Dual-polarization base station radiator with high gain and high frequency notch

Abstract

The present invention is applicable to the technical field of base station antenna equipment, and provides a dual-polarization base station radiation array with high gain and high-frequency trap, including: a reflective bottom plate; at least one low-frequency radiation array, fixedly mounted on the reflective bottom plate; at least four high-frequency radiation arrays, fixedly mounted on the reflective bottom plate, and evenly surrounding the low-frequency radiation array; at least four metal wires, independently and symmetrically erected on support frames distributed around the low-frequency radiation array. In this way, the metal wires arranged around the low-frequency antenna array of the present invention play the role of a parasitic radiation antenna, and the radiation field generated by the parasitic antenna is superimposed on the radiation field generated by the low-frequency array, and the space resources are fully utilized to improve the gain of the low-frequency antenna without affecting the nested layout scheme.

Description

Technical Field

[0001] The present invention relates to the technical field of base station antenna equipment, and in particular to a dual-polarization base station radiator with high gain and high-frequency trap. Background Art

[0002] With the increasing perfection of the global communications field, mobile communication systems now coexist with multiple standards such as 2G / 3G / 4G, and will coexist with 5G in the future. In order to reduce the cost of network construction and operation and maintenance, and consider the long-term evolvability of the network, operators have put forward higher requirements for broadband, miniaturization, and multi-standard antennas. It is required that a pair of antennas can meet more network standards and cover all existing and future mobile communication frequency bands that may be used. In addition, the antenna is required to be small in size to facilitate base station site selection and save space resources. Therefore, it is necessary to study multi-frequency, broadband, and miniaturized base station antenna technology. The array antenna with high and low frequency nesting scheme is one of the main ways to achieve miniaturization.

[0003] In existing base station array antennas, high-frequency radiating arrays and low-frequency radiating arrays are often required to be installed together on the same floor to achieve multi-standard and miniaturized antenna systems. In order to reduce the shielding of high-frequency radiating units by low-frequency radiating units, existing patents propose to use horizontal radiating units and vertical radiating units to synthesize a ±45° polarized cross array, such as the low-frequency radiating array proposed in publication number CN104916910A. Since high-frequency antennas and low-frequency antennas coexist in base station antenna systems and are close to each other, mutual coupling is easily generated, resulting in distortion of the radiation pattern. The existing publication number CN206412463U proposes to load an H-shaped filter network on the low-frequency radiating plate to suppress the influence of the low-frequency array on the high-frequency radiation pattern.

[0004] In summary, the existing methods have many problems in practical use, so it is necessary to improve them. Summary of the invention

[0005] In view of the above-mentioned defects, the purpose of the present invention is to provide a dual-polarization base station radiating array with high gain and high-frequency notch. The metal wires arranged around the low-frequency antenna array play the role of a parasitic radiating antenna. The radiation field generated by the parasitic antenna is superimposed on the radiation field generated by the low-frequency array. Without affecting the nested layout scheme, the space resources are fully utilized to improve the gain of the low-frequency antenna.

[0006] In order to achieve the above object, the present invention provides a dual-polarization base station radiation array with high gain and high-frequency notch, comprising:

[0007] a reflective base;

[0008] At least one low-frequency radiation array, fixedly mounted on the reflective bottom plate;

[0009] At least four high-frequency radiation arrays are fixedly mounted on the reflective bottom plate and evenly surround the low-frequency radiation array;

[0010] At least four metal wires are independently and symmetrically erected on support frames distributed around the low-frequency radiation array.

[0011] According to the dual-polarization base station radiating array with high gain and high-frequency trap, the low-frequency radiating array includes a die-cast feeding structure, a PCB coupling feeding structure and four PCB radiating branches, the lower end of the die-cast feeding structure is fixedly mounted on the reflective base plate, and the PCB coupling feeding structure and the PCB radiating branches are mounted on the upper end of the die-cast feeding structure.

[0012] According to the dual-polarization base station radiation array with high gain and high-frequency trap, the PCB coupling feeding structure includes a dielectric plate, and four rectangular copper foils are printed on the upper and lower surfaces of the dielectric plate respectively, and the copper foils on the upper and lower surfaces of the dielectric plate are connected one by one through metallized vias; the four copper foils on the same surface of the dielectric plate are symmetrically distributed, and the four copper foils are adjacent to each other and separated by four spacing gaps; an open circuit gap is etched on each of the copper foils.

[0013] According to the dual-polarization base station radiator with high gain and high-frequency notch, the open slot is a linear slot or an L-shaped slot or a bent slot, and the total length of the open slot is a quarter wavelength of the corresponding frequency point.

[0014] According to the dual-polarization base station radiation array with high gain and high-frequency trap, one end of the four PCB radiation branches are respectively installed on the four spaced gaps on the upper end surface of the dielectric board, and the upper and lower surfaces of the PCB radiation branch are provided with at least one identical radiation plate, and the radiation plate has a rectangular and / or stepped and / or multi-fold line structure.

[0015] According to the dual-polarization base station radiator with high gain and high-frequency trap, the die-cast feeding structure includes an air microstrip line structure and at least two short-circuit metal columns, and the air microstrip line structure is connected to the short-circuit metal columns to form a balun of the antenna.

[0016] According to the dual-polarization base station radiation array with high gain and high-frequency notch, the air microstrip line structure includes a first microstrip ground, a second microstrip ground, a first microstrip feed plate and a second microstrip feed plate. The first microstrip ground and the first microstrip feed plate are connected to two copper foils on the lower end surface of the dielectric plate through a first printed metal conductor, and the second microstrip ground and the second microstrip feed plate are connected to the other two copper foils on the lower end surface of the dielectric plate through a second printed metal conductor.

[0017] According to the dual-polarization base station radiation array with high gain and high-frequency trap, the dielectric board is an FR4 substrate.

[0018] According to the dual-polarization base station radiation array with high gain and high-frequency trap, the support frame is made of plastic material and is vertically installed on the reflective bottom plate.

[0019] According to the dual-polarization base station radiation array with high gain and high-frequency trap, the metal wire is straight or right-angled or arc-shaped or irregular; and / or

[0020] The total length of a single metal wire is between 215 mm and 245 mm; and / or

[0021] The high-frequency radiation array is a conventional high-frequency die-cast array, and the low-frequency radiation array is nested in the center of the high-frequency radiation array.

[0022] The dual-polarization base station radiation array with high gain and high-frequency notch described in the present invention includes a reflective bottom plate; at least one low-frequency radiation array, fixedly mounted on the reflective bottom plate; at least four high-frequency radiation arrays, fixedly mounted on the reflective bottom plate and evenly surrounding the low-frequency radiation array; at least four metal wires, independently and symmetrically erected on support frames distributed around the low-frequency radiation array. In this way, the metal wires arranged around the low-frequency antenna array of the present invention play the role of a parasitic radiation antenna, and the radiation field generated by the parasitic antenna is superimposed on the radiation field generated by the low-frequency array, and the space resources are fully utilized to improve the gain of the low-frequency antenna without affecting the nested layout scheme. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of a dual-polarization base station radiation array with high gain and high-frequency notch according to a preferred embodiment of the present invention;

[0024] Figure 2 It is a structural schematic diagram of the low-frequency radiation array of the dual-polarization base station radiation array with high gain and high-frequency notch according to the preferred embodiment of the present invention;

[0025] Figure 3 A current distribution diagram on the PCB radiation branch of the low-frequency radiation array of the dual-polarization base station radiation array with high gain and high-frequency notch described in the preferred embodiment of the present invention;

[0026] Figure 4 It is a structural schematic diagram of the PCB coupling feeding structure of the low-frequency radiating array of the dual-polarization base station radiating array with high gain and high-frequency notch according to the preferred embodiment of the present invention;

[0027] Figure 5 It is a structural schematic diagram of the die-cast feeding structure of the low-frequency radiating array of the dual-polarization base station radiating array with high gain and high-frequency notch according to the preferred embodiment of the present invention;

[0028] Figure 6 The radiation pattern of the high-frequency radiating array at a frequency of 2690 MHz when there is or is not an etched open-circuit gap on the PCB coupling feeding structure of the low-frequency radiating array of the dual-polarization base station radiating array with high gain and high-frequency notch;

[0029] Figure 7 It is a curve showing the change of gain of the low-frequency radiation array with frequency when there are or are no metal wires around the dual-polarization base station radiation array. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] Figure 1 The dual-polarization base station radiation array with high gain and high-frequency trap described in the preferred embodiment of the present invention includes a reflective base plate 4; at least one low-frequency radiation array 1 is fixedly mounted on the reflective base plate 4, at least four high-frequency radiation arrays 2 are fixedly mounted on the reflective base plate 4 and are evenly surrounded by the low-frequency radiation array 2; at least four metal wires 3 are independently and symmetrically erected on support frames 5 distributed around the low-frequency radiation array 1; the low-frequency radiation array 1 is a cross array, and its operating frequency band is 698MHz~960MHz, the high-frequency radiation array 2 is in the operating frequency band of 1710MHz~2690MHz, and the high-frequency radiation The radiating array 2 and the low-frequency radiating array 1 are both ±45° polarized antennas; this embodiment includes four high-frequency radiating arrays 2 and four metal wires 3. The four high-frequency radiating arrays 2 are evenly and symmetrically distributed around the low-frequency radiating array 1. A number of support frames 5 are also provided near the four sides of the low-frequency radiating array 1. The four metal wires 3 are symmetrically mounted on the support frames 5. The parasitic radiation generated by the four metal wires 3 symmetrically around the array can be used to improve the gain of the array. The radiation field generated by the parasitic antenna is superimposed on the radiation field generated by the low-frequency array. Without affecting the nested layout scheme, the space resources are fully utilized to improve the gain of the low-frequency antenna.

[0032] After the low-frequency radiation array 1 radiates, the metal wire 3 can be coupled to the corresponding current. The electromagnetic waves radiated by this part of the coupled current are superimposed on the electromagnetic waves radiated by the low-frequency radiation array 1. Without affecting the nested layout plan, the spatial resources are fully utilized to improve the original radiation pattern of only the low-frequency array. Figure 7The curves of the gain of the low-frequency radiation array 1 changing with frequency with and without the metal wire 3 are given. It can be seen that after adding the metal wire 3, the average gain of the antenna is increased by about 0.7 dBi, and the gain is significantly increased.

[0033] See also Figure 2 The low-frequency radiation array 1 includes a die-cast feeding structure 8, a PCB coupling feeding structure 7 and four PCB radiation branches 6. The lower end of the die-cast feeding structure 8 is fixedly mounted on the reflective bottom plate 4, and the PCB coupling feeding structure 7 and the PCB radiation branches 6 are mounted on the upper end of the die-cast feeding structure 8. The PCB coupling feeding structure 7 includes a dielectric plate 16. Four rectangular copper foils are printed on the upper and lower surfaces of the dielectric plate 16, respectively, and the copper foils on the upper and lower surfaces of the dielectric plate 16 are connected one by one through metallized vias 15; the four copper foils on the same surface of the dielectric plate 16 are symmetrically distributed, and the four copper foils are adjacent to each other with four spacing gaps; an open circuit gap 17 is etched on each of the copper foils. Figure 4 , including a first copper foil 11, a second copper foil 12, a third copper foil 13 and a fourth copper foil 14, the dielectric plate 16 is rectangular, and the four copper foils are symmetrically distributed at the diagonals; the high-frequency radiation array 2 is excited to generate a coupling current on the PCB coupling feeding structure 7 and the PCB radiation branch 6 of the low-frequency radiation array 1, and this part of the current also participates in the radiation and is superimposed on the field radiated by the high-frequency radiation array 2, resulting in the distortion of the high-frequency radiation pattern, see Figure 6 ; In this embodiment, at the frequency point where the high-frequency directional pattern is distorted, the high-frequency coupling current is mainly concentrated on the low-frequency PCB coupling feeding structure 7, and the high-frequency current coupled on the low-frequency PCB radiation branch 6 is relatively weak, so an elongated open-circuit slot 17 is etched on each approximately rectangular copper foil of the PCB coupling feeding structure 7, and the high-frequency directional pattern of the corresponding frequency band can be improved by adjusting the length of the open-circuit slot 17. The open-circuit slot 17 in this embodiment is a straight slot, or in other embodiments it can also be an L-shaped slot or a bent slot, and the total length of the open-circuit slot 17 is a quarter wavelength of the corresponding frequency point, and the corresponding frequency point is the frequency point where the high-frequency directional pattern is distorted due to the strong current coupled on the PCB feeding plate; from Figure 6 It can be seen that when there is no open-circuit slot 17 on the PCB coupling feed structure 7 of the low-frequency radiating array 1, the high-frequency radiation pattern is greatly distorted, and when there is an open-circuit slot 17 on the PCB coupling feed structure 7 of the low-frequency radiating array 1, the high-frequency radiation pattern is less distorted and is close to the pattern when only high-frequency radiation is applied. If, under certain conditions, the high-frequency current coupled to the PCB radiation branch 6 of the low-frequency radiating array 1 is relatively concentrated, then it may be considered to etch a quarter-wavelength open-circuit slot on the PCB radiation branch 6.

[0034] Furthermore, one end of the four PCB radiation branches 6 is respectively mounted on the four spaced gaps on the upper end surface of the dielectric plate 16, and the upper and lower surfaces of the PCB radiation branches 6 are provided with at least one identical radiation sheet, and the radiation sheet is rectangular and / or stepped and / or multi-fold line structure. The PCB radiation branches 6 can couple electromagnetic waves and radiate, and adjusting the gap size and gap length of the coupling feed structure can adjust the impedance characteristics of the antenna. Figure 3 , the shapes of the PCB radiation branches 6 on the upper and lower surfaces are the same, and the shape of the radiation piece thereon can be rectangular and / or trapezoidal and / or bend lines. The present invention uses a combination of rectangular lines and bend lines as the radiation piece of the low-frequency radiation array 1. The bend lines can increase the effective flow path of the current and reduce the physical size of the radiation piece. When the +45° mouth of the low-frequency radiation array 1 is excited, the current 10 is formed on the four PCB radiation branches 6, and the fields radiated by these four currents can synthesize a +45° radiation field. Similarly, when the -45° mouth of the low-frequency radiation array 1 is excited, the fields radiated by the currents on the four PCB radiation branches 6 can synthesize a -45° radiation field. The distance between the reflective base plate 4 and the PCB radiation branch 6 of the low-frequency radiation array 1 is approximately one-quarter of the wavelength of the center frequency.

[0035] See also Figure 5 The die-cast feeding structure 8 includes an air microstrip line structure and at least two short-circuit metal pillars 22, and the air microstrip line structure is connected to the short-circuit metal pillars 22 to form the balun of the antenna. The length of the two metal pillars 22 is approximately one-quarter wavelength of the center frequency of the antenna. Furthermore, the air microstrip line structure includes a first microstrip ground 18, a second microstrip ground 20, a first microstrip feed plate 19 and a second microstrip feed plate 21, the first microstrip ground 18 and the first microstrip feed plate 19 are connected to the two copper foils on the lower end surface of the dielectric plate 16 through a first printed metal conductor, and the second microstrip ground 20 and the second microstrip feed plate 21 are connected to the other two copper foils on the lower end surface of the dielectric plate 16 through a second printed metal conductor. Specifically, the first microstrip ground 18 and the first microstrip feed plate 19 transmit the excitation signal to the approximately rectangular first copper foil 11 and the third copper foil 13 through a section of printed metal conductor; the PCB radiation branch 6 couples to the excitation signal on the approximately rectangular first copper foil 11 and the third copper foil 13, which can form a current 10 and generate a +45° radiation field. The second microstrip ground 20 and the second microstrip feed plate 21 transmit the excitation signal to the approximately rectangular second copper foil 12 and the fourth copper foil 14 through a section of printed metal conductor, which can generate a -45° radiation field.

[0036] Preferably, the dielectric plate 16 is a FR4 (a code for a flame resistant material grade) substrate. The support frame 5 is made of plastic material and is vertically mounted on the reflective bottom plate 4 .

[0037] The metal wire 3 of this embodiment is a right-angle type, and in other embodiments it can also be a straight line, an arc or an irregular type; specifically, the total length of a single metal wire is between 215 mm and 245 mm, that is, the total length of the metal wire 3 is approximately half the wavelength of the lowest frequency point of the working frequency band. Selecting a suitable shape and placement position of the metal wire 3 can improve the gain, bandwidth, front-to-back ratio and other indicators of the low-frequency array, and the cross-polarization ratio is slightly worse. The high-frequency radiation array 2 is a conventional high-frequency die-cast array, and the low-frequency radiation array 1 is nested in the center of the high-frequency radiation array 2, that is, a low-frequency radiation vibrator 1 is arranged in the center of the four high-frequency radiation vibrators 2, which can reduce the spatial size of the array antenna. The gain of the array is increased by using the parasitic radiation generated by adding four metal wires symmetrically around the array. By etching open circuit gaps on the coupling feed plate of the low-frequency array, the influence of the low-frequency array on the high-frequency radiation pattern is suppressed.

[0038] In summary, the metal wires arranged around the low-frequency antenna array of the present invention play the role of a parasitic radiating antenna. The radiation field generated by the parasitic antenna is superimposed on the radiation field generated by the low-frequency array, and the gain of the low-frequency antenna is improved by making full use of space resources without affecting the nested layout scheme. The open circuit gap etched on the approximately rectangular copper foil of the PCB coupling feed can produce a notch characteristic at the corresponding frequency point of the high frequency, which is used to suppress high-frequency electromagnetic waves, reduce the coupling between high and low frequencies, and improve the high-frequency radiation pattern; and the feed and balun structure composed of the die-cast air microstrip and the short-circuit metal column is more solid and convenient for batch processing and production.

[0039] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A dual-polarization base station radiator with high gain and high-frequency notch, characterized in that: Included are: a reflective base; At least one low-frequency radiation array, fixedly mounted on the reflective bottom plate; At least four high-frequency radiation arrays are fixedly mounted on the reflective bottom plate and evenly surround the low-frequency radiation array; At least four metal wires are independently and symmetrically erected on support frames distributed around the low-frequency radiation array; The low-frequency radiation array includes a die-cast feeding structure, a PCB coupling feeding structure and four PCB radiation branches, the lower end of the die-cast feeding structure is fixedly mounted on the reflection bottom plate, and the PCB coupling feeding structure and the PCB radiation branches are mounted on the upper end of the die-cast feeding structure; The PCB coupling feeding structure includes a dielectric plate, and four rectangular copper foils are printed on the upper and lower surfaces of the dielectric plate respectively, and the copper foils on the upper and lower surfaces of the dielectric plate are connected one by one through metallized vias; the four copper foils on the same surface of the dielectric plate are symmetrically distributed, and the four copper foils are adjacent to each other and separated by four spacing gaps; an open circuit gap is etched on each of the copper foils.

2. The dual-polarization base station radiator with high gain and high-frequency notch according to claim 1, characterized in that: The open slot is a straight slot, an L-shaped slot, or a bent slot, and the total length of the open slot is a quarter wavelength of the corresponding frequency point.

3. The dual-polarization base station radiator with high gain and high-frequency notch according to claim 1, characterized in that: One ends of the four PCB radiation branches are respectively installed on the four spacing gaps on the upper end surface of the dielectric board, and the upper and lower surfaces of the PCB radiation branch are provided with at least one identical radiation plate, and the radiation plate is rectangular and / or stepped and / or multi-fold line structure.

4. The dual-polarization base station radiator with high gain and high-frequency notch according to claim 1, characterized in that: The die-cast feeding structure includes an air microstrip line structure and at least two short-circuit metal columns, and the air microstrip line structure is connected with the short-circuit metal columns to form a balun of the antenna.

5. The dual-polarization base station radiator with high gain and high-frequency notch according to claim 4, characterized in that: The air microstrip line structure includes a first microstrip ground, a second microstrip ground, a first microstrip feed plate and a second microstrip feed plate. The first microstrip ground and the first microstrip feed plate are connected to two copper foils on the lower end surface of the dielectric plate through a first printed metal conductor, and the second microstrip ground and the second microstrip feed plate are connected to the other two copper foils on the lower end surface of the dielectric plate through a second printed metal conductor.

6. The dual-polarization base station radiator with high gain and high-frequency notch according to claim 1, characterized in that: The dielectric board is a FR4 substrate.

7. The dual-polarization base station radiator with high gain and high-frequency notch according to claim 1, characterized in that: The support frame is made of plastic material and is vertically installed on the reflective bottom plate.

8. The dual-polarization base station radiator with high gain and high-frequency notch according to any one of claims 1 to 7, characterized in that: The metal wire is straight, right-angled or arc-shaped; and / or The total length of a single metal wire is between 215 mm and 245 mm; and / or The high-frequency radiation array is a conventional high-frequency die-cast array, and the low-frequency radiation array is nested in the center of the high-frequency radiation array.

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