Low-profile VHF / UHF / L multi-frequency dual-port broadband composite antenna

Abstract

The invention provides a low-profile VHF / UHF / L multi-frequency dual-port broadband composite antenna. The low-profile VHF / UHF / L multi-frequency dual-port broadband composite antenna comprises a VHF / UHF frequency band radiator, a VHF / UHF frequency band grounding pole, a loading resistor, an L frequency band radiator, an L frequency band metal ground and an L frequency band feeder line, the VHF / UHF frequency band radiator is connected with the loading resistor through the VHF / UHF frequency band grounding pole and then is grounded; the L-band radiator and the VHF / UHF-band radiator are connected into a whole, and the L-band radiator uses an L-band feeder line for feeding. According to the invention, the technical problems of high profile and narrow working band of an airborne antenna are solved, the design of three-frequency-band coverage, high isolation, wide bandwidth and low profile is realized, and stable omnidirectional gain and good out-of-roundness can be provided; the antenna is simple in structure and easy to process and assemble; the mounting space is saved; the mounting and maintenance are convenient; the wind resistance is reduced; the concealment is enhanced;

Description

Technical Field

[0001] This invention belongs to the field of antenna technology, specifically relating to a low-profile VHF / UHF / L multi-frequency dual-port broadband composite antenna. Background Technology

[0002] As a crucial component of airborne radio frequency systems, antennas are increasingly demonstrating their vital role. Besides ensuring their own radiation performance, the aerodynamic performance of the aircraft is also critical for airborne antennas. High gain, wide bandwidth, and miniaturization are the future development trends for airborne antennas.

[0003] Traditional airborne antennas typically have a high profile to ensure gain, which not only affects the aerodynamic performance of the aircraft but also degrades its radar cross-section (RCS). In contrast, low-profile antennas can significantly reduce the impact on the aerodynamic and stealth performance of the aircraft, greatly improving its battlefield survivability.

[0004] Airborne radio frequency systems typically encompass multiple functions, including communication, positioning, reconnaissance, and jamming. However, traditional airborne antennas, due to size limitations, generally have narrow operating bandwidths and are mostly single-band antennas. To address the technical challenges of high profile and narrow operating bandwidth in airborne antennas, the following improved technical solutions are proposed. Summary of the Invention

[0005] The technical problem solved by this invention is to provide a low-profile VHF / UHF / L multi-frequency dual-port broadband composite antenna, which solves the technical problem of high profile and narrow operating bandwidth of airborne antennas.

[0006] The technical solution adopted in this invention is as follows: a low-profile VHF / UHF / L multi-frequency dual-port broadband composite antenna, comprising a VHF / UHF band radiator, a VHF / UHF band grounding post, a loading resistor, an L-band radiator, an L-band metallic ground, and an L-band feed line; the VHF / UHF band radiator is grounded after being connected to the loading resistor via the VHF / UHF band grounding post; the L-band radiator is integrated with the VHF / UHF band radiator, and the L-band radiator is fed by the L-band feed line.

[0007] In the above technical solution: the VHF / UHF band radiator is an inverted cone structure, and the longitudinal section of the inverted cone structure is a gradually changing broken line shape.

[0008] In the above technical solution: the top of the VHF / UHF band radiator is connected to the upper end of the VHF / UHF band grounding post, the lower end of the VHF / UHF band grounding post is connected to the top of the loading resistor, and the bottom end of the loading resistor is grounded.

[0009] In the above technical solution: the L-band radiator has an inverted cone-shaped structure.

[0010] In the above technical solution: the L-band radiator is located at the top of the L-band metal ground, and the L-band metal ground has a circular structure and is integrated with the VHF / UHF band radiator.

[0011] In the above technical solution: the L-band feeder is a 50-ohm coaxial cable.

[0012] In the above technical solution: the outer conductor of the L-band feeder is connected to the L-band metal ground, and the inner conductor of the L-band feeder is connected to the lower end of the L-band radiator.

[0013] In the above technical solution, the cross-sectional height of the composite antenna does not exceed 200mm.

[0014] In the above technical solution, the VHF / UHF band antenna operates in the range of 30–680 MHz, and the L-band antenna operates in the range of 1300–1950 MHz.

[0015] Advantages of this invention compared to existing technologies:

[0016] 1. This invention achieves three-band coverage, high isolation, wide bandwidth and low profile design within a limited space, and can also provide stable omnidirectional gain and good non-circularity; the antenna structure is simple and easy to process and assemble.

[0017] 2. The present invention provides a VHF / UHF band radiator with a gradually changing polygonal shape, achieving a relative bandwidth of 1800%; the current flows in segments along the polygonal shape, with the bottom polygonal shape still participating in radiation, thus improving low-frequency efficiency; the bandwidth is extended through segmented resonance superposition; and the applied resistor works in conjunction with the gradually changing polygonal shape to achieve high-efficiency radiation under ultra-low profile.

[0018] 3. The setting of the loading resistor in this invention significantly improves the electrical performance of the antenna in the low-frequency band, especially the VHF band, through impedance matching optimization and energy loss control, while also taking into account the radiation efficiency in the high-frequency UHF band.

[0019] 4. The L-band metal ground of this invention has a circular structure and is integrated with the VHF / UHF band radiator. The L-band metal ground and the L-band radiator work together to realize the L-band function, and at the same time, it can also serve as a decoupling structure between the VHF / UHF band and the L-band. No additional decoupling structure is needed, which reduces the system complexity. The isolation between the VHF / UHF band and the L-band is >21dB.

[0020] 5. The L-band feeder of this invention is a 50-ohm coaxial cable, which can achieve good impedance matching with most common RF devices. It eliminates the need to design a complex matching network to match different impedances, simplifies system circuit design, reduces design costs and complexity, and also helps to improve system reliability and stability, and enhances system flexibility and versatility.

[0021] 6. The cross-sectional height of the composite antenna of the present invention does not exceed 200mm, which saves installation space, facilitates installation and maintenance, reduces wind resistance, enhances concealment, improves aesthetics, reduces environmental impact, and adapts to different installation angles.

[0022] 7. The VHF / UHF band antenna of this invention operates in the range of 30 to 680 MHz, and the L-band antenna operates in the range of 1300 to 1950 MHz. The wide frequency band coverage meets diverse needs, realizes seamless switching between multiple frequency bands, reduces the number of antennas and equipment complexity, facilitates system upgrades and expansion, and the complementary nature of different frequency bands enhances anti-interference capabilities. Frequency dispersion reduces the risk of co-channel interference, optimizes antenna radiation characteristics, and adapts to different application scenarios. Attached Figure Description

[0023] Figure 1 This is a perspective view of the overall structure of the present invention;

[0024] Figure 2 This is a front view of the overall structure of the present invention;

[0025] Figure 3 This is a voltage standing wave ratio (VSWR) curve of the VHF / UHF band antenna of this invention;

[0026] Figure 4 This is a voltage standing wave ratio (VSWR) curve of the L-band antenna of the present invention;

[0027] Figure 5 This is a gain curve diagram of the VHF / UHF band antenna of the present invention;

[0028] Figure 6 This is a gain curve diagram of the L-band antenna of the present invention;

[0029] Figure 7 This is a diagram showing the isolation curves for the VHF / UHF bands of this invention.

[0030] Figure 8 This is a graph showing the isolation of the L-band of this invention.

[0031] In the diagram: 1 - VHF / UHF band radiator, 2 - VHF / UHF band grounding post, 3 - Loading resistor, 4 - L band radiator, 5 - L band metallic ground, 6 - L band feeder. Detailed Implementation

[0032] The following will refer to the appendices in the embodiments of the present invention. Figure 1-8The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] (like Figure 1 , Figure 2 (As shown) A low-profile VHF / UHF / L multi-frequency dual-port broadband composite antenna includes a VHF / UHF band radiator 1, a VHF / UHF band grounding post 2, a loading resistor 3, an L-band radiator 4, an L-band metallic ground 5, and an L-band feed line 6; the VHF / UHF band radiator 1 is grounded after being connected to the loading resistor 3 through the VHF / UHF band grounding post 2; the L-band radiator 4 is integrated with the VHF / UHF band radiator 1, and the L-band radiator 4 is fed by the L-band feed line 6.

[0034] It should be noted that this invention employs a multi-band collaborative design to achieve broadband coverage. A resistor 3 is connected in series at the lower end of the VHF / UHF band grounding post 2. This resistor absorbs reflected waves from the low-frequency band through resistance loss, improving impedance matching and achieving VHF band (30-88MHz) coverage within a 200mm height, breaking through the limitations of traditional antenna size. It achieves core advantages such as three-band coverage, high isolation, wide bandwidth, and low profile within a limited space, making it particularly suitable for scenarios with stringent requirements for antenna performance and integration, such as emergency rescue and the Internet of Things.

[0035] In the above embodiments, as a further improvement of the present invention: the VHF / UHF band radiator 1 is an inverted cone structure, and the longitudinal section of its inverted cone structure is a gradually changing broken line shape, which is used to broaden the bandwidth of the antenna VHF / UHF band.

[0036] It should be noted that by simulating a continuous gradient curve using multiple segmented polygonal lines, multiple resonant points are introduced within the 30–680MHz frequency band, and superimposed to achieve broadband coverage. The gradient polygonal structure can extend the bandwidth to 22:1 (30–680MHz), with a relative bandwidth of 1800%.

[0037] In the above embodiment: the top of the VHF / UHF band radiator 1 is connected to the upper end of the VHF / UHF band grounding post 2, the lower end of the VHF / UHF band grounding post 2 is connected to the top of the loading resistor 3, and the bottom end of the loading resistor 3 is grounded, thereby improving the low-frequency electrical performance of the antenna.

[0038] It should be noted that by optimizing impedance matching and controlling energy loss, the electrical performance of the antenna in the low-frequency band, especially the VHF band, has been significantly improved, while also taking into account the radiation efficiency in the high-frequency UHF band.

[0039] In the above embodiment: the L-band radiator 4 is a circular structure, located at the top of the L-band metal ground 5 and integrated with the VHF / UHF band radiator 1.

[0040] It should be noted that the structure of the VHF / UHF band radiator 1 remains largely unchanged, while also reducing the mutual coupling between the VHF / UHF band and the L band. This results in high antenna isolation and good electrical performance in both the VHF / UHF and L bands. The L band metal ground 5 works in conjunction with the L band radiator 4 to achieve L band functionality, while also serving as a decoupling structure between the VHF / UHF and L bands. This eliminates the need for additional decoupling structures, improving space utilization and reducing system complexity.

[0041] In the above embodiment: the L-band feeder 6 is a 50-ohm coaxial line. The outer conductor of the 50-ohm coaxial line is connected to the L-band metal ground 5, and the inner conductor of the 50-ohm coaxial line is connected to the lower end of the L-band radiator 4. The feeding method is simple.

[0042] It should be noted that 50-ohm coaxial cable is a widely used standard impedance value in the radio frequency (RF) field, enabling good impedance matching with most common RF devices. Because 50 ohms is a standard impedance, when designing and building L-band communication systems, there is no need to design complex matching networks to match different impedances. This simplifies system circuit design, reduces design costs and complexity, and also helps improve system reliability and stability, enhancing system flexibility and versatility.

[0043] In the above embodiments, the cross-sectional height of the composite antenna does not exceed 200mm. This saves installation space, facilitates installation and maintenance, reduces wind resistance, enhances concealment, improves aesthetics, reduces environmental impact, and adapts to different installation angles.

[0044] In the above embodiments, the VHF / UHF band antenna operates in the range of 30–680 MHz, and the L-band antenna operates in the range of 1300–1950 MHz. Wideband coverage meets diverse needs, enables seamless switching between multiple frequency bands, reduces the number of antennas and equipment complexity, facilitates system upgrades and expansion, allows different frequency bands to complement each other to enhance anti-interference capabilities, reduces the risk of co-channel interference through frequency dispersion, optimizes antenna radiation characteristics, and adapts to different application scenarios.

[0045] This invention not only provides operating bandwidths of 30–680 MHz and 1300–1950 MHz, but also offers stable omnidirectional gain and good non-circularity. It features high isolation between the VHF / UHF band antenna and the L-band antenna, a simple antenna structure, and ease of fabrication and assembly, enabling high-gain, wide-bandwidth, and miniaturized antenna designs.

[0046] The present invention features a low profile height, wide operating bandwidth, multi-band composite, and essentially unchanged electrical performance. Structurally, it is an integral unit, which facilitates transportation, installation, and use. At the same time, it can effectively reduce the number of antennas to be installed and reduce mutual coupling between antennas.

[0047] This invention achieves VHF / UHF / L band coverage, 21dB high isolation, and 1800% relative bandwidth within a 200mm profile height, resolving the contradiction between low profile and wide bandwidth, and providing a high-performance, highly integrated antenna solution for fields such as emergency rescue and the Internet of Things.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications and equivalent substitutions made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A low-profile VHF / UHF / L multi-frequency dual-port broadband composite antenna, characterized in that: It includes a VHF / UHF band radiator (1), a VHF / UHF band grounding post (2), a loading resistor (3), an L-band radiator (4), an L-band metal ground (5), and an L-band feeder (6); the VHF / UHF band radiator (1) is grounded after being connected to the loading resistor (3) through the VHF / UHF band grounding post (2); the L-band radiator (4) is integrated with the VHF / UHF band radiator (1), and the L-band radiator (4) is fed by the L-band feeder (6).

2. The composite antenna according to claim 1, characterized in that: The VHF / UHF band radiator (1) has an inverted cone structure, and the longitudinal section of the inverted cone structure is a gradually changing broken line shape.

3. The composite antenna according to claim 1 or 2, characterized in that: The top of the VHF / UHF band radiator (1) is connected to the upper end of the VHF / UHF band grounding post (2), the lower end of the VHF / UHF band grounding post (2) is connected to the top of the loading resistor (3), and the bottom end of the loading resistor (3) is grounded.

4. The composite antenna according to claim 1, characterized in that: The L-band radiator (4) has an inverted cone-shaped structure.

5. The composite antenna according to claim 1 or 4, characterized in that: The L-band radiator (4) is located at the top of the L-band metal ground (5), which is a circular structure and is integrated with the VHF / UHF band radiator (1).

6. The composite antenna according to claim 1, characterized in that: The L-band feeder (6) is a 50-ohm coaxial cable.

7. The composite antenna according to claim 1 or 6, characterized in that: The outer conductor of the L-band feeder (6) is connected to the L-band metal ground (5), and the inner conductor of the L-band feeder (6) is connected to the lower end of the L-band radiator (4).

8. The composite antenna according to claim 1, characterized in that: The cross-sectional height of the composite antenna does not exceed 200mm.

9. The composite antenna according to claim 1, characterized in that: VHF / UHF band antennas operate in the range of 30–680 MHz, while L-band antennas operate in the range of 1300–1950 MHz.

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