Ultra-wideband dual-polarization filter antenna

Abstract

The present invention provides an ultra-wideband dual-polarization filtering antenna, comprising: a radiator, a feeding balun, a resonator and a reflector; the radiator is arranged above the reflector through the feeding balun, the radiator comprises a radiating dielectric substrate, two pairs of radiating arms are arranged on the radiating dielectric substrate, the two pairs of radiating arms are arranged orthogonally with polarization of ±45°, and the resonator is arranged on the side of the radiating dielectric substrate facing the reflector. A current is coupled to the resonator, and outside the passband, the direction of the coupling current on the resonator is opposite to the direction of the current on the radiator, thereby causing zero radiation, and within the passband, the direction of the coupling current on the resonator is the same as the direction of the current on the radiator, thereby improving the radiation performance of the antenna, and the radiation zero point can be generated and controlled by adjusting the length of the resonator, that is, the resonator is introduced below the radiator to improve out-of-band suppression.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to an ultra-wideband dual-polarization filtering antenna. Background Art

[0002] In order to save antenna resources, multi-band antennas have become an important research direction in the field of wireless communications. Multi-band antennas are usually composed of sub-antennas working in different frequency bands. Each sub-antenna in a multi-band antenna is placed in a limited space. There will be strong cross-band scattering interference between different sub-antennas, which will seriously deteriorate the performance of the multi-band antenna. Specifically, the port isolation between sub-antennas of different frequency bands is deteriorated, the radiation pattern of the antenna is distorted, etc. Filter antennas are usually a good way to solve interference.

[0003] Currently, there are only a few dual-polarization filter antennas. For example, by simply changing the feed balun structure, three radiation zero points are introduced outside the band. Another example is by introducing complex filtering branches, thereby reducing the scattering interference of the low-frequency sub-antenna on the high-frequency sub-antenna. However, these dual-polarization filter antennas all have the problems of narrow working bandwidth and low cross-polarization ratio. Summary of the invention

[0004] The invention provides an ultra-wideband dual-polarization filtering antenna, which is used to solve the problems of narrow working bandwidth and low cross-polarization ratio of the dual-polarization filtering antenna in the prior art.

[0005] The present invention provides an ultra-wideband dual-polarization filtering antenna, comprising: a radiator, a feeding balun, a resonator and a reflecting plate;

[0006] The radiator is arranged above the reflector through the feeding balun, the radiator includes a radiation medium substrate, two pairs of radiation arms are arranged on the radiation medium substrate, the two pairs of radiation arms are orthogonally arranged with polarization of ±45°, and the resonator is arranged on the side of the radiation medium substrate facing the reflector.

[0007] According to an ultra-wideband dual-polarization filtering antenna provided by the present invention, the four radiating arms each include a first radiating patch and a second radiating patch;

[0008] The first radiation patch and the second radiation patch are both annular structures. The first radiation patch is provided with a gap, and the second radiation patch extends in a direction away from the center of the second radiation patch to form an extension portion; the first radiation patch is arranged around the second radiation patch, and the extension portion is located in the gap.

[0009] According to an ultra-wideband dual-polarization filtering antenna provided by the present invention, the first radiation patch and the second radiation patch are both located on a side of the radiation medium substrate away from the reflection plate.

[0010] According to an ultra-wideband dual-polarization filtering antenna provided by the present invention, the first radiation patch is located on a side of the radiation medium substrate away from the reflection plate, and the second radiation patch is located on a side of the radiation medium substrate facing the reflection plate.

[0011] According to an ultra-wideband dual-polarization filtering antenna provided by the present invention, the resonator is suspended on a side of the radiation dielectric substrate facing the reflector, and the distance between the resonator and the radiation dielectric substrate is 1 to 3 mm.

[0012] According to an ultra-wideband dual-polarization filtering antenna provided by the present invention, the radiator further includes a short-circuit branch, and the short-circuit branch is connected between two adjacent first radiation patches.

[0013] According to an ultra-wideband dual-polarization filtering antenna provided by the present invention, the extending direction of the slot is the same as the diagonal direction of the radiation dielectric substrate.

[0014] According to an ultra-wideband dual-polarization filtering antenna provided by the present invention, the feeding balun includes a first feeding balun and a second feeding balun;

[0015] The first feeding balun and the second feeding balun are orthogonal to each other. The first feeding balun feeds a pair of the radiating arms with a polarization of +45 degrees, and the second feeding balun feeds another pair of the radiating arms with a polarization of -45 degrees.

[0016] According to an ultra-wideband dual-polarization filtering antenna provided by the present invention, the resonator is a square ring resonator, a circular ring resonator or an elliptical ring resonator.

[0017] According to an ultra-wideband dual-polarization filtering antenna provided by the present invention, the length of the resonator is 1 / 2 wavelength of the suppressed frequency point.

[0018] The ultra-wideband dual-polarization filtering antenna provided by the present invention has a current coupled on the resonator. Outside the passband, the direction of the coupled current on the resonator is opposite to the direction of the current on the radiator, thereby resulting in zero radiation. Within the passband, the direction of the coupled current on the resonator is the same as the direction of the current on the radiator, thereby improving the radiation performance of the antenna. The radiation zero point can be generated and controlled by adjusting the length of the resonator, that is, the resonator is introduced below the radiator to improve out-of-band suppression. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 This is one of the structural schematic diagrams of the ultra-wideband dual-polarization filtering antenna provided by the present invention;

[0021] Figure 2 This is one of the structural schematic diagrams of the radiator provided by the present invention;

[0022] Figure 3 This is the second structural schematic diagram of the radiator provided by the present invention;

[0023] Figure 4 This is the second structural schematic diagram of the ultra-wideband dual-polarization filtering antenna provided by the present invention;

[0024] Figure 5 This is the third structural schematic diagram of the radiator provided by the present invention;

[0025] Figure 6 This is the fourth structural schematic diagram of the radiator provided by the present invention;

[0026] Figure 7 is a schematic structural diagram of a resonator provided by the present invention;

[0027] Figure 8 It is one of the structural schematic diagrams of the feeding balun provided by the present invention;

[0028] Fig. 9 This is the second structural schematic diagram of the feeding balun provided by the present invention;

[0029] Fig.10 This is the third structural schematic diagram of the feed balun provided by the present invention;

[0030] Fig.11 This is the fourth structural schematic diagram of the feed balun provided by the present invention;

[0031] Fig.12 It is a gain-frequency curve diagram of the relationship between the gain zero point and the resonator length of the ultra-wideband dual-polarization filtering antenna provided by the present invention;

[0032] Fig.13 It is a VSWR curve diagram of the ultra-wideband dual-polarization filtering antenna provided by the present invention;

[0033] Fig.14 It is an isolation curve diagram of the ultra-wideband dual-polarization filtering antenna provided by the present invention;

[0034] Fig.15 It is one of the radiation patterns of the ultra-wideband dual-polarization filtering antenna provided by the present invention at 1690MHz;

[0035] Fig.16 This is the second radiation pattern of the ultra-wideband dual-polarization filtering antenna provided by the present invention at 1690MHz;

[0036] Fig.17 It is one of the radiation patterns of the ultra-wideband dual-polarization filtering antenna provided by the present invention at 2190MHz;

[0037] Fig.18 This is the second radiation pattern of the ultra-wideband dual-polarization filtering antenna provided by the present invention at 2190MHz;

[0038] Fig.19 It is one of the radiation patterns of the ultra-wideband dual-polarization filtering antenna provided by the present invention at 2690MHz;

[0039] Fig. 20 This is the second radiation pattern of the ultra-wideband dual-polarization filtering antenna provided by the present invention at 2690MHz;

[0040] Reference numerals:

[0041] 1: radiator; 11: first radiating patch; 12: second radiating patch;

[0042] 13: gap; 14: short-circuit branch; 15: radiation medium substrate;

[0043] 2: resonator; 3: feed balun; 31: first feed balun;

[0044] 311: long line trough; 312: first ground; 313: first feeder line;

[0045] 32: second feeding balun; 321: short line slot; 322: second ground;

[0046] 323: second feed line; 4: reflection plate. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] Combine the following Figures 1 to 20The ultra-wideband dual-polarization filtering antenna of the present invention is described.

[0049] The ultra-wideband dual-polarization filtering antenna according to the embodiment of the present invention comprises: a radiator 1 , a feeding balun 3 , a resonator 2 and a reflector 4 .

[0050] The radiator 1 is arranged above the reflector 4 through the feeding balun 3. The radiator 1 includes a radiating dielectric substrate 15. Two pairs of radiating arms are arranged on the radiating dielectric substrate 15. The two pairs of radiating arms are arranged orthogonally with polarizations of ±45°. That is, one pair of radiating arms is arranged orthogonally with polarizations of positive 45°, and the other pair of radiating arms is arranged orthogonally with polarizations of negative 45°.

[0051] The resonator 2 is disposed on the side of the radiation dielectric substrate 15 facing the reflection plate 4 , that is, the resonator 2 is located between the radiation dielectric substrate 15 and the reflection plate 4 .

[0052] In the embodiment of the present invention, a current is coupled to the resonator 2. Outside the passband, the direction of the coupled current on the resonator 2 is opposite to the direction of the current on the radiator 1, resulting in zero radiation. Within the passband, the direction of the coupled current on the resonator 2 is the same as the direction of the current on the radiator 1, thereby improving the radiation performance of the antenna. The radiation zero point can be generated and controlled by adjusting the length of the resonator 2. That is to say, the resonator 2 is introduced below the radiator 1 to improve out-of-band suppression.

[0053] In an optional embodiment, each of the four radiation arms includes a first radiation patch 11 and a second radiation patch 12 .

[0054] The first radiation patch 11 and the second radiation patch 12 are both annular structures. The first radiation patch 11 is provided with a gap 13, that is, the first radiation patch 11 is disconnected from the gap 13. The extension direction of the gap 13 is the same as the diagonal direction of the radiation medium substrate 15.

[0055] For example, the two opening directions of the two first radiation patches 11 of a pair of radiation arms arranged orthogonally with a positive polarization of 45° are arranged opposite to each other. When the radiation medium substrate 15 is a rectangular structure, the two opening directions of the two first radiation patches 11 are respectively oriented towards two right angles.

[0056] The second radiation patch 12 extends in a direction away from the center of the second radiation patch 12 to form an extension portion; the first radiation patch 11 is arranged around the second radiation patch 12 , and the extension portion is located in the gap 13 .

[0057] It should be noted that the first radiation patch 11 and the second radiation patch 12 are coupled through the gap 13. By adjusting the width and length of the gap 13, the current distribution can be changed to expand the antenna bandwidth. The gap 13 is arranged along the diagonal direction, which suppresses the current in the middle of the antenna radiation patch and improves the antenna port isolation.

[0058] In an optional embodiment, the radiator 1 further includes a short-circuit branch 14 , and the short-circuit branch 14 is connected between two adjacent first radiation patches 11 .

[0059] It should be noted that the short-circuit branch 14 can guide the current on the radiation patch to a horizontal or vertical direction, reducing the current in the cross-polarization direction, thereby reducing the cross-polarization component of the antenna.

[0060] In an optional embodiment, if Figure 8 , Fig. 9 , Fig.10 as well as Fig.11 As shown, the feeding balun 3 includes a first feeding balun 31 and a second feeding balun 32 .

[0061] The first feeding balun 31 and the second feeding balun 32 are orthogonal to each other. The first feeding balun 31 feeds a pair of +45 degree polarized radiation arms, and the second feeding balun 32 feeds another pair of -45 degree polarized radiation arms.

[0062] The radiation medium substrate 15 is in the shape of a square, and a first rectangular slot and a second rectangular slot are arranged on two diagonal lines thereof for mounting two feeding baluns.

[0063] The first feed balun includes a first dielectric plate, a first feed line 313 printed on the upper surface of the first dielectric plate, and two first ground surfaces 312 on the lower surface. The first feed line 313 adopts a three-segment gradient microstrip line structure and cooperates with the two first ground surfaces 312 on the lower surface of the first dielectric plate to achieve the conversion of unbalanced current to balanced current and broadband impedance matching. The top of the first dielectric plate is provided with two rectangular protrusions with metal coating on the back, which are used to cooperate with the first rectangular gap and the second rectangular gap on the radiation dielectric substrate 15, and are welded with the two first radiation patches 11 of a pair of radiation arms orthogonally arranged at a positive 45° polarization. The bottom of the first dielectric plate is also provided with two rectangular protrusions with metal coating on the back, which are used to cooperate with the rectangular gap on the reflector 4; the position of the rectangular protrusion is preferably to ensure the stability of the structure, and the length of the rectangular protrusion is generally selected from 3 to 8 mm, and the height is generally selected from 2 to 5 mm; a long line groove 311 is provided on the longitudinal center axis of the first dielectric plate, and the length of the long line groove 311 cannot exceed the height of the first feed line 313 on the upper surface.

[0064] The second feeding balun 32 comprises a second dielectric plate, a second feeding line 323 printed on the upper surface of the second dielectric plate and two second ground planes 322 on the lower surface. The width and height of the second feeding balun 32 are equal to those of the first feeding balun 31. The second feeding line 323 adopts a two-segment gradient microstrip line structure and cooperates with the two second ground planes 322 on the lower surface of the second dielectric plate to achieve the conversion from unbalanced current to balanced current and broadband impedance matching. The top of the second dielectric plate is provided with two rectangular protrusions with metal coating on the back, which are used to cooperate with the first rectangular slot and the second rectangular slot on the radiation dielectric substrate 15 and are welded with the two first radiation patches 11 of a pair of radiation arms arranged orthogonally at a polarization angle of negative 45°. The bottom of the second dielectric plate Two rectangular protrusions with metal coatings on the back are also provided, which are used to cooperate with the rectangular gaps on the reflector 4. The position of the rectangular protrusions is preferably to ensure the stability of the structure. The length of the rectangular protrusions is generally selected from 3 to 8 mm, and the height is generally selected from 2 to 5 mm. A short line slot 321 is provided on the longitudinal center axis of the second dielectric plate. The length of the short line slot 321 cannot exceed the height of the second feed line 323 on the upper surface. The sum of the lengths of the long line slot 311 and the short line slot 321 should be the height of the first feed balun 31 or the second feed balun 32. The width of the long line slot 311 and the short line slot 321 is generally selected from 0.8 to 1 mm, which is convenient for the first dielectric plate and the second dielectric plate to be clamped together and kept orthogonal to each other at the same height.

[0065] In an optional embodiment, if Figure 1 , Figure 2 and Figure 3 As shown, the first radiation patch 11 and the second radiation patch 12 are both located on the side of the radiation medium substrate 15 away from the reflection plate 4 .

[0066] It should be noted that the resonator 2 is printed on the lower surface of the radiation dielectric substrate 15 .

[0067] like Fig.13 As shown, the antenna has a VSWR of <1.4 in the 1690-2690MHz frequency band and a bandwidth of 45.7%.

[0068] like Fig.14 As shown, the antenna isolation is greater than 34dB in the 1690-2690MHz frequency band.

[0069] like Fig.15 , Fig.16 , Fig.17 , Fig.18 , Fig.19 as well as Fig. 20 As shown, it can be seen that the axial cross-polarization ratio of the antenna is greater than 33dB, and the cross-polarization ratio within ±60° is greater than 13dB.

[0070] In an optional embodiment, if Figure 4, Figure 5 , Figure 6 and Figure 7 As shown, the first radiation patch 11 is located on the side of the radiation medium substrate 15 facing away from the reflection plate 4 , and the second radiation patch 12 is located on the side of the radiation medium substrate 15 facing the reflection plate 4 .

[0071] The thickness of the radiation medium substrate 15 may be 0.8 mm.

[0072] It should be noted that the resonator 2 is suspended on the side of the radiation dielectric substrate 15 facing the reflector 4 , and the distance between the resonator 2 and the radiation dielectric substrate 15 is 1 to 3 mm.

[0073] For example, the resonator 2 is a sheet metal part, which is fixed below the radiation medium substrate 15 through a plastic support.

[0074] In an optional embodiment, the resonator 2 is a square ring resonator, a circular ring resonator or an elliptical ring resonator.

[0075] It should be noted that the length of the resonator 2 is 1 / 2 wavelength of the suppression frequency.

[0076] Fig.12 The relationship between the gain zero point and the length of resonator 2 is given. It can be seen that the radiation zero point can be controlled by adjusting the length of resonator 2. When the circumference of resonator 2 is 160 mm, the radiation zero frequency is 800 MHz and the out-of-band suppression reaches 15.5 dB.

[0077] The ultra-wideband dual-polarization filtering antenna of the embodiment of the present invention can support the frequency band of 1690-2690 MHz, has good in-band port isolation, high cross-polarization ratio, good out-of-band suppression, and has a simple structure and is easy to implement.

[0078] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ultra-wideband dual-polarization filtering antenna, characterized in that: include: radiators, feed baluns, resonators, and reflectors; The radiator is arranged above the reflector through the feeding balun, the radiator comprises a radiation medium substrate, two pairs of radiation arms are arranged on the radiation medium substrate, the two pairs of radiation arms are arranged orthogonally with polarization of ±45°, and the resonator is arranged on a side of the radiation medium substrate facing the reflector; The four radiation arms each include a first radiation patch and a second radiation patch; the first radiation patch and the second radiation patch are both annular structures, the first radiation patch is provided with a gap, and the second radiation patch extends in a direction away from the center of the second radiation patch to form an extension portion; the first radiation patch is arranged around the second radiation patch, and the extension portion is located in the gap; the first radiation patch and the second radiation patch are coupled through the gap; The radiator further includes a short-circuit branch, and the short-circuit branch is connected between two adjacent first radiation patches; The extending direction of the slot is the same as the diagonal direction of the radiation medium substrate; the length of the resonator is 1 / 2 wavelength of the suppression frequency point; The distance between the resonator and the radiation medium substrate is 1 to 3 mm. There is current coupled on the resonator. Outside the passband, the direction of the coupled current on the resonator is opposite to the direction of the current on the radiator, resulting in zero radiation. Within the passband, the direction of the coupled current on the resonator is the same as the direction of the current on the radiator, thereby improving the radiation performance of the antenna.

2. The ultra-wideband dual-polarization filtering antenna according to claim 1, characterized in that: The first radiation patch and the second radiation patch are both located on a side of the radiation medium substrate away from the reflection plate.

3. The ultra-wideband dual-polarization filtering antenna according to claim 1, characterized in that: The first radiation patch is located on a side of the radiation medium substrate facing away from the reflection plate, and the second radiation patch is located on a side of the radiation medium substrate facing the reflection plate.

4. The ultra-wideband dual-polarization filtering antenna according to claim 3, characterized in that: The resonator is suspended on a side of the radiation medium substrate facing the reflection plate, and a distance between the resonator and the radiation medium substrate is 1 to 3 mm.

5. The ultra-wideband dual-polarization filtering antenna according to claim 1, characterized in that: The feed balun includes a first feed balun and a second feed balun; The first feeding balun and the second feeding balun are orthogonal to each other. The first feeding balun feeds a pair of the radiating arms with a polarization of +45 degrees, and the second feeding balun feeds another pair of the radiating arms with a polarization of -45 degrees.

6. The ultra-wideband dual-polarization filtering antenna according to claim 1, characterized in that: The resonator is a square ring resonator, a circular ring resonator or an elliptical ring resonator.

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