Miniaturized microwave and millimeter wave terminal MIMO antenna system based on structure multiplexing technology

Abstract

The invention discloses a miniaturized microwave and millimeter wave terminal MIMO antenna system based on a structure multiplexing technology, particularly relates to the technical field of microwave and millimeter wave communication, and solves the technical problem that microwave MIMO cannot be realized under the condition of compact size of a microwave / millimeter wave antenna in the prior art. According to the technical scheme, two rows of orthogonal metallized cavities are introduced into a microwave MIMO system as two millimeter wave arrays as decoupling structures; the metalized cavity can be in butt joint with four microwave units, and satisfactory isolation between the microwave units is achieved within the compact size.

Description

Technical Field

[0001] The present invention relates to the field of microwave and millimeter wave communications, and in particular to a miniaturized microwave and millimeter wave terminal MIMO antenna system based on structure multiplexing technology. Background Art

[0002] Compact wireless terminals greatly benefit from co-aperture antennas that support microwave and millimeter wave frequency bands and occupy a small space. To meet terminal applications, co-aperture antennas need to meet the requirements of both millimeter wave and millimeter wave frequency bands. In the microwave band, multiple-input multiple-output (MIMO) technology is critical because it improves data throughput without increasing power input or bandwidth. In the millimeter wave band, antennas should be in the form of phased arrays, which are widely considered to be the most effective millimeter wave antenna solution in 5G networks, with both high gain and wide-angle coverage. These requirements pose great challenges to shared aperture antennas.

[0003] To date, there have been many studies on co-aperture antennas using various technologies. To achieve co-aperture antennas, microwave antennas are placed adjacent to millimeter wave antennas, or microwave antennas are placed above and below millimeter wave antennas. These implementation methods are relatively simple and have low space utilization, among which the adjacent placement scheme leads to a larger footprint and the above-and-below placement structure leads to a higher profile. Embedded structures are usually more compact in size, and the independent design capabilities of microwave and millimeter wave antennas are also better, which can realize the integrated design of millimeter wave phased arrays and microwave antennas that support beam scanning, which is of great reference significance for solving practical problems of terminal antennas. However, the embedding of millimeter wave antennas will destroy the structure of microwave antennas, thereby further deteriorating the already limited performance of small-sized microwave antennas. Structural reuse technology reuses the structure of microwave antennas into millimeter wave antennas, which has the significant advantage of high aperture utilization. In some designs, almost 100% of the radiation structure of microwave antennas is reused by millimeter wave antennas, but due to the high degree of mutual inclusion, it is difficult to add multiple feed ports, which limits the realization of millimeter wave beam scanning. In some designs, parts of microwave antennas are reused as millimeter-wave antennas to achieve good dual-band operation with satisfactory millimeter-wave beam scanning capabilities. However, most of these antennas have not been widely studied for microwave MIMO. Although MIMO is implemented in some designs, it occupies a large planar size. It remains a major challenge to achieve microwave MIMO in the compact size of microwave / millimeter-wave antennas. Summary of the invention

[0004] Therefore, the present invention solves the technical problem in the prior art that microwave MIMO cannot be realized in the compact size of microwave / millimeter wave antennas; the present invention provides a miniaturized microwave millimeter wave terminal MIMO antenna system based on structural multiplexing technology, and for the first time introduces two rows of orthogonal metallized cavities as two millimeter wave arrays as decoupling structures into the microwave MIMO system; the metallized cavity can be connected to up to four microwave units, achieving satisfactory isolation between microwave units in a compact size.

[0005] The inventive concept of the present invention is to apply structural multiplexing technology to microwave MIMO. In the microwave frequency band, four microwave patches are used as a multiple-input multiple-output (MIMO) system, and the parasitic patch provides an additional resonant mode for each microwave unit. This mode is combined with the original microwave patch mode to achieve dual-mode operation. The two rows of orthogonal metallized cavities have a dual role, serving as a decoupling structure in the microwave frequency band and as two arrays in the millimeter wave frequency band to achieve two-dimensional beam scanning. The antenna is implemented using only one antenna substrate and one feed substrate, with a size of (λ 01 is 4.85 GHz vacuum wavelength).

[0006] The present invention provides a miniaturized microwave millimeter wave terminal MIMO antenna system based on structural multiplexing technology, comprising an antenna substrate, a feeding substrate is arranged below the antenna substrate; a metal patch for microwave radiation, a metal parasitic patch for microwave enhanced bandwidth, a metallized slot for millimeter wave radiation and a metallized through hole for microwave feeding are arranged on the antenna substrate.

[0007] Preferably, a metal ground is provided on the upper surface of the feed substrate.

[0008] Preferably, gaps are provided on the metal floor.

[0009] Preferably, the gap is in an H shape.

[0010] Preferably, the H-shaped slot is used for millimeter wave antenna feeding.

[0011] Preferably, a microstrip line structure for microwave antenna feeding and a probe structure for millimeter wave antenna feeding are provided on the lower surface of the antenna substrate.

[0012] Preferably, the metallized through hole is connected to a metal patch.

[0013] Preferably, the metallized grooves and the gaps are arranged orthogonally and correspond one to another up and down; the area of ​​the metal parasitic patch corresponding to the metallized groove is hollowed out so that the metallized groove leaks out.

[0014] In the above technical solution, the technical effects and advantages provided by the present invention are:

[0015] 1. The miniaturized microwave millimeter wave terminal MIMO antenna system based on structural multiplexing technology provided by the present invention introduces two rows of orthogonal metallized cavities as two millimeter wave arrays as decoupling structures into the microwave MIMO system for the first time. The metallized cavity can be docked with up to four microwave units, achieving satisfactory isolation between microwave units in a compact size.

[0016] 2. The miniaturized microwave millimeter-wave terminal MIMO antenna system based on structural multiplexing technology provided by the present invention not only realizes the structural multiplexing between the microwave antenna and the millimeter-wave antenna, but also introduces the sharing of parasitic patches between microwave units, thereby enhancing the bandwidth of the microwave antenna while maintaining the compact size of the microwave antenna.

[0017] 3. The miniaturized microwave millimeter wave terminal MIMO antenna system based on structural multiplexing technology provided by the present invention has two rows of orthogonal millimeter wave arrays to achieve dual-polarization wide-angle beam scanning; it is composed of only one antenna substrate and one feeding substrate, with a simple structure and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a schematic diagram of the overall structure of the antenna of the present invention;

[0020] Figure 2a The impedance bandwidth diagram of the microwave frequency band antenna of the antenna of the present invention;

[0021] Figure 2b This is a diagram of the isolation simulation results of the microwave frequency band antenna of the antenna of the present invention;

[0022] Figure 3a It is the envelope coefficient diagram of the microwave frequency band antenna of the present invention;

[0023] Figure 3b This is a diagram showing the efficiency simulation results of the microwave frequency band antenna of the present invention;

[0024] 4a to 4d are simulation directional diagrams of the microwave unit of the present invention;

[0025] Figure 5 The simulation result of the impedance bandwidth of the millimeter wave frequency band antenna of the present invention;

[0026] Figure 6a The beam scanning simulation result of the x-direction array of the millimeter wave antenna array of the present invention;

[0027] Figure 6b It is the beam scanning simulation result of the y-direction array of the millimeter wave antenna array of the present invention;

[0028] Figure 7 It is a simulation diagram of the isolation between the millimeter wave port and the microwave port of the antenna of the present invention, as well as the isolation between the millimeter wave ports.

[0029] Description of reference numerals:

[0030] 1. Metal parasitic patch; 2. Metal patch; 3. Antenna substrate; 4. Metal ground; 5. Feed substrate; 6. Probe structure; 7. Metallized groove; 8. Metallized through hole; 9. Gap; 10. Microstrip line structure. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0032] The present invention provides a miniaturized microwave millimeter wave terminal MIMO antenna system based on structure multiplexing technology, such as Figure 1 As shown, including:

[0033] An antenna substrate 3, a feeding substrate 5 is arranged below the antenna substrate 3; a metal patch 2 for microwave radiation, a metal parasitic patch 1 for microwave enhanced bandwidth, a metallized slot 7 for millimeter wave radiation and a metallized through hole 8 for microwave feeding are arranged on the antenna substrate 3. A metal ground 4 is arranged on the upper surface of the feeding substrate 5. A gap 9 is arranged on the metal ground 4. The gap 9 is in an H shape. The H-shaped gap 9 is used for millimeter wave antenna feeding. A microstrip line structure 10 for microwave antenna feeding and a probe structure 6 for millimeter wave antenna feeding are arranged on the lower surface of the antenna substrate 3. The metallized through hole 8 is connected to the metal patch 2.

[0034] Structural multiplexing technology is used in microwave MIMO. In the microwave frequency band, four metal patches 2 act as a multiple-input multiple-output (MIMO) system, and the metal parasitic patch 1 provides an additional resonant mode for each microwave unit, which is combined with the original microwave patch mode to achieve dual-mode operation. Two rows of orthogonal metallized slots 7 have a dual role, acting as a decoupling structure in the microwave frequency band and as two arrays in the millimeter wave frequency band to achieve two-dimensional beam scanning. The antenna is implemented using only one antenna substrate 3 and one feed substrate 5. For the first time, two rows of orthogonal metallized slots 7 are introduced as two millimeter wave arrays as decoupling structures in a microwave MIMO system. The metallized cavity can be docked with up to four microwave units to achieve satisfactory isolation between microwave units in a compact size. In addition to realizing the multiplexing of the structure between the microwave antenna and the millimeter wave antenna, the sharing of parasitic patches between microwave units is introduced, which enhances the bandwidth of the microwave antenna while maintaining the compact size of the microwave antenna. Two rows of orthogonal millimeter wave arrays achieve dual-polarization wide-angle beam scanning.

[0035] Based on the above scheme, the present application conducted the following experiment: the dielectric constant of the antenna substrate 3 is 4.4, the loss angle is 0.02, and the thickness is 2 mm; the dielectric constant of the feed substrate 5 is 3.55, the loss angle is 0.027, and the thickness is 0.305 mm. The overall cross-sectional height is 2.305 mm (~ 0.03λ0@4.85 GHz). The impedance bandwidth and isolation between units of the microwave antenna are shown in Figure 2. For S11≤-10dB, the bandwidth ranges from 4.62–5.12GHz, which shows that the Sub-6 GHz band (4.8–5GHz) is well covered. The total efficiency and envelope coefficient of the microwave antenna are shown in Figure 3. The total efficiency of each antenna unit is between 51% and 55%, and the envelope coefficient ECC is less than 0.11, indicating good performance. Figure 4 shows the 4.7GHz and 5GHz radiation patterns of microwave unit one (as shown in Figures 4a to 4b) and unit two (as shown in Figures 4c to 4d) in the xoz and yoz planes. These complementary radiation patterns indicate strong diversity performance, confirming the comprehensive spatial coverage capability of the MIMO system. The impedance bandwidth of the millimeter wave antenna is shown in Figure 2. Figure 5 As shown, for S11≤-10dB, the bandwidth range is 25.5–30.5GHz, which shows that the 5G millimeter wave frequency band n257 (26.5-29.5GHz) is well covered. Figure 6 is a beam scanning simulation diagram of the x-direction millimeter wave antenna array and the y-direction millimeter wave antenna array at 28GHz. The beam scanning performance can meet the ±50° range in both polarization directions. Figure 7 This is a simulation diagram of antenna isolation between millimeter wave and microwave frequency bands. The isolation between microwave and millimeter wave antenna ports is greater than 30dB in the microwave band and greater than 40dB in the millimeter wave band.

[0036] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A miniaturized microwave millimeter wave terminal MIMO antenna system based on structural multiplexing technology, characterized in that: The invention comprises an antenna substrate (3), wherein a feeding substrate (5) is arranged below the antenna substrate (3); and a metal patch (2) for microwave radiation, a metal parasitic patch (1) for microwave bandwidth enhancement, a metallized slot (7) for millimeter wave radiation, and a metallized through hole (8) for microwave feeding are arranged on the antenna substrate (3).

2. The miniaturized microwave millimeter wave terminal MIMO antenna system based on structure multiplexing technology according to claim 1 is characterized in that: The upper surface of the feed substrate (5) is provided with a metal ground (4).

3. The miniaturized microwave millimeter wave terminal MIMO antenna system based on structure multiplexing technology according to claim 2 is characterized in that: The metal ground (4) is provided with gaps (9).

4. The miniaturized microwave millimeter wave terminal MIMO antenna system based on structure multiplexing technology according to claim 3 is characterized in that: The shape of the gap (9) is H-shaped.

5. The miniaturized microwave millimeter wave terminal MIMO antenna system based on structure multiplexing technology according to claim 4 is characterized in that: The H-shaped slot (9) is used for millimeter wave antenna feeding.

6. The miniaturized microwave millimeter wave terminal MIMO antenna system based on structure multiplexing technology according to claim 1, characterized in that: The lower surface of the antenna substrate (3) is provided with a microstrip line structure (10) for microwave antenna feeding and a probe structure (6) for millimeter wave antenna feeding.

7. The miniaturized microwave millimeter wave terminal MIMO antenna system based on structure multiplexing technology according to claim 1, characterized in that: The metallized through hole (8) is connected to the metal patch (2).

8. The miniaturized microwave millimeter wave terminal MIMO antenna system based on structure multiplexing technology according to claim 3 is characterized in that: The metallized grooves (7) and the gaps (9) are arranged orthogonally and correspond one to another; the area of ​​the metal parasitic patch (1) corresponding to the metallized grooves (7) is hollowed out.

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