Structural multiplexing low profile dual-band coplanar antenna and communication device

Abstract

The application discloses a kind of structural multiplexing low profile dual-frequency coplanar antennas and communication equipment, including low-frequency radiation surface structure, dielectric substrate and reflector, the dielectric substrate is set above reflector, and low-frequency radiation surface structure is set on the dielectric substrate;The low-frequency radiation surface structure includes first low-frequency radiation surface and second low-frequency radiation surface, and the first low-frequency radiation surface is as multiplexing structure to realize high-frequency radiation surface structure, so that low-frequency radiation surface structure and high-frequency radiation surface structure are coplanar.The application is simple in structure, and the overall profile of antenna is low, and isolation is high.

Description

Technical Field

[0001] The present invention relates to the field of mobile communications, and in particular to a structurally reused low-profile dual-frequency coplanar antenna and communication equipment. Background Art

[0002] With the continuous development of mobile communication systems, various standards for different frequency bands have been proposed, such as GSM 900 (890-960MHz), PCS (1850-1990MHz), UMTS (1920-2160MHz), LTE 2300 (2300-2400MHz), LTE 2500 (2500-2690MHz), and the 5G frequency band standard. With the emergence of different frequency band standards, communication systems will also evolve accordingly, and the coexistence of multiple communication systems will also occur. In communication systems, antennas are responsible for transmitting and receiving radio signals, directly affecting the performance of communication systems. Therefore, they play a vital role and are an indispensable part of wireless communications. With the continuous emergence of frequency band standards, the upgrading of communication systems means an increase in the number of base station antennas. However, base station site selection is difficult and costly. Therefore, research on how to arrange antennas for the coexistence of multiple standards in a limited space is of great industrial value.

[0003] In the field of multi-standard coexistence antenna research, most scholars adopt the method of co-aperture operation of multiple frequency band antennas. This method can reduce the footprint of the antenna, but it is necessary to solve the deterioration of antenna performance caused by the mutual coupling between different frequency band antennas under the co-aperture arrangement, the mutual coupling between different frequency band antennas, and the shielding between antennas, such as impedance mismatch, poor port isolation, and directional pattern distortion. Furthermore, some scholars have adopted the method of co-planar operation of multiple frequency band antennas based on the co-aperture antenna, which reduces the shielding problem between antennas of different frequency bands, but increases the complexity of the feeding structure. The cross-section of the antenna for multi-standard coexistence is mostly 0.25λ. L (where λ L is the free space wavelength of the lowest operating frequency of the low-frequency antenna), there is still room to miniaturize the antenna to further save antenna resources. Summary of the Invention

[0004] In order to solve the problems and shortcomings of the above-mentioned multi-standard coexistence antenna, the purpose of the present invention is to provide a low-profile dual-frequency coplanar antenna with structural reuse.

[0005] Another object of the present invention is to provide a communication device.

[0006] The present invention reuses part of the unit structure of the low-frequency radiating surface and uses the reused structure as the high-frequency radiating surface. While the low-frequency radiating surface works normally, the high-frequency radiating surface is used as part of the low-frequency radiating surface. Therefore, it is coplanar with the low-frequency radiating surface and is not blocked by the low-frequency radiating surface, thereby solving the blockage problem in the co-aperture antenna.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A structurally reused low-profile dual-frequency coplanar antenna comprises a low-frequency radiation surface structure, a dielectric substrate and a reflector, wherein the dielectric substrate is arranged above the reflector, and the dielectric substrate is provided with the low-frequency radiation surface structure;

[0009] The low-frequency radiation surface structure includes a first low-frequency radiation surface and a second low-frequency radiation surface. The first low-frequency radiation surface is used as a multiplexing structure to realize the high-frequency radiation surface structure, so that the low-frequency radiation surface structure and the high-frequency radiation surface structure are coplanar.

[0010] Furthermore, the low-frequency radiation surface structure is a symmetrical structure, specifically composed of M×N low-frequency radiation surface units arranged in a matrix shape, the matrix shape is square, and the low-frequency radiation surface units are composed of square rings.

[0011] Furthermore, the four low-frequency radiation surface units located at the center of the square constitute a first low-frequency radiation surface, and the low-frequency radiation surface units surrounding the first low-frequency radiation surface constitute a second low-frequency radiation surface;

[0012] The four low-frequency radiation surface units of the first low-frequency radiation surface are respectively arranged on the first surface and the second surface of the dielectric substrate;

[0013] The second low-frequency radiation surface is arranged on the first surface of the dielectric substrate.

[0014] Furthermore, it also includes four low-frequency feeding patches, which are respectively arranged on the low-frequency radiation surface units located at the four corners of the square, and the low-frequency feeding patches are arranged on the first surface of the dielectric substrate;

[0015] The low-frequency radiation surface structure adopts a differential feeding structure.

[0016] Furthermore, it includes two high-frequency feeding patches, which are respectively arranged on the first surface and the second surface of the dielectric substrate, and the two low-frequency radiating units of the first low-frequency radiating surface are tangent to the high-frequency feeding patch to form a tangent angle.

[0017] Furthermore, the high-frequency radiation surface structure is specifically a dipole antenna.

[0018] Furthermore, the square ring sizes of the first low-frequency radiating surface and the second low-frequency radiating surface are different, specifically, the outer ring lengths are equal, and the inner ring lengths are different; the inner ring length of the first low-frequency radiating surface adjusts the matching of the high-frequency working frequency band, and the inner ring length of the second low-frequency radiating surface adjusts the low-frequency working frequency band.

[0019] Furthermore, a distance between adjacent low-frequency radiation surface units in the first low-frequency radiation surface is different from a distance between adjacent low-frequency radiation surface units in the second low-frequency radiation surface.

[0020] Furthermore, the low-frequency radiation surface structure is 0.16λ away from the reflection surface. L , where λ L It is the free space wavelength of the lowest frequency point of low-frequency operation.

[0021] A communication device comprises the low-profile dual-frequency coplanar antenna.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0023] (1) The present invention covers two frequency bands: 1380MHz-1530MHz and 1760MHz-2060MHz, with gains of 6.65±0.04dBi and 8.7±0.4dBi respectively. Its overall profile is 0.16λ L , compared with the profiles of other co-aperture antennas, it has the advantage of low profile;

[0024] (2) The present invention cleverly reuses part of the low-frequency radiation surface structure to form a high-frequency radiation surface structure. The low-frequency radiation surface structure and the high-frequency radiation surface structure are coplanar, thus avoiding the shielding problem between antennas of different frequency bands in the co-aperture arrangement. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the present invention;

[0026] Figure 2 yes Figure 1 The main view;

[0027] Figure 3 yes Figure 1 Top view after hiding the low-frequency feed patch and high-frequency feed patch;

[0028] FIG4( a ) is a schematic diagram of impedance matching of a low-frequency antenna radiation unit according to Embodiment 1 of the present invention;

[0029] FIG4( b ) is a schematic diagram of the gain of the low-frequency antenna radiation unit according to Embodiment 1 of the present invention;

[0030] Figure 4(c)-Figure 4(e)The directional patterns of the low-frequency antenna radiating unit of embodiment 1 of the present invention at 1.38 GHz, 1.46 GHz, and 1.53 GHz;

[0031] FIG5( a ) is a schematic diagram of impedance matching of a high-frequency antenna radiation unit according to Embodiment 1 of the present invention;

[0032] FIG5( b ) is a schematic diagram of the gain of the high-frequency antenna radiation unit according to Embodiment 1 of the present invention;

[0033] Figure 5(c)-Figure 5(e) This is the directional pattern of the high-frequency antenna radiation unit of embodiment 1 of the present invention at 1.76 GHz, 1.91 GHz and 2.06 GHz. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below with reference to the examples, but the embodiments of the present invention are not limited thereto.

[0035] Example 1

[0036] like Figure 1-Figure 3 As shown, a structurally reused low-profile dual-frequency coplanar antenna includes a low-frequency radiation surface structure 1, a dielectric substrate and a reflector 3. The dielectric substrate is arranged above the reflector, and the low-frequency radiation surface structure is arranged on the dielectric substrate.

[0037] The low-frequency radiation surface structure includes a first low-frequency radiation surface and a second low-frequency radiation surface. The first low-frequency radiation surface is used as a multiplexing structure to realize a high-frequency radiation surface structure. Figure 3 The low-frequency radiation surface units 7A, 7B, 7C and 7D make the low-frequency radiation surface structure and the high-frequency radiation surface structure coplanar. The non-multiplexed structure of the low-frequency radiation surface structure is the second low-frequency radiation surface unit, which is also Figure 3 The low-frequency radiation surface unit 7E.

[0038] Furthermore, the low-frequency radiation surface structure 1 is a symmetrical structure, symmetrical about the center point of the dielectric substrate, and is composed of M×N low-frequency radiation surface units arranged in a matrix. The matrix shape is square and dual polarization is achieved in the ±45° direction. The low-frequency radiation surface units are composed of square rings.

[0039] In this embodiment 1, the low-frequency radiation surface is composed of 4×4 low-frequency radiation units, and the low-frequency radiation surface units are composed of square rings, and the matrix shape is a square.

[0040] In this embodiment, the first low-frequency radiation surface includes four low-frequency radiation surface units, specifically low-frequency radiation surface unit 7A, low-frequency radiation surface unit 7B, low-frequency radiation surface unit 7C and low-frequency radiation surface unit 7D. The four low-frequency radiation surface units are symmetrical about the center point of the dielectric substrate.

[0041] Specifically, the first low-frequency radiating surface is multiplexed into a high-frequency radiating surface structure, specifically a dipole antenna, and also includes high-frequency feed patches 4A, 4B and high-frequency coaxial lines 5A, 5B. The first low-frequency radiating surface units 7A and 7D constitute a -45° linearly polarized dipole, fed by the high-frequency feed patch 4B connected to the high-frequency coaxial line 5B. The first low-frequency radiating surface units 7B and 7C constitute a +45° linearly polarized dipole, fed by the high-frequency feed patch 4A connected to the high-frequency coaxial line 5A.

[0042] Furthermore, the low-frequency radiation surface units 7B, 7D and the high-frequency feeding patch 4A are arranged on the first surface of the dielectric substrate, and the low-frequency radiation surface units 7A, 7C and the high-frequency feeding patch 4B are arranged on the second surface of the dielectric substrate. The first surface and the second surface are opposite surfaces. In this embodiment, the first surface is the upper surface of the dielectric substrate, and the second surface is the lower surface of the dielectric substrate.

[0043] The two high-frequency feeding patches are of the same size and perpendicular to each other, and the intersection is located at the center point of the dielectric substrate.

[0044] The high-frequency feeding patch 4A and the high-frequency feeding patch 4B are perpendicular to the high-frequency coaxial line.

[0045] In addition, the low-frequency radiation surface unit 7A and the low-frequency radiation unit 7B are provided with a cut angle, and the cut angle is obtained by the tangency between the multiplexing structure and the high-frequency feeding patches 4A and 4B.

[0046] In this embodiment, the second low-frequency radiating surface is composed of twelve low-frequency radiating surface units 7E, evenly spaced around the first low-frequency radiating surface. The second low-frequency radiating surface is disposed on the first surface of the dielectric substrate. It also includes a low-frequency feed patch 2, which is positioned at the same height as the low-frequency radiating surface units 7E and is disposed on the first surface of the dielectric substrate.

[0047] Furthermore, there are four low-frequency feeding patches, all of which are square in shape and are respectively arranged in the second low-frequency radiation surface units located at the four corners of the square. The size of the low-frequency feeding patches can adjust the low-frequency working frequency band.

[0048] The low-frequency radiating surface structure uses differential feeding and is implemented using four low-frequency coaxial lines. The outer cores of the low-frequency coaxial lines are connected to the reflector, and the inner cores of the four low-frequency coaxial lines 6A, 6B, 6C, and 6D are connected to the low-frequency feed patches 2 located at the four corners. Low-frequency coaxial lines 6A and 6C form a pair of differential feeds. When they are simultaneously fed with equal-amplitude, opposite-phase excitation, the low-frequency antenna radiates outward with a -45° linear polarization direction. Low-frequency coaxial lines 6B and 6D form another pair of differential feeds. When they are simultaneously fed with equal-amplitude, opposite-phase excitation, the low-frequency antenna radiates outward with a +45° linear polarization direction.

[0049] Further explanation: The square rings of the first and second low-frequency radiating surfaces differ in size. Specifically, the outer rings are equal in length, while the inner rings are unequal in length. The outer ring size adjusts the high- and low-frequency operating bands and their matching. The inner ring length of the first low-frequency radiating surface adjusts the matching of the high-frequency operating band, while the inner ring length of the second low-frequency radiating surface adjusts the low-frequency operating band.

[0050] The spacing between adjacent units in the first low-frequency radiation surface and the second low-frequency radiation surface is different. The spacing between adjacent units in the first low-frequency radiation surface can adjust the high-frequency operating frequency band, and the spacing between adjacent units in the second low-frequency radiation surface can adjust the low-frequency operating frequency band. In this embodiment, the height between the lower surface of the dielectric substrate and the reflector is 35mm, specifically 0.16λ L , where λ L It is the free space wavelength of the lowest frequency point of low-frequency operation.

[0051] This embodiment implements a coplanar dual-band antenna. In traditional co-aperture antennas with a patchwork layout, the low-frequency antenna is typically placed above the high-frequency antenna, obstructing the high-frequency antenna. Because the low-frequency antenna is electrically larger than the high-frequency antenna, the high-frequency radiating element is obscured by the low-frequency radiating element in the high-frequency operating band. This manifests as impedance mismatch and distorted radiation patterns in the high-frequency operating band. To overcome these drawbacks, the present invention cleverly reuses a portion of the low-frequency radiating surface structure as the high-frequency radiating surface structure, making the low-frequency and high-frequency radiating surface structures coplanar and avoiding the problem of obstruction between the high-frequency and low-frequency antennas.

[0052] In this embodiment, the preferred dimensions of the low-frequency radiation surface structure are:

[0053] The low-frequency radiation surface structure adopts the form of a 4×4 low-frequency radiation surface unit layout. The low-frequency radiation surface units are all square rings. In this embodiment, the outer ring length of the low-frequency radiation surface unit is 20mm, the inner ring length of the first low-frequency radiation surface is 12mm, and the inner ring length of the second low-frequency radiation surface is 15mm. The spacing between adjacent units in the first low-frequency radiation surface is 1.8mm, and the spacing between adjacent units in the second low-frequency radiation surface is 3.5mm. The side length of the low-frequency feed patch is 4.3mm, and the relative dielectric constant of the dielectric substrate of the low-frequency radiation surface structure is 3.55 and the thickness is 0.813mm.

[0054] The low-frequency operating frequency band of the coplanar dual-frequency antenna is 1380MHz-1530MHz, and the high-frequency operating frequency band is 1760MHz-2060MHz.

[0055] like Figure 4(a)-Figure 4(e)The impedance bandwidth, isolation, gain and radiation pattern of the low-frequency antenna in the working frequency band of this embodiment are shown respectively. In the present invention, the low-frequency antenna has a port isolation of up to 43dB and a gain of 6.65±0.04dBi in the working frequency band of 1380MHz-1530MHz.

[0056] like Figure 5(a)-Figure 5(e) The impedance bandwidth, isolation, gain and radiation pattern of the high-frequency antenna in the working frequency band of this embodiment are shown respectively. In the present invention, the low-frequency antenna has a port isolation of up to 30dB and a gain of 8.7±0.4dBi in the working frequency band of 1760MHz-2060MHz.

[0057] Example 2

[0058] A communication device includes the structurally multiplexed low-profile dual-frequency coplanar antenna as described in Example 1, wherein the structurally multiplexed low-profile dual-frequency coplanar antenna includes a low-frequency radiating surface structure, a dielectric substrate, and a reflector, wherein the dielectric substrate is disposed above the reflector, and the low-frequency radiating surface structure is disposed on the dielectric substrate;

[0059] The low-frequency radiation surface structure includes a first low-frequency radiation surface and a second low-frequency radiation surface. The first low-frequency radiation surface is used as a multiplexing structure to realize the high-frequency radiation surface structure, so that the low-frequency radiation surface structure and the high-frequency radiation surface structure are coplanar.

[0060] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A low-profile dual-band coplanar antenna with structural reuse, characterized in that: It includes a low-frequency radiation surface structure, a dielectric substrate and a reflector, wherein the dielectric substrate is arranged above the reflector, and the dielectric substrate is provided with the low-frequency radiation surface structure; The low-frequency radiation surface structure includes a first low-frequency radiation surface and a second low-frequency radiation surface, wherein the first low-frequency radiation surface is used as a multiplexing structure to realize the high-frequency radiation surface structure, so that the low-frequency radiation surface structure and the high-frequency radiation surface structure are coplanar; The low-frequency radiation surface structure is a symmetrical structure, specifically composed of 4×4 low-frequency radiation surface units arranged in a matrix, the matrix shape is square, and the low-frequency radiation surface units are composed of square rings; The four first low-frequency radiation surface units located at the center of the square constitute a first low-frequency radiation surface, and the second low-frequency radiation surface units surrounding the first low-frequency radiation surface constitute a second low-frequency radiation surface; The four first low-frequency radiation surface units of the first low-frequency radiation surface form a square; It also includes two high-frequency feeding patches, two first low-frequency radiating surface units arranged on one diagonal line of the square and one high-frequency feeding patch are located on the first surface of the dielectric substrate, and two first low-frequency radiating surface units arranged on the other diagonal line of the square and another high-frequency feeding patch are located on the second surface of the dielectric substrate; It also includes four low-frequency feeding patches, which are respectively arranged on the second low-frequency radiation surface units located at the four corners of the square. The low-frequency feeding patches and the second low-frequency radiation surface are arranged on the first surface of the dielectric substrate.

2. The low-profile dual-band coplanar antenna according to claim 1, characterized in that: The low-frequency radiation surface structure adopts a differential feeding structure.

3. The low-profile dual-band coplanar antenna according to claim 1, characterized in that: The high-frequency radiation surface structure is specifically a dipole antenna.

4. The low-profile dual-band coplanar antenna according to claim 1, characterized in that: The square ring sizes of the first low-frequency radiation surface unit and the second low-frequency radiation surface unit are different, specifically, the outer ring lengths are equal, and the inner ring lengths are different; the inner ring length of the first low-frequency radiation surface unit adjusts the matching of the high-frequency working frequency band, and the inner ring length of the second low-frequency radiation surface unit adjusts the low-frequency working frequency band.

5. The low-profile dual-band coplanar antenna according to claim 1, characterized in that: The spacing between adjacent first low-frequency radiation surface units in the first low-frequency radiation surface is different from the spacing between adjacent second low-frequency radiation surface units in the second low-frequency radiation surface.

6. The low-profile dual-band coplanar antenna according to any one of claims 1 to 5, characterized in that: The height of the low-frequency radiation surface structure from the reflection surface is 0.16λ L , where λ L It is the free space wavelength of the lowest frequency point of low-frequency operation.

7. A communication device, characterized in that: It comprises a low-profile dual-band coplanar antenna as described in any one of claims 1-6.

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