Non-shaped ultra-wideband decoupling structure used for small-spacing antenna array loading resistor and pattern maintenance

Abstract

The invention relates to a non-shaped ultra-wideband decoupling structure used for loading resistors in a small-spacing antenna array and maintaining the shape of a directional diagram, which is loaded between two antenna units and is positioned above a metal reflection floor. Comprising a dielectric substrate, three pairs of metal branches are symmetrically printed on the front side and the back side of the dielectric substrate, the three pairs of metal branches are of bent structures and are arranged in parallel, the three pairs of metal branches are connected through transmission lines, resistors are loaded on the transmission lines, the heights of the three pairs of metal branches meet the requirement that the branches do not make short-circuit contact, and the total height is equal to the height of the antenna; according to the invention, the non-shaped ultra-wideband decoupling structure loaded with the resistor is loaded in the middle of the array antenna unit, so that the field distribution of the antenna is changed, and the decoupling of space waves is realized. The design height is equivalent to the antenna height, so that the antenna profile is not increased; a plurality of resonant branches are designed to realize the decoupling requirement of the broadband antenna array; the loading resistor is used for absorbing the coupling current on the resonance branch knot, and the shape-preserving design of each frequency point directional diagram is met.

Description

Technical Field

[0001] The present invention belongs to the field of communication technologies, and particularly relates to a "non"-type ultra-wideband decoupling structure for loading resistors on a small-spacing antenna array and maintaining the pattern conformal. Background Art

[0002] With the rapid development of wireless communication technologies, driven by the demand for high data rates and high system capacities, antenna arrays are widely used in various communication systems and military fields. The application of multi-element antenna arrays, such as multiple-input multiple-output antenna systems, is an effective method to improve reliability and increase channel capacity. However, with the emergence of multi-antenna applications such as antenna diversity, ultra-wideband arrays, phased arrays, smart antennas, MIMO systems, and GPS, the mutual coupling between antenna elements has increased significantly, thus becoming a bottleneck in the application of multi-antenna systems. Due to the low cost of miniaturization and the flexible radiation characteristics, small-spacing antenna arrays are widely used in modern communication. At the same time, there are gradually higher requirements for the bandwidth of antenna arrays in practical applications. Loading a design structure in a compact space and improving the isolation bandwidth of antennas have become the key points and difficulties.

[0003] For decoupling methods classified according to different coupling types, there are port current decoupling, surface wave decoupling, and space wave decoupling. For space wave decoupling, a patent application with the publication number CN111129769A and the title "Decoupling Method for Antenna Array and Antenna Array with Novel Decoupling Structure" discloses an antenna array with a novel decoupling structure. A metasurface cladding is provided above the antenna array. The cladding includes a dielectric substrate and unit structures, and the unit structures are used to adjust the dielectric constant. By adjusting the size and spacing of the unit structures of the metasurface cladding and the height between the metasurface cladding and the array antenna, the dielectric constant of the metasurface cladding is adjusted to eliminate the coupling between antenna elements. The coupling between each unit of the antenna array can be reduced to below 20 or 25 decibels within the operating frequency band of 13.75 - 14.25 GHz, and the relative bandwidth is 3.6%. A patent application with the publication number CN107240770B and the title "A Periodic Space Wave Blocking Decoupling Structure for Microstrip Antenna Array" discloses a three-dimensional periodic space wave blocking decoupling structure for reducing the coupling between array antennas. Five layers of dielectric substrates are erected at equal distances between the antennas. Three microstrip lines are printed on the upper surface and the left and right sides of the dielectric substrate. The middle one is the thickest, and the left and right widths are equal. The effective operating frequency band is 2.4 - 2.6 GHz, and the relative bandwidth is 8%.

[0004] For port current decoupling, a patent application with the publication number CN114759345A and the title "A Tunable Multi-Frequency Decoupling Structure between Two Antennas Based on Parasitics" discloses a tunable multi-frequency decoupling structure between two antennas based on parasitics. This decoupling structure is composed of a parasitic structure and a topological structure, and its main components are capacitors, inductors, and transmission lines. In practical applications, the sizes of the chip capacitors and chip inductors for implementing this structure are relatively small. The parasitic structure and the topological structure are both placed between the two antennas, with a relatively simple composition, having no excessive requirements for the antenna structure, and the influence of external factors on the capacitors and inductors is relatively small. This structure is simple and has low requirements for the spatial environment. It can be applied to the decoupling between two antennas with a single frequency point, as well as to the decoupling between two antennas with dual frequency points and more than dual frequency points, and has strong scalability. However, the relative decoupling bandwidth at each frequency point does not exceed 10%, and the isolation at some frequency points is not lower than -20 dB.

[0005] According to the analysis of the above prior art, the existing space wave decoupling technology usually loads the structure above the antenna element, which will increase the antenna profile to a certain extent; the method of using a cladding or frequency selective surface to achieve partial reflection decoupling has bandwidth limitations, with a small absolute bandwidth and a relative bandwidth that often does not exceed 20%; the absorbing structure with a loaded resistor can effectively absorb space waves, but in a compact array, it often brings an unacceptable reduction in antenna gain and seriously deteriorates the antenna pattern. Port current decoupling is to load a decoupling network or a neutralizing line to make the real and imaginary parts of the mutual admittance between the antennas approximately zero, thereby suppressing the coupling current at the port and achieving the purpose of decoupling. It does not fundamentally solve the coupling problem from the field distribution and also has bandwidth limitation problems. Summary of the Invention

[0006] In order to overcome the above deficiencies of the prior art, the purpose of the present invention is to provide a "non"-type ultra-wideband decoupling structure for loading a resistor on a small-spacing antenna array with pattern conformal protection. By loading the "non"-type ultra-wideband decoupling structure with a loaded resistor in the middle of the array antenna element, the field distribution of the antenna is changed to achieve the decoupling of space waves; the designed height of this structure is equivalent to the antenna height, so it will not cause an increase in the antenna profile; at the same time, multiple resonant stubs are designed to break through the conventional bandwidth limitations and meet the decoupling requirements of a broadband antenna array; the loaded resistor is used to absorb the coupling current on the resonant stubs to meet the pattern conformal design at each frequency point.

[0007] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0008] A "non"-type ultra-wideband decoupling structure for loading resistors in a small-spacing antenna array with pattern conformal protection. The "non"-type ultra-wideband decoupling structure is loaded between the first antenna element 206 and the second antenna element 207 and is located above the metal reflection floor 208. The "non"-type ultra-wideband decoupling structure includes a dielectric substrate 106. Three pairs of metal branches are symmetrically printed on both the front and back sides of the dielectric substrate 106. The three pairs of metal branches are all in a bent structure and are arranged in a parallel form. The three pairs of metal branches are connected by transmission lines, and resistors are loaded on the transmission lines.

[0009] The three pairs of metal branches include the first metal branch 101 and the second metal branch 201 printed symmetrically, the third metal branch 102 and the fourth metal branch 202 printed symmetrically, and the fifth metal branch 103 and the sixth metal branch 203 printed symmetrically; the transmission lines include a first transmission line 100 and a second transmission line 200; the first metal branch 101, the third metal branch 102, and the fifth metal branch 103 are all connected to the first transmission line 100, the second metal branch 201, the fourth metal branch 202, and the sixth metal branch 203 are all connected to the second transmission line 200. The first transmission line 100 and the second transmission line 200 extend from the top to the bottom of the dielectric substrate 106. Resistors are loaded on the first transmission line 100 between the first metal branch 101, the third metal branch 102, and the fifth metal branch 103 and on the second transmission line 200 between the second metal branch 201, the fourth metal branch 202, and the sixth metal branch 203. The resistors loaded on the first transmission line 100 and the resistors loaded on the second transmission line 200 are symmetrically arranged.

[0010] The first metal branch 101 and the second metal branch 201 are both Γ-shaped with two perpendicular bends. One end of the unbent long side is perpendicularly connected to the first transmission line 100 and the second transmission line 200 respectively. The third metal branch 102 and the fourth metal branch 202 are downward L-shaped, and the fifth metal branch 103 and the sixth metal branch 203 are upward L-shaped. The L-shaped includes a long side and a short side that are perpendicularly connected. One end of the long side of the third metal branch 102 and the fifth metal branch 103 that is not connected to the short side is perpendicularly connected to the first transmission line 100, and one end of the long side of the fourth metal branch 202 and the sixth metal branch 203 that is not connected to the short side is perpendicularly connected to the second transmission line 200.

[0011] The resistors include a first resistor 104 symmetrically arranged above the connection point of the third metal branch 102 and the first transmission line 100 and a second resistor 204 symmetrically arranged above the connection point of the fourth metal branch 202 and the second transmission line 200, a third resistor 105 symmetrically arranged above the connection point of the fifth metal branch 103 and the first transmission line 100 and a fourth resistor 205 symmetrically arranged above the connection point of the sixth metal branch 203 and the second transmission line 200.

[0012] The broadband operating frequency band includes a high-frequency band, a medium-frequency band, and a low-frequency band. The lengths of the three pairs of metal stubs respectively correspond to half-wavelengths of the center frequencies of each frequency band. Among them, the first metal stub 101 and the second metal stub 201 correspond to the low-frequency band of the broadband operating frequency band, and the length is the half-wavelength corresponding to the center frequency of the low-frequency band. The fifth metal stub 103 and the sixth metal stub 203 correspond to the medium-frequency band of the broadband operating frequency band, and the length is the half-wavelength corresponding to the center frequency of the medium-frequency band. The third metal stub 102 and the fourth metal stub 202 correspond to the high-frequency band of the broadband operating frequency band, and the length is the half-wavelength corresponding to the center frequency of the high-frequency band.

[0013] The heights of the three pairs of metal stubs satisfy that the stubs do not contact in a short-circuit manner, and the total height is equivalent to the height of the antenna.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] 1. By printing Γ-shaped, upward L-shaped, and downward L-shaped metal stubs with different sizes on both sides of the dielectric substrate 106, the present invention realizes the decoupling of low-frequency, medium-frequency, and high-frequency in the wide frequency band, thereby achieving the purpose of broadband decoupling. This structure has a large improvement in isolation in the entire operating frequency band of 6 - 14 GHz, up to 30 dB at most; except near the 7.5 GHz frequency point, the isolation in the remaining frequency bands is less than -25 dB, and the relative bandwidth exceeds 80%. Compared with the prior art, the decoupling operating bandwidth and the isolation improvement effect have significant advantages.

[0016] 2. By loading the "non"-type ultra-wideband decoupling structure in the middle of each antenna element, the stubs of each form are arranged compactly, and the designed height is equivalent to the height of the antenna element 206 or the antenna element 207, which can avoid increasing the profile height of the antenna array. Compared with the loading structures such as metasurface and cladding type above the antenna, it has an advantage in maintaining the original profile height of the antenna array.

[0017] 3. By symmetrically loading resistors on the first transmission line 100 and the second transmission line 200, the present invention absorbs the coupling current, changes the current distribution, further improves the isolation improvement performance of the "non"-type decoupling structure, and does not cause an obvious decrease in the antenna gain within the frequency band; for most frequency bands, it can keep the antenna pattern conformal, and at the same time has the effect of broadening the beam. Compared with the wave-absorbing decoupling structure with loaded resistors, it has more advantages in maintaining and optimizing the antenna performance.

[0018] In summary, the present invention proposes a "non"-type ultra-wideband decoupling structure with loaded resistors, which effectively solves the decoupling problem of binary and multi-element broadband antenna arrays. Compared with other related prior arts, it has significant advantages in aspects such as decoupling bandwidth, improvement of port isolation, control of the antenna array profile height, maintenance of antenna gain, pattern conformal, and beam broadening. Description of the Drawings

[0019] Figure 1 It is the front view of the "non"-type ultra-wideband decoupling structure of the present invention.

[0020] Figure 2 It is the current distribution diagram of the "non"-type ultra-wideband decoupling structure with loaded resistors of the present invention.

[0021] Figure 3 It is the binary antenna array diagram loaded with the "non"-type ultra-wideband decoupling structure of the present invention.

[0022] Figure 4 It is the comparison diagram of the isolation degree between the two antenna ports before and after loading the "non"-type ultra-wideband decoupling structure of the present invention.

[0023] Figure 5 It is the comparison diagram of the gain before and after loading the "non"-type ultra-wideband decoupling structure of the present invention. Among them, Figure 5 (a) is the comparison diagram of the gain at 8 GHz before and after loading the "non"-type ultra-wideband decoupling structure, Figure 5 (b) is the comparison diagram of the gain at 10 GHz before and after loading the "non"-type ultra-wideband decoupling structure, Figure 5 (c) is the comparison diagram of the gain at 12 GHz before and after loading the "non"-type ultra-wideband decoupling structure.

[0024] Figure 6 It is the port isolation degree diagram after loading the "non"-type ultra-wideband decoupling structure for four antenna elements of the present invention. Detailed implementation manners

[0025] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0026] For miniaturized antenna arrays, due to the limited array area, there is strong mutual coupling between array elements. When the spacing between antenna elements is very small, the strong coupling between elements will seriously affect the impedance matching and radiation characteristics of the array elements, making the antenna unable to work properly. Usually, in order to reduce the coupling between antennas, it is required to increase the distance between antenna elements (generally greater than half a wavelength). However, this conflicts with the growing trend of miniaturization of array antennas. The development of miniaturization of array antennas limits the minimum spacing between array antenna elements and the size of the array. The smaller the spacing between antenna elements, the greater the mutual coupling effect. With the continuous development of technology, ultra-wideband antennas, as a new type of wireless communication technology, have the characteristics of wide spectrum, high data rate, low power consumption and high-precision positioning. They are widely used in communications, sensors, positioning and navigation, radar and detection. The use of broadband decoupling structure may have a greater impact on the gain of the antenna, which is also not allowed. Therefore, in the context of small-pitch broadband antenna arrays, designing an ultra-wideband decoupling structure to reduce the coupling between antenna elements and improve the isolation between antenna ports, while ensuring that the antenna gain is not affected to a certain extent, and improving the radiation characteristics of each element and the antenna system become the key to achieving high-performance small-pitch broadband array antennas.

[0027] The present invention designs a "non" type ultra-wideband decoupling structure for loading resistors for small-pitch antenna arrays and maintaining the directional pattern, which has an operating bandwidth greater than twice the frequency, can not only improve the isolation between antenna unit ports, but also improve the deteriorated antenna radiation performance caused by inter-unit coupling, while maintaining the radiation pattern of the antenna, so that the antenna design meets the needs of practical applications. The "non" type ultra-wideband decoupling structure described in the present invention refers to the overall structure of the transmission line and metal branches printed on the dielectric substrate 106, which is similar to the structure of the Chinese character "non".

[0028] like Figure 1 As shown, the present invention proposes a "non-" type ultra-wideband decoupling structure for loading resistors on small-pitch antenna arrays and preserving the radiation pattern, which mainly solves the problem of narrow decoupling bandwidth in the prior art, while satisfying the radiation pattern preservation and widening the beam width to a certain extent. Figure 1 The front view of the "non" type ultra-wideband decoupling structure with a loaded resistor. The "non" type ultra-wideband decoupling structure includes a dielectric substrate 106, and three pairs of metal branches are symmetrically printed on both sides of the dielectric substrate 106. The three pairs of metal branches are bent and arranged in parallel. The three pairs of metal branches are connected by transmission lines. The transmission lines are loaded with resistors to absorb current and change current distribution. The height of the three pairs of metal branches is sufficient to ensure that the branches do not short-circuit contact, and the total height is equivalent to the actual antenna height.

[0029] The height of the non-type ultra-wideband decoupling structure differs from the antenna height by ±0.04λL Just inside.

[0030] The thickness and material of the dielectric substrate 106 can be selected from a very wide range. The "non"-type ultra-wideband decoupling structure is overall left-right symmetric. The thickness of the dielectric substrate 106 is 0.5 - 1.5 mm, and low-loss materials such as F4B are preferably selected.

[0031] The three pairs of metal branches include the first metal branch 101 and the second metal branch 201 printed symmetrically, the third metal branch 102 and the fourth metal branch 202 printed symmetrically, and the fifth metal branch 103 and the sixth metal branch 203 printed symmetrically; the transmission lines include the first transmission line 100 and the second transmission line 200; the first metal branch 101, the third metal branch 102, and the fifth metal branch 103 are all connected to the first transmission line 100, the second metal branch 201, the fourth metal branch 202, and the sixth metal branch 203 are all connected to the second transmission line 200. The first transmission line 100 and the second transmission line 200 extend from the top to the bottom of the dielectric substrate 106. Resistors are loaded on the first transmission line 100 between the first metal branch 101, the third metal branch 102, and the fifth metal branch 103 and on the second transmission line 200 between the second metal branch 201, the fourth metal branch 202, and the sixth metal branch 203. The resistors loaded on the first transmission line 100 and the resistors loaded on the second transmission line 200 are symmetrically arranged.

[0032] The first metal branch 101 and the second metal branch 201 are Γ-shaped with two vertical bends. After the second bend, the width is halved. One end of the unbent long side is perpendicularly connected to the first transmission line 100 and the second transmission line 200 respectively. The third metal branch 102 and the fourth metal branch 202 are downward L-shaped, and the fifth metal branch 103 and the sixth metal branch 203 are upward L-shaped. The L-shaped includes a long side and a short side that are perpendicularly connected. One end of the long side of the third metal branch 102 and the fifth metal branch 103 that is not connected to the short side is perpendicularly connected to the first transmission line 100, and one end of the long side of the fourth metal branch 202 and the sixth metal branch 203 that is not connected to the short side is perpendicularly connected to the first transmission line 200; such a design facilitates compact arrangement in terms of height.

[0033] The resistor includes a first resistor 104 and a second resistor 204 that are symmetrically arranged above the connection point of the third metal branch 102 and the first transmission line 100, and a third resistor 105 and a fourth resistor 205 that are symmetrically arranged above the connection point of the fourth metal branch 202 and the second transmission line 200. The distance between the first resistor 104 and the third resistor 105 vertically, and the distance between the second resistor 204 and the fourth resistor 205 vertically are both at a distance of one-eighth of a wavelength apart.

[0034] The heights of the three pairs of metal branches satisfy that the branches do not short-circuit and contact, and the total height is equivalent to the actual antenna height. The broadband operating frequency band is divided into a high-frequency band, a medium-frequency band, and a low-frequency band. The lengths of the three pairs of metal branches respectively correspond to half of the wavelength of the center frequency of each frequency band. Among them, the first metal branch 101 and the second metal branch 201 correspond to the low-frequency band of the broadband operating frequency band, and the length is half of the wavelength corresponding to the center frequency of the low-frequency band. The fifth metal branch 103 and the sixth metal branch 203 correspond to the medium-frequency band of the broadband operating frequency band, and the length is half of the wavelength corresponding to the center frequency of the medium-frequency band. The third metal branch 102 and the fourth metal branch 202 correspond to the high-frequency band of the broadband operating frequency band, and the length is half of the wavelength corresponding to the center frequency of the high-frequency band.

[0035] The three pairs of metal branches are arranged in parallel at different heights, and the left and right symmetric parts of the "non"-type ultra-wideband decoupling structure are not short-circuited and connected. The first resistor 104, the second resistor 204, the third resistor 105, and the fourth resistor 205 are symmetrically loaded on the "non"-type ultra-wideband decoupling structure to absorb current and change the current distribution, and also satisfy the characteristic of left-right symmetry. The distance between the first resistor 104 and the third resistor 105 vertically, and the distance between the second resistor 204 and the fourth resistor 205 vertically are at a distance of about one-eighth of a wavelength apart, and the range of their resistance values can be widely selected. The resistance values of the first resistor 104 and the third resistor 105 are selected as 160 Ω, and the resistance values of the second resistor 204 to the fourth resistor 205 are selected as 110 Ω. These resistors, through a specific circuit connection method, cooperate with the metal branches of the "non"-type ultra-wideband decoupling structure to jointly achieve the function of ultra-wideband decoupling. The schematic diagram of its structure is as Figure 1 shown.

[0036] Figure 2 is the current distribution diagram of the "non"-type ultra-wideband decoupling structure with loaded resistors of the present invention. Each bent metal branch is arranged in parallel and corresponds to different heights. The resistors are symmetrically loaded on the metal branches, and the whole structure is left-right symmetric.

[0037] Figure 3It is a diagram of a dual antenna array of the present invention loaded with a "non"-type ultra-wideband decoupling structure. The "non"-type ultra-wideband decoupling structure is loaded between the first antenna element 206 and the second antenna element 207, above the metal reflection floor 208. The first antenna element 206 and the second antenna element 207 are miniaturized magnetoelectric dipoles, operating at 6 - 14 GHz.

[0038] The designed height of the "non"-type ultra-wideband decoupling structure is equivalent to that of the first antenna element 206 and the second antenna element 207, without additionally increasing the array profile.

[0039] Figure 4 It is a comparison diagram of the isolation between the two antenna ports before and after loading the "non"-type ultra-wideband decoupling structure in the present invention. The present invention realizes wideband decoupling by printing three forms of symmetric metal branches on both sides of the dielectric substrate 106 and loading resistors. The port isolation of the antenna is improved within the entire operating frequency band, up to 30 dB at most. Except near the 7.5 GHz frequency point, the isolation in the remaining frequency bands is less than -25 dB.

[0040] Figure 5 It is a comparison diagram of the gain before and after loading the "non"-type ultra-wideband decoupling structure in the present invention. Before and after loading the "non"-type ultra-wideband decoupling structure, the gain curves at the 8 GHz, 10 GHz, and 12 GHz frequency points fit. Therefore, the influence on the gain before and after loading the "non"-type ultra-wideband decoupling structure in the present invention is minimal, and it will not distort the antenna pattern, meeting the requirement of pattern conformal design.

[0041] Figure 6 It is a diagram of the port isolation after loading the "non"-type ultra-wideband decoupling structure for four antenna elements in the present invention. When the antenna spacing is 22 mm (0.44 times the wavelength corresponding to the lowest frequency), the antenna ports 1 to 4 are defined from left to right. The isolation of each port after loading the "non"-type ultra-wideband decoupling structure is as follows: within the entire frequency band, the isolation between adjacent unit ports is less than -20 dB, and the isolation between ports of every other unit is less than -30 dB. Thus, it can be seen that the present invention has a broadband decoupling effect between the antenna elements of dual and multi-element antenna arrays.

[0042] The "non"-type ultra-wideband decoupling structure with loaded resistors proposed in the present invention realizes decoupling by relying on three pairs of multi-resonant branches with different forms and sizes. When the form, size design of the resonant branches meets the target frequency band and there is a certain pattern in the quantity and arrangement, the invention purpose can still be achieved.

[0043] The application prospect of the present invention:

[0044] The present invention can be used for ultra-wideband decoupling of small-spacing broadband array antennas of various scales.

[0045] Miniaturized array antennas of various scales currently in use all adopt complex decoupling structures to improve the isolation between ports. Usually, an array decoupling surface (ADS) and a decoupling cladding are used, but the bandwidth is very limited, and at the same time, it will cause an increase in the profile of the array antenna. Using a loaded decoupling network and a neutralization line for port current decoupling, the relative bandwidth is narrow, and it is also difficult to meet the decoupling requirements of broadband antenna arrays. Using an absorbing structure with a loaded resistor, the bandwidth and the isolation improvement effect are relatively ideal, but it will cause a large attenuation of the antenna gain and also affect the radiation performance of the antenna.

[0046] A "not" - type ultra - wideband decoupling structure with a loaded resistor proposed by the present invention is placed exactly in the middle between two antenna elements and does not increase the profile. This structure effectively expands the bandwidth of isolation improvement, with the relative bandwidth breaking through 80%, achieving ultra - wideband decoupling; the decoupling effect is good, meeting the requirement of the highest improvement of 30 dB within the full operating frequency band; except near the 7 - GHz frequency point, the isolation degree in the remaining frequency bands is less than - 25 dB; it avoids gain attenuation, the radiation pattern is stable at each frequency point, and it has the effect of broadening the antenna beam in some frequency bands, meeting the conformal design of the radiation pattern.

Claims

1. A non-type ultra-wideband decoupling structure for loading resistors on a small-pitch antenna array and preserving the directional pattern, characterized in that: The non-type ultra-wideband decoupling structure is loaded between the first antenna unit (206) and the second antenna unit (207), and is located above the metal reflective floor (208), and comprises a dielectric substrate (106), and three pairs of metal branches are symmetrically printed on both the front and back sides of the dielectric substrate (106), and the three pairs of metal branches are all bent structures and arranged in parallel, and the three pairs of metal branches are connected by transmission lines, and the transmission lines are loaded with resistors.

2. According to claim 1, a non-type ultra-wideband decoupling structure for loading resistors on a small-pitch antenna array and preserving the directional pattern, characterized in that: The three pairs of metal branches include a first metal branch (101) and a second metal branch (201) that are symmetrically printed, a third metal branch (102) and a fourth metal branch (202) that are symmetrically printed, and a fifth metal branch (103) and a sixth metal branch (203) that are symmetrically printed; the transmission line includes a first transmission line (100) and a second transmission line (200); the first metal branch (101), the third metal branch (102) and the fifth metal branch (103) are all connected to the first transmission line (100), and the second metal branch (201), the fourth metal branch (202) and the sixth metal branch The nodes (203) are all connected to the second transmission line (200), the first transmission line (100) and the second transmission line (200) extend from the top to the bottom of the dielectric substrate (106), and resistors are loaded on the first transmission line (100) between the first metal branch node (101), the third metal branch node (102) and the fifth metal branch node (103) and on the second transmission line (200) between the second metal branch node (201), the fourth metal branch node (202) and the sixth metal branch node (203), and the resistors loaded on the first transmission line (100) and the resistors loaded on the second transmission line (200) are symmetrically arranged.

3. According to claim 2, a non-type ultra-wideband decoupling structure for loading resistors on a small-pitch antenna array and preserving the directional pattern, characterized in that: The first metal branch (101) and the second metal branch (201) are both Γ-shaped with two vertical bends, and one end of the unbent long side is vertically connected to the first transmission line (100) and the second transmission line (200) respectively; the third metal branch (102) and the fourth metal branch (202) are downward L-shaped, and the fifth metal branch (103) and the sixth metal branch (203) are upward L-shaped, and the L-shaped includes a long side and a short side that are vertically connected to each other; the end of the long side of the third metal branch (102) and the fifth metal branch (103) that is not connected to the short side is vertically connected to the first transmission line (100), and the end of the long side of the fourth metal branch (202) and the sixth metal branch (203) that is not connected to the short side is vertically connected to the first transmission line (200).

4. According to claim 2, a non-type ultra-wideband decoupling structure for loading resistors and preserving the directional pattern for a small-pitch antenna array, characterized in that: The resistors include a first resistor (104) symmetrically arranged above a connection point between a third metal branch (102) and a first transmission line (100), a second resistor (204) symmetrically arranged above a connection point between a fourth metal branch (202) and a second transmission line (200), a third resistor (105) symmetrically arranged above a connection point between a fifth metal branch (103) and the first transmission line (100), and a fourth resistor (205) symmetrically arranged above a connection point between a sixth metal branch (203) and the second transmission line (200).

5. According to claim 2, a non-type ultra-wideband decoupling structure for loading resistors on a small-pitch antenna array and preserving the directional pattern, characterized in that: The broadband working frequency band includes a high frequency band, a medium frequency band and a low frequency band, and the lengths of the three pairs of metal branches correspond to half the wavelength of the center frequency of each frequency band, wherein the first metal branch (101) and the second metal branch (201) correspond to the low frequency band of the broadband working frequency band, and the lengths are half the wavelength corresponding to the center frequency of the low frequency band, the fifth metal branch (103) and the sixth metal branch (203) correspond to the medium frequency band of the broadband working frequency band, and the lengths are half the wavelength corresponding to the center frequency of the medium frequency band, and the third metal branch (102) and the fourth metal branch (202) correspond to the high frequency band of the broadband working frequency band, and the lengths are half the wavelength corresponding to the center frequency of the high frequency band.

6. According to claim 1, a non-type ultra-wideband decoupling structure for loading resistors on a small-pitch antenna array and preserving the directional pattern, characterized in that: The heights of the three pairs of metal branches are such that the branches do not short-circuit in contact, and the total height is equivalent to the height of the antenna.

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