An integrated broadband dielectric patch antenna array with beam scanning capability

Abstract

The present invention belongs to the field of wireless communication technology, and specifically relates to an integrated broadband dielectric patch antenna array with beam scanning function. The array comprises a bottom substrate, a metal reflector, a top substrate, and a dielectric patch, which are stacked in sequence from bottom to top. Several pairs of air slot groups are etched in the center of the dielectric patch; the spacing between the pairs of air slot groups is unequal; the air slot groups include two parallel rows of air slots symmetrical about a perpendicular midplane of the dielectric patch; the lengths of the two parallel rows of air slots are unequal; the lower surface of the bottom substrate is provided with several ports and microstrip feed lines for coupling and feeding; the microstrip feed line is an L-shaped microstrip feed line; the L-shaped microstrip feed line consists of a 50Ω transmission line near the port and a λ / 4 impedance transformation line for matching; several coupling slots are etched in the metal reflector; the projection of the λ / 4 impedance transformation line on the metal reflector intersects the coupling slots perpendicularly; and the coupling slots are symmetrical about the center line of the projection of the λ / 4 impedance transformation line on the metal reflector.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless communications, and in particular relates to an integrated broadband dielectric patch antenna array with a beam scanning function. Background Art

[0002] With the rapid development of wireless communication technology, Multiple-Input Multiple-Output (MIMO) technology plays an extremely important role in communication systems. At the same time, as the bandwidth requirements of MIMO systems continue to increase, the demand for broadband antennas is becoming increasingly urgent. Antenna arrays with beam scanning capabilities are the core and soul of MIMO technology. Since beam scanning requires the spacing between antennas to be maintained at 0.5 wavelengths, small antenna spacing can lead to mutual coupling between antennas, which can significantly reduce antenna impedance matching, gain, and radiation pattern performance, thereby affecting the performance of the entire base station antenna. Therefore, research on decoupling technology for broadband antennas is of great significance.

[0003] A lot of work has been done on antenna decoupling. In recent years, some decoupling methods have been proposed for two main types of antennas (metal patch antennas and dielectric resonator antennas). In order to obtain satisfactory port-to-port isolation, a variety of technologies have been adopted, such as metasurfaces, electromagnetic band gaps (EBG), split ring resonators (SRR), metamaterials, dielectric substrates, etc. However, the introduction of additional decoupling structures will inevitably take up additional space and increase the complexity of the design. The use of simple structures such as metal strips and metal through-holes directly on the DR enhances the isolation of the antenna elements, and has the characteristics of compact size and good isolation. At the same time, self-decoupling technology has also been widely studied. In the prior art, a method working on TM is proposed. 01 The self-decoupling method of MPA in the mode or by exciting TE in a DRA 113 mode, the synthetic mode of another DRA becomes TE 211 mode, thereby achieving high isolation. However, the above decoupling methods are all aimed at antennas operating in a single mode, so the operating bandwidth is relatively narrow. In order to adapt to the broadband trend of antennas / arrays, broadband decoupling methods have become a research hotspot in recent years. In the prior art, two sets of through holes are used at the non-radiating edge to realize a short patch antenna, thereby widening the impedance bandwidth of the antenna, while improving the isolation and obtaining a stable radiation pattern. However, the available bandwidth is limited, still less than 10%. The metallized bridge has a bandwidth of 26.7% and a higher isolation. However, during the decoupling process, the radiation pattern of the antenna will be distorted.

[0004] As a quasi-planar antenna, the dielectric patch antenna not only offers similar characteristics to dielectric patch antennas, such as multimode and design freedom, but also possesses characteristics similar to traditional metal patches. Therefore, the DPA can be viewed as a compromise between the traditional DRA and the MPA. However, few broadband decoupling methods for DPAs have been proposed. Summary of the Invention

[0005] In view of the problems existing in the above-mentioned prior art, the present invention proposes an integrated broadband dielectric patch antenna array with beam scanning function.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0007] An integrated broadband dielectric patch antenna array with beam scanning capability comprises a bottom substrate, a metal reflector, a top substrate, and a dielectric patch stacked in sequence from bottom to top. The dielectric patch has a plurality of pairs of air slot groups etched in its center; the spacing between the pairs of air slot groups is unequal; the air slot groups include two parallel rows of air slots symmetrical about a perpendicular midplane of the dielectric patch; the lengths of the two parallel rows of air slots are unequal; the lower surface of the bottom substrate is provided with a plurality of ports and microstrip feed lines for coupling and feeding; the microstrip feed lines are L-shaped microstrip feed lines, comprising a 50Ω transmission line proximate the ports and a λ / 4 impedance transformation line for matching; the metal reflector has a plurality of coupling slots etched in its center; the projections of the coupling slots on the dielectric patch are perpendicular to and do not intersect with the air slot groups; the projections of the λ / 4 impedance transformation line on the metal reflector intersect the coupling slots perpendicularly; and the coupling slots are symmetrical about the centerline of the projection of the λ / 4 impedance transformation line on the metal reflector.

[0008] Furthermore, as a preferred technical solution of the present invention, the dielectric patch is a rectangular dielectric patch, which is glued to the center of the top substrate by glue.

[0009] Furthermore, as a preferred technical solution of the present invention, the bottom substrate is a double-sided printed circuit board, the top layer of the double-sided printed circuit board is a metal reflective ground, and the bottom layer is a microstrip feeder.

[0010] Furthermore, as a preferred technical solution of the present invention, the top substrate is a Rogers RO3003 dielectric substrate.

[0011] Furthermore, as a preferred technical solution of the present invention, the bottom substrate is a Rogers RO4003 dielectric substrate.

[0012] The integrated broadband dielectric patch antenna array with beam scanning function described in the present invention, using the above technical solution, has the following technical effects compared with the prior art:

[0013] The present invention introduces gaps of different sizes on a single dielectric patch, reducing the effective dielectric constant of the region. Therefore, the two resonant modes (TM) inside the dielectric patch are 10 and TE 12 The electric field distribution of the antenna pattern is shifted to the unetched slot portion, thereby improving the isolation between antennas. This invention has the advantages of wide bandwidth, integration, high isolation, low profile, simple structure, and beam scanning, and has broad application prospects in MIMO systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a stereogram of the integrated broadband dielectric patch antenna array of the present invention;

[0015] Figure 2 This is a schematic diagram of the structure of the integrated broadband dielectric patch antenna array of the present invention;

[0016] Figure 3 Schematic diagram of the S parameters of the integrated broadband dielectric patch antenna array of the present invention;

[0017] Figure 4 This is a beam scanning diagram of the integrated broadband dielectric patch antenna array of the present invention at 5.17 GHz;

[0018] Figure 5 This is a beam scanning diagram of the integrated broadband dielectric patch antenna array of the present invention at 5.67 GHz;

[0019] In the accompanying drawings, 1-dielectric patch, 2-air slot group, 3-top substrate, 4-metal reflective ground, 5-coupling gap, 6-bottom substrate, 7-microstrip feed line. DETAILED DESCRIPTION

[0020] The present invention will be further explained below in detail with reference to the accompanying drawings so that those skilled in the art can have a deeper understanding of the present invention and be able to implement it. However, the following reference examples are only used to explain the present invention and are not intended to limit the present invention.

[0021] like Figure 1 and Figure 2As shown, an integrated broadband dielectric patch antenna array with beam scanning function includes a bottom substrate 6, a metal reflector 4, a top substrate 3 and a dielectric patch 1 stacked in sequence from bottom to top. Three pairs of air slot groups 2 are etched in the center of the dielectric patch 1; the spacing between the three pairs of air slot groups 2 is unequal; the air slot group 2 includes two parallel rows of air slots and is symmetrical about the vertical midplane of the dielectric patch 1; the lengths of the two parallel rows of air slots are unequal; the lower surface of the bottom substrate 6 is provided with four coupling feed Port and microstrip feed line 7; microstrip feed line 7 is an L-shaped microstrip feed line; the L-shaped microstrip feed line consists of a 50Ω transmission line near the port and a λ / 4 impedance transformation line for matching; four coupling slots 5 are etched on the metal reflective ground 4; the projection of the coupling slots 5 on the dielectric patch 1 is perpendicular to and does not intersect with the air slot group 2; the projection of the λ / 4 impedance transformation line on the metal reflective ground 4 intersects the coupling slots 5 at right angles; the coupling slots 5 are symmetrical about the center line of the projection of the λ / 4 impedance transformation line on the metal reflective ground 4.

[0022] The dielectric patch 1 is a rectangular dielectric patch, which is glued to the center of the top substrate 3. The bottom substrate 6 is a double-sided printed circuit board, the top layer of which is a metal reflective ground 4 and the bottom layer is a microstrip feed line 7.

[0023] The present invention consists of a rectangular dielectric patch with an etched air slot group 2, two substrates, and a metal reflector 4. The dielectric patch 1 is placed on the top substrate 3. Air slots of different sizes are introduced on the dielectric patch 1 to reduce the effective dielectric constant of the area. Therefore, the two resonant modes (TM) in the dielectric patch 1 are 10 and TE 12 The electric field distribution of the TM mode is moved to the unetched gap portion, thereby improving the isolation between ports. 10 and TE 12 The integrated broadband dielectric patch antenna array with a single mode significantly improves isolation between ports across a wide operating frequency band. A metal reflective ground plane 4 is placed between two substrates, with an air slot group 2 etched into it for aperture coupling between the dielectric patch resonator and a microstrip feed line 7 located at the bottom of the bottom substrate 6.

[0024] The embodiment of the present invention optimizes the dimensions of various parts of the antenna. Specific antenna parameters are shown in the table below:

[0025] parameter <![CDATA[w s ]]> <![CDATA[l s ]]> w <![CDATA[w1]]> <![CDATA[w2]]> <![CDATA[w3]]> <![CDATA[w4]]> <![CDATA[w c ]]> <![CDATA[d1]]> <![CDATA[d2]]> dh <![CDATA[h1]]> Value (mm) 60 139 1.8 2.5 2.5 4.5 2.2 2.8 5 2.1 1 1.524 parameter <![CDATA[d3]]> <![CDATA[d4]]> <![CDATA[d5]]> <![CDATA[l1]]> <![CDATA[l2]]> <![CDATA[l3]]> <![CDATA[l4]]> <![CDATA[l5]]> <![CDATA[l c ]]> <![CDATA[h2]]> <![CDATA[w d ]]> <![CDATA[l d ]]> Value (mm) 1.7 0.7 12 16 8 30.9 0.2 14.9 8.4 0.813 33 123.2

[0026] In the table, h1 is the height of the top substrate 3, h2 is the height of the bottom substrate 6, and l d is the length of the dielectric patch, w d is the width of the dielectric patch, h dis the thickness of the dielectric patch, l1 and l2 are the lengths of the air slots etched on the dielectric patch, w1, w2 and w3 are the widths of the air slots, d1, d2, d3 and d4 are the distances between the air slots, l c is the length of the coupling gap 5, w c is the width of the coupling gap.

[0027] The design uses two layers of substrates. The top substrate 3 is Rogers RO3003, which has a dielectric constant of ε r =3, the loss tangent is tanδ=1.3×10 -3 , the bottom substrate 6 is Rogers RO4003, and its dielectric constant is ε r =3.38, loss tangent is tanδ=2.7×10 -3 , the volume of the top substrate 3 is l s ×w s ×h1, the volume of the bottom substrate 6 is l s ×w s ×h2.

[0028] Figure 3 These are the S parameters of the integrated dielectric patch antenna array in this example. It can be observed that the bandwidth is 16.4%, and the in-band isolation is greater than 21.0 dB.

[0029] Figure 4 This is the beam scanning diagram of the integrated dielectric patch antenna array in this example at 5.17 GHz. It can be seen that the maximum scanning angle can reach 46°.

[0030] Figure 5 This is the beam scanning diagram of the integrated dielectric patch antenna array in this example at 5.67 GHz. It can be seen that the maximum scanning angle can reach 36°.

[0031] The present invention introduces air slots of different sizes into the single dielectric patch 1, which reduces the effective dielectric constant of the region. Therefore, the two resonant modes (TM) inside the dielectric patch 1 10 and TE 12 The electric field distribution of the mode is moved to the unetched gap part, thereby improving the isolation between ports, and the center-to-center spacing of the antenna is kept at 0.5 wavelength, with the function of beam scanning. 10 and TE 12 The broadband dielectric patch antenna array with a 100 nm mode significantly improves the port isolation within a wider operating frequency band while maintaining the antenna center spacing at 0.5 wavelengths. At the same time, the antenna array has the function of beam scanning.

[0032] The specific implementation scheme described above further illustrates in detail the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above is only a specific implementation scheme of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any technician in this field without departing from the concept and principle of the present invention should fall within the scope of protection of the present invention.

Claims

1. An integrated broadband dielectric patch antenna array with a beam scanning function, comprising a bottom substrate (6), a metal reflective ground (4), a top substrate (3) and a dielectric patch (1) stacked in sequence from bottom to top, characterized in that: The dielectric patch (1) is etched with a plurality of pairs of air slot groups (2) in the center; the air slot group (2) includes two parallel rows of air slots and is symmetrical about the vertical midplane of the dielectric patch (1); one row of air slots in the two parallel rows of air slots is symmetrical with the other row of air slots and the lengths of all slots in each row of air slots are not equal; the spacing between each pair of air slot groups (2) is not equal to the spacing between other pairs of air slot groups (2); the lower surface of the bottom substrate (6) is provided with a plurality of ports and microstrip feed lines (7) for coupling feeding; the microstrip feed line (7) is an L-shaped microstrip feed line; the L-shaped microstrip feed line is composed of a 50Ω transmission line near the port and a section for matching. λ / 4 impedance transformation line; a plurality of coupling slots (5) are etched on the metal reflective ground (4); the projection of the coupling slots (5) on the dielectric patch (1) is perpendicular to and does not intersect with the air slot group (2); the λ The projection of the / 4 impedance transformation line on the metal reflection ground (4) intersects the coupling gap (5) vertically; The coupling gap (5) is about λ The projection center line of the / 4 impedance transformation line on the metal reflection ground (4) is symmetrical.

2. The integrated broadband dielectric patch antenna array with beam scanning function according to claim 1, characterized in that: The dielectric patch (1) is a rectangular dielectric patch and is glued to the center of the top substrate (3) by glue.

3. The integrated broadband dielectric patch antenna array with beam scanning function according to claim 1, characterized in that: The bottom substrate (6) is a double-sided printed circuit board, the top layer of the double-sided printed circuit board is a metal reflective ground (4), and the bottom layer is a microstrip feed line (7).

4. The integrated broadband dielectric patch antenna array with beam scanning function according to claim 1, characterized in that: The top substrate (3) is a Rogers RO3003 dielectric substrate.

5. The integrated broadband dielectric patch antenna array with beam scanning function according to claim 1, characterized in that: The bottom substrate (6) is a Rogers RO4003 dielectric substrate.

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