CN118801091A - A high-gain, low-out-of-round omnidirectional antenna based on printed oscillators - Google Patents

Abstract

The invention belongs to the technical field of wireless communication, and discloses a high-gain low-out-of-roundness omnidirectional antenna based on a printed oscillator, which comprises an antenna housing, a medium base, a radiation medium plate and a coaxial cable component, wherein the antenna housing and the radiation medium plate are both arranged on the medium base, the radiation medium plate is arranged in the antenna housing, the shape and the size of the radiation medium plate are matched with those of the antenna housing, both the front side and the back side of the radiation medium plate are printed with metal radiation patches and feed lines, the coaxial cable component is arranged below the medium base, and the coaxial cable component is electrically connected with the metal radiation patches and the feed lines to realize feed. The invention is applicable to the airborne environment, has the advantages of high gain and low out-of-roundness, has the characteristics of wide frequency band, stable radiation pattern and the like, and can improve the communication stability of an airborne communication system.

Description

A high-gain, low-out-of-round omnidirectional antenna based on printed oscillators

Technical Field

The invention belongs to the technical field of wireless communication, and in particular relates to a high-gain and low-out-of-roundness omnidirectional antenna based on a printed vibrator.

Background Art

Airborne omnidirectional antennas are an important part of aircraft communication systems. The electrical performance of the antenna determines the communication distance and stability of the entire communication system, and the research on airborne antennas is of great significance.

Due to the requirements for aerodynamic performance, airborne antennas mostly use flat printed antennas, which are mostly made in the form of wings. However, the influence of the plane structure and the carrier on the antenna will cause the horizontal plane radiation pattern to be distorted and produce a large non-circularity, which makes it difficult to meet the actual needs of airborne antennas in complex flight postures.

In the prior art, the designed knife-shaped omnidirectional antenna mostly adopts a resistance loading method in order to broaden the working bandwidth of the antenna and reduce the antenna height. However, this method will also lose the gain, resulting in lower gain, and will produce a large out-of-roundness, reducing the communication stability of the system.

In summary, the problems existing in the prior art are: in order to meet the aerodynamic performance of airborne antennas, existing airborne omnidirectional antennas cannot simultaneously achieve wide bandwidth, high gain and small non-circularity of the radiation pattern. When the bandwidth is insufficient, the frequency performance at the edge of the band is poor, which limits its application in the field of wireless communications.

Summary of the invention

In view of the shortcomings of the prior art, the present invention provides a high-gain, low-non-circularity omnidirectional antenna based on a printed vibrator, which is used to solve the problems that the existing airborne omnidirectional antenna cannot simultaneously achieve wide bandwidth, high gain and small non-circularity of the radiation pattern, the frequency performance at the edge of the band is poor when the bandwidth is insufficient, and the communication stability of the system is poor, which limits its application in the field of wireless communications.

In order to achieve the invention objective of this application, the present invention provides the following technical solutions:

A high-gain, low-out-of-roundness omnidirectional antenna based on a printed vibrator comprises an antenna cover, a dielectric base, a radiation dielectric plate and a coaxial cable assembly. The antenna cover and the radiation dielectric plate are both mounted on the dielectric base, and the radiation dielectric plate is arranged in the antenna cover. The shape and size of the radiation dielectric plate match the antenna cover. Metal radiation patches and feed lines are printed on both sides of the radiation dielectric plate. The coaxial cable assembly is arranged below the dielectric base, and the coaxial cable assembly is electrically connected to the metal radiation patch and the feed line to achieve feeding.

Furthermore, as a preferred technical solution, the antenna cover is a knife-shaped antenna cover, the cover body of which is integrally formed using FR4 material, the bottom of the cover body has a cover opening, and the antenna cover is fixed to the dielectric base through the cover opening.

Furthermore, as a preferred technical solution, the dielectric base is made by machining FR4 material, and the antenna cover and the radiation dielectric plate are fixed to the dielectric base by a metal frame and metal screws.

Furthermore, as a preferred technical solution, the radiation medium plate adopts a polytetrafluoroethylene glass fiber cloth substrate, whose dielectric constant is 2.55, and the substrate is copper-clad on both sides.

Furthermore, as a preferred technical solution, the cavity between the radiation dielectric plate and the antenna cover is filled with foaming material.

Furthermore, as a preferred technical solution, series feeding circuits are printed on both sides of the radiating dielectric plate, and evenly arranged parasitic metal patches and trapezoidal gradient metal radiation patches are printed on the radiating dielectric plates on both sides of the series feeding circuit, forming a 4-element symmetrical dipole antenna array.

Furthermore, as a preferred technical solution, the lengths of the parasitic metal patches are different, and the length of each parasitic metal patch is 0.2λ ₀ -0.27λ ₀ , wherein λ ₀ is the free space wavelength of the center frequency.

Further, as a preferred technical solution, the upper base of the trapezoidal gradient metal radiation patch is 0.02λ ₀ , the lower base is 0.04λ ₀ , and the height is 0.2λ ₀ , wherein λ ₀ is the free space wavelength of the center frequency.

Furthermore, as a preferred technical solution, the front and back sides of the radiation dielectric plate are respectively printed with a series feed line and a feed balun, the inner conductor of the coaxial cable assembly is electrically connected to the series feed line printed on the front side of the radiation dielectric plate, and the outer conductor of the coaxial cable assembly is connected to the feed balun printed on the back side of the radiation dielectric plate.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention expands the bandwidth of the antenna by printing the oscillator on both sides of the radiation medium plate, and further improves the impedance matching and widens the impedance bandwidth of the antenna by designing a symmetrical oscillator with a trapezoidal gradient shape and a wide-band feeding balun structure.

(2) The present invention prints series feed lines on both sides of the radiation dielectric plate, and prints evenly arranged parasitic metal patches and trapezoidal gradient metal radiation patches on the radiation dielectric plates on both sides of the series feed lines to form a 4-element symmetrical dipole antenna array, thereby effectively improving the gain of the antenna to 4.9 dB, thereby achieving high gain of the antenna. By optimizing the lengths of different parasitic metal patches, the non-circularity of the omnidirectional radiation pattern is reduced, and the maximum non-circularity is 0.9 dB, thereby truly achieving wide bandwidth, high gain and small non-circularity of the radiation pattern, thereby improving the stability of airborne communications and facilitating better applications in the field of wireless communications.

(3) The present invention solves the problem that existing airborne omnidirectional antennas cannot achieve wide bandwidth, high gain and small non-circularity of the radiation pattern at the same time, and the frequency performance at the edge of the band is poor when the bandwidth is insufficient. At the same time, the airborne antenna achieves good aerodynamic performance, and the overall structural strength of the antenna is high, which can be used for a long time and has great practical significance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of a high-gain, low-out-of-roundness omnidirectional antenna based on a printed vibrator according to the present invention;

FIG2 is a side view of FIG1;

3 is a schematic diagram of the positional relationship between the series feeder circuit, the metal radiation patch, and the parasitic metal patch of the present invention;

FIG4 is a voltage standing wave ratio curve diagram of the present invention;

FIG5 is a gain curve diagram of the present invention;

FIG6 is an azimuth radiation pattern of the present invention at a frequency of 1.45 GHz;

FIG7 is an azimuth radiation pattern of the present invention at a frequency of 1.6 GHz;

FIG8 is an azimuth radiation pattern of the present invention at a frequency of 1.75 GHz.

The names corresponding to the reference numerals in the figure are: 1. antenna cover, 2. dielectric base, 3. radiation dielectric plate, 4. printed metal patch and feeding line, 5. coaxial cable assembly, 41. series feeding line, 42. metal radiation patch, 43. parasitic metal patch.

DETAILED DESCRIPTION

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", "top/bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted/connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

As shown in Figures 1 and 2, an embodiment of the present invention provides a high-gain, low-non-circularity omnidirectional antenna based on a printed vibrator, including an antenna cover 1, a dielectric base 2, a radiation dielectric plate 3 and a coaxial cable assembly 5. The antenna cover 1 and the radiation dielectric plate 3 are both installed on the dielectric base 2, and the radiation dielectric plate 3 is arranged in the antenna cover 1. The shape and size of the radiation dielectric plate 3 match the antenna cover 1. Metal radiation patches and feeding lines 4 are printed on both sides of the radiation dielectric plate 3. The coaxial cable assembly 5 is arranged below the dielectric base 2, and the coaxial cable assembly 5 is electrically connected to the metal radiation patch and the feeding line 4 to achieve feeding.

Preferably, the antenna cover 1 of this embodiment is a knife-shaped antenna cover, and its cover body is integrally formed by FR4 material, and the bottom of the cover body has a cover opening, and the antenna cover 1 is fixed on the dielectric base 2 through the cover opening. The knife-shaped antenna cover can reduce the wind resistance, thereby reducing the impact on the aerodynamic performance of the carrier, and the cover body is integrally formed by FR4 material, which ensures the overall structural strength of the antenna and enables the antenna to be used for a long time without breaking. FR4 material is mainly composed of epoxy resin, glass fiber cloth layer and filler. This material can extinguish itself in the burning state, so it has excellent flame retardancy. In addition, it also has stable electrical insulation performance, good flatness, smooth surface, no pits and thickness tolerance standards. These characteristics make it very suitable for use in products with high-performance electronic insulation requirements, and it also has good heat resistance, flame retardancy, mechanical strength and corrosion resistance.

FIG4 shows the measured voltage standing wave ratio of the present invention. It can be seen from the figure that the voltage standing wave ratio of the present invention is less than 2, indicating that the standing wave of the present invention is good and can fully meet the requirements of the antenna.

Preferably, the radiation dielectric plate 3 of this embodiment adopts a polytetrafluoroethylene glass fiber cloth substrate, whose dielectric constant is 2.55, and the substrate is copper-clad on both sides.

In order to enhance the structural strength of the antenna and reduce the impact on the radiation performance of the antenna, the dielectric base 2 of this embodiment is machined from FR4 material, and the antenna cover 1 and the radiation dielectric plate 3 are fixed to the dielectric base 2 by a metal frame and metal screws.

Preferably, the cavity between the radiation dielectric plate 3 and the antenna cover 1 of this embodiment is filled with foaming material, so that the antenna is not deformed due to the movement of the carrier and the electrical performance is not affected.

As shown in FIG3 , the two sides of the radiation dielectric plate 3 of this embodiment are printed with series feed lines 41, and the radiation dielectric plates 2 on both sides of the series feed lines 41 are printed with uniformly arranged parasitic metal patches 43 and trapezoidal gradient metal radiation patches 42, forming a 4-element symmetrical dipole antenna array. Specifically, the copper-clad areas on the front and back sides of the radiation dielectric plate 3 are printed metal patches and series feed lines, and the antenna is fed with a series feed network, which reduces the space occupied; at the same time, since the metal radiation patches 42 are uniformly arranged on both sides of the feed circuit, the trapezoidal gradient metal radiation patches 42 together with the parasitic metal patches 43 form a 4-element symmetrical dipole antenna array, which is printed on the front and back sides of the substrate and radiates through electric field coupling, which can broaden the bandwidth of the antenna and improve the gain of the antenna, so that the gain reaches 4.9dB, and an omnidirectional radiation pattern with good roundness is achieved, as shown in FIG5-FIG8.

It should be noted that the 4-element symmetrical dipole antenna array is composed of 4 symmetrical dipoles with a fixed element spacing, wherein two metal radiation patches 42 are a symmetrical dipole and correspond to a parasitic metal patch 43, and the uniform arrangement of the parasitic metal patch 42 and the trapezoidal gradient metal radiation patch 43 mentioned above usually refers to an axial element spacing of 0.35λ ₀ , wherein λ ₀ is the free space wavelength of the center frequency. The innovation of the present invention lies in the combination of the dipole array and the parasitic metal patch, and the optimization of the out-of-roundness by the parasitic metal patch.

In this embodiment, the lengths of the parasitic metal patches are different. The length of each parasitic metal patch is 0.2λ ₀ to 0.27λ ₀ , where λ ₀ is the free space wavelength of the center frequency. The upper base of the trapezoidal gradient metal radiation patch is 0.02λ ₀ , the lower base is 0.04λ ₀ , and the height is 0.2λ ₀ . The trapezoidal gradient metal radiation patch can further broaden the impedance bandwidth of the antenna, and the length of each parasitic metal patch is designed to be within the range of 0.2λ ₀ to 0.27λ ₀ , which has a guiding effect. By optimizing the lengths of different parasitic patches, the non-circularity of the antenna radiation pattern can be reduced. Specifically, the length optimization of the parasitic patch is automatically optimized by the simulation software after the initial value is given, and the optimization target is the non-circularity of the antenna. This is very easy to implement for those skilled in the art, so its principle and effect will not be described in detail.

In this embodiment, a series feed line and a feed balun are printed on the front and back sides of the radiation dielectric plate 3, respectively. The inner conductor of the coaxial cable assembly 5 is electrically connected to the series feed line printed on the front side of the radiation dielectric plate 3, and the outer conductor of the coaxial cable assembly 5 is connected to the feed balun printed on the back side of the radiation dielectric plate 3. Such a design can improve impedance matching and broaden the impedance bandwidth of the antenna.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (9)

1. A high-gain, low-out-of-roundness omnidirectional antenna based on a printed vibrator, characterized in that it comprises an antenna cover (1), a dielectric base (2), a radiation dielectric plate (3) and a coaxial cable assembly (5), wherein the antenna cover (1) and the radiation dielectric plate (3) are both mounted on the dielectric base (2), and the radiation dielectric plate (3) is arranged in the antenna cover (1), and the shape and size of the radiation dielectric plate (3) match the antenna cover (1), and the front and back surfaces of the radiation dielectric plate (3) are printed with metal radiation patches and a feed line (4), and the coaxial cable assembly (5) is arranged below the dielectric base (2), and the coaxial cable assembly (5) is electrically connected to the metal radiation patch and the feed line (4) to achieve feeding. 2. According to claim 1, a high-gain, low-non-roundness omnidirectional antenna based on a printed vibrator is characterized in that the antenna cover (1) is a knife-shaped antenna cover, and its cover body is integrally formed using FR4 material, and the bottom of the cover body has a cover opening, and the antenna cover (1) is fixed on the dielectric base (2) through the cover opening. 3. According to the high-gain, low-non-roundness omnidirectional antenna based on printed oscillators in claim 1, it is characterized in that the dielectric base (2) is made of FR4 material by machining, and the antenna cover (1) and the radiation dielectric plate (3) are fixed to the dielectric base (2) by a metal frame and metal screws. 4. A high-gain, low-non-circularity omnidirectional antenna based on a printed vibrator according to claim 1, characterized in that the radiation dielectric plate (3) adopts a polytetrafluoroethylene glass fiber cloth substrate with a dielectric constant of 2.55, and the substrate is copper-clad on both sides. 5. A high-gain, low-non-circularity omnidirectional antenna based on a printed vibrator according to claim 1, characterized in that the cavity between the radiation dielectric plate (3) and the antenna cover (1) is filled with foaming material. 6. According to claim 1, a high-gain, low-non-circularity omnidirectional antenna based on printed oscillators is characterized in that series feeding lines (41) are printed on both sides of the radiating dielectric plate (3), and uniformly arranged parasitic metal patches (43) and trapezoidal gradient metal radiation patches (42) are printed on the radiating dielectric plates (2) on both sides of the series feeding lines (41), forming a 4-element symmetrical oscillator antenna array. 7. A high-gain, low-non-circularity omnidirectional antenna based on a printed vibrator according to claim 6, characterized in that the lengths of the parasitic metal patches are different, and the length of each parasitic metal patch is 0.2λ ₀ to 0.27λ ₀ , wherein λ ₀ is the free space wavelength of the center frequency. 8. A high-gain, low-non-roundness omnidirectional antenna based on a printed vibrator according to claim 6 or 7, characterized in that the upper base of the trapezoidal gradient metal radiation patch is 0.02λ ₀ , the lower base is 0.04λ ₀ , and the height is 0.2λ ₀ , wherein λ ₀ is the free space wavelength of the center frequency. 9. A high-gain, low-non-roundness omnidirectional antenna based on a printed vibrator according to claim 1, characterized in that a series feed line and a feed balun are printed on the front and back sides of the radiation dielectric plate (3), respectively, the inner conductor of the coaxial cable assembly (5) is electrically connected to the series feed line printed on the front side of the radiation dielectric plate (3), and the outer conductor of the coaxial cable assembly (5) is connected to the feed balun printed on the back side of the radiation dielectric plate (3).