KR20140139310A - multi-band circular polarization hexagonal slot microstrip antenna using multiful L-shaped slit - Google Patents

Abstract

The present invention relates to a multi-band circular polarization antenna. The multi-band circular polarization antenna includes: a dielectric substrate; a ground surface which is formed on a surface of the dielectric substrate and includes slots and slits connected to the slots; a power supply line formed the other surface of the dielectric substrate which is the opposite surface of the ground surface; and a reflection surface which is arranged below the dielectric substrate while being spaced apart from the dielectric substrate by a predetermined distance. The multi-band circular polarization antenna has multiple resonant bands according to the shapes of the slots and slits.

Description

The present invention relates to a triple-band circularly polarized hexagonal slot microstrip antenna using a plurality of L-shaped slits,

The present invention relates to a multi-band circularly polarized antenna, and more particularly, to a multi-band circularly polarized antenna having multiple bands by forming slots and slits on a ground plane of a dielectric substrate.

Microstrip antennas are low-profile, low weight, easy to fabricate, and can easily implement circular polarization, which is widely used to implement circularly polarized antennas. Circular polarization has excellent transmission characteristics in base station, mobile communication, and satellite communication environments in which polarity changes such as reflection, scattering, and diffraction are concerned, as well as polarity changes such as in the case of rainfall. It is progressing. Currently, various communication services such as satellite communication and global positioning system require antennas having multi-band circular polarization characteristics covering multi-band such as L1 band, L2 band, or GLONASS. However, it is difficult to fabricate the multi - band circularly polarized wave with narrow bandwidth and stacking type.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a multiband circularly polarized antenna having multiple bands by forming slots and slits.

In order to solve the above-described problems, the present invention provides a dielectric substrate comprising: a dielectric substrate; A ground plane formed on one surface of the dielectric substrate and having a slot and a slit connected to the slot; A feed line formed on both surfaces of the dielectric substrate opposite to the ground plane; And a reflection plate spaced apart from the dielectric substrate by a predetermined length. The multi-band circularly polarized antenna has a plurality of resonance bands according to the shape of the slot and the slit.

According to an embodiment of the present invention, a first resonance band is determined according to the shape and size of the slot, and the slot is a hexagonal shape.

According to another embodiment of the present invention, the number and frequency of the resonant bands of the antenna are determined according to the number of the slits, the length of the slit, and the position where the slit is connected to the slot, and as the length of the slit becomes longer And a resonance band frequency corresponding to the slit is reduced.

According to another embodiment of the present invention, the slit includes: a first slit connected to one side of the slot; And two second slits connected to both sides of a side to which the first slit is connected, of the sides of the slot, wherein a second resonant band is determined by the first slit, And a third resonant band is determined.

According to another embodiment of the present invention, the first slit and the second slit are in the form of an " L " shape, the length of the first slit is different from the length of the second slit, And the third resonance band according to the length of the two second slits can be independently adjusted.

According to another embodiment of the present invention, the feed line may be a multi-band circularly polarized antenna having a taper shape and having an impedance of 50 ohms.

According to another embodiment of the present invention, the distance between the dielectric substrate and the reflection plate is varied according to the frequency of the antenna.

According to the present invention, a slot and a slit can be used to provide a multi-band circularly polarized antenna. In addition, by including the reflector, the gain of the antenna can be increased. Furthermore, it is easier to fabricate than existing antennas, and a narrow circular polarization band can be improved.

1 illustrates a multi-band circularly polarized antenna according to an embodiment of the present invention.
2 shows a multi-band circularly polarized antenna according to an embodiment of the present invention.
3 is a graph showing the reflection coefficient and the axial ratio according to the embodiment of the present invention with and without the slit.
4 is a graph showing the reflection coefficient and the axial ratio according to the length change of the second slit according to the embodiment of the present invention.
5 is a graph showing the reflection coefficient and the axial ratio according to the variation of the length of the first slit according to the embodiment of the present invention.
6 illustrates a multi-band circularly polarized antenna according to an embodiment of the present invention.
7 is a graph showing the measured reflection coefficient of the multi-band circularly polarized antenna of FIG.
8 is a graph illustrating measured axial ratios of the multi-band circularly polarized antenna of FIG.
FIG. 9 is a graph illustrating the measured gain of the multi-band circularly polarized antenna of FIG. 6. FIG.
10 is a graph showing the measured radiation pattern of the multi-band circularly polarized antenna of FIG.

Prior to the description of the concrete contents of the present invention, for the sake of understanding, the outline of the solution of the problem to be solved by the present invention or the core of the technical idea is first given.

A multi-band circularly polarized antenna according to an embodiment of the present invention includes a dielectric substrate, a ground plane formed on one surface of the dielectric substrate and having a slot and a slit connected to the slot, And a reflection plate spaced apart from the dielectric substrate by a predetermined length and having a plurality of resonance bands according to the shape of the slot and the slit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It will be apparent to those skilled in the art, however, that these examples are provided to further illustrate the present invention, and the scope of the present invention is not limited thereto.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which: It is possible to quote the above. In the following detailed description of the principles of operation of the preferred embodiments of the present invention, it is to be understood that the present invention is not limited to the details of the known functions and configurations, and other matters may be unnecessarily obscured, A detailed description thereof will be omitted.

1 illustrates a multi-band circularly polarized antenna according to an embodiment of the present invention.

In order to realize the multi-band circular polarization characteristic, other devices must be stacked so as to have different resonance bands in the conventional antenna, which makes it difficult to manufacture an antenna. In order to simplify and miniaturize antenna fabrication, a multi-band circularly polarized antenna according to an embodiment of the present invention uses a slot 130 and slits 140 and 150.

The multi-band circularly polarized antenna according to an exemplary embodiment of the present invention includes a dielectric substrate 110, a ground plane 120, a feed line 160, and a reflection plate 170. The ground plane 120 includes a slot 130 And slits 140 and 150, respectively.

A triple band circularly polarized antenna is realized by the hexagonal slot 130 and the "L" -shaped slits 140 and 150 according to the embodiment of FIG. 1 is an example in which a multi-band circularly polarized antenna according to an embodiment of the present invention is implemented, and its configuration is not limited to FIG.

A ground plane is formed on one surface of the dielectric substrate 110, and a feed line 160 is formed on the other surface.

More specifically, a ground plane 120 formed with a slot 130 and slits 140 and 150 is formed on one surface of the dielectric substrate 110, and a feed line 160 is formed on the other surface. As the dielectric substrate 110, an RF-35 substrate can be used.

The ground plane 120 is formed on one surface of the dielectric substrate 110 and slits 140 and 150 connected to the slot 130 and the slot 130 are formed. And may have a plurality of resonance bands depending on the shape of the slot 130 and the slits 140 and 150.

More specifically, the ground plane 120 is formed on one surface of the dielectric substrate 110 in its entirety. A slot 130 for radiating a circularly polarized wave is formed on a ground plane 120 formed on one surface of the dielectric substrate 110 and slits 140 and 150 are connected to the slot 130 to form a multiple resonance band . The slits 140 and 150 may be one. It is easy to fabricate using the slot 130, has a bi-directional radiation pattern, and can have broadband characteristics. The slits 140 and 150 may be connected to the slot 130. A multiband antenna can be realized by the slits 140 and 150 implementing the resonant band characteristics other than the resonant band by the slot 130 and the slot 130 implementing one resonant band characteristic.

The first resonance band may be determined according to the shape and size of the slot 130.

More specifically, the shape and size of the slot 130 may vary. The slot 130 may be in the form of a hexagon. A hexagonally shaped slot can consist of two pairs of vertical-horizontal lines and two diagonal lines. The hexagonal shape may be a shape in which a diagonal edge is cut out into a regular triangle shape in a square shape. The hexagonal slot 130 generates a circular polarized wave by making an orthogonal electric field component have a phase difference of? / 2. That is, the slot 130 generates a circular polarization characteristic at a high frequency, and thus a first resonance band is determined.

The number and frequency of the resonant bands of the antenna can be determined according to the number of the slits 140 and 150, the length of the slits 140 and 150, and the position where the slits 140 and 150 are connected to the slot 130.

More specifically, a first resonant band is determined by the slot 130, and another resonant band is determined by the slits 140, 150 connected to the slot 130, so that a multi-band circularly polarized antenna can be realized. The number and frequencies of the multibands to be implemented by the multiband circularly polarized antenna according to the embodiment of the present invention are different from the number of the first resonant bands implemented by the slots 130 and the resonant frequencies of other resonant bands implemented by the slits 140 and 150 Lt; / RTI > The slits 140 and 150 are implemented in connection with the slots 130 and the number and frequency of the resonance bands implemented according to the number and length of the slits 140 and 150 and the positions connected to the slots 130 are determined . Two or more slits 140 and 150 may implement the same resonance band and frequency. Accordingly, the number of slits 140 and 150 may be the same as the number of the resonance bands, but may be different.

As the length of the slits 140 and 150 becomes longer, the resonance frequency corresponding to the slits 140 and 150 may be reduced. The electrical length is reduced or increased according to the length of the slits 140 and 150 and the longer the length of the slits 140 and 150 is, the smaller the resonance frequency corresponding to the slits 140 and 150 . That is, the resonance frequency corresponding to the slits 140 and 150 can be adjusted by adjusting the length of the slits 140 and 150.

The slot 130 and the slits 140 and 150 are formed in a hexagonal shape as shown in FIG. 1, and the slit includes a first slit 140 connected to one side of the slot, 130 and two second slits 150 connected to both sides of a side to which the first slit 140 is connected. The second resonant band can be determined by the first slit 140 and the third resonant band can be determined by the two second slits 150. [ The first slit 140 and the two second slits 150 are in the form of an L shape and the length of the first slit 140 and the length of the second slit 150 may be different. The second resonant band according to the length of the first slit 140 and the third resonant band according to the length of the two second slits 150 can be independently adjusted.

More specifically, the slits connected to the slot 130 may be implemented in the form of an "L" shape. The slits 140 and 150 may be formed of a first slit 140 formed at a diagonal position of the hexagonal slot 130 and two second slits 150 formed at a vertical position of the hexagonal slot and a horizontal position have. The second resonant band is determined by the first slit 140, and the two second slits 150 are implemented in the same shape to determine the third resonant band. Since the first slit 140 and the second slit 150 do not affect the resonance band of each other, the second resonance band and the third resonance band can be adjusted independently by adjusting the length of each slit.

The feed line 160 is formed on both surfaces of the dielectric substrate 110 on the opposite side of the ground plane 120.

More specifically, a ground plane formed with a slot 130 and slits 140 and 150 is formed on an upper surface of the dielectric substrate 110, and a feed line 160 is formed on the opposite surface. The feed line 160 is implemented in the form of a microstrip, and may be tapered for broadband resonance characteristics. The taper shape is implemented in a linearly widened form in the stripline structure. The reflection loss bandwidth of the antenna can be improved by the tapered feed line 160. The feed line 160 may be implemented to have an impedance of 50 ohms.

The reflection plate 170 is located a predetermined distance below the dielectric substrate 110.

More specifically, the pattern bi-directionality occurring in the microstrip slot antenna reduces the gain of the antenna. Thus, the signals in the opposite direction of the desired radial direction are reflected by the reflector 170 in the desired radial direction, thereby improving the gain of the antenna. For this, the reflector 170 is implemented at a position spaced apart from the dielectric substrate 110 by a predetermined length in the direction in which the feed line 160 is formed. It is possible to fix the reflection plate 170 to the dielectric substrate by using foam or the like which is non-conductive.

The distance between the dielectric substrate 110 and the reflection plate 170 may vary depending on the frequency of the antenna. The distance away from the dielectric substrate 110 may be determined according to the frequency of the first resonant band implemented by the slot 130. The length of the frequency of the first resonance band can be set to the length thereof.

A multi-band circularly polarized antenna according to an embodiment of the present invention may be used in a communication device. That is, it can be used in communication devices used in wireless communication and satellite communication in which high gain and multi-band circular polarization characteristics are required. A dielectric substrate, a ground plane formed on one surface of the dielectric substrate, the ground plane having a slot and a slit connected to the slot, a feed line formed on the opposite surface of the dielectric substrate to the ground plane, And a plurality of resonance bands are provided according to the shape of the slots and the slits. The multi-band circularly polarized antenna may be used to transmit or receive signals to perform communication. The detailed description of the communication device according to the embodiment of the present invention corresponds to the detailed description of the multi-band circularly polarized antenna of FIG. 1, and is replaced with a detailed description of the multi-band circularly polarized antenna of FIG.

2 illustrates a triple-band circularly polarized antenna according to an embodiment of the present invention.

A triple-band circularly polarized antenna according to an embodiment of the present invention includes a hexagonal slot 130 in which three L-shaped slits 140 and 150 having triple-band circular polarization characteristics are connected to a ground plane, and a taper taper type feeder line, and a reflector plate disposed at the lower portion by k from the feeder line. The hexagonal slot 130 having the triple-band circular polarization characteristic is composed of two diagonal lines having a vertical-horizontal line having a size of two pairs of Rw-tw and a size of √2 tw, and a ground plane center having a size of 60 mm × 60 mm Located. The L-shaped second slit 150 having the length of L1 and the height of h1 is connected to the vertical-horizontal line of the hexagonal slot by a distance d1 from the right point of each line, and the length of L2 and the height of h2 The L-shaped first slit 140 is located a distance d2 from the right point of the line. Each L-shaped slit has a thickness of 0.95 mm. The single feed line was a strip of 1.5 mm thick RF-35 substrate (relative dielectric constant = 3.5, loss tangent = 0.0018) with a 50-Ω impedance on the underside and a stripline structure with a thickness of 3.4 mm and a thickness of fh1- And is formed in a taper shape that linearly widens from fw to fw. The optimized design values of the triple-band circularly polarized antenna are shown in Table 1 below.

parameter value parameter value Rw 27.5 tw 11.5 fw 14.9 k 15 fh1 26.3 fh2 14.55 h1 2 h2 1.95 L1 10.25 L2 12.65 d1 5.72 d2 5.75 d3 0.63

FIGS. 3-5 are graphs of values of a triple-band circularly polarized antenna according to an embodiment of the present invention implemented by the values in Table 1 above.

3 is a graph showing the reflection coefficient and the axial ratio according to the embodiment of the present invention with and without a slit. The reflection loss and axial ratio of the hexagonal slot depend on the presence or absence of the L-shaped slit. First, the hexagonal slot structure generates a circular polarization characteristic at 4.8 GHz. By adding the "L" shaped slit of the hexagonal slot, circular polarization characteristics can be obtained in the other two frequency bands. As can be seen in FIG. 3, another circular polarization occurs at 4.2 GHz and 3.5 GHz when the L-shaped slit is added to the vertical-horizontal line and the diagonal line of the hexagonal slot.

4 is a graph showing the reflection coefficient and the axial ratio according to the length change of the second slit according to the embodiment of the present invention. And a simulation according to the change of the length L1 of the second L-shaped slit is shown. As the length L1 of the L-shaped slits 1 and 3 increased from 9.5 mm to 11 mm, the resonance band and the circular polarization characteristic near 4.2 GHz were lowered to the low frequency band, and the resonance band and the circular polarization characteristic of 3.5 GHz were not changed have.

5 is a graph showing the reflection coefficient and the axial ratio according to the variation of the length of the first slit according to the embodiment of the present invention. It can be confirmed that the change in the length L2 of the "L" -shaped first slit only affects the low-frequency resonance band and the circularly polarized characteristic as in the case of L1. Therefore, the L-shaped first slit, the second slit, and the hexagonal slot can independently adjust the circular polarization characteristic in the three frequency bands.

6 illustrates a multi-band circularly polarized antenna according to an embodiment of the present invention. It is an aerial photograph based on optimized parameters. The fabricated antenna was supported by using four foam on reflector. The antenna was powered by a 50-Ω coaxial cable and the reflection coefficient was measured using an Agilent 8510C network analyzer. The fabricated antenna meets the bandwidth of less than -10 dB reflection coefficient of 33.16% and 22.72%, and the axial ratio of less than 3 dB in three frequency bands was measured. Also, unidirectional patterns were measured at all frequencies.

7 is a graph showing the measured reflection coefficient of the multi-band circularly polarized antenna of FIG. Simulation results and measurement results show that the reflection coefficient bandwidth of less than -10 dB is 3.22 - 4.5 GHz (33.16%) in the low frequency band and 4.76 - 5.98 GHz (22.72%) in the high frequency band Respectively.

FIG. 8 is a graph illustrating measured axial ratios of the multi-band circularly polarized antenna of FIG. 6, and FIG. 9 is a graph illustrating measured gains of the multi-band circularly polarized antenna of FIG. The measured 3 dB axial ratio was measured at θ = 0 ° and was 1.7% (3.49 - 3.55 GHz), 3.86% (4.06 - 4.22 GHz) and 5.23% (5.03 - 5.3 GHz) ) Bandwidth. The antenna maximum gains within the measured 3 dB axial ratio bandwidth are 5.54 dBi, 4.68 dBi, and 6.85 dBi, respectively, as shown in Fig.

10 is a graph showing the measured radiation pattern of the multi-band circularly polarized antenna of FIG. (a), (b) and (c) show RHCP (co-polarization) and LHCP (cross-polarization) patterns measured at 3.53 GHz, 4.15 GHz and 5.08 GHz in the xz and yz planes. Since the co-polarization (RHCP) in the + z-axis direction is 16 dB higher than the cross-polarization (LHCP), it can be confirmed that the proposed antenna has unidirectionality in the + z-axis.

As described above, the present invention has been described with reference to particular embodiments, such as specific elements, and specific embodiments and drawings. However, it should be understood that the present invention is not limited to the above- And various modifications and changes may be made thereto by those skilled in the art to which the present invention pertains.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

110: dielectric substrate
120: ground plane
130: Slot
140: first slit
150: second slit
160: feeder line
170: reflector

Claims (13)

A dielectric substrate;
A ground plane formed on one surface of the dielectric substrate and having a slot and a slit connected to the slot;
A feed line formed on both surfaces of the dielectric substrate opposite to the ground plane; And
And a reflector disposed below the dielectric substrate and spaced apart by a predetermined length,
Wherein the resonator has a plurality of resonance bands depending on the shape of the slot and the slit.
The method according to claim 1,
Wherein a first resonant band is determined according to the shape and size of the slot.
The method according to claim 1,
Wherein the slot is a hexagonal shape.
The method according to claim 1,
Wherein the number and frequency of the resonant bands of the antenna are determined according to the number of the slits, the length of the slits, and the position where the slits are connected to the slots.
5. The method of claim 4,
Wherein a resonance band frequency corresponding to the slit becomes smaller as a length of the slit becomes longer.
The method of claim 3,
The slit
A first slit connected to one side of the slot; And
And two second slits connected to both sides of the side where the first slit is connected, of the sides of the slot.
The method according to claim 6,
A second resonance band is determined by the first slit,
And a third resonance band is determined by the two second slits.
The method according to claim 6,
Wherein the first slit and the second slit are in an " L " shape and the length of the first slit is different from the length of the second slit.
9. The method of claim 8,
Wherein a second resonance band along the length of the first slit and a third resonance band along the length of the two second slits can be independently adjusted.
The method according to claim 1,
Wherein the feed line is in the form of a taper.
The method according to claim 1,
Wherein the feed line has an impedance of 50 ohms.
The method according to claim 1,
Wherein a distance between the dielectric substrate and the reflector varies depending on a frequency of the antenna.
13. A communication device comprising a multi-band circularly polarized antenna according to any one of the preceding claims.

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