Circularly polarized electromagnetic dipole antenna based on polarized torsion artificial magnetic conductor

Abstract

The invention relates to a circularly polarized electromagnetic dipole antenna based on a polarized torsion artificial magnetic conductor, and belongs to the field of antennas. Comprising a planar dipole antenna, a 2 * 2 polarization torsion artificial magnetic conductor (PRAMC) array, a reflecting plate, a Balun feeder line, a dielectric substrate I and a dielectric substrate II, the planar dipole antenna is printed on the upper surface of the dielectric substrate I and serves as an equivalent electric dipole; the Balun feeder is printed on the lower surface of the dielectric substrate I and is used for feeding the planar dipole antenna; the 2 * 2 PRAMC array is printed on the upper surface of the dielectric substrate II to serve as an equivalent magnetic dipole; the reflecting plate is printed on the lower surface of the dielectric substrate II and is used for enhancing forward radiation and inhibiting backward leakage; according to the circularly polarized electromagnetic dipole antenna, the 2 * 2 PRAMC array is loaded, no extra metal aperture needs to be introduced, and a complex feed network does not need to be designed, so that the design complexity of the circularly polarized electromagnetic dipole antenna is remarkably reduced, and meanwhile, the circularly polarized electromagnetic dipole antenna has good end-fire characteristics and circularly polarized performance.

Description

Technical Field

[0001] This invention relates to a circularly polarized electromagnetic dipole antenna based on a polarized torsion artificial magnetic conductor, belonging to the field of antenna technology. Background Technology

[0002] With the rapid development of wireless communication technology, especially its widespread application in key areas such as 5G / 6G communication, satellite communication, the Internet of Things (IoT), and radar systems, modern wireless applications are placing increasingly stringent and diverse demands on antenna performance. Traditional circularly polarized electromagnetic dipole antennas mainly use a metal aperture equivalent to a magnetic dipole, achieving circular polarization radiation through techniques such as truncated corners, slotting, and feeding networks. However, this type of design results in a three-dimensional structure, leading to problems such as excessive size, high profile, and structural complexity. Summary of the Invention

[0003] To address the problems and shortcomings of traditional circularly polarized electromagnetic dipole antennas, this invention provides a circularly polarized electromagnetic dipole antenna based on a polarization-twisted artificial magnetic conductor. This antenna fully utilizes the unique polarization twisting and phase modulation capabilities of PRAMCs, making a 2×2 PRAMC array equivalent to a magnetic dipole while transforming a single electric dipole into an equivalent Huygens source composed of orthogonal electric and magnetic dipoles with a 90° phase difference. Furthermore, it converts linearized radiation into circularly polarized radiation, designing a planar circularly polarized electromagnetic dipole antenna with complementary end-fire characteristics. This invention significantly reduces design complexity without introducing metal apertures or complex feeding networks, while exhibiting excellent end-fire characteristics and circular polarization performance.

[0004] The technical solution of this invention is: a circularly polarized electromagnetic dipole antenna based on a polarized torsion artificial magnetic conductor, comprising a planar dipole antenna 1, a 2×2 PRAMC array 2, a reflector 3, a balun feed line 4, a dielectric substrate I 5, and a dielectric substrate II 6. The planar dipole antenna 1 is printed on the upper surface of the dielectric substrate I5, and the balun feed line 4 is printed on the lower surface of the dielectric substrate I5 for feeding the planar dipole antenna 1. The 2×2 PRAMC array 2 is printed on the upper surface of the dielectric substrate II 6, and the reflector 3 is printed on the lower surface of the dielectric substrate II 6.

[0005] As a further embodiment of the present invention, the planar dipole antenna 1 is an equivalent electric dipole, and the 2×2 PRAMC array 2 is an equivalent magnetic dipole. The equivalent electric dipole and the magnetic dipole are placed orthogonally in space to form an electromagnetic dipole antenna with complementary end-fire characteristics, and can generate a circularly polarized radiation beam in the end-fire direction.

[0006] As a further embodiment of the present invention, the planar dipole antenna 1 printed on the upper surface of the dielectric substrate I5 is a T-type dipole, and the middle part of the T-type dipole is slotted and symmetrical along the slot line.

[0007] As a further embodiment of the present invention, the 2×2 PRAMC array 2 printed on the upper surface of the dielectric substrate II 6 consists of four identical segmented circular rings with a gap angle α=15° between the rings. The lower surface is printed with a reflective plate 3, which is a metal floor with a size of 70mm×70mm.

[0008] As a further aspect of the present invention, the height of the 2×2 PRAMC array 2 printed on the upper surface of the dielectric substrate II 6 from the balun feed line 4 printed on the lower surface of the dielectric substrate I 5 is 7 mm.

[0009] As a further embodiment of the present invention, the balun feed line 4 printed on the lower surface of the dielectric substrate I5 is formed by sequentially connecting a first microstrip line, a second microstrip line, a third microstrip line, and a fourth microstrip line.

[0010] As a further embodiment of the present invention, both dielectric substrate I5 and dielectric substrate II6 are made of FR4 material with a size of 70mm×70mm, the dielectric constant of the dielectric substrate is 4.4, the loss tangent is 0.02, and the thicknesses of dielectric substrate I5 and dielectric substrate II6 are 0.8mm and 4mm, respectively.

[0011] The beneficial effects of this invention are: 1. A circularly polarized electromagnetic dipole antenna based on a polarized torsional artificial magnetic conductor, which has a planar structure, is simple in structure, and is easy to fabricate and integrate; 2. This invention uses a 2×2 PRAMC array as an equivalent magnetic dipole to replace the traditional magnetic dipole. It eliminates the need for additional metal apertures and complex feeding networks, significantly reducing the complexity of circularly polarized electromagnetic dipole antenna design while exhibiting good end-fire characteristics and circular polarization performance. 3. The operating frequency band covered by this invention is 2.19-3.30GHz, which can cover the 2.45GHz ISM band, and the operating frequency bandwidth is wide; 4. This invention transforms a simple electric dipole into an equivalent Huygens source using a 2×2 PRAMC array and converts linearized radiation into circularly polarized radiation, thus designing a planar circularly polarized electromagnetic dipole antenna with complementary end-fire characteristics. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the layered structure of a circularly polarized electromagnetic dipole antenna based on a polarized torsional artificial magnetic conductor according to the present invention. Figure 2 This is a schematic diagram of the planar dipole antenna of the present invention; Figure 3 This is a schematic diagram of the structure of the 2×2 PRAMC array of the present invention; Figure 4 The diagram shows the reflection coefficient and axial ratio of the circularly polarized electromagnetic dipole antenna of this invention. Figure 5 This is a diagram showing the gain and front-to-back ratio of the circularly polarized electromagnetic dipole antenna of this invention. Figure 6 The normalized radiation pattern of the circularly polarized electromagnetic dipole antenna of the present invention when operating at 2.45 GHz; Figure 7 This is a surface current distribution diagram for one cycle of the circularly polarized electromagnetic dipole antenna of the present invention when it operates at 2.45 GHz.

[0013] Figure 1 The labels are as follows: 1-Planar dipole antenna, 2-2×2 PRAMC array, 3-Reflector, 4-Ballon feeder, 5-Dielectric substrate I, 6-Dielectric substrate II. Detailed Implementation

[0014] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0015] Example 1: As Figures 1-7 As shown, a circularly polarized electromagnetic dipole antenna based on a polarized torsion artificial magnetic conductor includes a planar dipole antenna 1, a 2×2 PRAMC (polarized torsion artificial magnetic conductor) array 2, a reflector 3, a balun feed line 4, a dielectric substrate I 5, and a dielectric substrate II 6. The planar dipole antenna 1 is printed on the upper surface of the dielectric substrate I5, and the balun feed line 4 is printed on the lower surface of the dielectric substrate I5 for feeding the planar dipole antenna 1. The 2×2 PRAMC array 2 is printed on the upper surface of the dielectric substrate II 6, and the reflector 3 is printed on the lower surface of the dielectric substrate II 6.

[0016] As a further embodiment of the present invention, the planar dipole antenna 1 is an equivalent electric dipole, and the 2×2 PRAMC array 2 is an equivalent magnetic dipole. The equivalent electric dipole and the magnetic dipole are placed orthogonally in space, decomposing the incident linearly polarized wave into two orthogonal components with equal amplitude and a phase difference of 90°. The simple electric dipole is transformed into an equivalent Huygens source, forming an electromagnetic dipole antenna with complementary end-fire characteristics, and capable of generating a circularly polarized radiation beam in the end-fire direction.

[0017] As a further embodiment of the present invention, the planar dipole antenna 1 printed on the upper surface of the dielectric substrate I5 is a T-type dipole, and the middle part of the T-type dipole is slotted and symmetrical along the slot line.

[0018] As a further embodiment of the present invention, the 2×2 PRAMC array 2 printed on the upper surface of the dielectric substrate II 6 consists of four identical segmented circular rings with a gap angle α=15° between the rings. The lower surface is printed with a reflective plate 3, which is a metal floor with a size of 70mm×70mm.

[0019] As a further aspect of the present invention, the height of the 2×2 PRAMC array 2 printed on the upper surface of the dielectric substrate II 6 from the balun feed line 4 printed on the lower surface of the dielectric substrate I 5 is 7 mm.

[0020] As a further embodiment of the present invention, the balun feed line 4 printed on the lower surface of the dielectric substrate I5 is formed by sequentially connecting a first microstrip line, a second microstrip line, a third microstrip line, and a fourth microstrip line.

[0021] As a further embodiment of the present invention, both dielectric substrate I5 and dielectric substrate II6 are made of FR4 material with a size of 70mm×70mm, the dielectric constant of the dielectric substrate is 4.4, the loss tangent is 0.02, and the thicknesses of dielectric substrate I5 and dielectric substrate II6 are 0.8mm and 4mm, respectively.

[0022] In this invention, a planar dipole antenna 1 and a balun feed line 4 are printed on the upper and lower surfaces of a dielectric substrate I 5, respectively. The planar dipole is printed on the upper surface of the dielectric substrate I 5 as an equivalent electric dipole, and the balun feed line 4 is printed on the lower surface. A 2×2 PRAMC array 2 and a reflector 3 are printed on the upper and lower surfaces of a dielectric substrate II 6, respectively. The 2×2 PRAMC array 2 is printed on the upper surface of the dielectric substrate II 6 as an equivalent magnetic dipole, and the reflector 3 is printed on the lower surface to enhance forward radiation and suppress backward leakage. The planar dipole and the PRAMC array can be constructed as an equivalent Huygens source, forming an electromagnetic dipole antenna with complementary end-fire characteristics, converting linearized radiation into circularly polarized radiation, and operating in the 2.45 GHz ISM band. By loading a 2×2 PRAMC array, the antenna of this invention eliminates the need for additional metal apertures and complex feed network designs, significantly reducing the complexity of circularly polarized electromagnetic dipole antenna design while exhibiting excellent end-fire characteristics and circular polarization performance.

[0023] The working principle of this invention is: The present invention forms an equivalent electric dipole that generates linearly polarized radiation at 2.45 GHz using a dielectric substrate I5, a planar dipole antenna 1, and a balun feed line 4; and forms an equivalent magnetic dipole using a dielectric substrate II6, a 2×2 PRAMC array 2, and a reflector 3.

[0024] The planar dipole antenna 1 is placed above the 2×2 PRAMC array 2, and the two are orthogonally placed in space. This transforms the simple electric dipole into an equivalent Huygens source and converts linearized radiation into circularly polarized radiation, forming a planar circularly polarized electromagnetic dipole antenna with complementary end-fire characteristics.

[0025] Figure 4 The diagram shows the reflection coefficient and axial ratio of a circularly polarized electromagnetic dipole antenna. The antenna's -10dB impedance bandwidth is 45.3% (2.19-3.30GHz), and its 3dB axial ratio bandwidth is 3.6% (2.40-2.49GHz). Figure 5 The diagram shows the gain and front-to-back ratio of a circularly polarized electromagnetic dipole antenna. The antenna has a peak gain of 6.55 dBi and a maximum front-to-back ratio of 22.28 dB. Figure 6 The image shows the normalized radiation pattern of a circularly polarized electromagnetic dipole antenna at 2.45 GHz. The antenna in the 2.45 GHz band... xz and yz The gain of left-hand circularly polarized (LHCP) in the main beam direction of the plane is 6.55 dBic, while the gain of right-hand circularly polarized (RHCP) is -18.1 dBic. The results show that the antenna exhibits good left-hand circularly polarized radiation characteristics at 2.45 GHz.

[0026] Figure 7 The image shows the surface current distribution of a circularly polarized electromagnetic dipole antenna operating at 2.45 GHz for one cycle. At t=0 and t=T / 2, the current flows uniformly along the +y and -y directions, respectively, and the surface current of the PRAMC array is at its minimum. At t=T / 4 and t=3T / 4, the surface current of the PRAMC mainly flows along the +45° and -45° directions, respectively. Although no physical closed loop is formed, due to the in-phase reflection characteristics of the AMC, parallel and in-phase mirror currents are generated below its structure according to the mirror principle. In far-field radiation, the parallel currents are equivalent to a magnetic dipole in a vertical loop. Crucially, when the radiated current of the equivalent magnetic dipole reaches its peak, the current of the electric dipole is at its minimum, indicating a 90-degree time phase difference between them. This phase difference, combined with their spatial orthogonality, precisely constructs an equivalent Huygens source, perfectly satisfying the phase conditions for electromagnetic dipole antennas to achieve complementary end-fire and circularly polarized radiation.

[0027] In summary, based on the experimental results above, it can be seen that the antenna of the present invention uses a 2×2 PRAMC array as an equivalent magnetic dipole to replace the traditional magnetic dipole. This eliminates the need to introduce additional metal apertures and design complex feeding networks, significantly reducing the complexity of circularly polarized electromagnetic dipole antenna design while exhibiting good end-fire characteristics and circular polarization performance.

[0028] The specific embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A circularly polarized electromagnetic dipole antenna based on a polarized torsional artificial magnetic conductor, characterized in that: It includes a planar dipole antenna (1), a 2×2 PRAMC array (2), a reflector (3), a balun feed (4), a dielectric substrate I (5), and a dielectric substrate II (6); The planar dipole antenna (1) is printed on the upper surface of the dielectric substrate I (5), and the balun feed line (4) is printed on the lower surface of the dielectric substrate I (5) for feeding the planar dipole antenna (1). The 2×2 PRAMC array (2) is printed on the upper surface of the dielectric substrate II (6), and the reflector (3) is printed on the lower surface of the dielectric substrate II (6).

2. The circularly polarized electromagnetic dipole antenna based on a polarized torsional artificial magnetic conductor according to claim 1, characterized in that: The planar dipole antenna (1) is an equivalent electric dipole, and the 2×2 PRAMC array (2) is an equivalent magnetic dipole. The equivalent electric dipole and the magnetic dipole are placed orthogonally in space to form an electromagnetic dipole antenna with complementary end-fire characteristics, and can generate a circularly polarized radiation beam in the end-fire direction.

3. The circularly polarized electromagnetic dipole antenna based on a polarized torsional artificial magnetic conductor according to claim 1, characterized in that: The planar dipole antenna (1) printed on the upper surface of the dielectric substrate I (5) is a T-type dipole, and the middle part of the T-type dipole is slotted and symmetrical along the slot line.

4. The circularly polarized electromagnetic dipole antenna based on a polarized torsional artificial magnetic conductor according to claim 1, characterized in that: The upper surface of the dielectric substrate II (6) is printed with a 2×2 PRAMC array (2) consisting of four identical segmented rings with a ring gap angle α=15°. The lower surface is printed with a reflector (3), which is a metal floor with a size of 70mm×70mm.

5. A circularly polarized electromagnetic dipole antenna based on a polarized torsional artificial magnetic conductor according to claim 1, characterized in that: The 2×2 PRAMC array (2) printed on the upper surface of the dielectric substrate II (6) is 7 mm above the balun feed line (4) printed on the lower surface of the dielectric substrate I (5).

6. The circularly polarized electromagnetic dipole antenna based on a polarized torsional artificial magnetic conductor according to claim 1, characterized in that: The balun feed line (4) printed on the lower surface of the dielectric substrate I (5) is formed by connecting the first microstrip line, the second microstrip line, the third microstrip line and the fourth microstrip line in sequence.

7. A circularly polarized electromagnetic dipole antenna based on a polarized torsional artificial magnetic conductor according to claim 1, characterized in that: Both dielectric substrate I (5) and dielectric substrate II (6) are made of FR4 material with a size of 70mm×70mm. The dielectric constant of the dielectric substrate is 4.4, the loss tangent is 0.02, and the thicknesses of dielectric substrate I (5) and dielectric substrate II (6) are 0.8mm and 4mm, respectively.

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