CN203983456U - A kind of broadband circle polarized omnidirectional antenna based on inclination oscillator - Google Patents

Abstract

The utility model discloses a broadband circularly polarized omnidirectional antenna based on an inclined vibrator, which comprises an antenna radiating part, a flexible dielectric board, a broadband feeding network and a feeding substrate. The antenna radiating part includes four inclined vibrators, each of which is It consists of a main radiation oscillator and a parasitic oscillator. The main radiation oscillator and the parasitic oscillator have different lengths and inclination angles. The flexible dielectric plate is bent into a hollow cylinder, and the four inclined oscillators are arranged in an evenly divided ring on the flexible dielectric plate. , the broadband feed network is printed on the front and back of the feed substrate, and it is placed horizontally in the center of the dielectric hollow cylinder to realize equal-amplitude and in-phase feed to the four inclined oscillators. The utility model has the advantages of flexible realization of left and right circular polarization, good omnidirectionality and broadband, and is suitable for the field of mobile communication base stations.

Description

A Broadband Circularly Polarized Omnidirectional Antenna Based on Inclined Vibrator

technical field

The utility model relates to the field of wireless communication, in particular to a broadband circularly polarized omnidirectional antenna based on an inclined vibrator.

Background technique

With the continuous development of society, the performance requirements of antennas are getting higher and higher. In modern wireless application systems, it is difficult to meet people's needs with purely linearly polarized antennas. Circularly polarized antennas are more and more popular Widely concerned, and the omnidirectional circularly polarized antenna is widely used in communication, remote sensing and telemetry, radar, electronic reconnaissance and electronic jamming because of its special performance.

In antenna theory, the electric dipole perpendicular to the ground radiates omnidirectional vertically polarized waves, and the uniform current loop parallel to the ground radiates omnidirectional horizontally polarized waves. The vertical and horizontal polarized electric fields radiated by the two naturally produce 90° Phase difference, when their amplitudes are equal, two orthogonally polarized waves can be superimposed in the far field to generate omnidirectional circularly polarized waves, thereby realizing omnidirectional circularly polarized radiation. When using a tilted dipole array to realize an omnidirectional circularly polarized antenna, each tilted dipole can be decomposed into a horizontal component and a vertical component. When multiple tilted dipoles are arranged around the circumference, its horizontal component can be equivalent to a horizontal uniform current ring, the vertical component is equivalent to a vertical dipole, and the two generate omnidirectional circularly polarized waves in the far field. The omnidirectional antenna realized by this method can achieve a wide circular polarization bandwidth, but the impedance matching is difficult to achieve.

Utility model content

In order to overcome the shortcomings and deficiencies of the prior art, the utility model provides a broadband circularly polarized omnidirectional antenna with a low profile, wide bandwidth and omnidirectional radiation on a horizontal plane based on an inclined vibrator.

The utility model adopts the following technical solutions:

A broadband circularly polarized omnidirectional antenna based on a tilted vibrator, including an antenna radiating part, a flexible dielectric board, a broadband feed network and a feed substrate, the broadband feed network is printed on both sides of the feed substrate, and the The flexible dielectric plate is bent into a hollow cylinder, the feed substrate is horizontally placed in the center of the hollow cylinder, and the antenna radiation part includes four inclined vibrators, and the four inclined vibrators are equally divided and evenly ring-shaped on the outer surface of the hollow cylinder arrangement.

The inclined oscillator is composed of a main radiation oscillator and a parasitic oscillator, the angle between the main radiation oscillator and the positive direction of the horizontal plane is 0<α<180°, and the angle between the parasitic oscillator and the positive direction of the horizontal plane is 0<β<180°.

The diameter of the hollow cylinder is 0.17λ ₀ -0.2λ ₀ , and the height is 0.4λ ₀ , where λ ₀ is the wavelength of free space corresponding to the center frequency of 2GHz.

The main radiation oscillator and the parasitic oscillator have widths of 0.05λ ₀ and 0.02λ ₀ and lengths of 0.47λ ₀ and 0.31λ ₀ respectively.

There is no direct connection between the main radiation oscillator and the parasitic oscillator, wherein the vertical distance d ₁ between the highest point of the main radiation oscillator and the highest point of the parasitic oscillator is 0.1λ ₀ , and the horizontal distance d ₂ is 0.05λ ₀ .

The main radiation oscillator breaks a crack in the middle of the length direction, and the crack is connected to the broadband feeding network through a welding point.

The broadband feed network includes four broadband baluns and impedance matching circuits. Each broadband balun is composed of a slot on the back of the feed substrate and an L-shaped microstrip line with a 45° chamfer on the front. The L-shaped microstrip line The end is open circuit, the other end is connected with one end of the impedance matching circuit, and the other end of the impedance matching circuit is connected with the central feed point of the hollow cylinder.

A cross-shaped conductor patch with a 45° chamfer is also printed on the back of the feeder substrate.

The impedance matching network is cross-connected in the center of the feed substrate in a cross shape.

When the angle between the inclined vibrator and the positive direction of the horizontal plane is 0<α<90°, a right-handed circularly polarized omnidirectional antenna is formed; when the angle between the inclined vibrator and the positive direction of the horizontal plane is 90°<α<180°, then Constitutes a left-handed circularly polarized omnidirectional antenna.

The beneficial effects of the utility model:

(1) The four inclined oscillators adopted in the utility model are arranged in a uniform ring around the hollow cylinder to realize omnidirectional circular polarization radiation, and the broadband circular polarization is realized by using the parasitic oscillator and the broadband feed network;

(2) The polarization rotation of the circularly polarized omnidirectional antenna is determined by the tilt angle α between the tilted oscillator and the positive direction of the horizontal plane. When the angle between the tilted oscillator and the positive direction of the horizontal plane is 0<α<90°, a right-handed circle is formed Polarized omnidirectional antenna, and when the angle between the inclined vibrator and the positive direction of the horizontal plane is 90°<α<180°, it constitutes a left-handed circularly polarized omnidirectional antenna with flexible conversion methods;

(3) Each tilted oscillator includes a main radiation oscillator and a parasitic oscillator, which are uniformly arranged in a ring around the hollow cylinder. The tilt angle of the main radiation oscillator and the radius of the cylinder are the keys to realize omnidirectional circularly polarized radiation. Using the parasitic The coupling between the oscillator and the main radiation oscillator broadens the bandwidth of the antenna, thereby realizing the broadband circular polarization characteristics;

(4) The broadband feed network only affects the antenna impedance performance, and has almost no effect on the circular polarization and omnidirectional characteristics of the antenna; the broadband feed network feeds the four inclined oscillators with equal amplitude and phase, realizing broadband impedance matching. The 10dB return loss bandwidth of the optimized omnidirectional antenna can reach 61% (1.35-2.54GHz), and the 3dB axial ratio bandwidth is 44% (1.69-2.64GHz). In the 1.7-2.4GHz frequency band, the horizontal plane pattern is not round Less than 1.5dB, cross polarization less than -15dB, easy to achieve dual circular polarization function.

Description of drawings

Fig. 1 is a schematic structural diagram of a broadband circularly polarized omnidirectional antenna based on a tilted vibrator of the present invention;

Fig. 2 is a schematic diagram of the structure of the inclined vibrator in Fig. 1;

Fig. 3 is a schematic structural diagram of the broadband feed network in Fig. 1;

Figure 4(a) is a comparison chart of the simulation results and test results of the return loss of the embodiment of the utility model, and Figure 4(b) is a comparison chart of the simulation results and test results of the axial ratio of the embodiment of the utility model.

The figure shows:

1-antenna radiation part; 2-flexible dielectric board; 3-broadband feed network; 4-feed substrate; 5-main radiation oscillator; 6-parasitic oscillator; Gap; 10-L-type microstrip line; 11-impedance matching circuit; 12-cross-shaped conductor patch.

Detailed ways

The utility model will be described in further detail below in conjunction with the embodiments and accompanying drawings, but the implementation of the utility model is not limited thereto.

Example

As shown in Figure 1, a broadband circularly polarized omnidirectional antenna based on a tilted vibrator includes an antenna radiating part 1, a flexible dielectric board 2, a broadband feed network 3 and a feed substrate 4, and the broadband feed network 3 prints Made on the front and back sides of the feeder substrate 4, the flexible dielectric plate 2 is bent into a hollow cylinder, the diameter of the hollow cylinder is 0.17λ ₀ ~0.2λ ₀ , and the height is 0.4λ ₀ , where λ ₀ is the center frequency The wavelength of free space corresponding to 2GHz, the feed substrate 4 is horizontally placed in the center of the hollow cylinder, and the diameter of the feed substrate is equal to the diameter of the hollow cylinder, the antenna radiation part 1 includes four inclined oscillators, the four The inclined vibrator is arranged in an evenly divided ring on the outer surface of the hollow cylinder.

As shown in Figure 2, each inclined oscillator is composed of a main radiation oscillator 5 and a parasitic oscillator 6. In this embodiment, the length _k1 of the main radiation oscillator is 73mm, the width _h1 is 7.5mm, and the angle between the positive direction of the horizontal plane α is 35°, the length k ₂ of the parasitic oscillator is 47 mm, the width h ₂ is 3 mm, and the angle β with the positive direction of the horizontal plane is 40°. There is no direct connection between the main radiating oscillator and the parasitic oscillator, wherein the vertical distance d ₁ between the highest point of the main radiating oscillator and the highest point of the parasitic oscillator is 14.8 mm, and the horizontal distance d ₂ is 7.3 mm. The main radiation oscillator breaks a crack at the middle position in the length direction, and the crack width is 1.2mm, and the crack is connected to the broadband feed network 3 through the welding point 7 .

The thickness of the flexible dielectric plate in this embodiment is 0.05mm high-frequency plate Panasonic R-F775 plate, the relative dielectric constant is 3.2, the loss tangent is 0.0015, the diameter is 0.185λ ₀ , and the height is 0.4λ ₀ , where λ ₀ is the center frequency 2GHz corresponds to the wavelength in free space.

The feed substrate 4 is a Taconic TLY-5 plate with a thickness of 0.8 mm, a relative dielectric constant of 2.2, a loss tangent of 0.0009, and a diameter of 27.95 mm.

The coaxial cable adopts flexible coaxial cable Johnson/Emerson RG-178 with a diameter of 2.5mm and a characteristic impedance of 50Ω.

As shown in Figure 3, the feeder substrate is horizontally placed in the center of the curved hollow cylinder of the flexible dielectric plate, and the broadband feeder network 3 is printed on the front and back sides of the substrate, and the broadband feeder network includes four broadband baluns And the impedance matching circuit 11, the broadband balun is composed of the slit 9 on the back of the feed substrate and the L-shaped microstrip line 10 with a 45-degree chamfer on the front, the end of the L-shaped microstrip line is open, and the other end is connected to the impedance matching circuit 11, the other end of the impedance matching circuit is connected to the central feeding point 8 of the cylinder, and connected to the 50Ω coaxial line used for feeding, and a cross-shaped conductor patch 12 with chamfers is also printed on the back of the feeding substrate , the chamfering angle of the conductor patch is 45°, the length l ₈ of the first part of the chamfer is 2 mm, the length l ₉ of the second part of the chamfer is also 2 mm, the patch is etched with a gap, and the patch width w _g It is 12mm.

The broadband feed network can feed the four inclined oscillators with equal amplitude and same phase. The parameters are described as follows: l _s is the slot length of 19mm, w _s is the slot width of 1.2mm, l ₁ is the length of the first section of the impedance matching network is 4mm, l ₂ is the length of the second section of the impedance matching network is 23.5mm, l ₃ is the length of the third section of the impedance matching network is 3mm, w ₁ is the width of the first, second and third sections of the impedance matching network 0.4mm, l ₄ is the length of the chamfered microstrip line is 4mm, and the chamfer angle is also 45°, l ₅ is the length of the first section of the microstrip line chamfer is 1.5mm, l ₆ is the second section of the microstrip line chamfer The length of the second section is 1.5 mm, l ₇ is the length of the bending part of the microstrip line with chamfering is 15.5 mm, and w ₂ is the width of the microstrip line with chamfering is 1.5 mm.

The length w _f of the welding point connecting the inclined vibrator to the broadband feed network is 1.5 mm, and the distance h _f connecting the welding point 7 to the cross-shaped conductor patch 12 is 2.5 mm.

The impedance matching circuit is cross-connected in the center of the feed substrate in a cross shape. When the angle between the inclined vibrator and the positive direction of the horizontal plane is 0<α<90°, a right-handed circularly polarized omnidirectional antenna is formed, and when the angle between the inclined vibrator and the positive direction of the horizontal plane is 90°<α<180°, then A left-handed circularly polarized omnidirectional antenna is formed, and the conversion method is simple and flexible.

As shown in Fig. 4 (a), the antenna of this embodiment shown in Fig. 4 (b) feeds four inclined oscillators with equal amplitude and in-phase feed through a broadband feed network, and realizes broadband impedance matching. The 10dB of this circularly polarized omnidirectional antenna The return loss bandwidth can reach 61% (1.35-2.54GHz), the 3dB axial ratio bandwidth is 44% (1.69-2.64GHz), in the 1.7-2.4GHz frequency band, the horizontal plane pattern is less than 1.5dB, and the cross pole Polarization is less than -15dB, easy to achieve dual circular polarization function.

The utility model provides a way to arrange and combine multiple inclined oscillators. By making the same four-unit inclined oscillators conform to the surface of a hollow cylinder, each antenna unit superimposes in the far field to produce an omnidirectional circularly polarized wave principle. , and then through the design of the parasitic unit and the broadband feed network, the broadband circular polarization omnidirectional radiation is finally realized.

The utility model can also be used to form an antenna array to form a multi-unit horizontally polarized omnidirectional antenna array to improve antenna gain, thereby meeting the high-gain requirement of mobile communication base station antennas.

The above-mentioned embodiment is a preferred implementation mode of the present utility model, but the implementation mode of the present utility model is not limited by the described embodiment, and any other changes, modifications, modifications, Substitution, combination, and simplification should all be equivalent replacement methods, and are all included in the protection scope of the present utility model.

Claims (10)

1. the broadband circle polarized omnidirectional antenna based on inclination oscillator, comprise aerial radiation part, flexible media plate, broadband feeding network and feed substrate, described broadband feeding network is printed on the positive and negative two sides of feed substrate, it is characterized in that, described flexible media plate bends to hollow cylinder, described feed substrate is placed horizontally at the center of hollow cylinder, and described aerial radiation partly comprises four inclination oscillators, and described four inclination oscillators are the even annular arrangement of decile at hollow cylinder outer surface.

2. a kind of broadband circle polarized omnidirectional antenna based on inclination oscillator according to claim 1, it is characterized in that, described inclination oscillator consists of primary radiation oscillator and parasitic oscillator, primary radiation oscillator and horizontal plane positive direction angle are 0< α <180 °, and described parasitic oscillator and horizontal plane positive direction angle are 0< β <180 °.

3. a kind of broadband circle polarized omnidirectional antenna based on inclination oscillator according to claim 1, is characterized in that, the diameter of described hollow cylinder is 0.17 λ ₀～0.2 λ ₀, be highly 0.4 λ ₀, λ wherein ₀centered by frequency 2GHz the wavelength of corresponding free space.

4. a kind of broadband circle polarized omnidirectional antenna based on inclination oscillator according to claim 2, is characterized in that, the width of described primary radiation oscillator and parasitic oscillator is respectively 0.05 λ ₀with 0.02 λ ₀, length is respectively 0.47 λ ₀with 0.31 λ ₀.

5. a kind of broadband circle polarized omnidirectional antenna based on inclination oscillator according to claim 4, is characterized in that, described primary radiation oscillator and parasitic oscillator be without direct connection, wherein, and distance d in primary radiation oscillator peak and parasitic oscillator peak vertical direction ₁0.1 λ ₀, distance d in horizontal direction ₂0.05 λ ₀.

6. a kind of broadband circle polarized omnidirectional antenna based on inclination oscillator according to claim 5, is characterized in that, described primary radiation oscillator is in disconnection crack, the centre position of length direction, and this crack is connected with broadband feeding network by solder joint.

7. a kind of broadband circle polarized omnidirectional antenna based on inclination oscillator according to claim 1, it is characterized in that, described broadband feeding network comprises four wideband baluns and impedance matching circuit, each wideband balun consists of gap and the positive L-type microstrip line with 45 ° of chamferings of feed substrate back, the terminal open circuit of L-type microstrip line, the other end is connected with impedance matching circuit one end, and the other end of impedance matching circuit is connected with the centre feed point of hollow cylinder.

8. a kind of broadband circle polarized omnidirectional antenna based on inclination oscillator according to claim 1, is characterized in that, described feed substrate back is also printed with the cross conductor patch with 45 ° of chamferings.

9. a kind of broadband circle polarized omnidirectional antenna based on inclination oscillator according to claim 7, is characterized in that, described impedance matching networking is decussation in feed substrate center and connects.

10. according to the broadband circle polarized omnidirectional antenna based on inclination oscillator described in claim 1-9 any one, it is characterized in that, when the angle of inclination oscillator and horizontal plane positive direction is <90 ° of 0< α, form right-handed circular polarization omnidirectional antenna, when the angle of inclination oscillator and horizontal plane positive direction is <180 ° of 90 ° of < α, form left-hand circular polarization omnidirectional antenna.