KR102282029B1 - Circular polarization antenna - Google Patents

Abstract

The present invention relates to a circular polarization antenna simple in structure and generating four independently controlled circular polarization modes. The circular polarization antenna includes a substrate, a power supply portion formed on one surface of the substrate and supplied with external power, and an emitter electrically connected to the power supply portion. A polygonal ring is formed in the emitter. A gap and a notch are connected to one edge of the polygonal ring. A slot is formed so as to surround the polygonal ring. The gap and the notch generate at least one first circular polarization mode. The slot generates a second circular polarization mode. The first and second circular polarization modes are independently controlled and differ in frequency.

Description

Circularly polarized antenna {CIRCULAR POLARIZATION ANTENNA}

The present invention relates to a circularly polarized antenna generating four circularly polarized modes.

The conventional circular polarization antenna has a complex structure to generate a plurality of circular polarization modes, and as a result, the size of the antenna is increased.

US 10-2064175 B

An object of the present invention is to provide a circularly polarized antenna that generates four independently controlled circularly polarized modes with a simple structure.

In order to achieve the above object, a circularly polarized antenna according to an embodiment of the present invention includes a substrate; a power supply unit formed on one surface of the substrate and supplied with external power; and a radiator electrically connected to the power supply unit. Here, a polygonal ring is formed inside the radiator, a gap and a notch are connected to one edge of the polygonal ring, a slot is formed to surround the polygonal ring, and the gap and the notch are at least one first circular polarization mode , the slot generates a second circular polarization mode, the first circular polarization mode and the second circular polarization mode are independently controlled, the frequency of the first circular polarization mode and the second circular polarization mode different frequencies.

An antenna according to another embodiment of the present invention includes a substrate; a feeding unit formed on one surface of the substrate; a radiator electrically connected to the feeding unit; and an 'inverted V'-shaped parasitic element spaced apart from the radiator. Here, an open loop rectangular ring is formed inside the radiator, a gap and a notch are connected to one edge of the rectangular ring, and a rhombic slot is formed to surround the rectangular ring.

The circularly polarized antenna according to the present invention can generate four independently controlled circularly polarized modes using a gap and a notch, a rhombic slot, and a parasitic element. In particular, the circularly polarized antenna may be implemented with a simple structure.

1 and 2 are views illustrating a circularly polarized antenna according to an embodiment of the present invention.
3 is a diagram illustrating the structure of various antennas.
4 is a diagram illustrating current distributions of antenna 1 and antenna 1*.
5 is a diagram illustrating performance results of antenna 1, antenna 1*, and antenna 2;
6 to 9 are diagrams illustrating current distributions of antennas 2 to 4;
10 is a diagram illustrating performance results of antennas 2 to 4;
11 is a diagram illustrating a radiation pattern of an antenna at frequencies according to an embodiment of the present invention.
12 is a diagram illustrating simulation and measurement results, and FIG. 13 is a diagram illustrating a circularly polarized antenna in which variables are displayed.
14 to 17 are diagrams illustrating changes in antenna performance results according to variable changes.

As used herein, the singular expression includes the plural expression unless the context clearly dictates otherwise. In this specification, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various components or various steps described in the specification, some of which components or some steps are It should be construed that it may not include, or may further include additional components or steps. In addition, terms such as "...unit" and "module" described in the specification mean a unit that processes at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software. .

The present invention relates to an antenna that generates multi-band circularly polarized waves, for example, four circularly polarized waves while having a simple structure, and the circularly polarized waves can be independently controlled.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 are diagrams showing a circularly polarized antenna according to an embodiment of the present invention, FIG. 3 is a diagram showing the structures of various antennas, and FIG. 4 is a diagram showing the current distribution of antenna 1 and antenna 1* it is one drawing 5 is a view showing the performance results of antenna 1, antenna 1*, and antenna 2, FIGS. 6 to 9 are diagrams showing the current distribution of antenna 2 to antenna 4, and FIG. 10 is an antenna 2 to antenna 4 It is a diagram showing the performance result. 11 is a diagram illustrating a radiation pattern of an antenna at frequencies according to an embodiment of the present invention. 12 is a diagram illustrating simulation and measurement results, FIG. 13 is a diagram illustrating a circularly polarized antenna with parameters displayed, and FIGS. 14 to 17 are diagrams illustrating changes in antenna performance results according to changes in parameters.

1 and 2, the circularly polarized antenna of this embodiment may include a dielectric substrate 100, a power feeding unit 102, a radiator 104, a ground 106, and a parasitic element (parasitic pattern, 118). there is.

The radiator 104 and the parasitic element 118 may be formed on one surface of the substrate 100 , and the ground 106 may be formed on the other surface (opposite surface) of the substrate 100 . At this time, power supplied from an external power source (not shown) is directly supplied to the ground 106 , and as a result, the supplied power may be coupled and transferred from the ground 106 to the power supply unit 102 . Of course, the power may be provided directly to the power supply unit 102 instead of the ground 106 .

The power feeding unit 102 may transmit external power to the radiator 104 as a conductor.

According to an embodiment, the radiator 104 is electrically connected to the power feeding unit 102 as a conductor, and may have, for example, a rhombus shape, and may have an open loop structure.

An open loop polygonal ring, for example, a square ring 110 , a gap 112 , a notch 114 , and a rhombus-shaped slot 116 may be formed on the radiator 104 .

The square ring 110 is formed in the central portion of the radiator 104, and the gap 112 and the notch 114 may be formed at an angle of, for example, 90 degrees to each other based on one edge of the square ring 110, , the slot 116 may have a rhombus shape in a state separated from the square ring 110 and surround the square ring 110 . In this case, the slot 116 may be spaced apart from the gap 112 and the notch 114 .

As a conductor, the parasitic element 118 may have an 'inverted V' shape and be spaced apart from the radiator 104 to receive coupling power from the radiator 104 .

According to one embodiment, a notch 120 may be formed on the ground 106 . For example, the notch 120 may be formed at a position corresponding to the power feeding unit 102 in the central portion of the substrate 100 in the width direction.

An antenna of this structure can generate circularly polarized waves of four different frequencies. In particular, each of the circularly polarized waves can be independently controlled.

The conventional circularly polarized antenna has a complicated structure to generate three circularly polarized waves, but the circularly polarized antenna of the present invention can generate four circularly polarized waves with a simple structure. As a result, the circularly polarized antenna may be lightweight and easy to integrate into equipment.

In addition, since the four circularly polarized waves are independently controlled, they can be adaptively used for various communications according to a user's purpose.

Hereinafter, a process of generating four circularly polarized waves will be described with reference to FIG. 3 . However, reference numerals are omitted for convenience of description.

Antenna 1 has a structure in which only a square ring is formed in the center of the radiator, Antenna 2 has a structure in which a square ring, a gap, and a notch are formed on the radiator, and Antenna 3 has a structure in which a square ring, a gap, a notch, and a rhombic slot are formed on the radiator The antenna 4 has a structure in which a square ring, a gap, a notch, and a rhombus-shaped slot are formed on a radiator, and a parasitic element is separated from the radiator.

Since antenna 1 is a corner-fed closed-loop antenna and has a symmetrical structure around a square ring, the horizontal component is canceled and only the E field (electric field), which is the vertical component, remains, as a result, as shown in FIG. It generates a linear polarization. At this time, as shown in (a) of FIG. 4, the surface currents are strongly distributed on the outer periphery of the square ring, and can have a basic mode of TM11 at a frequency of 4.8 GHz.

Antenna 1* has a structure in which a square ring and a gap are formed, and by adding such a gap, additional resonance occurs at frequencies of 2.8 GHz and 3.7 GHz, thereby realizing a wide bandwidth.

When there is only a square ring, it has a symmetrical surface current distribution, but by adding such a gap, the symmetrical surface current distribution is broken as shown in (b) of FIG. 4 . That is, an asymmetrical surface current distribution is formed. As a result, a surface current distribution is generated in the horizontal direction as shown in Fig. 4(b). That is, when there is only the rectangular ring, the horizontal component is removed due to the symmetrical current distribution, but the horizontal component is present by adding the gap.

Referring back to FIG. 4(b), the surface current distribution is strongly concentrated near the inner edge (edge of the square ring) and the outer edge (edge of the emitter) having different current paths, as a result of FIG. 5(d) As shown in Fig. 2, circularly polarized waves are generated at 2.9 GHz and 5.6 GHz, respectively. That is, antenna 1* can generate two circularly polarized waves.

However, since the axial ratio at 5.6 GHz does not satisfy the circular polarization requirement and the circular polarization mode does not cover the target application band, a notch may be additionally formed as shown in antenna 2.

The notch in antenna 2 shifts the axial ratio curve to a lower frequency because it increases the current path as shown in FIGS. 6 and 7, and as a result, at 2.5 GHz and 5.4 GHz as shown in FIG. Efficient circular polarizations can be generated. Such a notch may reduce the size of the antenna.

At 2.5 GHz, left-hand circular polarization (LHCP) is generated as shown in FIG. 6, and at 5.4 GHz, as shown in FIG. 7, right-hand circular polarization (RHCP) can cause

Here, the resonant frequency of the circularly polarized waves is determined by the outer edge length (edge length of the emitter, W1 in Fig. 13) and the inner edge length (edge length of the square ring, W2 in Fig. 13), and the positions of the notch and the gap are at least It can be used to have an axis ratio of However, the notch and the gap may be formed to be separated by a predetermined angle in consideration of the axial ratio while being connected to one edge of the square ring.

Varying the inner edge length W2, that is, varying the size of the square ring, affects the circular polarization at 2.5 GHz. For example, if the inner edge length W2 is increased, the axial ratio curve at 2.5 GHz moves to a lower frequency as shown in FIG. 14(b) because the inner loop circumference is increased.

At this time, the change of the inner edge length W2 does not affect other circular polarization modes due to the rhombic slot and parasitic elements. That is, the circular polarization generated by the gap and the notch is independently controlled by the outer edge length and the inner edge length, but the outer edge length and inner edge length change do not affect other circular polarization modes.

Although not shown, if the outer edge length W1 is changed, the frequency of the circular polarization mode at 5.4 GHz may shift to another frequency. That is, the circular polarization mode of 5.4 GHz can be controlled by varying the outer edge length W1.

Antenna 3 is further formed with a rhombus slot, the rhombus slot may be formed to surround a square ring. In particular, the rhombic slot is symmetrically formed with respect to the square ring. These diamond-shaped slots are used to balance horizontal and vertical currents at intermediate frequencies. As a result, a new circular polarization mode may occur at 3.5 GHz as shown in FIG. 10(d).

This circularly polarized wave has a current distribution as shown in FIG. 8, and as a result, it may be a left-handed circularly polarized wave.

The resonant frequency of the new circular polarization mode due to the rhombic slot may be determined by the perimeter of the rhombic slot. For example, if D2 is increased in FIG. 13, that is, if the circumferential length of the slot is increased, the axial ratio curve moves to a frequency lower than 3.5 GHz as shown in FIG. 16(b). At this time, the frequency of the other circular polarization mode does not change. That is, the frequency of the new circular polarization mode is independently controlled by the circumferential length of the rhombus slot, but does not affect circular polarization modes having different perimeter lengths of the rhombus slot.

On the other hand, although a curved slot other than the rhombic slot may be formed around the square ring, the efficiency is better than the curved slot because the rhombic slot has an edge and the current distribution is strongly concentrated around the edge. Therefore, a rhombic slot is preferred.

In the antenna 4, a parasitic element is additionally formed, and the parasitic element may be formed symmetrically with an 'inverted V' shape outside the radiator. Such a parasitic element may generate a new circular polarization mode at a frequency of 2.9 GHz as shown in FIG. 10(d) , but may generate a left-handed circular polarization mode as shown in FIG. 9 .

The resonant frequency of this new circular polarization mode may be determined by the length of the parasitic element (W3 in FIG. 13 ). For example, when W3 is decreased, the axial ratio curve is shifted to a higher frequency as shown in FIG. 15B because the circumference of the current path of the parasitic element is reduced. At this time, the frequency of the other circular polarization mode is not changed. That is, the resonant frequency of the new circular polarization mode is independently controlled by the length of the parasitic element, but a change in the length of the parasitic element does not affect other circular polarization modes.

A notch in the ground is used to increase the impedance bandwidth.

In summary, the circularly polarized antenna of the present invention uses a gap and a notch, a rhombus-shaped slot, and a parasitic element, as shown in FIG. 11, with four circularly polarized waves (2.5 GHz, 2.9 GHz, 3.5 GHz and 5.4 GHz) ) can occur. At this time, the circularly polarized waves are each independently controlled.

Meanwhile, the simulation and measurement results of the circular polarization modes are shown in FIG. 12 .

On the other hand, the components of the above-described embodiment can be easily grasped from a process point of view. That is, each component may be identified as a respective process. In addition, the process of the above-described embodiment can be easily understood from the viewpoint of the components of the apparatus.

The above-described embodiments of the present invention have been disclosed for the purpose of illustration, and various modifications, changes, and additions will be possible within the spirit and scope of the present invention by those skilled in the art having ordinary knowledge of the present invention. should be regarded as belonging to the following claims.

100: substrate 102: power supply unit
104: radiator 106: ground
110: square ring 112: gap
114: notch 116: rhombic slot
118: parasitic element 120: notch

Claims (7)

Board;
a power supply unit formed on one surface of the substrate and supplied with external power; and
Including a radiator electrically connected to the feeding unit,
A polygonal ring is formed inside the radiator, a gap and a notch are connected to one edge of the polygonal ring, and a slot is formed to surround the polygonal ring,
wherein the gap and notch generate at least one first circular polarization mode, the slot generates a second circular polarization mode, the first circular polarization mode and the second circular polarization mode are independently controlled; A circular polarization antenna, characterized in that the frequency of the first circular polarization mode and the frequency of the second circular polarization mode are different. According to claim 1,
Further comprising a parasitic element formed to be spaced apart from the radiator,
the parasitic element generates a third circularly polarized mode, and the third circularly polarized mode is also independently controlled;
wherein said polygonal ring is an open loop rectangular ring, said gap and notch generating two first circular polarization modes;
The circularly polarized antenna, characterized in that the frequencies of the first circularly polarized mode, the second circularly polarized mode and the third circularly polarized mode are different from each other. 3. The method of claim 2, wherein the frequencies of the first circular polarization modes are determined by the size of the rectangular ring or the size of the radiator,
The circular polarization antenna, characterized in that the change in the size of the square ring does not affect the remaining circular polarization modes except for the first circular polarization modes. 3. The method of claim 2, wherein the slot surrounds the polygonal ring with a rhombic slot,
The frequency of the second circular polarization mode due to the slot is determined by the circumferential length of the slot, and the change in the circumferential length of the slot does not affect the other circular polarization modes except for the second circular polarization mode. Circularly polarized antenna. The method of claim 2, wherein the parasitic element has an 'inverted V' shape,
The frequency of the third circular polarization mode due to the parasitic element is determined by the length of the parasitic element, and the change in the length of the parasitic element does not affect the other circular polarization modes except for the third circular polarization mode. Circularly polarized antenna. According to claim 1,
Further comprising a ground formed on the other surface of the substrate,
The external power is supplied to the ground, the supplied power is coupled to the radiator, and a notch is formed in the ground. Board;
a feeding unit formed on one surface of the substrate;
a radiator electrically connected to the feeding unit; and
Including a parasitic element of an 'inverted V' shape formed to be spaced apart from the radiator,
An open-loop rectangular ring is formed inside the radiator, a gap and a notch are connected to one edge of the rectangular ring, and a rhombus-shaped slot is formed to surround the rectangular ring.

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