High-fusion-degree common-aperture antenna based on structure multiplexing

Abstract

The invention discloses a high-fusion-degree common-aperture antenna based on structure multiplexing, and belongs to the technical field of antennas. In the antenna, an upper metal layer comprises a microwave frequency band radiation patch and a millimeter wave frequency band array patch, a millimeter wave feed network is distributed on the upper surface of a lower dielectric substrate, and a lower metal layer is a microwave differential feed network. According to the antenna, the millimeter wave antenna is tightly embedded into the middle area of the microwave band antenna, and the antenna units of different frequency bands are structural components of each other in a structural multiplexing mode, so that the common-caliber antenna with a compact structure and high fusion is realized; a power divider structure is introduced into the feed network, a single-ended signal is converted into a differential signal through a power divider in a microwave band, and equal-amplitude in-phase distribution of four paths of signals is realized through the power divider network in a millimeter wave band. The antenna has practical application value for 5G communication, has the characteristics of wide wave beam, wide frequency band and high isolation, and is simple in structure, low in cost and easy to process.

Description

Technical Field

[0001] The present invention belongs to the field of antenna technology, and in particular relates to a highly integrated common-aperture antenna based on structural multiplexing. Background Art

[0002] In modern communication systems, antennas are key components for signal transmission and reception. Their performance directly impacts key indicators such as communication quality, signal power, signal bandwidth, and connection speed. With the development of 5G technology, the communication frequency band has expanded from the traditional sub-6 GHz to the millimeter wave band (above 24 GHz), posing new challenges to antenna design.

[0003] Modern mobile communication technology is rapidly developing towards multifunctionality and integration. Antennas, as an integral component of wireless communication systems, are entering an era of multi-frequency, miniaturization, and integration. Multi-frequency antennas can simultaneously support multiple frequency bands, offering advantages such as compactness and versatility. Multi-frequency antennas have become an inevitable development trend. The high frequency characteristics of the millimeter-wave band introduce greater feeder losses and more complex design requirements, making traditional antenna design methods increasingly unable to meet these demands.

[0004] To meet these challenges, antenna technology is developing towards higher integration, smaller size and lower loss. For example, AiP (Antenna in Package) technology reduces feeder loss, improves radiation efficiency and reduces antenna size by integrating the antenna with the RF front end. In addition, substrate integrated waveguide (SIW) technology has become a popular choice for millimeter wave band antenna design due to its low insertion loss, low radiation and high integration. However, existing technologies still have shortcomings in multi-band coverage, miniaturization and high performance. Especially in the 5G millimeter wave band, how to achieve wide-band coverage, high gain and low loss while maintaining the miniaturization of the antenna has become an urgent problem to be solved. Therefore, the development of a cross-frequency domain multi-band antenna that can simultaneously cover multiple frequency bands, has high gain and low loss, is of great significance to promoting the development of 5G technology. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned defects of the prior art and provide a high-integration co-aperture antenna based on structural multiplexing.

[0006] The technical problem proposed by the present invention is solved as follows:

[0007] A highly integrated common-aperture antenna based on structural reuse comprises an upper metal layer, an upper dielectric substrate, an intermediate air layer, a lower dielectric substrate, and a lower metal layer that are tightly attached to each other from top to bottom.

[0008] The upper metal layer includes a microwave band radiation patch and a millimeter wave band array patch; the microwave band radiation patch is rectangular and located at the center of the upper surface of the upper dielectric substrate; a square hole is etched at the center of the microwave band radiation patch, and the millimeter wave band array patch is arranged in a 2×2 pattern and located within the square hole;

[0009] Several nylon columns are loaded between the upper dielectric substrate and the lower dielectric substrate to form an intermediate air layer;

[0010] The millimeter-wave feeding network is distributed on the upper surface of the lower dielectric substrate, including a one-to-four feeding network structure, a feeding dielectric substrate, and a metal floor stacked from bottom right to top. The one-to-four feeding network structure includes a cascade of millimeter-wave feeding microstrip branches and an H-shaped power-dividing structure. The metal floor has holes corresponding to the ends of the H-shaped power-dividing structure, and millimeter-wave feeding metal probes are placed in the holes. The millimeter-wave feeding metal probes pass through the holes of the feeding dielectric substrate and the metal floor and connect to the metal floor at the end of the H-shaped power-dividing structure and the millimeter-wave frequency band array patch respectively.

[0011] The lower metal layer is a microwave differential feeding network, which feeds the microwave frequency band radiation patch.

[0012] Furthermore, two symmetrical metal grooves are etched on the microwave band radiation patch. The metal grooves are parallel to the short sides of the microwave band radiation patch and are distributed on the left and right sides.

[0013] Furthermore, the microwave band radiation patch is also etched with four metal perturbation holes, which are located between the metal slot and the millimeter wave band array patch on the side close to the metal slot.

[0014] Furthermore, the microwave differential feeding network includes three microstrip branches, the first microstrip branch extends upward from the edge of the lower dielectric substrate, the second microstrip branch and the third microstrip branch start from the end of the first microstrip branch, and are L-shaped and open rectangular, respectively. The length difference between the second microstrip branch and the third microstrip branch is half a wavelength, and the phase difference is 180°; two microwave feeding metal columns pass through the lower dielectric substrate and the upper dielectric substrate respectively, and the lower ends are connected to the ends of the second microstrip branch and the third microstrip branch, respectively, and the upper ends are connected to the microwave frequency band radiation patch.

[0015] Furthermore, the air layer height H=4.2 mm.

[0016] Furthermore, the radius of the metal perturbation hole is 1 mm.

[0017] The beneficial effects of the present invention are:

[0018] In the co-aperture antenna described in the present invention, the millimeter wave array antenna is tightly nested between the microwave band antennas to achieve dual-band operation with a large frequency ratio; these two frequency bands are widely used in wireless communications, radar systems, satellite communications and other fields. Integrating microwave band and millimeter wave band antennas into the same structure can not only reduce the size and complexity of the antenna, but also meet the needs of multi-band communication systems, which has important practical significance; the structure of the millimeter wave antenna can serve as the introduction capacitor part of the microwave band antenna, effectively improving the impedance matching characteristics of the microwave band antenna; the microwave band antenna meets the wide area coverage requirements through its wide beam and broadband characteristics, while the millimeter wave antenna achieves long-distance communication through high gain and narrow beam; in the structural design, the problem of non-interference in dual-band operation is solved, and by optimizing the patch shape and layout, the impedance change introduced by the feeding part is improved, thereby achieving good frequency band isolation and impedance matching.

[0019] In the co-aperture antenna described in the present invention, a power divider structure is introduced into the feeding network: in the microwave band, the single-ended signal is converted into a differential signal through the power divider, and in the millimeter wave band, the equal amplitude and in-phase distribution of the four signals is achieved through the power division network; after such optimization, the entire dual-band antenna system only needs to retain two feeding ports, microwave and millimeter wave, which not only maintains the original radiation performance but also significantly improves the system's integration and practicality; this multi-port design ensures the performance of each frequency band and reduces the complexity in actual system integration.

[0020] In the co-aperture antenna described in the present invention, by tightly embedding the millimeter-wave antenna in the middle area of the microwave-band antenna, a compact structure is achieved without the need for additional radiation surfaces. This design not only makes full use of space, but also avoids mutual interference between the two frequency bands through structural optimization. In addition, the structure of the millimeter-wave antenna can serve as the introduction capacitor part of the microwave-band antenna, effectively improving the impedance matching characteristics of the microwave-band antenna.

[0021] The co-aperture antenna described in the present invention has a -10dB bandwidth of 2.05-2.4GHz in the microwave band and a maximum gain of 8.44dBi; the -10dB bandwidth of the millimeter wave band antenna is 28.7-31GHz, the maximum gain is 11.4dBi, and the dual-band center frequency ratio is 14; it has practical application value for 5G communications, has the characteristics of wide beam, wide bandwidth, and high isolation, and at the same time has a simple structure, low cost, and easy processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the three-dimensional structure of the antenna of the present invention;

[0023] Figure 2 Schematic diagram of the structure of the upper metal layer in the antenna of the present invention;

[0024] Figure 3Schematic diagram of the structure of the microwave differential feeding network in the antenna of the present invention;

[0025] Figure 4 Schematic diagram of the structure of the millimeter wave feeding network in the antenna of the present invention;

[0026] Figure 5 Schematic diagram of the structure of the one-to-four power division network in the antenna of the present invention;

[0027] Figure 6 This is a comparison chart of the S11 simulation results of the co-aperture antenna and the independent microwave frequency band antenna described in the embodiment;

[0028] Figure 7 This is a comparison chart of the S11 simulation results of the co-aperture antenna and the independent millimeter wave frequency band antenna described in the embodiment;

[0029] Figure 8 This is a diagram showing the S21 simulation results of the millimeter wave port versus the microwave port of the co-aperture antenna described in the embodiment;

[0030] Figure 9 This is a diagram showing the S21 simulation results of the microwave port to the millimeter wave port of the co-aperture antenna described in the embodiment. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to the accompanying drawings and examples.

[0032] Microwave antennas typically require wide beams and large bandwidths to achieve wide-area coverage and high-speed data transmission, while millimeter-wave antennas prioritize narrow beams and high gain to meet the requirements of high directivity and long-distance communication. Therefore, a high-isolation, wide-bandwidth, cross-band antenna was required that could operate simultaneously in both microwave and millimeter-wave bands.

[0033] In the design of microwave band antennas, mode selection is one of the key factors that determine antenna performance. It is necessary to select a suitable mode to enable the microwave band antenna to achieve a wider beamwidth and better radiation efficiency, as well as to support higher gain and narrower beamwidth.

[0034] In the antenna design of the millimeter wave frequency band, since a single unit antenna often cannot meet the requirements of high gain and long-distance transmission, it is necessary to use array antennas. By arranging and exciting multiple antenna units in a specific way, the antenna gain can be significantly improved, and a narrower beam width and higher directivity can be achieved.

[0035] This embodiment provides a high-integration co-aperture antenna based on structural reuse, and its three-dimensional structural diagram is shown in FIG. Figure 1 As shown, it includes an upper metal layer, an upper dielectric substrate, an intermediate air layer, a lower dielectric substrate and a lower metal layer that are tightly attached to each other from top to bottom.

[0036] The upper metal layer includes a microwave band radiation patch and a millimeter wave band array patch 3; the microwave band radiation patch is rectangular and located at the center of the upper surface of the upper dielectric substrate; a square hole is etched at the center of the microwave band radiation patch, and the millimeter wave band array patch is arranged in a 2×2 manner and is located in the square hole; the microwave band radiation patch is etched with two symmetrical metal grooves 1, which are parallel to the short sides of the microwave band radiation patch and distributed on the left and right sides; the microwave band radiation patch is also etched with four metal perturbation holes 2, which are located between the metal groove and the millimeter wave band array patch on the side close to the metal groove.

[0037] Several nylon columns are loaded between the upper dielectric substrate and the lower dielectric substrate to form an intermediate air layer with a height of H=4.2 mm.

[0038] A millimeter-wave feeding network is distributed on the upper surface of the lower dielectric substrate, including a one-to-four feeding network structure, a feeding dielectric substrate, and a metal floor stacked sequentially from the bottom right to the top; the one-to-four feeding network structure includes sequentially cascaded millimeter-wave feeding microstrip branches and an H-type power dividing structure; the metal floor has holes at the corresponding positions at the ends of the H-type power dividing structure, and millimeter-wave feeding metal probes are respectively configured in the holes; the millimeter-wave feeding metal probes pass through the holes of the feeding dielectric substrate and the metal floor and are connected to the metal floor at the end of the H-type power dividing structure and the millimeter-wave frequency band array patch respectively.

[0039] The lower metal layer is a microwave differential feeding network, which includes three microstrip branches. The first microstrip branch extends upward from the edge of the lower dielectric substrate, and the second and third microstrip branches start from the end of the first microstrip branch, and are L-shaped and open rectangular respectively. The length difference between the second and third microstrip branches is half a wavelength, and the phase difference is 180°; two microwave feeding metal columns pass through the lower dielectric substrate and the upper dielectric substrate respectively, and the lower ends are connected to the ends of the second and third microstrip branches respectively, and the upper ends are connected to the microwave frequency band radiation patch.

[0040] The structural diagram of the upper metal layer is as follows Figure 2 As shown in the figure, there are symmetrical metal slots on the left and right sides of the millimeter wave band array patch on the microwave band radiation patch. The metal slots can affect the TM of the millimeter wave band patch antenna. 30 The surface current distribution of the mode is used to change the working frequency of the working mode and expand the bandwidth of the common aperture antenna; two pairs of metal perturbation holes with a radius of R = 1mm are loaded on the left and right sides of the millimeter wave band array patch on the microwave band radiation patch, which can be used to affect the microwave band radiation patch antenna TM 10 The electric field of the TM mode changes the operating frequency of this working mode. 10As the basic mode of microstrip patch antenna, TM mode has a simple field distribution structure and a low resonant frequency. In addition, the impedance matching of this mode is relatively easy to achieve, which can achieve a wider beam width and better radiation efficiency, and also reduces the design complexity. It is very suitable for wide area coverage and broadband communication scenarios, making it the preferred mode for microwave band antenna design. In contrast, TM 30 Although the resonant frequency of the mode is higher, its field distribution characteristics enable it to support higher main modes.

[0041] The overall antenna structure achieves a compact design by tightly embedding the millimeter-wave antenna within the center region of the microwave antenna, eliminating the need for additional radiating surfaces. This design not only fully utilizes space but also minimizes interference between the two frequency bands through structural optimization. Furthermore, the millimeter-wave array patch structure, serving as the capacitor for the microwave antenna, effectively improves the impedance matching characteristics of the microwave antenna.

[0042] The structural diagram of the millimeter wave feeding network is as follows: Figure 4 As shown, the millimeter wave frequency band array patches are arranged in 2×2, requiring four feeding ports. The antenna described in this embodiment introduces a one-to-four power splitting network as the millimeter wave feeding network to achieve equal amplitude and in-phase distribution of four signals. The structural diagram of the one-to-four power splitting network is shown in Figure 5 By introducing the millimeter wave feeding network described in this embodiment, the millimeter wave antenna array only needs to retain one millimeter wave feeding port instead of four feeding ports.

[0043] The structural diagram of the microwave differential feeding network is as follows: Figure 3 As shown in the figure, differential feeding technology can significantly improve the anti-interference capability of communication systems and reduce noise figures. The two output ports of the microwave power splitter use microstrip lines of different lengths to achieve differential feeding. The two feeding positions of the microwave radiation patch are symmetrical, and the signals in the two coaxial lines have a 180° phase difference and equal amplitude. The microwave antenna uses differential signal feeding, requiring only one microwave feed port, rather than two.

[0044] The antenna incorporates an air layer between the patch and the metal floor, and the patch's height is increased, increasing the distribution range of the antenna's equivalent dielectric constant and thus extending its bandwidth. The introduction of this air layer and the increased patch height introduce additional inductance into the antenna, potentially adversely affecting its impedance matching. However, the millimeter-wave antenna structure introduces capacitance into the microwave-band antenna, effectively improving its impedance matching.

[0045] The millimeter wave feeding network and microwave differential feeding network described in this embodiment can maintain the original antenna radiation performance while significantly improving the system integration and practicality.

[0046] The antenna described in this embodiment is simulated and verified. Figure 6 This is a comparison chart of the S11 simulation results of the co-aperture antenna (red solid line) and the independent microwave frequency band antenna (black dotted line) described in this embodiment. Figure 7 This is a comparison chart of the S11 simulation results of the common aperture antenna (red solid line) and the independent millimeter wave frequency band antenna (black dotted line) described in this embodiment. Figure 6 and Figure 7 It can be seen that when the millimeter-wave antenna structure is added to the microwave antenna structure, the introduction of a new part of the structure has a certain change in the impedance, and compared with the original differential patch antenna, the bandwidth of the antenna is significantly improved; and the loading of the microwave structure near the millimeter-wave structure does not have much impact on the main working mode of the millimeter-wave antenna, and can also achieve good radiation performance.

[0047] Figure 8 This is a diagram showing the S21 simulation results of the millimeter wave port to the microwave port of the co-aperture antenna described in this embodiment. Figure 9 This is the S21 simulation result diagram of the microwave port to the millimeter wave port of the co-aperture antenna described in this embodiment. Figure 8 and Figure 9 It can be seen that the reflection coefficient between the microwave port and the millimeter-wave port remains at a low level, indicating that the mutual interference between the two operating frequency bands is effectively suppressed. This good isolation characteristic ensures that when the antenna is working simultaneously, the microwave and millimeter-wave signals can be transmitted independently without interfering with each other.

[0048] The antenna described in this embodiment has a -10dB bandwidth of 2.05-2.4GHz in the microwave band and a maximum gain of 8.44dBi. The antenna has a -10dB bandwidth of 28.7-31GHz in the millimeter wave band and a maximum gain of 11.4dBi, with a dual-band center frequency ratio of 14. These two frequency bands are widely used in wireless communications, radar systems, satellite communications, and other fields. Integrating microwave and millimeter wave antennas into the same structure not only reduces the size and complexity of the antenna, but also meets the requirements of multi-band communication systems. It has certain practical application value for 5G communications, and has the characteristics of wide beam, wide bandwidth, and high isolation. At the same time, it has a simple structure, low cost, and easy processing.

[0049] In summary, simulation results demonstrate that the millimeter-wave antenna is tightly integrated within the microwave antenna, achieving a compact design without the need for additional radiating surfaces. This design not only fully utilizes space but also, through structural optimization, avoids mutual interference between the two frequency bands. Furthermore, the millimeter-wave antenna structure can serve as the capacitor for the microwave antenna, effectively improving the impedance matching characteristics of the microwave antenna.

[0050] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make several improvements and modifications without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A highly integrated common-aperture antenna based on structural reuse, characterized in that: It includes an upper metal layer, an upper dielectric substrate, an intermediate air layer, a lower dielectric substrate and a lower metal layer that are tightly attached to each other from top to bottom; The upper metal layer includes a microwave band radiation patch and a millimeter wave band array patch; the microwave band radiation patch is rectangular and located at the center of the upper surface of the upper dielectric substrate; a square hole is etched at the center of the microwave band radiation patch, and the millimeter wave band array patch is arranged in a 2×2 pattern and located within the square hole; Several nylon columns are loaded between the upper dielectric substrate and the lower dielectric substrate to form an intermediate air layer; The millimeter-wave feeding network is distributed on the upper surface of the lower dielectric substrate, including a one-to-four feeding network structure, a feeding dielectric substrate, and a metal floor stacked from bottom right to top. The one-to-four feeding network structure includes a cascade of millimeter-wave feeding microstrip branches and an H-shaped power splitter structure. The metal floor has holes at the corresponding positions of the ends of the H-shaped power splitter structure, and millimeter-wave feeding metal probes are respectively configured in the holes. The millimeter-wave feeding metal probe passes through the holes of the feeding dielectric substrate and the metal floor and is connected to the metal floor at the end of the H-type power dividing structure and the millimeter-wave frequency band array patch respectively; The lower metal layer is a microwave differential feeding network, which feeds the microwave frequency band radiation patch.

2. The highly integrated common-aperture antenna based on structural reuse according to claim 1, characterized in that: The microwave band radiation patch is etched with two symmetrical metal grooves, which are parallel to the short sides of the microwave band radiation patch and are distributed on the left and right sides.

3. The highly integrated common-aperture antenna based on structural reuse according to claim 2, characterized in that: The microwave band radiation patch is also etched with four metal perturbation holes, which are located between the metal slot and the millimeter wave band array patch on the side close to the metal slot.

4. The highly integrated common-aperture antenna based on structural reuse according to claim 1, characterized in that: The microwave differential feeding network includes three microstrip branches. The first microstrip branch extends upward from the edge of the lower dielectric substrate. The second and third microstrip branches start from the end of the first microstrip branch and are L-shaped and open rectangular, respectively. The length difference between the second and third microstrip branches is half a wavelength, and the phase difference is 180°. Two microwave feeding metal pillars pass through the lower dielectric substrate and the upper dielectric substrate respectively. The lower ends are connected to the ends of the second and third microstrip branches, respectively, and the upper ends are connected to the microwave frequency band radiation patch.

5. The highly integrated common-aperture antenna based on structural reuse according to claim 1, characterized in that: The air layer height H = 4.2 mm.

6. The highly integrated common-aperture antenna based on structural reuse according to claim 1, characterized in that: The radius of the metal perturbation hole is 1 mm.

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