Circularly polarized antenna and circularly polarized antenna group

Abstract

The circularly polarized antenna comprises a first antenna unit, a second antenna unit and a third antenna unit, wherein the first antenna unit is arranged on a first side edge of a mobile phone frame; the second antenna unit is arranged on a second side edge of the mobile phone frame; the antenna coupling slot is used for forming a coupling capacitor and is arranged between the first end of the first antenna unit and the first end of the second antenna unit; and the radio frequency feed unit is arranged on the inner side of the first antenna unit or the inner side of the second antenna unit.

Description

Technical Field

[0001] The present application relates to the field of wireless communications, and more specifically to a circularly polarized antenna. Background Art

[0002] When linearly polarized electromagnetic waves pass through the atmospheric ionosphere, their polarization plane rotates. In addition, the ground terminal antenna also rotates in direction during movement. Therefore, there is a polarization mismatch problem when using linearly polarized antennas in satellite communication systems. Circular polarization can overcome the above problems well, so satellite communication antennas generally use circular polarization.

[0003] In addition, satellites are hundreds to tens of thousands of kilometers away from the ground, and space losses are large due to long distances. The built-in antenna gain of mobile phone terminals is also difficult to increase due to size and structural limitations. Summary of the invention

[0004] The present application provides a circular polarization antenna including: a first antenna unit, which is arranged on the first side of the mobile phone frame; a second antenna unit, which is arranged on the second side of the mobile phone frame; an antenna coupling gap, which is used to form a coupling capacitor, arranged between the first end of the first antenna unit and the first end of the second antenna unit; and a radio frequency feeding unit, which is arranged inside the first antenna unit or inside the second antenna unit. The above circular polarization antenna has a significantly improved gain compared to the built-in antenna of the mobile phone. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] In order to better describe and illustrate the embodiments of the present application, reference may be made to one or more drawings, but the additional details or examples used to describe the drawings should not be considered as limiting the scope of the invention of the present application, any of the currently described embodiments or preferred methods.

[0006] Figure 1 This is the schematic diagram of a circularly polarized antenna.

[0007] Figure 2 It is the structural diagram of a single circular polarization antenna.

[0008] Figure 3 It is a multi-antenna layout diagram.

[0009] Figure 4 is a single antenna axis and gain diagram.

[0010] Figure 5 It is a diagram showing the relationship between the 3D directional pattern of a single antenna 1 and a mobile phone.

[0011] Figure 6 It is the composite axial ratio and gain diagram of two left-hand polarized antennas.

[0012] Figure 7 This is the relationship diagram between the 3D radiation pattern after the gain of antenna 1 and antenna 3 is synthesized and the mobile phone.

[0013] Figure 8 It is the composite axial ratio and gain diagram of two right-hand polarized antennas.

[0014] Fig. 9 This is the relationship diagram between the 3D radiation pattern after the gain of antenna 2 and antenna 4 is synthesized and the mobile phone. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0016] Figure 1 This is the schematic diagram of the circular polarization antenna. The following introduces the principle and implementation of the circular polarization antenna.

[0017] The two perpendicular linear polarization electric fields are Ex and Ey respectively. are mutually perpendicular unit vectors

[0018] Ex=Vx*cos(ωt)

[0019]

[0020] The electric fields perpendicular to each other differ in phase by 90° and the synthesized electric field is:

[0021]

[0022] A phase difference of +90° or -90° can change the direction of circular polarization rotation. Changing the ratio of Ex and Ey can change the circular polarization axis ratio. The direction of the circular polarization electric field rotates in a circle over time.

[0023] Figure 2 This is a diagram of the structure of a single circular polarization antenna. The following describes the structure and implementation of a single circular polarization antenna. The horizontal and vertical frames of the mobile phone are used to generate two vertical electric fields respectively. Capacitive coupling or inductive coupling is generated between the horizontal and vertical frames to form a 90° phase difference between the two vertical electric fields. Here, the RF feeds the vertical frame to generate a vertical electric field, and the energy is coupled to the horizontal frame through the gap to generate a horizontal electric field. The gap coupling is equivalent to the capacitance effect to generate a 90-degree phase difference. The horizontal electric field + vertical electric field + 90° phase difference, all three conditions for circular polarization are met.

[0024] In one embodiment, a circularly polarized antenna includes: a first antenna unit, which is arranged on a first side of a mobile phone frame; a second antenna unit, which is arranged on a second side of the mobile phone frame; an antenna coupling gap, which is used to form a coupling capacitor and is arranged between a first end of the first antenna unit and a first end of the second antenna unit; and a radio frequency feeding unit, which is arranged on the inner side of the first antenna unit or the inner side of the second antenna unit.

[0025] In one embodiment, the first antenna unit and the second antenna unit are one of a monopole antenna and an inverted F antenna, and the implementation process is one of a flexible printed circuit antenna, a laser direct forming antenna or a frame antenna.

[0026] Figure 3 This is a multi-antenna arrangement diagram. The following introduces the multi-antenna arrangement and gain synthesis. Here, antennas 1, 2, 3, and 4 are designed according to the separate circularly polarized antenna structure at the four corners of the mobile phone. Antenna 1 and antenna 3 form left-hand circular polarization, and antenna 2 and antenna 4 form right-hand circular polarization. Antennas with the same polarization can achieve gain synthesis by adjusting the phase relationship. Here, antenna 1 and antenna 3 perform gain synthesis, and antenna 2 and antenna 4 perform gain synthesis.

[0027] In one embodiment, a circularly polarized antenna group includes: a first circularly polarized antenna and a third circularly polarized antenna, which are configured to form a left-handed circularly polarized antenna for gain synthesis; a second circularly polarized antenna and a fourth circularly polarized antenna, which are configured to form a right-handed circularly polarized antenna for gain synthesis; wherein the first circularly polarized antenna is arranged on the first side and the second side of the mobile phone, and the first antenna coupling slot is arranged at the corner formed by the first side and the second side; the second circularly polarized antenna is arranged on the second side and the third side of the mobile phone, and the second antenna coupling slot is arranged at the corner formed by the second side and the third side; the third circularly polarized antenna is arranged on the third side and the fourth side of the mobile phone, and the third antenna coupling slot is arranged at the corner formed by the third side and the fourth side; the fourth circularly polarized antenna is arranged on the fourth side and the first side of the mobile phone, and the fourth antenna coupling slot is arranged at the corner formed by the fourth side and the first side.

[0028] Figure 4 This is a single antenna axis and gain diagram. Taking a single antenna 1 as an example, a single antenna forms left-hand circular polarization within the range of 60±20° (right-hand circular polarization is generated near the symmetrical position -60°), the gain is 1dBi, the axis ratio is <9dB, and the axis ratio is as small as 1.8dB around Theta=60°. Figure 5 As shown in the red frame area, the circular polarization effect is significant. Figure 5 This is the relationship between the 3D radiation pattern of a single antenna 1 and a mobile phone. The relationship between the 3D radiation pattern of a single antenna 1 and a mobile phone, with a left-hand circular polarization gain of 1dBi in the zenith direction.

[0029] Figure 6This is the axial ratio and gain diagram of two left-hand polarized antennas. Antenna 1 and antenna 3 form left-hand circular polarization. The gain and axial ratio of the two antennas after synthesis are as follows: Axis ratio <10dB in the range of Theta=88±20° Theta=88° left-hand circular polarization gain 2.9dBi (right-hand circular polarization is also generated near the symmetrical position -88°), the minimum axial ratio is 4.5dB, and the circular polarization effect is significant, see Figure 7 As shown in the box, the gain of the two antennas after synthesis is increased by 1.9 dB compared with that of a single antenna, and there is a certain gain synthesis effect. Figure 7 This is the relationship diagram between the 3D radiation pattern after the gain of antenna 1 and antenna 3 is synthesized and the mobile phone.

[0030] Figure 8 This is the axial ratio and gain diagram of two right-hand polarized antennas. The relationship between the 3D directional diagram and the mobile phone after the gain of antenna 1 and antenna 3 is synthesized, and the left-hand circular polarization gain in the zenith direction is 2.9dBi. Antenna 2 and antenna 4 form right-hand circular polarization. The gain and axial ratio of the two antennas after synthesis are as follows: the axial ratio is <6.5dB in the range of Theta=45±30°, the circular polarization effect is significant, the right-hand gain is 2.4dBi (left-hand circular polarization is generated near the symmetrical position of -45°), and the gain of the two antennas after synthesis is increased by 1.4dB compared with a single antenna. Fig. 9 This is the relationship diagram between the 3D radiation pattern after the gain of antenna 2 and antenna 4 is synthesized and the mobile phone. The left-hand circular polarization gain in the zenith direction is 2.4dBi.

[0031] The following introduces orthogonal circular polarization antennas. Antennas 1 and 3 are combined to form left-hand circular polarization in a specific direction, and antennas 2 and 4 are combined to form right-hand circular polarization in a specific direction. The two sets of antennas are used simultaneously in the overlapping area to form orthogonal circular polarization, which not only improves the gain, but also orthogonal circular polarization can multiply the communication performance in MIMO communication systems. When the gain allows or the space is limited, one of antennas 1 and 3 is selected as a left-hand circular polarization antenna, and one of antennas 2 and 4 is selected as a right-hand circular polarization antenna. The two antennas are used simultaneously in the overlapping area to form orthogonal circular polarization. Although the gain is not as good as the previous one, it can also significantly improve the communication performance in the MIMO communication system.

[0032] The two sides separated by the gap in the horizontal and vertical directions are used as part of the antenna. One of them generates a vertical electric field and the other generates a horizontal electric field. One of them is fed, and the capacitance effect formed by the gap coupling between the two creates a 90° phase difference, forming a circularly polarized antenna. In a specific direction, left-hand circular polarization is formed, and the symmetrical direction is right-hand circular polarization. The two diagonal antennas are circularly polarized in the same rotation direction, and the antenna gain effect can be improved by combining the two antennas.

[0033] Some of the antennas at the four corners form left-hand circular polarization in a specific direction, while others form right-hand circular polarization. Making two sets of antennas with different polarization rotation directions can form orthogonal circular polarization antennas, which is conducive to doubling the communication performance. When the gain allows and the number of antennas or the space size is limited, one of antenna 1 or antenna 3 is selected as left-hand circular polarization, and one of antenna 2 or antenna 4 is selected as right-hand circular polarization, which can form low-gain orthogonal circular polarization.

[0034] Antenna 1 and antenna 3 are left-hand circular polarization. After the two antennas are combined, the rotation direction remains unchanged and becomes left-hand circular polarization, and the gain is improved. Similarly, antenna 2 and antenna 4 are right-hand circular polarization. After the two antennas are combined, the rotation direction remains unchanged and becomes right-hand circular polarization, and the gain is improved. In this way, after gain synthesis, the two pairs of antennas can form high-gain orthogonal circular polarization.

[0035] Slot coupling is used between the two horizontal and vertical antenna parts to produce capacitive coupling effect to form a 90° phase difference. If other forms of slots are used or direct-connected capacitors or inductors or capacitor-inductor type devices or capacitor-inductor effect coupling are used between the two antennas, a 90° phase difference can also be generated to achieve a circular polarization effect.

[0036] The horizontal and vertical antennas use a partitioned antenna frame. If other structures of frames or other built-in antenna forms such as FPC LDS are used to make similar two-part structures that are perpendicular to each other, circular polarization can also be formed by adding capacitors or inductive coupling between the two parts.

[0037] The circular polarization rotation directions of the two diagonal antennas of the mobile phone are the same. The two sets of antennas with the same polarization rotation direction can improve the antenna gain after phase synthesis. If the two corner antennas on the same side, such as antennas 1 and 2 or antennas 1 and 4 in the figure, are designed with circular polarization in the same rotation direction, the two antennas on the same side can also be synthesized to improve the gain.

[0038] The diagonal antennas 1 and 3 are both left-hand circular polarization, and the antennas 2 and 4 are both right-hand circular polarization. After the two groups are combined, the gain is improved and orthogonal circular polarization is formed. If the two groups of antennas on one side are designed to be left-hand circular polarization (such as antennas 1 and 2 or antennas 1 and 4 in the figure), and the two groups of antennas on the other side are designed to be right-hand circular polarization (such as antennas 3 and 4 or antennas 3 and 2 in the figure), the gain of the antennas on both sides can be improved after synthesis and they are orthogonal circular polarization antennas.

[0039] In order to improve the antenna gain, the two orthogonal circularly polarized antennas are both synthesized using two antennas. If the gain requirement is not high or the antenna space is limited, two separate left-hand circularly polarized and right-hand circularly polarized antennas can also form an orthogonal circularly polarized antenna. For example, antenna 1 is used for left-hand circular polarization and antenna 2 is used for right-hand circular polarization (or antennas 1 and 4 are a group of orthogonal circular polarization, antennas 3 and 2 are a group of orthogonal circular polarization, and antennas 3 and 4 are a group of orthogonal circular polarization). Orthogonal circularly polarized antennas can also be formed.

[0040] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0041] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A circularly polarized antenna, It is characterized in that include: A first antenna unit, which is arranged on a first side of the mobile phone frame; A second antenna unit, which is arranged on a second side of the mobile phone frame; An antenna coupling gap, which is used to form a coupling capacitor and is arranged between the first end of the first antenna unit and the first end of the second antenna unit; The radio frequency feeding unit is arranged inside the first antenna unit or inside the second antenna unit.

2. The circularly polarized antenna according to claim 1, It is characterized in that The first antenna unit and the second antenna unit are one of a monopole antenna and an inverted F antenna, and the implementation process is one of a flexible printed circuit antenna, a laser direct forming antenna or a frame antenna.

3. A circular polarization antenna group, It is characterized in that include: a first circularly polarized antenna, a second circularly polarized antenna, a third circularly polarized antenna, and a fourth circularly polarized antenna, wherein the first circularly polarized antenna, the second circularly polarized antenna, the third circularly polarized antenna, and the fourth circularly polarized antenna are all circularly polarized antennas as claimed in claim 1, wherein the first circularly polarized antenna and the third circularly polarized antenna are configured to form a left-handed circularly polarized antenna for gain synthesis; and the second circularly polarized antenna and the fourth circularly polarized antenna are configured to form a right-handed circularly polarized antenna for gain synthesis; Wherein, the first circularly polarized antenna is arranged on the first side and the second side of the mobile phone, and the first antenna coupling slot is arranged at the corner formed by the first side and the second side; The second circularly polarized antenna is arranged on the second side and the third side of the mobile phone, and the second antenna coupling slot is arranged at the corner formed by the second side and the third side; The third circularly polarized antenna is arranged on the third side and the fourth side of the mobile phone, and the third antenna coupling slot is arranged at the corner formed by the third side and the fourth side; The fourth circularly polarized antenna is arranged on the fourth side and the first side of the mobile phone, and the fourth antenna coupling slot is arranged at the corner formed by the fourth side and the first side.

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