiment shown, the length of the second loading branch 222, the size of the gap between the ends of the two second loading branches 222, and the width of the two slots 21 are all adjustable to adjust the reactance loaded by the LC circuit.

[0058] In a preferred embodiment, the length of the second loading branch 222 is 1 / 8 wavelength.

[0059] Figure 8 FIG. 1 is a schematic structural diagram of a balun circuit board of a radiator in the third embodiment of the present invention. Figure 8 As shown, each oscillator balun further includes:

[0060] Feed circuit 23;

[0061] The parasitic feed circuit 24 is adjacent to at least a portion of the feed circuit 23 to be coupled with the feed circuit 23 .

[0062] Feed circuit 23 is used to power the oscillator balun. Its feeding point is mostly located at the bottom edge of the oscillator balun and extends upward from the bottom edge of the oscillator balun. In this embodiment, a parasitic feed circuit 24 is provided near and coupled to feed circuit 23. Through parasitic coupling with feed circuit 23, co-polarization isolation is achieved within the frequency band.

[0063] The scheme of setting up the parasitic feeding circuit in this embodiment can be combined with the scheme of setting up a short-circuited parallel loading branch in the dipole balun of the first embodiment to simultaneously improve the co-polarization isolation and the heteropolarization isolation of the radiating unit; it can also be combined with the scheme of setting up a short-circuited parallel loading branch and an open-circuited parallel loading branch in the dipole balun of the second embodiment to further widen the bandwidth on the basis of improving the co-polarization isolation and the heteropolarization isolation of the radiating unit, so as to improve the radiation performance of the radiating antenna.

[0064] Among them, such as Figure 8 As shown, in order to achieve better antenna performance in a limited space, the parasitic feeding circuit 24 includes a first parasitic branch 241 and a second parasitic branch 242 arranged parallel to each other. The first parasitic branch 241 and the second parasitic branch 242 are arranged along the height direction of the oscillator balun circuit board 2, and the top ends are connected as a whole.

[0065] That is, the parasitic feed circuit 24 is formed into an inverted U-shape to increase the length of the parasitic feed circuit 24 .

[0066] The reason for forming the inverted U-shape is that the parasitic feeding circuit 24 needs to be grounded. Therefore, the bottom ends of the first parasitic branch 241 and the second parasitic branch 242 are arranged at the bottom edge of the oscillator balun circuit board 2; at least one of the first parasitic branch 241 and the second parasitic branch 242 is grounded through its bottom end.

[0067] The parasitic feed circuit 24 can be grounded at one end or both ends simultaneously, allowing for selective adjustment of co-polarization isolation within the frequency band by combining parasitic coupling with the feed circuit. In one embodiment, the radiating element of this embodiment can improve co-polarization isolation by approximately 2 dB and further extend bandwidth.

[0068] Typically, the feed circuit extends from the bottom edge of the balun. Due to its characteristic of feeding various components in the balun, it needs to be distributed over most of the area on the balun circuit board 2, including both the width and height directions. Specifically, the feed circuit 23 includes a first feed stub 231 arranged along the height direction of the balun circuit board 2 and a second feed stub 232 bent inward from the top of the first feed stub 231. That is, the feed circuit 23 needs to extend from one end of the balun circuit board to the other end in the width direction, and therefore needs to have the second feed stub 232 bent inward.

[0069] In order to increase the space for the parasitic feeding circuit 24 and to increase the length of the parasitic feeding circuit 24 as much as possible, the parasitic feeding circuit 24 is arranged outside the first feeding branch 231 so as to avoid the inwardly bent second feeding branch 232 in its upward extension direction.

[0070] In another embodiment of the present invention, a radiating antenna is provided, which includes a plurality of radiating units as described above, wherein the plurality of radiating units are arranged at intervals on a substrate, and there are no boundary conditions such as isolation walls, isolation walls, and reflection plates between adjacent radiating units.

[0071] It can be seen from the above technical solution that in this embodiment, by forming two slots extending in the horizontal direction on the oscillator balun, this double-slit loading structure can form a loading branch extending in the horizontal direction between the two slots, and the loading branches on the two oscillator baluns (two polarization directions) are connected in parallel to each other. In this embodiment, the two parallel loading branches are short-circuited to form a high impedance equivalent to a quarter wavelength, thereby curbing the scattering field caused by low-profile mismatch, so as to achieve the purpose of improving the antenna polarization isolation.

[0072] The radiating elements of this embodiment combine slots with shorted loading stubs, using parallel loading and polarization shorting to address the bandwidth and performance degradation caused by size reduction. In this embodiment, polarization isolation is achieved through shorted loading stubs, eliminating the need for separate isolation walls and reflectors between adjacent radiating elements. This reduces process and material costs, eases mold development, and improves consistency.

[0073] Furthermore, the scheme of setting up a parasitic feeding circuit in this embodiment can be combined with the scheme of setting up a short-circuited parallel loading branch in the dipole balun in the first embodiment to simultaneously improve the co-polarization isolation and the heteropolarization isolation of the radiating unit; it can also be combined with the scheme of setting up a short-circuited parallel loading branch and an open-circuited parallel loading branch in the dipole balun in the second embodiment to further widen the bandwidth on the basis of improving the co-polarization isolation and the heteropolarization isolation of the radiating unit, so as to improve the radiation performance of the radiating antenna.

[0074] Herein, “a” or “an” does not mean limiting the number of the relevant parts of the present invention to “only one”, and “a” or “an” does not mean excluding the situation where the number of the relevant parts of the present invention is “more than one”.

[0075] Unless otherwise stated, numerical ranges herein include not only the entire range between its two endpoints but also the several sub-ranges contained therein.

[0076] The series of detailed descriptions listed above are merely specific descriptions of feasible implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not depart from the technical spirit of the present invention, such as the combination, division or repetition of features, should be included in the scope of protection of the present invention.

Claims

1. A radiating element of an antenna, characterized in that: The radiation unit includes: A vibrator radiation circuit board (1) on which a pair of vibrator radiation arms are printed; A pair of oscillator balun circuit boards (2) are used to support the oscillator radiation circuit board (1), on which the oscillator balun is printed, and the pair of oscillator balun circuit boards (2) are perpendicularly crossed to form oscillators with two mutually perpendicular polarization directions; Each of the oscillator baluns has two slots (21) extending in the horizontal direction, and the two slots (21) are arranged in parallel and spaced apart in the height direction to form a loading branch (22) extending in the horizontal direction between the two slots (21); The loading branches (22) of a pair of oscillator balun circuit boards (2) are short-circuited to form polarization isolation; Each of the loading branches (22) comprises a first loading branch (221) and a second loading branch (222), the first loading branch (221) and the second loading branch (222) respectively extending horizontally from two ends of the vibrator balun circuit board (2) toward the center line of the vibrator balun circuit board (2), and the ends of the first loading branch (221) and the second loading branch (222) are spaced apart.

2. The radiation unit according to claim 1, characterized in that The ends of the first loading branches (221) of a pair of vibrator balun circuit boards (2) are short-circuited.

3. The radiation unit according to claim 1, characterized in that The ends of the second loading branches (222) of a pair of oscillator balun circuit boards (2) are open-circuited and connected in parallel.

4. The radiation unit according to claim 1, characterized in that The length of the second loading branch (222) is 1 / 8 wavelength.

5. The radiation unit according to any one of claims 1 to 3, characterized in that: Each of the oscillator baluns further comprises: Feed circuit (23); A parasitic feed circuit (24) is adjacent to at least a portion of the feed circuit (23) to couple with the feed circuit (23).

6. The radiation unit according to claim 5, characterized in that The parasitic feeding circuit (24) comprises a first parasitic branch (241) and a second parasitic branch (242) arranged in parallel with each other, the first parasitic branch (241) and the second parasitic branch (242) being arranged along the height direction of the vibrator balun circuit board (2) and being connected as one at their top ends.

7. The radiation unit according to claim 6, characterized in that: The bottom ends of the first parasitic branch (241) and the second parasitic branch (242) share a common ground with the oscillator balun circuit board (2); At least one of the first parasitic branch (241) and the second parasitic branch (242) is grounded via its bottom end.

8. The radiation unit according to claim 5, characterized in that: The feeding circuit (23) comprises a first feeding branch (231) arranged along the height direction of the vibrator balun circuit board (2) and a second feeding branch (232) bent inward from the top end of the first feeding branch (231). The parasitic feeding circuit (24) is arranged outside the first feeding branch (231).

9. A radiating antenna, characterized in that: The method comprises a plurality of radiation units according to any one of claims 1 to 8, wherein the radiation units are arranged at intervals on a substrate, and no isolation walls are provided between adjacent radiation units.

Images