KR100835994B1 - The circular polarization folded microstrip antenna in which a miniaturization is possible of three dimensional structure - Google Patents

Abstract

A circular polarization folded microstrip antenna of a three dimensional structure is provided to perform miniaturization without deterioration of radiation efficiency and a gain due to dielectric loss by adjusting a length of a bottom side. A circular polarization folded microstrip antenna of a three dimensional structure includes a metallic triangle patch(110), a ground plate(120), and a dielectric. The triangle patch includes a flat panel part(111), a first iris(112a), a second iris(112b), a third iris(112c), and a fourth iris(112d), and a first folded portion(113a), a second folded portion(113b), a third folded portion(113c), and a fourth folded portion(113d). When the first to fourth folded portions are converged in a central direction of the flat panel part, both oblique sides of each folded portion are separated from one oblique side of a folded portion adjacent thereto by a predetermined gap.

Description

The circular polarization folded microstrip antenna in which a miniaturization is possible of three dimensional structure}

1A is a plan view showing the structure of a triangular patch antenna according to a first embodiment of the present invention;

1B is a graph showing the return loss of the triangular patch antenna according to the first embodiment of the present invention;

Figure 1c is a view showing a radiation pattern of the triangular patch antenna according to the first embodiment of the present invention,

1D is a view showing an axial ratio of a triangular patch antenna according to a first embodiment of the present invention;

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3A is a plan view showing the structure of a planar linearly polarized microstrip antenna according to a first comparative example of the present invention;

3b is a graph showing the return loss of the planar linearly polarized microstrip antenna according to the first comparative example of the present invention;

3c is a plan view of a linearly polarized folded microstrip antenna with plates attached to both ends according to a first comparative example of the present invention;

Figure 3d is a graph showing the frequency change according to the height of the plate attached to both ends according to the first comparative example of the present invention,

3E is an exemplary view showing a current path change according to plate attachment according to a first comparative example of the present invention;

3F is a plan view showing the structure of a linearly polarized folded microstrip antenna with an optimized plate according to a first comparative example of the present invention;

3g is a diagram showing radiation loss of a linearly polarized folded microstrip antenna with an optimized plate according to a first comparative example of the present invention;

4A is a plan view illustrating a structure of a linearly polarized folded microstrip antenna in which a plate bent vertically to a lower side according to a second comparative example of the present invention is bent horizontally in a patch center direction;

4b is a view showing a frequency change according to the bottom length of a folded microstrip antenna according to a second comparative example of the present invention;

4C is a plan view showing the structure of an optimized linearly polarized folded microstrip antenna having a center frequency of 1.575 GHz according to a second comparative example of the present invention;

4d is a graph showing the return loss of the final linearly polarized folded microstrip antenna according to the second comparative example of the present invention;

4E illustrates a radiation pattern of a final linearly polarized folded microstrip antenna according to a second comparative example of the present invention.

<Description of Symbols for Main Parts of Drawings>

100: triangular patch antenna 110: triangular patch

111: flat plate portion 111a, 111b, 111c, 111d: right angle

113a, 113b, 113c, 113d: Folding portion 120: Ground plate

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The present invention relates to a bottom structure of a microstrip antenna, and in particular, by forming a circular polarization by changing a triangular or quadrangular structure of the patch base of the folded microstrip antenna, the miniaturization of the folded microstrip antenna can be made smaller. The present invention relates to a circularly polarized folded microstrip antenna having a three-dimensional structure.

Microstrip antennas, currently widely used as antennas for global positioning systems (GPS), are low profile and easy to attach, regardless of surface shape. In the case of using printing technology, it is easy to manufacture and inexpensive, so it is easy to use for applications in which air resistance, size and weight are important. For example, it is mainly used in aircraft, satellite systems, missiles or mobile communication systems [Microstrip Antennas, 1982].

As another method of miniaturizing the above-described antennas, short-circuit pins, slits, and slots are used [Microstrip Antenna Design Handbook, 2001], or three-dimensional shape deformation methods that change the shape in three dimensions. The structures used were studied ["Corrugated circular microstrip patch antennas for miniaturization", 2001./ "Miniaturization of microstrip patch antenna using perturbation of radiating slot", 2003. / "Study on Miniaturization of Iris Attached 3D Linearly Polarized Microstrip Patch Antenna", 2003.].

Recently, a method of miniaturizing an antenna using a dielectric as a dielectric having a high dielectric constant has been mainly used. However, there is a difficulty in miniaturizing the microstrip antenna because antenna characteristics such as bandwidth and radiation efficiency are deteriorated.

The present invention, which was devised to solve the above problems, by changing the structure of the patch base of the folded microstrip antenna in a triangular or square structure to form a circular polarization, so that the folded microstrip antenna can be miniaturized Its purpose is to provide a circularly polarized folded microstrip antenna with a three-dimensional structure that can be miniaturized.

In addition, the present invention is designed to obtain a more stable axial ratio characteristics by adjusting the length of the base in the same state of the visible width and length of the antenna.

In order to realize the technical features as described above, the present invention provides a triangular patch of a metal material, a ground plate performing a normal grounding function, and a predetermined dielectric constant and is charged between the triangular patch and the ground plate to support them. A triangularly polarized folded microstrip antenna having a triangular bottom structure composed of a dielectric material, the triangular patch comprising: a flat plate having a right angle cut at right angles at each end of a quadrangle; First iris, second iris, third iris and fourth iris extending perpendicularly to the ground plate in each end of the flat plate; And a first fold portion, a second fold portion, a third fold portion in which extension ends of each of the first iris, the second iris, the third iris and the fourth iris extend in parallel to the plate portion inside the triangular patch; A fourth fold; It consists of.

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Before describing the present invention in detail, it should be noted that the detailed description of known functions and configurations related to the present invention is omitted if it is determined that the gist of the present invention may unnecessarily obscure the subject matter of the present invention. .

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

The structure and features of the triangular bottom polarized folded microstrip antenna 100 (hereinafter referred to as 'triangular patch antenna') according to the first embodiment of the present invention will be described with reference to FIGS. 1A to 1D.

Figure 1a is a view showing the structure of a circular polarized folded microstrip antenna of the triangular bottom structure according to the first embodiment of the present invention, Figure 1b is a circular polarized folded of the triangular bottom structure according to the first embodiment of the present invention Figure 1c is a graph showing the radiation loss measured using a microstrip antenna, Figure 1c is a diagram showing a radiation pattern measured using a circularly polarized folded microstrip antenna of the triangular bottom structure according to the first embodiment of the present invention, 1D is a diagram illustrating an axial ratio bandwidth using a circularly polarized folded microstrip antenna having a triangular bottom structure according to a first embodiment of the present invention.

First, as shown in FIG. 1A, the triangular patch antenna 100 includes a triangular patch 110 of a rectangular metal material, a ground plate 120 performing a normal ground (GND) function, and a predetermined dielectric constant. And a dielectric (not shown) that is charged between the triangular patch 110 and the ground plate 120 to support them, wherein the conductive coupling is connected to the feed point A of the triangular patch 110. Means B are connected.

At this time, the ground plate 120 is preferably set in a rectangular shape of a metal material, but the shape is not limited to this can be set in various shapes.

As mentioned above, the dielectric (not shown) is filled between the triangular patch 110 and the ground plate 120, so that the triangular patch 110 is maintained in the shape as shown in Figure 1a.

Here, the triangular patch 110 includes a flat plate 111 at which right angles 111a, 111b, 111c, and 111d are cut at right angles at each end of a quadrangle, and at each end of the flat plate 111. A first iris 112a, a second iris 112b, a third iris 112c and a fourth iris 112d extending perpendicularly to the ground plate 120, and the first iris 112a, The first folding portion 113a, in which an extended tip of each of the second iris 112b, the third iris 112c, and the fourth iris 112d extends in the triangular patch 110 in parallel with the flat plate 111. And a second folding part 113b, a third folding part 113c and a fourth folding part 113d.

Here, the first folding portion 113a, the second folding portion 113b, the third folding portion 113c, and the fourth folding portion 113d may have respective triangles Δ in the center direction of the flat plate portion 111. Keep the prize. The vertices of the first folding portion 113a, the second folding portion 113b, the third folding portion 113c and the fourth folding portion 113d having the triangular shape are centered on the flat portion 111. When converging in the direction, both hypotenuses of each of the first foldable portion 113a, the second foldable portion 113b, the third foldable portion 113c, and the fourth foldable portion 113d are defined by one side hypotenuse and a predetermined side of the adjacent foldable portion. Spaced apart.

In the first embodiment, the separation distances of the folding portions 113a, 113b, 113c, and 113d are set to 1 mm, but the present invention is not limited thereto.

For reference, in the folding portion 113, the first folding portion 113a and the third folding portion 113c, and the second folding portion 113b and the fourth folding portion 113d are symmetrical with each other (對稱, symmetry), but the present invention is not limited thereto.

On the other hand, a feeding point A is located near the center of the flat plate part 111. This feed point A is preferably changed in position depending on the resonance frequency setting of the antenna.

In the first embodiment of the present invention, the triangular patch antenna 100 is the flat plate 111, the iris (112: 112a, 112b, 112c, 112d) and the folding portion (113: 113a, 113b, 113c, 113d) ) Is not individually coupled to each other, but the first iris 112a, the second iris 112b, the third iris 112c and the fourth iris 112d in an integrally formed state, and the flat plate 111 The first iris 112a, the second iris 112b, the third iris 112c, and the fourth iris 112d that are bent vertically with respect to each other and are vertically bent with respect to the first fold portion 113a and the second, respectively. It is preferable to bend perpendicularly to the folding part 113b, the 3rd folding part 113c, and the 4th folding part 113d.

In the triangular patch antenna 100 having the above-described configuration, the frequency is set to 1.575 GHz, the triangular patch 110 is set to a size of 40 mm x 45 mm, and the ground plate 120 is 15.75 lambda x 15.75 lambda (300 mm). X300mm, λ: wavelength), the height of the iris 112a, 112b, 112c, and 112d was set to 8mm, and the separation distance between the triangular patch 110 and the ground plate 120 was set to 1mm. .

When the above conditions are set, the triangular patch antenna 100 exhibits an area reduction rate of 71.5% compared to the planar circular polarization microstrip patch antenna having a size of 76 mm (length) × 83 mm (width).

As shown in Fig. 1B, it has a return loss of -12.1 dB, a bandwidth of -10 dB is 84 MHz, and a gain value is 3.96 dBd.

At this time, the bandwidth of the triangular patch antenna 100 having a 84MHz value showed a reduction rate of 5.3% compared to the 85MHz value and the gain value of 4.2dBd when the -10dB bandwidth of the planar circularly polarized microstrip antenna.

As shown in FIG. 1C, the radiation pattern of the y-axis parallel polarization HPBW (Half Power Beam Width) was 80.64 ° in the z-x plane, and the x-axis parallel polarization HPBW was 82.08 ° in the z-y plane. This shows a radiation pattern with a wider beam width than that of a planar circular polarized microstrip antenna.

The axial ratio had a value of 1.2 dB as shown in Fig. 1D at the frequency set at 1.575 GHz, and a good 2 dB axial ratio bandwidth of 8 MHz was obtained.

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Hereinafter, with reference to the comparative example and the accompanying drawings, the present invention has been sequentially and through the various techniques considered to implement the circular polarized folded microstrip antenna of the three-dimensional structure capable of miniaturization of the present invention Let's take a closer look at the advantages of this antenna.

[Comparative Example 1]

First, as a first comparative example, a general planar linear polarization microstrip patch antenna was designed for miniaturization of an antenna.

Referring to FIG. 3A, in order to adjust the center frequency of the antenna according to the first comparative example to 1.575 GHz used in GPS, the size of the ground plate is set to 15.75λ × 15.75λ (300mm × 300mm), and the dielectric constant ε The height of the dielectric having _r ) of 1.06 is set to 9 mm and the size of the antenna (W × L) is designed to be 80.5 mm × 90 mm, and the return loss is -21.14 dB,-as shown in FIG. The 10 dB bandwidth is shown at 87 MHz. In other words, a -10dB bandwidth represents a 5.5% reduction.

By fixing the size of the antenna in the set state as described above and adding plates on both sides of the patch, a low resonance frequency can be obtained. It is obvious that the lower the resonant frequency can be obtained by placing the plate at both ends of the patch through the "research on miniaturization of an Iris-attached 3D linearly polarized microstrip patch antenna".

Accordingly, in the first comparative example, as shown in FIG. 3C, two plates are bent vertically at both ends of the patch, and then the height of the plate is increased by 1 mm from 1 mm to 8 mm to obtain a frequency graph as shown in FIG. 3D. can do.

That is, the center frequency decreases as the height of the plate increases.

Therefore, when the maximum height of the plate was 8 mm, the frequency reduction of 0.365 GHz was shown as the resonance frequency of 1.575 GHz decreased to 1.21 GHz. Also, a -10dB bandwidth appears at 365MHz. In other words, the -10dB bandwidth represents a 23.2% reduction.

Specifically, referring to FIG. 3E, the above-described lowering of the center frequency increases the current path by 2h due to one plate having a height h of the current path at the bottom of the antenna. The effect of increasing the current path is to appear.

For example, when h is 8 mm, the current path becomes 8 mm x 2 + 8 mm x 2 = 32 mm, whereby an increase effect of 28.4% can be obtained.

Meanwhile, the linearly polarized folded microstrip antenna with an optimized plate is as follows.

First, if the frequency is set to 1.575 GHz, and then the size of the antenna is set to 55 mm (length) x 90 mm (width) as shown in FIG. 3F, a planar hit is obtained while obtaining a good impedance match as shown in FIG. 3G. When my size is 80.5mm (length) x 90mm (width), it can be seen that 25.5mm is shortened in the longitudinal direction and 31.7% is shortened.

In this case, the return loss is -30.32dB and the -10dB bandwidth is 108MHz. In other words, the -10dB bandwidth represents a 6.86% reduction.

[Comparative Example 2]

As a second comparative example, based on the possibility of the deformed design of the patch considered in the first comparative example, as shown in FIG. 4A, a plate bent vertically to the lower side in order to obtain a miniaturization characteristic is horizontally arranged in the patch center direction. It is characterized by being bent.

In the case of increasing the length of the horizontally bent surface by 1 mm, as shown in FIG. 4B, as the length of the bottom surface is increased, the continuous resonance frequency is downward, and when the length of the bottom surface is 27 mm, the resonance frequency is increased. It was lowered to 0.715 GHz, resulting in a frequency degradation of 0.860 GHz, or 54.6%.

That is, referring to FIG. 4B, the decrease in the center frequency described above increases the current path by 2h due to one plate having a height h of the current path at the bottom of the antenna. The effect of increasing the current path is to appear.

For example, when h is 27 mm, the current path becomes 27 mm x 2 + 8 mm x 2 = 108 mm, indicating an increase of 151%.

Therefore, the final linearly polarized folded microstrip antenna with an optimized center frequency of 1.575 GHz was fabricated and the return loss and radiation pattern as shown in FIGS. 4C to 4E were obtained.

Specifically, the size of the linearly polarized folded microstrip antenna is set to 21 mm (length) × 90 mm (width) as shown in FIG. 4c, which shows a shortening ratio of 73.9% in the longitudinal direction than the general microstrip patch antenna. Return loss was -27.6 dB at 1.575 GHz designed as shown in FIG. 4D. At this time, a hole was made at the meeting portion of the feed portion and the bottom of the antenna to avoid a short circuit.

In addition, as shown in FIG. 4E, the -10 dB bandwidth is 64 MHz, and the gain is measured at 5.12 dBd, 2.88 dB lower than the linearly polarized folded microstrip antenna, and the HPBW is 151 ° for the E-plane and the H-plane, respectively. 79.2 °. In other words, a -10dB bandwidth represents a 4% reduction.

And, the beam width was wider in the E-plane than in the linearly polarized folded microstrip antenna. This may be due to the wide angle of the beam caused by narrowing the gap between the openings due to the miniaturization.

Comparing Comparative Examples 1 and 2 as described above, the linearly polarized folded microstrip antenna was first reduced to 21 mm, which is 59.5 mm smaller than the flat 80.5 mm, resulting in a length reduction effect of 73.9%. The square bottom circularly polarized folded microstrip antenna, which is a structure that folds in four directions, has a 79.5% smaller area than the planar circularly polarized microstrip antenna, and can implement a circularly polarized folded microstrip antenna with an axis ratio of 1.61 dB.

That is, in the case of circular polarization, the folded structure of the linearly polarized antenna is applied in all four directions, and the folded bottom is designed in a triangular and square structure to increase the utilization of the area. At this time, the visible area reduction ratio of the optimized square bottom antenna was 79.5% and the gain was 2.56dBd. The -10 dB bandwidth was 8 MHz (5.1%), the y-axis parallel polarization HPBW was 91 ° on the z-x plane, and the x-axis parallel polarization HPBW was 124 ° on the z-y plane.

Accordingly, all three-dimensional antennas of the present invention, which have been developed based on these technical ideas, are all designed to be 1.575 GHz (GPS), thereby achieving a characteristic purpose of miniaturizing a microstrip antenna.

As described above and described with reference to a preferred embodiment for illustrating the technical idea of the present invention, the present invention is not limited to the configuration and operation as shown and described as described above, it is a deviation from the scope of the technical idea It will be understood by those skilled in the art that many modifications and variations can be made to the invention without departing from the scope of the invention. Accordingly, all such suitable changes and modifications and equivalents should be considered to be within the scope of the present invention.

According to the present invention having the characteristic configuration and function as described above, by forming a circular polarization by changing the triangular or square structure of the patch base of the folded microstrip antenna, in the case of a linearly polarized folded microstrip antenna The length was reduced to 21 mm, which is 59.5 mm smaller than the flat 80.5 mm, resulting in a 73.9% reduction in length.In the case of a four-fold folding structure, the rectangular bottom polarized folded microstrip antenna is 79.5 smaller than the planar circular polarized microstrip antenna. % Area was reduced. Accordingly, by adjusting the length of the bottom surface, there is an effect that the stable folded microstrip antenna can be miniaturized without lowering the radiation efficiency and the gain due to the dielectric loss.

Claims (11)

A triangular bottom 110 made of a metal triangular patch 110, a ground plate 120 performing a normal grounding function, and a dielectric having a predetermined dielectric constant and filled between the triangular patch and the ground plate to support them. In the circularly polarized folded microstrip antenna 100 of the structure, The triangular patch 110, A flat plate portion 111 having right angles 111a, 111b, 111c, and 111d cut at right angles at each end of the quadrangle; The first iris 112a, the second iris 112b, the third iris 112c, and the fourth iris 112d extending vertically from each end of the flat plate 111 in the direction of the ground plate 120, respectively. ; And An extension tip of each of the first iris 112a, the second iris 112b, the third iris 112c, and the fourth iris 112d extends in parallel to the flat plate 111 inside the triangular patch. A first folding portion 113a, a second folding portion 113b, a third folding portion 113c and a fourth folding portion 113d; Consists of, When the first folding portion 113a, the second folding portion 113b, the third folding portion 113c and the fourth folding portion 113d converge toward the center of the flat plate portion 111, the first folding portion Both hypotenuses of each of the portion 113a, the second folding portion 113b, the third folding portion 113c, and the fourth folding portion 113d are spaced apart from one side of the adjacent folding portion at a predetermined interval. Miniature 3D circular polarized folded microstrip antenna. The method of claim 1, The first folding portion 113a, the second folding portion 113b, the third folding portion 113c and the fourth folding portion 113d maintain their respective triangular shapes in the center direction of the flat plate portion 111. A circularly polarized folded microstrip antenna having a three-dimensional structure that can be miniaturized. delete delete The method of claim 1, The first folding portion 113a and the third folding portion 113c, and the second folding portion 113b and the fourth folding portion 113d are symmetrical to each other, and can be miniaturized circularly polarized three-dimensional structure. Folded microstrip antenna. The method of claim 1, Circularly polarized folded microstrip antenna 100 of the triangular bottom structure, The first iris 112a, the second iris 112b, the third iris 112c, and the fourth iris 112d are vertically bent with respect to the flat plate 111, and are vertically bent. 112a, the second iris 112b, the third iris 112c, and the fourth iris 112d each include a first fold portion 113a, a second fold portion 113b, a third fold portion 113c, and Miniaturized circularly polarized folded microstrip antenna having a three-dimensional structure, which is bent vertically with respect to the fourth folding portion (113d). delete delete delete delete delete

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