KR102601186B1 - Multi-band Multi-array Base Station Antenna - Google Patents

Abstract

The present invention discloses a compact base station antenna with multi-band multi-column dual polarization based on a new low-band radiation element having a filtering balun and a radiating arm to prevent re-radiation.
The small base station antenna according to the present invention is particularly useful when a large number of radiating elements are densely arranged on a reflector having a narrow width.

Description

Multi-band Multi-array Base Station Antenna}

The present invention relates to a mobile communication base station antenna, and particularly to a multi-band, multi-array base station antenna that supports the implementation of LTE-Advanced and 5G or higher generation mobile communication networks.

The recent construction of 5G mobile communication networks using new operating frequency bands, high order multi-stream MIMO (Multi-Input & Multi-Output), and new beamforming technology requires upgrading the base station antenna system. At the same time, existing 3G and 4G mobile network services must be maintained.

A next-generation multi-band base station antenna with multiple arrays highly integrated within a slim form factor antenna radome can solve the challenge of upgrading overloaded base station towers due to the emergence of 5G communication networks.

Innovative engineering and consideration of higher levels of antenna integration must address one of the key issues in dual-polarization radiator design for arrays of different frequency bands. In order to obtain stable frequencies, standard radiation patterns, and stable 3D RF beam spot coverage for each band and each MIMO stream, these radiating elements must be RF-invisible to each other in terms of multiple bands and multiple arrays. It's ideal.

Additionally, to prevent degradation of MIMO gain performance, 5G standard data throughput and capacity, it is recommended to maintain high inter-band isolation of RF signals (> 20dB) of the multi-band multi-array base station antenna.

This problem can be solved through dual-polarized radiating devices that are designed to be "cloaked" or "choked," in which case the radiating devices only radiate/radiate signals in frequency bands for which they are designed to be transparent to other RF signal bands. Reception is possible.

Cloaked or choked double-polarized radiation elements for multi-band antennas are known, and representative prior arts include US Patent US 9,912,076 B2 and US 10,439,285 B2 (CommScope Technologies LLC.).

The US 9,912,076 B2 patent (Figure 1) discloses an LBB radiator arm choked by a quasi-coaxial quarter lambda radiator section. The choke resonates near the antenna's second high-band frequency.

The US 10,439,285 B2 patent (FIG. 2) discloses an LBB radiating element arm cloaked by dividing a number of conductive segments with a length of less than half a wavelength in a second high frequency band of operation. The conductive segments are connected in series by a number of inductive elements comprising planar inductive traces. This LBB radiation element arm structure represents a low-pass filtering circuit to prevent propagation and reradiation of high-band current induced from HBB radiation elements in a secondary array arranged in parallel with the LBB array.

CommScope Technologies LLC's US 10,644,401 B2 patent (FIG. 3) and US 2021/0104813 A1 (FIG. 4) patents are for multi-band multiplexing based on cloaked or choked dual polarized LBB radiating elements. A lot of detailed technical information for the implementation of array compact base station antennas is disclosed.

The antennas disclosed in US 10,644,401 and US 2021/0104813 have a 1L2H type integrated array structure. Here, 1L2H (one LBB array with two side-by-side HBB arrays) refers to a structure in which two HBB arrays are arranged side by side around one LBB array. Typically, this type of base station antenna is allocated within a radome with a relatively narrow width in the range of 300 to 380 mm. Additionally, the 1L2H type antenna can only support 2T2R MIMO mode in low bands and 4T4R MIMO mode in high bands.

For 4T4R full-band MIMO operation or 8T8R HBB beamforming, there is a highly integrated array structure of type 2L4H. Wind load limitations and available space constraints in base station towers make a 2L4H compact antenna housed inside a 500 mm wide radome realistically acceptable and desirable.

Integrating two low-band arrays and four or more HBB arrays side-by-side in a relatively small shared space while maintaining acceptable RF performance and key performance indicators (KPIs) for all base station antennas will be a very difficult innovation engineering challenge. .

CommScope Technologies LLC's US 11,018,437 B2 patent (FIG. 5) and US 10,431,877 B2 (FIG. 6) disclose a 2L4H type multi-band base station antenna with broadband decoupling radiating elements and parasitic coupling units. do. In a 2L4H base station antenna housed within a 500 mm wide radome, the parasitic coupling units and the broadband decoupling radiating elements require significant complexity to maintain acceptable RF performance.

Another solution of a multi-band dual polarization base station antenna is disclosed in Huawei Technologies' patent application US 2021/0210854A1 (Figure 7). Embodiments of this invention disclose multi-band antennas equipped with HBB radiating elements including a balun structure, a coupling structure, a radiating arm structure, etc. The coupling structure is configured to transmit signals with frequencies higher than a preset threshold and block signals with frequencies lower than the preset threshold. HBB radiating elements with a high-band filter circuit integrated into the balun improve RF performance when LBB and HBB radiating elements are densely placed side by side in a compact multi-band array.

As another prior art, the invention of South China University of Technology SCUT, disclosed in Chinese Patent Publication CN 104916910B (FIG. 8), implements the next step in improving RF performance for compact multi-band arrays. This invention, together with the LBB and HBB dipole structures, provides a multi-band multi-array base station antenna array that solves the problem of shielding from each other between the high-band dipole arm and the low-band dipole arm. As a result of this invention, the mutual coupling between high-band dipoles and low-band dipoles can be reduced. The first embodiment of the invention discloses a cross-shaped (V/H arm direction) LBB radiating element, and the second embodiment discloses further performance improvements to the LBB radiating element in a compact multi-band array. A new structure for coupling the feeding from the balun to the dipole radiating arm has been proposed.

Nokia Shanghai Bell Lab's Korean published patent KR 10-2020-0118253 (FIGS. 9a, b, c) provides a low-band dipole and multi-band multi-port antenna arrangement. Here, the low-band dipole has four arms in a cross shape (V/H arm direction), and the four dipole arms are fed by at least one of coupling feeding or direct feeding. . At least one of the four dipole arms is choked by a quasi-coaxial (Figure 9b) or printed groove (Figure 9c) quarter lambda radiator section. The choke resonates near the frequency of the high-band radiating element of the antenna and reduces mutual coupling between the high-band radiating element and the low-band radiating element in a multi-band multi-array antenna arrangement.

Another complex problem in the development of multi-band multi-array antennas is the set of subbands with different beam and beam tilt angles between LTE service providers with different frequency bands (e.g., 1710 MHz to 2690 MHz) common to one column of radiating element arrays. The point is that it can be divided into . So-called filtered multi-band antennas of this type require an array feeder with a large number of diplexers and phase shifter devices. However, adding diplexers and phase shifters to existing dual and multi-band antennas presents several challenges. In other words, since the space between radiation elements within the antenna is limited by the array pitch and the width of the reflector is limited to the range of 300-370 mm by wind load, adding a device to the radome of a general base station antenna is subject to significant space limitations.

Therefore, developing compact, multi-band, multi-array base station antennas suitable for the functional and dimensional requirements of new 5G mobile communication systems is a common goal in this industry.

U.S. Registered Patent Publication No. US 9,912,076 (published on March 6, 2018) US Patent Publication No. US 10,439,285 (published on October 8, 2019)

The present invention is to provide an improved 2L4H type base station antenna with multiple bands and multiple columns.

The present invention is also intended to provide a 2L4H type base station antenna having LBB and HBB radiation elements with maximized isolation characteristics between frequency bands.

The present invention also provides for the antenna beam and industry standard key performance indicators (KPIs) for all base station antennas accommodated inside the relatively narrow radome width in the range of 400 to 500 mm required in new LTE-Advanced and 5G mobile communication systems. The purpose is to provide a 2L4H type base station antenna with acceptable RF performance.

The objects of the present invention are not limited to the objects mentioned above, and other objects not mentioned will be clearly understood by those skilled in the art from the description below.

A multi-band multi-array mobile communication base station antenna according to an embodiment of the present invention for solving the above problem has a low-frequency wide-band (LBB) radiating element array and at least one high-frequency wide-band (HBB) radiating element array, and the LBB radiates The element and the HBB radiation element array are a multi-band, multi-array mobile communication base station antenna disposed in a reflector, and include a plurality of LBB radiation elements arranged in the longitudinal direction of the reflector and the longitudinal direction of the reflector around the LBB radiation elements. It includes a plurality of HBB radiating elements arranged, wherein the LBB radiating elements include a balanced feed balun member and a radiating structure disposed on an upper end of the balanced feed balun member. member), wherein the radiating structure member of the LBB radiating element includes four or more radiating arms arranged in a cross shape to form a cross dipole-type radiating structure, the radiating arms (radiating arm) includes a plurality of conductive plates, wherein the conductive plates include a slot forming at least one notch resonator that prevents the radiating arm from re-radiating RF energy in the frequency band of the HBB radiating elements. can do.

A multi-band multi-array mobile communication base station antenna according to another embodiment of the present invention for solving the above problem has a low-frequency wide-band (LBB) radiating element array and at least one high-frequency wide-band (HBB) radiating element array, and the LBB radiates The element and the HBB radiation element array are a multi-band, multi-array mobile communication base station antenna disposed in a reflector, and include a plurality of LBB radiation elements arranged in the longitudinal direction of the reflector and the longitudinal direction of the reflector around the LBB radiation elements. It includes a plurality of HBB radiating elements arranged, wherein the LBB radiating elements include a balanced feed balun member and a radiating structure disposed on an upper end of the balanced feed balun member. member), wherein the radiating structure member of the LBB radiating element includes four or more radiating arms arranged in a cross shape to form a cross dipole-type radiating structure, the radiating arms (radiating arm) includes a plurality of conductive plates, and the conductive plate may include a V-shaped side arm connected to the balanced feed balun member, and an RF choke segment formed in parallel with the V-shaped side arm.

A multi-band multi-array mobile communication base station antenna according to another embodiment of the present invention for solving the above problem has a low-frequency wide-band (LBB) radiating element array and at least one high-frequency wide-band (HBB) radiating element array, and the LBB The radiation element and the HBB radiation element array are a multi-band, multi-array mobile communication base station antenna disposed in a reflector, and include a plurality of LBB radiation elements arranged in the longitudinal direction of the reflector and the length of the reflector around the LBB radiation elements. It includes a plurality of HBB radiating elements arranged in a direction, wherein the LBB radiating elements include a balanced feed balun member and a radiating structural member disposed on an upper end of the balanced feed balun member. structure member), wherein the radiating structure member of the LBB radiating element includes four or more radiating arms arranged in a cross shape to form a cross dipole-type radiating structure, and the LBB At least one balanced feed balun member of the radiating element may include a circuit structure of a low pass filter (LPF) with a cutoff frequency assigned below the operating frequency band of the HBB radiating element.

In each embodiment, the balanced feed balun member and the radiating structure member of the LBB radiating element may be connected by capacitive coupling feeding.

In each embodiment, the plurality of conductive plates may be arranged on the same plane.

In each embodiment, the reflector may be partitioned with an inner wall to accommodate each of the HBB radiation elements.

In some embodiments, the notch resonator may include an H-shaped slot.

In some embodiments, the H-shaped slot may have some areas bent downward.

In some embodiments, the V-shaped side arms may be formed along both edges of each radiation arm.

In some embodiments, the RF choke segment is formed shorter than the length of the V-shaped side arm, and one end is bent and connected to the end of the V-shaped side arm to form a meander shape with the V-shaped side arm. .

In each embodiment, the array of the LBB radiation elements and the HBB radiation elements disposed in the reflector may be a three-row arrangement including one row of LBB radiation elements and two rows of HBB radiation elements.

In some embodiments, a multi-band multi-array mobile communication base station antenna may be arranged so that six reflectors including the three-row array on each reflector have a hexagonal radiation structure surrounding the center.

These solutions will become more apparent from the description of specific details for carrying out the invention based on the attached drawings.

According to the present invention, a compact size multi-band dual polarized mobile communication base station antenna can be provided.

The present invention can also provide a base station antenna that prevents the LBB radiation element of the multi-band multi-array base station antenna from re-radiating RF energy to the frequency band of the HBB radiation element.

The present invention can also provide a 2L4H type base station antenna having LBB and HBB radiation elements with maximized isolation characteristics between frequency bands.

The present invention can also provide a broadband and compact base station antenna with low scattering characteristics of electromagnetic fields radiated by radiating elements disposed in close proximity.

The present invention also provides for the antenna beam and industry standard key performance indicators (KPIs) for all base station antennas accommodated inside the relatively narrow radome width in the range of 400 to 500 mm required in new LTE-Advanced and 5G mobile communication systems. It is possible to provide a 2L4H type base station antenna with acceptable RF performance.

The effects that can be obtained from the present invention are not limited to the above effects, and are not limited to the problems of the prior art mentioned above in the technical field of multi-band multi-column antennas and the radiation characteristics of a multi-column array closely arranged side by side in close proximity on a common reflector ( It can help solve various difficulties related to radiation characteristics.

Figure 1 shows a choked arm dipole for a multi-band array according to US patent US9912076 B2.
Figure 2 shows a cloaked low-band radiation element for a multi-band array according to US patent US10439285 B2.
Figure 3 shows an interspersed multi-band array with choked arm dipoles according to US patent US10644401 B2.
Figure 4 shows a base station antenna comprising a further multi-band array with choked arm dipoles according to US patent US20210104813 A1.
Figure 5 shows a base station antenna comprising a multi-band array with decoupling and a choked arm dipole according to US patent US11018437 B2.
Figure 6 shows a base station antenna comprising a multi-band array with parasitic coupling units according to US patent US10431877 B2.
Figure 7 shows a multi-band antenna according to US patent US20210210854 A1.
Figure 8 shows an embodiment of a multi-band antenna according to Chinese patent CN104916910 B.
Figure 9 shows an embodiment of a multi-band antenna according to Korean Patent Publication KR1020200118253 A.
Figure 10 shows a 4T4R multi-band base station antenna with a 2L4H array structure according to an embodiment of the present invention.
Figures 11 a, b, and c illustrate a multi-band 3-column base station antenna according to an embodiment of the present invention.
Figure 12 shows a state in which a low-band radiation element according to an embodiment of the present invention is disposed on a reflector.
Figure 13 shows a concrete diagram of a radiating structures member of a low-band radiation device according to an embodiment of the present invention.
Figure 14 is a top view of a radiating structures member in a low-band radiation device according to an embodiment of the present invention.
Figure 15 shows a frequency response characteristic (plot) of a low pass filter embedded in the balun of a low-band radiating element.
Figure 16 shows an impedance matching and isolation characteristic (plot) of a low-band radiation device having a filtering balun and a re-radiation prevention dipole arm according to an embodiment of the present invention.
Figure 17 shows a plot of radiation gain characteristics of a low-band radiation device equipped with a filtering balun and a re-radiation prevention dipole arm according to an embodiment of the present invention.
Figures 18a and 18b show polar plots of the azimuthal radiation pattern of a low-band radiation element according to theoretical and actual data.
Figures 19a, b, and c are concrete diagrams of a low-band radiation device equipped with a filtering balun and a bent arm structure to prevent re-radiation, according to another embodiment of the present invention.
Figures 20a and 20b show the polar coordinate characteristics of the azimuthal radiation pattern for a cluster of four isolated high-band radiation elements and one high-band radiation element.
Figures 21a and 21b show the polar coordinate characteristics of the azimuthal radiation pattern for a low-band radiation element of a conventional crossed dipole arm structure surrounded by four high-band radiation elements and one high-band radiation element.
22A and 22B show a low-band crossed dipole radiation element equipped with a filtering balun and a re-radiation prevention dipole arm and surrounded by a cluster of four high-band radiation elements, in accordance with an embodiment of the present invention, and one high-band radiation element herein. It shows the polar coordinate characteristics of the azimuthal radiation pattern for the radiation element.
Figures 23a and 23b show low-band crossed dipole radiating elements surrounded by a cluster of four high-band radiating elements, equipped with a filtering balun and a re-radiation prevention dipole arm, arranged on a bent reflector according to an embodiment of the present invention. Indicates the case where
Figures 24a and 24b show a multi-sector base station antenna arranged to have a hexagonal radiation structure surrounding the center using a multi-band three-row panel according to an embodiment of the present invention.

The foregoing and additional inventive aspects are embodied through embodiments described with reference to the accompanying drawings. However, the embodiments described below are merely illustrative and are not intended to limit the scope of the present invention to the described embodiments.

In addition, the components of each embodiment may be combined in various ways within or between embodiments unless otherwise stated or contradictory to each other, and in explaining the present invention, detailed descriptions of related known functions or components are provided. If it is judged that it may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

And, when a part "includes" a certain component, this means that it necessarily includes this component regardless of other components, and does not mean to exclude the possibility of including other components.

In addition, throughout the specification, when a part is said to be "connected" to another part, this refers not only to the case where it is "directly connected" but also to the case where it is "electrically connected" with another element in between. Includes. Furthermore, throughout the specification, a signal refers to an electric quantity such as voltage or current.

In addition, the flow charts shown in the drawings are merely exemplary sequences to obtain the most desirable results in carrying out the present invention, and of course, other steps may be added or some steps may be deleted.

Embodiments of the present invention disclose a compact base station antenna with multi-band multi-column dual polarization based on a new radiating element having a filtering balun and a radiating arm to prevent re-radiation.

The small base station antenna according to embodiments of the present invention is particularly useful, for example, in the case of 2L4H, when a large number of radiating elements are densely arranged on a reflector with a narrow width in the range of 400-500 mm.

In the following description, the LBB radiation device refers to a broadband radiation device that can operate in a low frequency band (617-960 MHz), and the HBB radiation device refers to a broadband radiation device that can operate in a high frequency band (1400-2700 MHz). However, it is clear to those skilled in the art that minor modifications such as tuning, replacement, and/or modification of the operating frequency bands of the disclosed LBB and HBB radiation elements can be easily made without departing from the scope and spirit of the present invention.

Figure 10 shows a 2L4H (2 low band columns & 4 high band columns) type multi-band multi-column compact base station antenna according to an embodiment of the present invention, and Figure 11 shows a 1L2H (1 low band column) type base station antenna. & 2 high band columns) is a perspective view showing various antennas of a multi-band multi-column type with 3 columns. FIG. 11A includes 3 types of antennas as shown in FIG. 10, and FIG. 11B includes 2 types of antennas. This is the case, and Figure 11c shows a radome covered over the antenna. In FIG. 10, the left diagram is a side view of the antenna, and the right diagram is a top view of the antenna.

In Figure 10, the total width of the two reflectors may range from 400-500 mm, and in Figure 11, the width of one reflector may range from 200-250 mm.

Referring to FIG. 10, a compact multi-band multi-column base station antenna according to an embodiment of the present invention is placed on two reflectors 10 each having a width of, for example, 230 mm, with the center of the reflector 10 positioned on each reflector 10. The LBB radiation elements 100 are disposed at the center in the longitudinal direction, and the first HBB radiation elements 200 are located in each quadrant area that divides the rectangular (e.g. square) area occupied by each LBB radiation element into four equal parts. It is arranged surrounding this one LBB radiation element 100. In addition, it has a structure in which second HBB radiation elements 300 are arranged in an area between one LBB radiation element 100 and another LBB radiation element 100 adjacent in the longitudinal direction.

Each of the LBB radiation elements and the HBB radiation elements includes an array of two pairs of dipoles, and each dipole radiates electromagnetic waves of +45 degree polarization and -45 degree polarization by feeding to each port.

Each of the HBB radiation elements is separated from each other by an inner wall on the reflector 10.

As shown above, the antenna of FIG. 10 includes an array of three types of radiation elements and is composed of two reflectors with a width of 230 mm, forming a 2L4H structure including 2 columns of LBB and 4 columns of HBB as a whole. The two reflectors may be arranged at different heights so that the LBB radiation element and the second HBB radiation element area have the same horizontal center line.

FIG. 11A shows a 1L2H 3-column antenna using one reflector in FIG. 10. All configurations included in the antenna are the same as those in FIG. 10, so description thereof will be omitted.

Figure 11b shows a 1L2H 3-column antenna like Figure 11a, but includes only one type of HBB, and Figure 11c shows the antenna covered with a radome 20. Unlike Figure 11a, it can be seen in Figures 11b and 11c that the end of the LBB radiation arm is bent, which will be described later.

In a three-column antenna such as Figure 11, the width of the reflector is generally limited to the range of 300-370 mm due to industry standards and wind load. The compact LBB radiation element column according to the present invention occupies only about 110 mm, which is much less than the typical 160-180 mm of existing LBB radiation element arrays. In addition, the compact HBB radiation element array placed to the right and left of the center line of the reflector panel occupies only about 45mm of installation space, unlike the 60-80mm of existing HBB radiation elements.

Therefore, the compact LBB and HBB radiating elements with a reflector width of 300 mm according to the present invention have a space of about 50 mm, in contrast to the three-column base station antenna based on the existing LBB and HBB radiating elements, which has no free space or even overlaps. Take your time.

FIG. 12 is a perspective view showing only one LBB in FIG. 10 separated, FIG. 13 is an exploded view for explaining the detailed configuration of this LBB, and FIG. 14 is a top view of this LBB.

Referring to FIGS. 12 to 14, the LBB 100 according to an embodiment of the present invention is a crossed dipole-type radiating element, and includes a balanced feed balun member (110) for supplying a signal to the radiating element, and , and includes a radiating structure member (120) disposed in a horizontal plane at the top of this balanced feed balun member.

Referring to FIG. 13, the low-band radiating element has a structure in which two balanced feeding balun members for double polarization are arranged vertically.

The balanced feed balun member and the radiating structure member of the LBB radiating element according to an embodiment of the present invention may be connected by capacitive coupling feeding.

A fairly large value of high-frequency band current can be induced in the dipole radiation arm of the low-band radiation elements densely arranged with the high-band radiation elements on a narrow reflector. Accordingly, the capacitive coupling between the balanced feed balun member and the dipole arm may be implemented to reduce high-band current flow through the low-band balanced feed balun circuit from the dipole radiating arm to the chassis reflector in common mode.

In addition, at least one of the balanced feed balun members of the LBB radiating element may include a circuit structure of a low pass filter (LPF) having a cutoff frequency assigned below the operating frequency band of the HBB radiating element. there is.

The lower right drawing of FIG. 13 shows that the circuit structure of the low-pass filter 111 is formed in a pattern on the balanced feed balun member 110.

The low-pass filter formed on the balun of the LBB radiation element prevents the HBB current induced in the LBB radiation element from flowing from the dipole arm of the LBB radiation element to the chassis reflection panel in differential mode.

Therefore, according to an embodiment of the present invention, the combination of a balun with a low-pass filtering function and a capacitive coupling method between a dipole radiation arm and a balun allows the current induced by the high-band radiation element to flow to the reflector through the low-band radiation element. This allows the flow to be greatly reduced in both common mode and differential mode.

Accordingly, the cross-band scattering of the multi-band, multi-column array is greatly alleviated, and a consistent radiation pattern can be maintained in both bands.

The radiating structural member 120 includes four or more radiating arms arranged in a cross shape (cross shape) to form a crossed dipole type radiating structure, wherein the radiating arms are coplanar arranged in a crossed dipole configuration. Contains a conductive plate.

The conductive plate of the radiation arm is a V-shaped side arm extending in a V shape from the feed coupling portion 121 coupled to the top of the balanced feed balun member 110 to each side of the cross-shaped substrate for supply of the antenna signal ( 122), a notch resonator 123 extending toward the end of the radiation arm, and an RF choke segment 125 formed in parallel with the V-shaped side arm 122.

The V-shaped side arms 122 are two pairs of coplanar conductive plates arranged in a crossed dipole structure, each pair of plates about an axis defined by a dual polarized radiating element array column (row). They are aligned and placed with a polarization angle of +/- 45° inclination. The V shape of the V-shaped side arm 122 may be formed at an angle of substantially 90 degrees, and each plate forming the V-shaped side arm 122 is arranged parallel to each other on the radiation arm to provide capacitive coupling power supply. forms.

The RF choke segment 125 functions to block (choke) current induced from the surrounding HBB radiation element from flowing into the V-shaped side arm 122 forming the dipole of the LBB radiation element.

The RF choke segment may be a quarter lambda (1/4 wavelength) long.

The resonance frequency of the quarter lambda RF choke segment may be selected within the operating frequency range of the high-band radiating device.

The notch resonator 123 functions to prevent the high-band frequency signal propagated from the surrounding HBB radiating element to the LBB radiating element from being reradiated back to the HBB radiating element.

The notch resonator 123 may include, for example, an H-shaped slot 124.

The conductive plates of the radiant arm are divided into three types: meander shaped segments, RF choke segments, and droop down or rises up segments. It may contain a plurality of segments of a type.

The RF choke segment is preferably combined with a meander-shaped segment and functions to reject radiated dark current in the high frequency band (above 1700 MHz). In Figure 14, the RF choke segment 125 is connected to the V-shaped side arm 122 to form a meander shape, and is formed shorter than the V-shaped side arm 122, so that a conductive plate is filled in the bend at the center of the V-shaped side arm. It leaves a small V-shaped void that has not been filled.

The droop segment is a configuration in which a portion of a conductive plate is bent at a predetermined angle and may be assigned to an end of each radiation arm.

If the droop segment is formed at the end of each radiation arm, as shown in FIG. 19b, the radius of the radome covering the antenna can be reduced by the bending angle, contributing to miniaturization of the antenna.

Referring again to FIG. 10, the compact HBB radiating element of the multi-band multi-column base station antenna according to an embodiment of the present invention is a balanced feed balun member with a radiating structure member disposed on the top. (balanced feed balun member) included. The radiant structural member includes two pairs of coplanar conductive plates arranged in a crossed dipole structure.

Each of the two plates is arranged diagonally substantially aligned with a polarization angle of +/- 45° relative to the axis defined by the dual polarized radiating element array rows. The alignment of each of these plate diagonals intersects at a right angle intersection located between the plates of each dipole.

The conductive plate forms a radiating arm extending radially from the diagonal intersection.

Figure 15 shows a frequency response characteristic (plot) of a low pass filter embedded in the balun of a low-band radiating element.

According to Figure 15, LPF (Low Pass Filter) is the operating band of the low-band radiating device and has a cutoff frequency of about 1000 MHz and a pass band below the cutoff frequency, and the suppression frequency band of 30 dB or more is in the operating band of the high-band radiating device. Expands up to 4500MHz.

Figure 16 shows an impedance matching and isolation characteristic (plot) of a low-band radiation device having a filtering balun and a re-radiation prevention dipole arm according to an embodiment of the present invention.

According to Figure 16, it shows good impedance matching characteristics in the LPF passband (band of about 500 MHz to 1000 MHz), which is the operating band of low-frequency radiating devices, and has an impedance matching characteristic of -50 dB or more in the band of about 1350 MHz to 2300 MHz, which is the operating band of high-frequency radiating devices. Since it shows excellent suppression characteristics, excellent isolation characteristics can be expected even when low-frequency radiation elements and high-frequency radiation elements are arranged together.

Figure 17 shows a plot of the radiation gain frequency variation characteristics of a low-band radiation device equipped with a filtering balun and a re-radiation prevention dipole arm according to an embodiment of the present invention. Fast roll-off radiation gain and over 20dB suppression in the high frequency range can be seen.

Figures 18a and 18b show polar plots of the azimuthal radiation pattern of the low-band radiation device according to theoretical (Dassault Systemes CST Studio Suite 3D EM simulation) data and actual measurement data. From FIG. 18, it can be seen that the theoretical data (FIG. 18A) and the measured data (FIG. 18B) results for beam gain, beam shape, and cross-polarization component suppression match well.

Figures 19a, b, and c are concrete diagrams of a low-band radiation device having a bent arm structure according to another embodiment of the present invention.

From Figure 19a, it can be seen that the base station antenna according to the embodiment of the present invention can be comfortably accommodated in a reflector with a width of 230 mm.

In the previous embodiment in which the radiation arm was not bent, the notch resonator disposed at the end of the radiation arm was disposed on a flat substrate, but in the embodiment of FIG. 19, a droop curved a portion of the outer region of the notch resonator having an H-shaped slot. (droop) forms a segment. In order to bend a portion of the outer area of the notch resonator, the support substrate of the radiation arm is made shorter rather than extending to the area below the notch resonator.

In this way, if a notch resonator is formed including a droop segment at the end of the radiation arm, the radius of the radome covering the antenna can be reduced by the bending angle, as shown in Figure 19b, contributing to miniaturization of the antenna. there is.

So far, a low-band radiation device with a filtering balun and a re-radiation prevention dipole arm according to several embodiments based on a combination of the proposed features of the present invention has been described.

In the following description related to FIGS. 20 to 23, a 1L2H array structure disposed on a compact reflector is disclosed.

For simplicity of explanation, only one low-band radiating element surrounded by four HBB radiating elements is shown and described, but the multi-band, multi-column base station antennas including the entire array previously described in Figures 10 and 11, etc. This is implemented by a collection of unit cells (one low-band radiating element surrounded by four HBB radiating elements).

Figures 20a, b show the polar coordinate characteristics of the azimuthal radiation pattern for a cluster of four isolated high-band radiation elements (when there is no low-band radiation element) and one high-band radiation element (HBB), 21 a and b show the polar coordinate characteristics of the azimuthal radiation pattern for a low-band radiation element (LBB) of a conventional standard crossed dipole arm structure surrounded by four high-band radiation elements and one high-band radiation element (HBB) herein. 22A and 22B are a low-band crossed dipole radiation element (LBB) surrounded by a cluster of four high-band radiation elements according to an embodiment of the present invention, and herein, one high-band radiation element (HBB) It shows the polar coordinate characteristics of the azimuthal radiation pattern for .

In each figure, the radiating elements are all arranged on a compact 230 mm reflector, and the conventional configuration of FIG. 21 does not include the low-pass filter of the feed balun and the choke and notch resonator of the radiating arm, and each beam pattern is 1700 ~ This is for the 2700 MHz band.

As can be seen in FIG. 21B, in the conventional configuration of FIG. 21A, a lot of distortion occurs in the beam pattern, and the distortion is particularly severe in the beam pattern of a specific frequency. And such large distortion at certain frequencies makes this antenna unusable as a base station antenna.

As can be seen in FIG. 22B, the polar coordinate characteristics of the result according to an embodiment of the present invention are much closer to the polar coordinate characteristics of FIG. 20 due to less distortion of the beam compared to the conventional configuration of FIG. 21. In one embodiment of the present invention, this is due to the re-radiation of high-band electromagnetic waves by the low-band radiation element (LBB) and the high-band radiation element due to the notch resonator and RF choke segment included in the radiation arm of the low-band radiation element (LBB). It can be seen that this is a result of a decrease in the current induced in the low-band radiation element.

Additional improvement over the results according to the embodiments of the present invention described above can be obtained by forming the reflector to be slightly inclined.

Figure 23a shows a low-band crossed dipole radiation device surrounded by four high-band radiation device clusters according to another embodiment of the present invention.

Unlike other embodiments in which both the low-band and high-band radiation elements are arranged on a flat reflector, in the embodiment of FIG. 23, the high-band radiation elements arranged around the central low-band radiation element are radiated from the left and right with respect to the central horizontal plane. It is placed on a reflector formed inclined at a predetermined angle.

FIG. 23B shows polar coordinate characteristics of the azimuthal radiation pattern for one high-band radiation element (HBB) in the same configuration as FIG. 23A.

Compared to other embodiments, it can be seen that Figure 23b is more similar to the polar coordinate characteristics of Figure 20b, and from this, it can be seen that the beam pattern of the high-band radiation element can be further improved by giving a slight inclination to the reflector. You can.

Figures 24a and 24b are top and front views illustrating a multi-sector base station antenna arranged to have a hexagonal radiation structure surrounding the center using a multi-band three-row panel according to an embodiment of the present invention.

Although a hexagonal structure is shown as an example in Figure 24, the polygonal structure to which the present invention can be applied can of course be changed in various ways as needed.

Although the present invention has been described as above, those skilled in the art will recognize that it can be implemented in other forms while maintaining the technical idea and essential features of the present invention. .

The scope of rights of the present invention will be defined by the scope of the patent claims, but all changes or modified forms derived from the configurations equivalent to the configurations directly derived from the claims are also included in the scope of the rights of the present invention. It should be interpreted as being

10: reflector
20: Radome
100: Low-bandwidth (LBB) radiation element
110: Balanced feed balun member
111: Low-pass filter (LPF) circuit pattern
120: radiation structure member
121: Power supply coupling part
122: V-shaped side arm
123: notch resonator
124: H-shaped slot
125: RF choke segment
200: 1st high bandwidth (HBB) radiation element
300: Second high bandwidth (HBB) radiation element

Claims (12)

delete A multi-band multi-array mobile communication base station antenna having a low-frequency broadband (LBB) radiating element array and at least one high-frequency broadband (HBB) radiating element array, wherein the LBB radiating element and the HBB radiating element array are disposed in a reflector,
A plurality of LBB radiation elements arranged in the longitudinal direction of the reflector; and
a plurality of HBB radiation elements arranged around the LBB radiation elements in the longitudinal direction of the reflector;
Including,
The LBB radiating element includes a balanced feed balun member and a radiating structure member disposed on an upper end of the balanced feed balun member,
The radiating structure member of the LBB radiating element includes four or more radiating arms arranged in a cross shape to form a cross dipole-type radiating structure,
The radiating arm includes a plurality of conductive plates,
The conductive plate includes a slot forming at least one notch resonator that prevents the radiation arm from re-radiating RF energy in the frequency band of the HBB radiation elements,
A multi-band multi-array mobile communication base station antenna, characterized in that a portion of the slot is bent downward. A multi-band multi-array mobile communication base station antenna having a low-frequency broadband (LBB) radiating element array and at least one high-frequency broadband (HBB) radiating element array, wherein the LBB radiating element and the HBB radiating element array are disposed in a reflector,
A plurality of LBB radiation elements arranged in the longitudinal direction of the reflector; and
a plurality of HBB radiation elements arranged around the LBB radiation elements in the longitudinal direction of the reflector;
Including,
The LBB radiating element includes a balanced feed balun member and a radiating structure member disposed on an upper end of the balanced feed balun member,
The radiating structure member of the LBB radiating element includes four or more radiating arms arranged in a cross shape to form a cross dipole-type radiating structure,
The radiating arm includes a plurality of conductive plates,
The conductive plate is formed along both edges of each radiation arm and includes a V-shaped side arm connected to the balanced feed balun member, and an RF choke segment formed in parallel with the V-shaped side arm. Multi-band multi-array mobile communication Base station antenna. According to paragraph 2 or 3,
The balanced feed balun member and the radiating structure member of the LBB radiating element are connected to each other by capacitive coupling feeding. Multi-band multi-array Mobile communication base station antenna. According to paragraph 2 or 3,
A multi-band multi-array mobile communication base station antenna, characterized in that the plurality of conductive plates are arranged on the same plane. According to paragraph 2 or 3,
The reflector is a multi-band multi-array mobile communication base station antenna, characterized in that the reflector is partitioned by an inner wall for accommodating each of the HBB radiation elements. According to paragraph 2,
A multi-band multi-array mobile communication base station antenna, characterized in that the slot is H-shaped. delete delete According to clause 3,
The RF choke segment is formed shorter than the length of the V-shaped side arm, and one end is bent and connected to the end of the V-shaped side arm to form a meander shape with the V-shaped side arm. Array mobile communication base station antenna. According to paragraph 2 or 3,
The LBB radiation element and the HBB radiation element array disposed in the reflector are a three-row arrangement including one row of LBB radiation elements and two rows of HBB radiation elements. A multi-band, multi-array mobile communication base station antenna. According to clause 11,
A multi-band multi-array mobile communication base station antenna, characterized in that six reflectors including the three-row array on each reflector are arranged to have a hexagonal radiation structure surrounding the center.