A miniaturized, lightweight, omnidirectional L-band broadband antenna

Abstract

This invention discloses an L-band broadband miniaturized lightweight omnidirectional antenna, comprising an antenna radiating body (1), an antenna ground plane (2), and an SMA coaxial feed connector (3). The SMA coaxial feed connector (3) is arranged below the antenna ground plane (2), and the antenna radiating body (1) is arranged above the antenna ground plane (2). A through-hole is formed on the antenna ground plane (2), and the bottom of the antenna radiating body (1) is connected to the inner core of the SMA coaxial feed connector (3) through the through-hole. This invention solves the problems of narrow bandwidth and heavy weight of commonly used single dipole antennas, and the complex structure, difficult debugging, and inconvenient installation of cross-fed antennas and waveguide slot antennas. The antenna structure is reliable and has advantages such as small size, light weight, and wide bandwidth.

Description

Technical Field

[0001] This invention belongs to the field of microwave antenna technology and relates to an L-band broadband miniaturized lightweight omnidirectional antenna. It operates in the L-band, is small in size and light in weight, and has good omnidirectional radiation characteristics over a wide frequency band. Its main applications are civilian and military communication systems. Background Technology

[0002] Microwave omnidirectional antennas are widely used in multiple access communications, and are applied in fields such as telemetry, remote control, military, and aerospace. With the rapid development of science and technology and the advent of the information age, the rapid development of wireless communication and the continuous upgrading of electronic devices have placed higher demands on omnidirectional antennas, requiring them to have smaller size, ease of installation, wide bandwidth, high radiation efficiency, and stable gain. In the L-band, microwave omnidirectional antennas mainly include single dipole antennas, cross-fed antennas, and waveguide slot antennas. Single dipole antennas have a simple structure but a narrow bandwidth, and their main structural components are copper or aluminum tubes, making them heavy. Cross-fed antennas and waveguide slot antennas have complex structures, resulting in high manufacturing costs, difficult debugging, and challenging feeding structures, which also contribute to their narrow bandwidth. Regardless of whether it is a single dipole antenna, a cross-fed antenna, or a waveguide slot antenna, the antenna height exceeds half a wavelength or a quarter wavelength. The excessive antenna height results in a large volume space occupied and a large antenna RCS (radar cross section), which also has a significant impact on the electromagnetic stealth characteristics of various carrier platforms.

[0003] Considering the above, it is necessary to develop an L-band broadband miniaturized lightweight omnidirectional antenna for practical communication platforms, providing more ideal structure, size and other performance, as well as more ideal electromagnetic characteristics such as broadband and omnidirectional radiation than existing antenna designs. Summary of the Invention

[0004] (I) Purpose of the Invention

[0005] The purpose of this invention is to overcome the shortcomings and defects of the prior art and provide an L-band broadband miniaturized lightweight omnidirectional antenna that solves the problems of narrow bandwidth and heavy weight of commonly used single dipole antennas, and complex structure, difficult debugging, and inconvenient installation of cross-fed antennas and waveguide slot antennas. The antenna structure is reliable and has the advantages of small size, light weight, and wide bandwidth.

[0006] (II) Technical Solution

[0007] To solve the above-mentioned technical problems, the present invention provides an L-band broadband miniaturized lightweight omnidirectional antenna, which includes an antenna radiating body 1, an antenna ground plane 2, and an SMA coaxial feed connector 3; the SMA coaxial feed connector 3 is arranged below the antenna ground plane 2, the antenna radiating body 1 is arranged above the antenna ground plane 2, the antenna ground plane 2 has an opening, and the bottom of the antenna radiating body 1 is connected to the inner core of the SMA coaxial feed connector 3 through the opening.

[0008] The antenna radiating body 1 includes a support rod 1.a and a multi-layer progressive step structure 1.b. The support rod 1.a is arranged vertically to the antenna floor 2, and the multi-layer progressive step structure 1.b is arranged radially on it. The support rod 1.a is a spiral structure formed by winding metal wires, and the multi-layer progressive step structure 1.b includes a spiral structure formed by winding multiple metal wires with increasing length from top to bottom.

[0009] The support rod 1.a and the multi-layer progressive step structure 1.b are both made of brass wire with a diameter of 0.5mm, and the spiral structure of the support rod 1.a and the multi-layer progressive step structure 1.b are both spiral structures with a diameter of 4mm and a pitch of 3.5mm.

[0010] In the multi-layer progressive stepped structure 1.b, the projections of multiple spiral structures on the antenna floor 2 coincide.

[0011] The SMA coaxial feed connector 3 includes a coaxial outer conductor 3.a, a coaxial medium 3.b, a coaxial inner core 3.c, and a coaxial flange 3.d. The coaxial outer conductor 3.a is cylindrical and filled with the coaxial medium 3.b. The coaxial inner core 3.c is arranged at the center of the coaxial medium 3.b. The coaxial flange 3.d is provided on the upper part of the coaxial outer conductor 3.a. The SMA coaxial feed connector 3 is mounted on the antenna floor 2 through the coaxial flange 3.d.

[0012] The coaxial inner core 3.c is a double-layer clip with a gap of 0.7mm. When installing the antenna, the copper wire at the lower support rod 1.a of the antenna radiating body 1 is inserted into the gap of the coaxial inner core 3.c clip and welded at the bottom feed point.

[0013] The lower support rod 1.a is fixed to the double-layer clip with silicone at the connection point.

[0014] The antenna floor 2 can be square or circular.

[0015] The antenna floor 2 is made of thin aluminum plate with a thickness of 0.5 mm.

[0016] The diameter of the through hole in the center of the antenna ground 2 is consistent with the outer diameter of the coaxial medium 3.b, so that the inner core 3.c of the SMA coaxial feed connector 3 can be inserted without short-circuiting with the antenna ground 2.

[0017] (III) Beneficial Effects

[0018] The L-band broadband miniaturized lightweight omnidirectional antenna provided by the above technical solution has the following beneficial effects:

[0019] 1) The antenna radiator of this invention adopts a fine copper wire structure, which makes the antenna very lightweight and meets the needs of civilian and military portable communication devices;

[0020] 2) The antenna radiator of this invention adopts a multi-layer progressive stepped structure, so that the surface current can be distributed in each layer for radiation, resulting in a wider antenna bandwidth;

[0021] 3) The antenna of this invention adopts a clip-on coaxial connector with an inner core, and is fixed with silicone after welding the antenna radiator, resulting in a stable structure;

[0022] 4) The antenna radiation field of this invention is uniformly distributed across the entire frequency band and 360 degrees of the horizontal plane, thus achieving excellent omnidirectional characteristics;

[0023] 5) The antenna ground plane of this invention can be round or square, and its size and shape can be adjusted appropriately according to actual application requirements, making the overall antenna structure and application scenarios flexible. Attached Figure Description

[0024] Figure 1 This is a front view of the antenna of the present invention.

[0025] Figure 2 This is a top view of the antenna of the present invention.

[0026] Figure 3 This is the antenna standing wave ratio diagram of this invention.

[0027] Figure 4 This is the horizontal radiation pattern of the antenna of the present invention.

[0028] In the diagram: 1. Antenna radiating body 1.a. Support rod 1.b. Multi-layer progressive stepped structure 2. Circular floor 3. SMA coaxial feed connector 3.a. Coaxial outer conductor 3.b. Coaxial dielectric 3.c. Coaxial inner core 3.d. Coaxial flange. Detailed Implementation

[0029] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0030] The design concept of this invention is as follows: It provides an L-band broadband miniaturized lightweight omnidirectional antenna. The antenna radiator employs a thin copper wire structure, resulting in a very light antenna weight, meeting the needs of portable communication devices for both civilian and military use. The antenna radiator utilizes a multi-layered progressive stepped structure, allowing surface current to be distributed across each layer for radiation, thus achieving a wide antenna bandwidth. By adjusting the dimensions of the antenna radiator support rod, the multi-layered progressive stepped structure, and the feed spacing, the antenna can operate in the L-band and achieve the desired horizontal omnidirectional radiation pattern and other characteristics over a wide frequency range.

[0031] See Figure 1 , Figure 2 As shown, the L-band broadband miniaturized lightweight omnidirectional antenna of this embodiment includes an antenna radiating body 1, an antenna ground plane 2, and an SMA coaxial feed connector 3; the SMA coaxial feed connector 3 is arranged below the antenna ground plane 2, the antenna radiating body 1 is arranged above the antenna ground plane 2, the antenna ground plane 2 has an opening, and the bottom of the antenna radiating body 1 is connected to the inner core 3.c of the SMA coaxial feed connector 3 through the opening.

[0032] The antenna radiating body 1 includes a support rod 1.a and a multi-layer progressive step structure 1.b. The support rod 1.a is arranged vertically to the antenna floor 2, and the multi-layer progressive step structure 1.b is arranged radially on it. The support rod 1.a is a spiral structure with a diameter of 4mm and a pitch of 3.5mm formed by winding metal wires. The multi-layer progressive step structure 1.b includes a spiral structure with a diameter of 4mm and a pitch of 3.5mm formed by winding multiple metal wires with progressively increasing length from top to bottom.

[0033] Both the support rod 1.a and the multi-layer progressive stepped structure 1.b use brass wire with a diameter of 0.5 mm. In the multi-layer progressive stepped structure 1.b, the projections of multiple spiral structures on the antenna floor 2 coincide.

[0034] The SMA coaxial feed connector 3 includes a coaxial outer conductor 3.a, a coaxial medium 3.b, a coaxial inner core 3.c, and a coaxial flange 3.d. The coaxial outer conductor 3.a is cylindrical and filled with the coaxial medium 3.b. The coaxial inner core 3.c is arranged at the center of the coaxial medium 3.b. The coaxial flange 3.d is provided on the upper part of the coaxial outer conductor 3.a. The SMA coaxial feed connector 3 is mounted on the antenna floor 2 through the coaxial flange 3.d.

[0035] The coaxial inner core 3.c has a double-layer clip with a gap of 0.7mm. When installing the antenna, the copper wire at the lower support rod 1.a of the antenna radiating body 1 is inserted into the gap of the coaxial inner core 3.c clip and welded at the bottom feed point. Then it is fixed with silicone to enhance its mechanical strength.

[0036] The antenna ground plane 2 can be square or circular depending on actual needs. In this embodiment, a circular ground plane is selected. To reduce the weight of the antenna, a thin aluminum plate with a thickness of 0.5mm is selected. The diameter of the through hole in the center of the circular antenna ground plane 2 is consistent with the outer diameter of the coaxial medium 3.b, so that the inner core 3.c of the SMA coaxial feed connector 3 can be inserted without short-circuiting with the antenna ground plane 2.

[0037] The coaxial outer conductor 3.a and coaxial flange 3.d of the SMA coaxial feed connector 3 are connected and in contact with the antenna ground plane 2. The energy output from the coaxial connector is fed into the feed end, thereby exciting the current on the surface of the antenna radiator, thus generating radiation.

[0038] In this invention, the antenna metal radiating body 1 is the most important component for radiation, used to radiate electromagnetic waves into space. When transmitting a signal, the SMA coaxial feed connector 3 inputs the transmission signal from the external transmitter through the connected coaxial cable. The energy output from the coaxial connector excites the surface current on the antenna metal radiating body 1, thereby generating radiation. Since the antenna radiating body 1 and the circular ground plate 2 are constructed only of fine copper wire and aluminum, they are easy to manufacture and have low cost. Because the antenna radiating body 1 uses a fine copper wire structure, the antenna is very lightweight, meeting the needs of civilian and military portable communication devices. The multi-layer progressive stepped structure 1.b adopts a multi-layer progressive stepped structure, allowing the surface current to be distributed and radiated at each level, resulting in a wider antenna bandwidth. Because the antenna uses a clip-on SMA coaxial connector 3 with a core, and the antenna radiator 1 is fixed with silicone after welding, the antenna radiator is lightweight and structurally stable. Due to the adoption of the basic form of a pole antenna, the antenna radiation field is uniformly distributed across the entire frequency band in a 360-degree horizontal plane, achieving excellent omnidirectional characteristics. Furthermore, the antenna ground plane 2 can be round or square in shape, and its size can be adjusted appropriately according to actual application requirements, making the overall antenna structure and application flexible.

[0039] The antenna of this invention has a height of 52mm (height of the radiator support rod), which is only 20.8% of the wavelength corresponding to the center operating frequency of 1.2GHz. In contrast, the height of a conventional dipole antenna is 50% of the wavelength corresponding to the center operating frequency, and the height of a conventional monopole antenna is 25% of the wavelength corresponding to the center operating frequency. Obviously, the antenna of this invention effectively reduces the antenna size.

[0040] When an antenna is used as a transmitting antenna, it is connected to the transmitter via a feed line system. As a load on the transmitter, the antenna radiates the power received from the transmitter into space. This raises the issue of impedance matching between the antenna and the transmission line; the quality of impedance matching affects the efficiency of power transmission. The standing wave ratio (VSWR) of an antenna is an important performance parameter. It reflects the impedance characteristics of the antenna under test and determines its impedance bandwidth. Generally, engineering applications require an antenna VSWR of less than 2. See also... Figure 3As shown, the frequency range where the antenna VSWR of the present invention is less than 2 is approximately 1.1864 GHz to 1.525 GHz. This indicates that the antenna can be well matched with a 50Ω coaxial cable within approximately 25% of the fractional bandwidth of the L band.

[0041] An antenna radiation pattern is a graphical representation of the relationship between the antenna's radiation characteristics and spatial angles. A complete radiation pattern is a three-dimensional spatial graph, drawn by measuring the radiation characteristics point by point on a sphere with the antenna's phase center as the center. In practical work, it is generally sufficient to measure the radiation pattern in either the horizontal or vertical plane. Figure 4 This is the horizontal normalized radiation pattern of the antenna of the present invention, see [link / reference]. Figure 4 As shown, the antenna radiates within a 360-degree range on the horizontal plane, with a maximum gain of -0.5dB and a non-circularity of less than 0.5dB, exhibiting excellent omnidirectional characteristics.

[0042] As can be seen from the above technical solution, the L-band broadband miniaturized lightweight omnidirectional antenna of the present invention is used to transmit and receive vertically polarized electromagnetic waves. Its structure is simple; the entire antenna radiator and ground plane are composed only of fine copper wire and aluminum, making it easy to manufacture and cost-effective. The fine copper wire structure of the antenna radiator makes the antenna very lightweight, meeting the needs of civilian and military portable communication devices. The multi-layered progressive stepped structure of the antenna radiator allows surface current to be distributed across each layer for radiation, resulting in a wide antenna bandwidth. The antenna is easy to match and can be directly fed with a 50Ω coaxial cable. The antenna structure is stable, using a clip-on coaxial connector with a core, and is fixed with silicone after welding the antenna radiator. The antenna radiation field is uniformly distributed across the entire frequency band in a 360-degree horizontal range, achieving excellent omnidirectional characteristics.

[0043] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A L-band broadband miniaturized lightweight omni-directional antenna, characterized in that, The antenna includes an antenna radiation body (1), an antenna floor (2) and an SMA coaxial feeder connector (3); the SMA coaxial feeder connector (3) is arranged below the antenna floor (2), the antenna radiation body (1) is arranged above the antenna floor (2), the antenna floor (2) is provided with a through hole, and the bottom of the antenna radiation body (1) is connected to the inner core of the SMA coaxial feeder connector (3) through the through hole; The antenna radiation body (1) includes a support rod (1.a) and a multi-layer progressive step structure (1.b); the support rod (1.a) is arranged vertically to the antenna floor (2), and the multi-layer progressive step structure (1.b) is arranged radially on the support rod (1.a); the support rod (1.a) is a spiral structure formed by winding a metal wire, and the multi-layer progressive step structure (1.b) includes a plurality of spiral structures formed by winding metal wires with increasing lengths from top to bottom.

2. The L-band broadband compact and lightweight omnidirectional antenna according to claim 1, wherein, The support rod (1.a) and the multi-layer progressive step structure (1.b) both adopt brass wires with a diameter of 0.5 mm, and the spiral structures of the support rod (1.a) and the multi-layer progressive step structure (1.b) both have a diameter of 4 mm and a pitch of 3.5 mm.

3. The L-band broadband compact and lightweight omnidirectional antenna according to claim 2, wherein, In the multi-layer progressive step structure (1.b), the projections of the plurality of spiral structures on the antenna floor (2) are coincident.

4. The L-band broadband compact and lightweight omnidirectional antenna according to claim 3, wherein, The SMA coaxial feeder connector (3) includes a coaxial outer conductor (3.a), a coaxial medium (3.b), a coaxial inner core (3.c) and a coaxial flange (3.d); the coaxial outer conductor (3.a) is in a cylindrical shape, filled with the coaxial medium (3.b) inside, and provided with the coaxial flange (3.d) on the upper part; and the SMA coaxial feeder connector (3) is installed on the antenna floor (2) through the coaxial flange (3.d).

5. The L-band broadband compact and lightweight omnidirectional antenna according to claim 4, wherein, The coaxial inner core (3.c) is a double-layer clamp piece with a gap of 0.7 mm; during installation of the antenna, the copper wire at the lower support rod (1.a) of the antenna radiation body (1) is inserted into the gap of the double-layer clamp piece, and welded at the bottom end.

6. The L-band broadband compact and lightweight omnidirectional antenna according to claim 5, wherein, The lower support rod (1.a) is fixed to the double-layer clamp piece by silicone.

7. The L-band broadband compact and lightweight omnidirectional antenna according to claim 6, wherein, The antenna floor (2) is square or circular.

8. The L-band broadband compact and lightweight omnidirectional antenna according to claim 7, wherein, The antenna floor (2) is made of thin aluminum plate with a thickness of 0.5 mm.

9. The L-band broadband compact and lightweight omnidirectional antenna according to claim 8, wherein, The diameter of the through hole in the antenna floor (2) is consistent with the outer diameter of the coaxial medium (3.b), so that the coaxial inner core (3.c) of the SMA coaxial feeder connector (3) is inserted without short circuiting with the antenna floor (2).

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