KR20090130521A - Dual band circularly polarized microstrip antenna using folded structure - Google Patents

Abstract

PURPOSE: A dual band circular polarization microstrip antenna using a folded structure is provided to feed sudden electricity to only an upper antenna and generate resonance by coupling effect in a lower antenna, thereby obtaining the characteristic of dual band circular polarization in a transceiving band. CONSTITUTION: A grounding surface(GND) performs a grounding function. A second patch(200) is laminated on the top of a first patch(100). A dielectric has a predetermined dielectric constant. The dielectric is located between the first patch and the second patch. Sudden electricity is supplied to only the second patch. Resonance by coupling effect is generated in the first patch. The first patch comprises a flat plate portion and an external plate having a predetermined size.

Description

Dual band circularly polarized microstrip antenna using folded structure {DUAL BAND CIRCULARLY POLARIZED MICROSTRIP ANTENNA USING FOLDED STRUCTURE}

The present invention relates to a circularly polarized microstrip antenna, and more particularly, to stack a single-band circularly polarized antenna in order to secure a dual-band circularly polarized transmit / receive band, using only a single feed to feed only the upper part antenna and the lower part antenna The present invention relates to an antenna capable of obtaining double band circular polarization characteristics for a transmission / reception band by causing resonance due to a coupling effect.

The development of modern wireless devices is accelerating day by day, and personal mobile communication, in particular, wants to provide communication services regardless of location, beyond its local limitations. In order to enable such a service, a communication service using satellites has been developed, and a corresponding personal mobile phone service for satellite communication has emerged, and it is necessary to miniaturize a terminal for portability.

The antenna for the satellite portable terminal needs to be miniaturized, circularly polarized, wide beam width and high gain in order to meet this situation. However, although an antenna such as Quadrifilar Helix, which is currently commercially used, is used, there is a problem that the portability is not easy due to its large volume.

In order to solve this problem, the present invention intends to miniaturize a microstrip patch antenna having a low profile, small volume, light weight, and mass production capability.

In general, the size of the microstrip patch antenna is related to the wavelength of the center frequency, and there are two methods of minimizing the antenna using a high dielectric constant and a method of making structural changes. There is a problem in that antenna performance such as radiation efficiency and narrow band characteristics is degraded.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and by using a single feed, only the upper portion of the antenna is fed and the lower portion of the antenna causes a resonance due to the coupling effect, so that the dual band circular polarization characteristics for the transmission and reception bands. Its characteristic purpose is to provide an antenna that can be obtained.

The present invention relates to a dual band circularly polarized microstrip antenna using a folded structure, comprising: a ground plane performing a grounding function; A dielectric having a predetermined dielectric constant and positioned between and supporting the ground plane and the first patch, and between the first and second patches; First patch; And a second patch stacked on the first patch, the second patch including a feed point FP on one side thereof. The dual band circularly polarized microstrip antenna using the folded structure uses a single feed, and feeds only the second patch, and the first patch is characterized in that resonance occurs due to a coupling effect.

In addition, the first patch, the flat plate having a predetermined size; First to fourth outer plates extending at a predetermined length in a direction of a ground plate from four front ends facing each other about the flat plate; First to fourth folds extending from the end of each outer plate in a first patch inward direction to extend a predetermined length in parallel with the flat plate; And first to third inner plates extending from the end portions of the first to third folding portions in a predetermined length toward the flat plate portion. Characterized in that it comprises a.

In addition, the second patch, the flat plate having a predetermined size; First to fourth outer plates extending at a predetermined length in a direction of a ground plate from four front ends facing each other about the flat plate; First to fourth folding portions extending from the end of each outer plate in a second patch inward direction and extending a predetermined length in parallel with the flat plate portion; And second and fourth inner plates extending from the ends of the second and fourth folding portions in the direction of the flat portion. Characterized in that it comprises a.

The flat plate and the outer plate may be bent perpendicularly to each other, and the folding portion may be bent perpendicularly to the outer plate and the inner plate.

The first patch 100 has a length of 22 mm × 44 mm in width, and the second patch 200 has a length of 24 mm × width of 46 mm. It is done.

According to the present invention as described above, by feeding only the upper portion of the antenna using a single feed and the lower portion of the antenna is caused by the resonance effect of the coupling effect, it is possible to obtain the dual-band circular polarization characteristics for the transmission and reception bands have.

Specific features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. In the meantime, when it is determined that the detailed description of the known function and the configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, it should be noted that the detailed description is omitted.

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

The folded dual-band circularly polarized microstrip antenna (A) according to an aspect of the present invention provides a dual-band circularly polarized transmit / receive band so that it can be used for commercial mobile communication of a global star. In order to secure, a single band circularly polarized antenna was stacked and designed. Each antenna will have a resonance mode corresponding to transmission and reception.

The feed was fed only to the second patch 200 (transmission band), which is the upper portion, by using a single feed, and the first patch 100 (reception band), which is the lower portion, caused resonance due to the coupling effect. The antennas were designed, fabricated, and measured to have antenna reception bands (1.610 to 1.6265 GHz) and transmission bands (2.4835 to 2.500 GHz).

To make a dual band, a 1.4 mm high foam (ε _r = 1.06) was used as the dielectric, and the first patch 100 was placed at the bottom, as shown in FIGS. The upper and lower two-stage stacked structure in which the second patch 200 is stacked on top of each other is stacked.

The dual band circularly polarized microstrip antenna A using the folded structure according to one aspect of the present invention includes a dielectric, a ground plane GND, a first patch 100 and a second patch 200. .

A dielectric having a predetermined dielectric constant (not shown) is located between the ground plane GND and the first patch 100 and between the first patch 100 and the second patch 200 to support them. Perform the function.

The ground plane GND is a metal material and provides a normal ground (GND) function. In this embodiment, the dielectric constant and shape of the dielectric may be set in various ways, but the present invention is not limited thereto. In addition, the ground plane may be set in various shapes, the present invention is not limited to the shape.

The first patch 100 is a basic linearly polarized microstrip fabricated at a center frequency of 1.542 GHz, and is designed with a folded structure of left-handed circular polarization and a plate-attached microstrip antenna. The size of the first patch 100 is 22 mm in length × width. ) 44 mm.

The first patch 100 according to the present invention includes a flat portion 110 having a predetermined size and a first length extending in a direction of a ground plate at four ends facing each other about the flat portion 110. First to fourth folds extending from the fourth outer plate 120 (121: 122, 123, 124) and at an end of each outer plate (120: 121, 122, 123, 124) to a predetermined length in parallel with the flat plate 110 in the first patch 100 inward direction. The parts 130: 131, 132, 133, and 134, and the first to third inner plates 141, 142, and 143 extending a predetermined length from the ends of the first to third folding parts 131, 132, and 133 toward the flat plate part 110.

In addition, the second patch 200 has a length of 24 mm × width of 46 mm, and includes four flat ends 210 having a predetermined size and four ends facing each other around the flat part 210. The first to the fourth outer plate (220: 221,222,223,224) extending a predetermined length in the direction of the ground plate, and at the end of each outer plate (220: 221,222,223,224), the flat portion 210 in the second patch 200 inward direction First to fourth folding portions 230: 231, 232, 233 and 234 extending in a predetermined length in parallel with the second and second and fourth extending lengths in a direction toward the flat plate portion 110 from the ends of the second and fourth folding portions 232 and 234. Inner plates 242 and 244.

In addition, a feeding point (FP) FP is located at one side of the flat plate 210 of the second patch 200 as shown in FIG. 1A. As described above, the power feed uses only a single feed, which is a simple structure, to feed only the second patch 200 as the upper portion, and the first patch 100 as the lower portion causes resonance due to the coupling effect.

In this embodiment, the feed point is set to exist in the second patch 200, but the present invention is not limited to this, when the feed point is located in the first patch 100 and the second patch 200, respectively In this case, the feed point is located only in the first patch 100, or the feed point is located in the first patch 100 and the second patch 200, which is the upper portion, causes resonance due to a coupling effect. Can be set.

At this time, the flat plate portion, the outer plate, the folding portion and the inner plate of the first patch 100 and the second patch 200 are not individually coupled to each other, and are formed integrally with the flat plate portion. It is desirable to understand that the outer plates are bent perpendicularly to each other and the folds are bent perpendicularly to the outer and inner plates. In the present embodiment, the outer plate is bent vertically in the direction of the ground plate with respect to the plate portion, the folding portion is bent vertically in the patch inner direction with respect to the outer plate, the inner plate is perpendicular to the patch plate portion with respect to the folding portion It will be set to be bent, but the present invention is not limited thereto.

At this time, the reflection loss characteristics are shown through FIG. 2A and it can be seen that circular polarization appears in the dual band. Also, as shown in FIGS. 2B and 2C, the reception band -10dB bandwidth is 1.600 to 1.655 GHz, 55 MHz (3.3%), and the transmission band -10 dB bandwidth is 2.385 to 2.535 GHz, 150 MHz (6%). This is because the height of the antenna at the top increases the fringing effect, thereby increasing the bandwidth. The bandwidth of less than 3.5dB of axial ratio obtained 1.627 ~ 1.642GHz (16MHz) in the reception band and 2.447∼2.468 GHz (22MHz) in the transmission band.

2D and 2E show reception band radiation patterns. For the reception band, the gain of x-axis pol. Was -0.61dBd, and HPBW was obtained 68 ° and 88 ° in E · H, respectively. The gain of y-axis pol. was 0.61dBd, and HPBW was obtained at 101 ° and 92 °, respectively. In the case of the E plane, the maximum in the 330 ° direction is because the antenna is narrow and the current distribution tends to be relatively large at the feed point.

2F and 2G show transmission band radiation patterns. In the transmission band, the gain of the x-axis pol is -0.19dBd, and the HPBW has obtained 101 ° and 76 ° in terms of E · H, respectively. The gain of y-axis pol. is 2.11dBd, which is relatively high, and HPBW has good characteristics such as 71 ° and 90 ° in the E · H plane, respectively. Here too, the feed point is offset in the x direction, and the size of the antenna is also considerably smaller than the wavelength, resulting in maximum directivity in the 340 ° direction of the E-plane.

In the present invention, the microstrip patch antenna is miniaturized using a folded structure and a plate structure, which are three-dimensional structural deformation methods, to be applied as a transmission / reception antenna of a mobile terminal for satellite communication. In the feeding method, a single feeding method is applied to the transmission band antenna, and the receiving band is coupled feeding. Through the present invention, it has been sufficiently confirmed that the miniaturized antenna of the stacked structure can be used as a dual band circular polarized 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.

1A is a block diagram showing a first patch and a second patch of a dual band circularly polarized microstrip antenna using a folded structure according to the present invention.

1B is a block diagram showing the first and second patches of the dual band circularly polarized microstrip antenna using the folded structure according to the present invention are stacked and coupled.

1C is a side view of a dual band circularly polarized microstrip antenna using a folded structure in accordance with the present invention.

Figure 2a is a graph showing the return loss of the dual band circularly polarized microstrip antenna using a folded structure according to the present invention.

2b is a graph showing the reception band axial ratio of a dual band circularly polarized microstrip antenna using a folded structure according to the present invention;

Figure 2c is a graph showing the transmission band axis ratio of the dual band circular polarization microstrip antenna using the folded structure according to the present invention.

FIG. 2D is a graph showing a reception band radiation pattern of an x-axis pol. Of a dual band circularly polarized microstrip antenna using a folded structure according to the present invention. FIG.

2E is a graph showing a reception band radiation pattern of the y-axis pol. Of a dual band circularly polarized microstrip antenna using a folded structure according to the present invention.

Figure 2f is a graph showing the transmission band radiation pattern of the x-axis pol. Of a dual band circularly polarized microstrip antenna using a folded structure according to the present invention.

FIG. 2G is a graph showing a transmission band radiation pattern of y-axis pol. Of a dual band circularly polarized microstrip antenna using a folded structure according to the present invention. FIG.

** Description of symbols for the main parts of the drawing **

A: dual band circularly polarized microstrip antenna using folded structure

100: first patch 110: flat plate

120: outer plate 130: folding part

140: inner plate 200: second patch

210: plate portion 220: outer plate

230: folding portion 240: inner plate

Claims (7)

In the dual band circularly polarized microstrip antenna using a folded structure, A ground plane performing a grounding function; A dielectric having a predetermined dielectric constant and positioned between the ground plane and the first patch 100 and between the first patch 100 and the second patch 200 to support them; First patch 100; And A second patch 200 stacked on top of the first patch 100 and including a feed point FP on one side thereof; Consists of, The dual band circularly polarized microstrip antenna using the folded structure uses only a single feed, and feeds only the second patch 200, and the first patch 100 has resonance due to a coupling effect. Dual band circularly polarized microstrip antenna using folded structure. The method of claim 1, The first patch 100, A flat plate unit 110 having a predetermined size; First to fourth outer plates 120: 121, 122, 123, and 124 extending a predetermined length in the direction of a ground plate from four front ends of the flat plate 110 opposite to each other; First to fourth folding portions 130 (131, 131, 132, 133, and 134) extending from the end portions of the outer plates (120: 121, 122, 123, and 124) to a predetermined length in parallel with the flat plate (110) in the direction toward the first patch (100); And First to third inner plates 141, 142 and 143 extending a predetermined length from the ends of the first to third folding portions 131, 132 and 133 toward the flat plate 110; Dual band circularly polarized microstrip antenna using a folded structure, characterized in that it comprises a. The method of claim 1, The second patch 200, A flat plate portion 210 having a predetermined size; First to fourth outer plates 220: 221, 222, 223, and 224 extending a predetermined length in a direction of a ground plate from four front ends of the flat plate portion 210 facing each other; First to fourth folds 230: 231, 232, 233, 234 extending a predetermined length in parallel with the flat plate 210 in the second patch 200 inward direction at the end of each outer plate 220: 221, 222, 223, 224; And Second and fourth inner plates 242 and 244 extending a predetermined length from the end portions of the second and fourth folding portions 232 and 234 toward the flat plate portion 110; Dual band circularly polarized microstrip antenna using a folded structure, characterized in that it comprises a. The method of claim 2 or 3, The flat plate portion and the outer plate, A dual band circularly polarized microstrip antenna using a folded structure, which is bent perpendicularly to each other. The method of claim 2 or 3, The folding portion is a dual band circularly polarized microstrip antenna using a folded structure, characterized in that bent perpendicularly to the outer plate and the inner plate. The method of claim 1, The first patch (100) is a dual band circularly polarized microstrip antenna using a folded structure, characterized in that it has a length of 22mm × 44mm in width. The method of claim 1, The second patch 200 is a dual band circularly polarized microstrip antenna using a folded structure, characterized in that it has a length of 24mm × width 46mm.

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