WIDE-BEAM PLANAR BACKFIRE AND BIDIRECTIONAL CIRCULARLY-POLARIZED ANTENNA

Abstract

A wide-beam planar backfire and bidirectional circularly-polarized antenna. An entire planar sectorial magnetic dipole is of a semi-closed structure, the planar sectorial magnetic dipole comprises two identical sectorial patches and a vertical short-circuit wall, and the vertical short-circuit wall is connected with straight sides of the two sectorial patches along a radial direction of the planar sectorial magnetic dipole; two sets of concentric annular electric dipoles are respectively used as a top concentric annular radiating element and a bottom concentric annular radiating element, as well as a top concentric annular reflector and a bottom anti-concentric annular reflector; and the top concentric annular radiating element is connected with an upper surface of the planar sectorial magnetic dipole through a top connecting branch, and the bottom concentric annular radiating element is connected with a lower surface of the planar sectorial magnetic dipole through a bottom connecting branch.

Claims

1. A wide-beam planar backfire and bidirectional circularly-polarized antenna, comprising a planar sectorial magnetic dipole and two sets of concentric annular electric dipoles, wherein the planar sectorial magnetic dipole comprises two identical sectorial patches and a vertical short-circuit wall, the two sectorial patches are symmetrically arranged in parallel from top to bottom, the vertical short-circuit wall is connected with straight sides of the two sectorial patches along a radial direction of the planar sectorial magnetic dipole, the entire planar sectorial magnetic dipole is a semi-closed structure, and an arc end of the planar sectorial magnetic dipole is an opening; one set of concentric annular electric dipoles are used as a top concentric annular radiating element and a bottom concentric annular radiating element, and the other set of concentric annular electric dipoles are used a top concentric annular reflector and a bottom anti-concentric annular reflector; the top concentric annular radiating element is connected with an upper surface of the planar sectorial magnetic dipole through a top connecting branch, and the bottom concentric annular radiating element is connected with a lower surface of the planar sectorial magnetic dipole through a bottom connecting branch; the top concentric annular radiating element and the bottom concentric annular radiating element have the same structure and size, and are symmetrically distributed about a central axis of the planar sectorial magnetic dipole; the top concentric annular reflector and the bottom anti-concentric annular reflector have the same structure and size, and are symmetrically distributed about the central axis of the planar sectorial magnetic dipole, and a distance among the top concentric annular reflector, the bottom anti-concentric annular reflector and the planar sectorial magnetic dipole is 5 mm to 10 mm; and the sectorial patch on the upper surface of the planar sectorial magnetic dipole, the top concentric annular radiating element and the top concentric annular reflector are in the same plane, and the sectorial patch on the lower surface of the planar sectorial magnetic dipole, the bottom concentric annular radiating element and the bottom anti-concentric annular reflector are in the same plane.

2. The wide-beam planar backfire and bidirectional circularly-polarized antenna according to claim 1, wherein a range of a central angle of the planar sectorial magnetic dipole is [90°, 360°].

3. The wide-beam planar backfire and bidirectional circularly-polarized antenna according to claim 2, wherein the range of the central angle of the planar sectorial magnetic dipole is [180°, 330°].

4. The wide-beam planar backfire and bidirectional circularly-polarized antenna according to claim 1, wherein the top concentric annular radiating element connected with the top connecting branch and the bottom concentric annular radiating element connected with the bottom connecting branch rotate around the central axis of the planar sectorial magnetic dipole in an angle range of [90°, 160°].

5. The wide-beam planar backfire and bidirectional circularly-polarized antenna according to claim 1, wherein a range of an flared angle of the concentric annular radiating elements is [30°, 60°]; and a range of an flared angle of the concentric annular reflectors is [45°, 135°].

6. The wide-beam planar backfire and bidirectional circularly-polarized antenna according to claim 5, wherein when the range of the flared angle of the top concentric annular radiating element and the bottom concentric annular radiating element is [30°, 45°] and the range of the flared angle of the top concentric annular reflector and the bottom concentric annular reflector is [45°, 90°], bidirectional circular polarization is realized; and when the range of the flared angle of the top concentric annular radiating element and the bottom concentric annular radiating element is [45°, 60°] and the range of the flared angle of the top concentric annular reflector and the bottom concentric annular reflector is [90°, 135°], backfire circular polarization is realized.

7. The wide-beam planar backfire and bidirectional circularly-polarized antenna according to claim 1, wherein a height between the upper and lower sectorial patches is 4 mm to 6 mm, and a dielectric constant of a dielectric substrate filled between the two sectorial patches is 1 to 20.

8. The wide-beam planar backfire and bidirectional circularly-polarized antenna according to claim 1, wherein a feed structure is arranged on the central axis of the planar sectorial magnetic dipole, and the feed structure comprises a coaxial inner conductor and a coaxial joint outer conductor.

9. The wide-beam planar backfire and bidirectional circularly-polarized antenna according to claim 1, wherein widths and lengths of the top connecting branch and the bottom connecting branch are 0.2 mm to 1.2 mm, and 0.6 mm to 3 mm respectively.

10. The wide-beam planar backfire and bidirectional circularly-polarized antenna according to claim 1, wherein widths of the two sets of concentric annular electric dipoles are all 4 mm to 8 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 is a diagram of a front structure and a reference coordinate of an antenna in the present invention.

[0017] FIG. 2 is a three-dimensional diagram and a reference coordinate diagram of the antenna in the present invention.

[0018] FIG. 3 illustrates an antenna reflection coefficient characteristic calculated by HFSS software in the embodiment.

[0019] FIG. 4 is a diagram of a bidirectional radiation direction of the antenna in xy plane calculated by HFSS software in the embodiment.

[0020] FIG. 5 is a diagram of a backfire radiation direction of the antenna in xy plane calculated by HFSS software in the embodiment.

DETAILED DESCRIPTION

[0021] The technical solutions of the present invention are described in detail below, but the protection scope of the present invention is not limited to the described embodiments.

[0022] As shown in FIG. 1 and FIG. 2, a wide-beam planar backfire and bidirectional circularly-polarized antenna according to the present invention comprises a planar sectorial magnetic dipole 1 and two sets of concentric annular electric dipoles, wherein the entire planar sectorial magnetic dipole 1 is a semi-closed structure (an opening direction is an arc end of the sectorial dipole), the planar sectorial magnetic dipole 1 comprises two identical sectorial patches and a vertical short-circuit wall, the two sectorial patches are symmetrically arranged in parallel from top to bottom, and the vertical short-circuit wall is connected with straight sides of the two sectorial patches along a radial direction of the planar sectorial magnetic dipole 1; one set of concentric annular electric dipoles are used as a top concentric annular radiating element 2 and a bottom concentric annular radiating element 3, and the other set of concentric annular electric dipoles are used a top concentric annular reflector 6 and a bottom anti-concentric annular reflector 7; the top concentric annular radiating element 2 is connected with an upper surface of the planar sectorial magnetic dipole 1 through a top connecting branch 4, and the bottom concentric annular radiating element 3 is connected with a lower surface of the planar sectorial magnetic dipole 1 through a bottom connecting branch 5; the top concentric annular radiating element 2 and the bottom concentric annular radiating element 3 have the same structure and size, and are symmetrically distributed about a central axis of the planar sectorial magnetic dipole 1; the top concentric annular reflector 6 and the bottom anti-concentric annular reflector 7 have the same structure and size, and are symmetrically distributed about the central axis of the planar sectorial magnetic dipole 1, and a distance among the top concentric annular reflector 6, the bottom anti-concentric annular reflector 7 and the planar sectorial magnetic dipole 1 is 5 mm to 10 mm; and

[0023] the sectorial patch on the upper surface of the planar sectorial magnetic dipole 1, the top concentric annular radiating element 2 and the top concentric annular reflector 6 are in the same plane, and the sectorial patch on the lower surface of the planar sectorial magnetic dipole 1, the bottom concentric annular radiating element 3 and the bottom anti-concentric annular reflector 7 are in the same plane.

[0024] A range of a central angle 10 of the planar sectorial magnetic dipole 1 is [180°, 330°] to reduce an antenna volume, and meanwhile, a wider beam width can be obtained. The top concentric annular radiating element 2 and the bottom concentric annular radiating element 3 rotate around the central axis of the planar sectorial magnetic dipole 1 in a range of a rotation angle 11 of [90°, 160°]. A range of an flared angle of the concentric annular radiating elements is [30°, 60°]; and a range of an flared angle of the concentric annular reflectors is [45°, 135°]. When the flared angles of the two sets of concentric annular electric dipoles are respectively [30°, 45°] and [45°, 90°], a bidirectional circular polarization characteristic can be realized; and when the flared angles of the two sets of concentric annular electric dipoles are respectively [45°, 60°] and [90°, 135°], a backfire circular polarization characteristic can be realized.

[0025] A feed structure is arranged on the central axis of the planar sectorial magnetic dipole 1, and the feed structure comprises a coaxial inner conductor 9 and a coaxial joint outer conductor 8. Further, widths and lengths of the top connecting branch 4 and the bottom connecting branch 5 are 0.2 mm to 1.2 mm, and 0.6 mm to 3 mm respectively. The widths of the two sets of concentric annular electric dipoles are both 4 mm to 8 mm.

Embodiment

[0026] The wide-beam planar backfire and bidirectional circularly-polarized antenna in the embodiment is manufactured on a dielectric with a dielectric constant of 1 to 20, the wide-beam planar backfire and bidirectional circularly-polarized antenna comprises a planar sectorial magnetic dipole 1, a top concentric annular radiating element 2, a bottom concentric annular radiating element 3, a top connecting branch 4, a bottom connecting branch 5, a top concentric annular reflector 6 and a bottom anti-concentric annular reflector 7.

[0027] The entire planar sectorial magnetic dipole is a semi-closed structure, and is composed of two identical sectorial patches and a vertical short-circuit wall connected with straight sides of the two sectorial patches. The top concentric annular radiating element 2 and the bottom concentric annular radiating element 3 have the same structure and size, and are symmetrically distributed about a central axis of the planar sectorial magnetic dipole 1; and the top concentric annular reflector 6 and the bottom anti-concentric annular reflector 7 have the same structure and size, and are symmetrically distributed about the central axis of the semi-closed planar sectorial magnetic dipole, and a distance among the top concentric annular reflector, the bottom anti-concentric annular reflector and the planar sectorial magnetic dipole 1 is 6 mm.

[0028] An upper surface of a semi-closed end of the planar sectorial magnetic dipole 1 is connected with the top concentric annular radiating element 2 through the top connecting branch 4, and a lower surface of the semi-closed end of the planar sectorial magnetic dipole 1 is connected with the bottom concentric annular radiating element 3 through the bottom connecting branch 5. The top connecting branch 4 and the bottom connecting branch 5 have the same structure and size, and adjustable lengths and widths. The top concentric annular radiating element 2 and the bottom concentric annular radiating element 3 rotate around the central axis of the antenna by a certain angle, wherein an angle range is between 90° to 160°.

[0029] In the embodiment, a distance between an air dielectric and upper and lower surfaces of the planar sectorial magnetic dipole 1 is 6 mm, the planar sectorial magnetic dipole 1 has a radius of 26 mm and a central angle 10 of 300°, the flared angle of the top concentric annular radiating element 2 and the bottom concentric annular radiating element 3 is 50°, the top concentric annular radiating element 2 and the bottom concentric annular radiating element 3 rotate around the central axis of the antenna by an angle of 135°, lengths and widths of the top connecting branch 4 and the bottom connecting branch 5 are respectively 2 mm and 0.6 mm, the flared angle of the top concentric annular reflector 6 and the bottom anti-concentric annular reflector 7 is 75°, widths of the two sets of concentric annular electric dipoles are 6 mm, and all characteristics of the antenna are simulated and calculated by HFSS software.

[0030] FIG. 3 illustrates an antenna reflection coefficient characteristic calculated by HFSS software, and an antenna impedance bandwidth in the embodiment covers a frequency band of 2.37 GHz to 2.50 GHz, with a center frequency of 2.44 GHz, which shows that the antenna has a wider impedance bandwidth.

[0031] FIG. 4 is a diagram of a bidirectional radiation direction of the antenna in xy plane calculated by HFSS software, the solid line indicates left-hand circular polarization and the dashed line indicates right-hand circular polarization, and it can be seen that the antenna in the embodiment has a 3 dB circularly-polarized beam width of 180°, thus having a hemispherical beam width.

[0032] FIG. 5 is a diagram of a backfire radiation direction of the antenna in the xy plane calculated by HFSS software, the solid line indicates left-hand circular polarization and the dashed line indicates right-hand circular polarization, and it can be seen that the antenna in the embodiment has a 3 dB circularly-polarized beam width of 165°, thus having a very wide beam width.

[0033] In conclusion, the wide-beam planar backfire and bidirectional circularly-polarized antenna of the present invention can realize a good backfire circular polarization characteristic (an azimuth planar beam width reaches 165°) and can also realize a bidirectional circular polarization characteristic.