KR100878707B1 - Multi resonant broadband antenna - Google Patents

Abstract

The present invention relates to a multi-resonant broadband antenna, and the multi-resonant broadband antenna according to the present invention stacks a fractal radiating element and a fractal parasitic radiating element, and forms a short circuit using conductor holes between the fractal radiating element and the fractal parasitic radiating element. By doing so, it is possible to realize a broadband antenna with high efficiency.

Antenna, resonant, broadband, fractal radiating element

Description

Multi resonant broadband antenna

1 is a view showing the structure of a conventional PIFA.

2 is a view showing a conventional Meander Line structure.

3 and 4 are front and side views showing an embodiment of a conventional Hilbert lattice monopole antenna.

5 is a diagram illustrating the return loss characteristics of the Hilbert lattice monopole antenna.

6 is a front view of a multi-resonant broadband antenna using a fractal radiation element according to an embodiment of the present invention.

FIG. 7 is a side view of the multiple resonant broadband antenna shown in FIG. 6.

8 is a side view of a multi-resonance broadband antenna using a fractal radiating element and a fractal parasitic radiating element according to another embodiment of the present invention.

9 is a side view of a multi-resonance broadband antenna using a fractal radiation device, a fractal parasitic radiation device, and a short circuit according to another embodiment of the present invention.

10 is a side view of a multiple resonance broadband antenna according to another embodiment of the present invention.

11 is a side view of a multiple resonance broadband antenna according to another embodiment of the present invention.

12 is a side view of a multiple resonance broadband antenna according to another embodiment of the present invention.

13 is a front view of a multiple resonance broadband antenna according to another embodiment of the present invention.

14 and 22 illustrate fractal structures according to another embodiment of the present invention.

FIG. 23 is a diagram illustrating return loss characteristics of a multi-resonant broadband antenna according to another exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

900: dielectric substrate 910: ground

920: feeder 930: fractal radiation element

940: fractal parasitic radiating element 950: conductor hole

The present invention relates to a wideband antenna that resonates in multiple frequency bands, and more particularly, to a multi-resonant broadband antenna using a fractal structure.

Currently used multi-band antennas include a Planar Inverted F Antenna (PIFA) shown in FIG. 1, an antenna having a Meander Line structure shown in FIG. 2, and a stacked patch antenna.

1 is a view showing the structure of a conventional PIFA.

It is composed of an inverted F shape on the ground 11, and is divided into a feed part 13 and a short circuit part 14. The shorting part 14 serves to short-circuit the radiating element 12 portion of the antenna to the ground 11 and exhibit different resonance characteristics depending on the distance and shape between the power feeding part 13 and the shorting part 14. . In order to implement the multi-resonance characteristic in the PIFA 10, the shape of the radiation element 12 on the antenna is divided into a plurality of different sizes and synthesized. That is, a combination of several antennas having a single band characteristic is used. The PIFA 10 has an advantage that a small antenna having a multi-band characteristic can be implemented. However, when synthesizing multiple antennas using the PIFA structure, problems such as a drastic decrease in antenna radiation efficiency and a decrease in gain occur. Therefore, it is not suitable for use as a multi-band antenna of more than triple resonance in reality.

In the case of using the Meander Line structure shown in FIG. 2, the characteristics are similar to those of the PIFA antenna.

That is, conventionally, a PIFA and a meander line structure are used to construct a small band multi-antenna, and a combination of multiple antennas having a single band characteristic is used. However, when such a structure is configured to exhibit a multi-resonance characteristic, the radiant efficiency of the antenna is sharply lowered. Therefore, there is a problem in antenna performance to be used as a multi-resonance antenna above the triple resonance.

In addition, a multi-resonant antenna using a stacked patch antenna structure is a structure that uses a patch radiation element of different sizes arranged in the up and down direction, has the disadvantage of increasing the antenna size, due to the structural limitations described above PIFA and Meander Line Like the structure, it is not suitable for use as a multi-band antenna above triple resonance.

3 and 4 are front and side views of an embodiment of a conventional Hilbert lattice monopole antenna, and FIG. 5 is a diagram illustrating return loss characteristics of the Hilbert lattice monopole antenna.

The Hilbert lattice monopole antenna shown in FIGS. 3 and 4 may implement a multi-band frequency characteristic, but as shown in FIG. 5, each resonance frequency band is narrowly formed. The resonant frequency band of N becomes narrower and antenna efficiency becomes lower. In addition, there are technical limitations in designing an antenna for a specific frequency band to be used.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a micro-antenna having multiple frequency bands and broadband characteristics.

In addition, another object is to provide a wide band, high efficiency antenna by stacking a fractal radiation element and a fractal parasitic radiation element and constructing a short circuit using conductor holes between the fractal radiation element and the fractal parasitic radiation element.

A multi-resonance broadband antenna for achieving the technical problem of the present invention is a dielectric substrate; A fractal radiating element disposed on the dielectric substrate and arranged in an arbitrary fractal lattice structure; A feeder positioned on the dielectric substrate and feeding the fractal radiation element; A ground existing at a position corresponding to the power feeding portion of the lower portion of the dielectric substrate; And a fractal parasitic radiation element present at a position corresponding to the fractal radiation element in the lower portion of the dielectric substrate.

Details and improvements of the invention are disclosed in the dependent claims.

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

6 and 7 are a front view and a side view respectively showing the configuration of an embodiment of a multi-resonant broadband antenna according to the present invention.

6 and 7, a multi-resonant broadband antenna according to an exemplary embodiment of the present invention may include dielectric substrates 600 and 700, grounds 610 and 710, feeders 620 and 720, and fractal radiating elements 630. And 730).

Dielectric substrates 600 and 700 are in the form of microstrip substrates, such as RF4 or thin films with excellent flexibility. Dielectric substrates 600 and 700 may use a double-sided or single-sided dielectric substrate, preferably, a double-sided dielectric substrate including a thin film type excellent in bending or flexibility.

Grounds 610 and 710 are located behind the dielectric substrates 600 and 700. In addition, the grounds 610 and 710 are used as ground reference planes of the feeders 620 and 720 for feeding the fractal radiation elements 630 and 730, that is, reference planes for impedance determination of the feed line.

The feeders 620 and 720 are composed of feed lines for supplying power to the fractal radiating elements 630 and 730, and the feed lines are located in front of the dielectric substrates 600 and 700. Grounds 610 and 710 are located on the back surface of the dielectric substrates 600 and 700 corresponding to the feeding portions 620 and 720, and on the back surface of the dielectric substrates 600 and 700 where the fractal radiation elements 630 and 730 are located. There are no grounds 610 and 710.

The fractal radiation elements 630 and 730 are arranged in an octagonal shape of a cross-shaped fractal grid structure. Here, a fractal refers to a structure in which a small structure is repeated in an endless manner similar to the entire structure. That is, it is a geometric structure that has the properties of "self-similarity" and "recursiveness" that parts and the whole have the same shape.

The overall size of the fractal radiation elements 630 and 730 can be implemented in a microminiature within 40x40mm, and the grounds 610 and 710 attached to the rear surfaces of the dielectric substrates 600 and 700 are communication equipment, for example, to which the radiation elements are mounted. For example, an outer case composed of a conductor such as a mobile phone or a communication terminal is shaped. Here, the fractal radiation elements 630 and 730 include not only the cross shape shown in FIG. 6 but also the comb-shaped shape, the lightning pattern, and the Hilbert fractal lattice shape.

In addition, preferably, an antenna having a multi-frequency band and a wideband characteristic may be implemented by using a radiation element having a structure in which a fractal grid of cross-shaped, comb-shaped or lightning-patterned dimensions are divided and rearranged. In addition, the present invention improves antenna radiation efficiency and broadband characteristics by modifying the dimensional partitioned fractal plaid and the arrangement structure again.

The reason for using the modified structure instead of the general fractal dimensional division structure is that the antenna radiation efficiency that can occur when the antenna is miniaturized by extending the length of the antenna lines per unit area and the antenna is miniaturized to the frequency wavelength Is to maximize.

8 is a side view of a multi-resonance broadband antenna using a fractal radiating element and a fractal parasitic radiating element according to another embodiment of the present invention.

8 shows a dielectric substrate 800, ground 810, feeder 820, fractal radiating element 830 and fractal parasitic radiating element 840. The difference from the antenna shown in FIG. 7 is that the fractal parasitic radiation element 840 is provided on the back side of the dielectric substrate 800 corresponding to the fractal radiation element 830.

Fractal radiating element 830 and fractal parasitic radiating element 840 exist independently while maintaining their respective characteristics, which are located on the backside of dielectric substrate 800 such as ground 810.

Thus, the primary radiation propagated from the fractal radiation element 830 is re-radiated by the fractal parasitic radiation element 840. That is, when the fractal radiating element 830 and the fractal parasitic radiating element 840 exist within a narrow interval, the re-radiation effect of the radio waves by the fractal parasitic radiating element and the fractal radiating element 830 and the fractal parasitic radiating element 840 It is possible to obtain a line length extension effect by mutual coupling of. This length extension effect can contribute to improved antenna performance in the low frequency band, improved return loss characteristics and gain, and smaller antennas.

Preferably, the fractal radiating element 830 and the fractal parasitic radiating element may each use the same type of fractal structure or different types of fractal structures. For example, the fractal radiating element 830 uses a cross-shaped fractal structure, and the fractal parasitic radiating element 840 uses a comb-shaped fractal structure.

9 is a side view of a multi-resonance broadband antenna using a fractal radiation device, a fractal parasitic radiation device, and a short circuit according to another embodiment of the present invention.

9 shows a dielectric substrate 900, ground 910, feeder 920, fractal radiating element 930, fractal parasitic radiating element 940, and conductor hole 950. The difference from FIG. 8 is that the fractal radiating element 930 and the fractal parasitic radiating element 940 are connected by a conducting hole 950.

 In the antenna illustrated in FIG. 9, the fractal radiation element 930 and the fractal parasitic radiation element 940 are connected through the conductor hole 950 to form a short circuit. When the fractal radiating element 930 and the fractal parasitic radiating element 940 are connected in a short circuit as described above, the effective radiation area of the antenna is increased within a narrow area. In addition, by installing the fractal parasitic radiating element 940 on the rear surface of the dielectric substrate 900 where the ground 910 is present, the disadvantage that the overall size of the antenna increases due to the fractal parasitic radiating element 940 can be eliminated. .

The conductor hole 950 is used to connect the fractal radiating element 930 and the fractal parasitic radiating element 940, but the performance of the stacked antenna is changed according to the position of the conductive hole 950. Therefore, in order to increase the effective radiated area of the antenna by using the conductor hole and to implement the multi-resonant and broadband small antenna, the conductor hole is used at a position far from the feeder 920, that is, at the outer edge of the antenna and in the middle of the antenna. It is desirable to. It is also possible to optionally use a combination of conductor holes in the antenna periphery and in the middle of the antenna.

10 is a side view of a multiple resonance broadband antenna according to another embodiment of the present invention.

FIG. 10 shows a dielectric substrate 1000, ground 1010, feeder 1020, fractal radiating element 1030, fractal parasitic radiating element 1040, and conductor hole 1050. And fractal parasitic radiation elements 1060 are sequentially stacked on the fractal radiation element 1030.

 Accordingly, by stacking and using fractal parasitic radiating elements 1040 and 1060 having the same or different types of inherent multi-resonance characteristics of the fractal radiating element 1040, the individual fractal radiating element and the fractal parasitic radiating element have Multiple resonant characteristics can be combined into one to obtain broadband characteristics.

11 is a side view of a multiple resonance broadband antenna according to another embodiment of the present invention.

FIG. 11 shows a dielectric substrate 1100, ground 1110, feeder 1120, fractal radiating element 1130 and fractal parasitic radiating elements 1140 and 1150, and dielectric substrate 1100 and fractal parasitic radiation. Devices 1150 are sequentially stacked under the fractal parasitic radiation device 1140.

 Therefore, by stacking and using fractal parasitic radiating elements 1140 and 1150 having the same or different types of inherent multi-resonance characteristics of the fractal radiating element 1130, the individual fractal radiating element and the fractal parasitic radiating element have Multiple resonant characteristics can be combined into one to obtain broadband characteristics.

12 is a side view of a multiple resonance broadband antenna according to another embodiment of the present invention.

12 shows dielectric substrate 1200, ground 1210, feeder 1220, fractal radiating element 1230, fractal parasitic radiating elements 1240, 1250 and 1260, and conductor hole 1270. The substrate 1200 and the fractal parasitic radiating element 1250 are not only stacked on the fractal radiating element 1230 in turn, but also the dielectric substrate 1200 and the fractal parasitic radiating element 1260 are in turn beneath the fractal parasitic radiating element 1240. It is stacked.

 Therefore, by stacking and using fractal parasitic radiating elements 1240, 1250, and 1260 having the same or different types of inherent multiple resonance characteristics of the fractal radiating element 1230, individual fractal radiating elements and fractal parasitic radiating elements are formed. Multiple resonant characteristics can be combined into one to obtain broadband characteristics.

  As shown in Figs. 10 to 12, the fractal parasitic radiating elements may be formed on both sides of the dielectric substrate, and fractals of the same type or different types of fractal parasitic radiating elements may be used. In addition, the asymmetric structure selectively stacked only on the upper side or the lower side of the dielectric substrate, and the symmetrical structure stacked on both the upper side and the lower side, and the asymmetric structure differs in that the number of fractal parasitic radiating elements stacked on both the upper side and the lower side is different It can be configured in various ways such as a mold structure. In addition, in the case of selectively stacking, a multilayer antenna may be implemented by mixing both a case of using a conductor hole and an independent layer structure having no conductor hole.

As described above, the fractal radiation element and fractal parasitics are formed by stacking one or more layers on the upper, lower, or both sides of a double-sided dielectric substrate which is a combination of fractal radiation element and fractal parasitic radiation element in the form of fractal parasitic radiation element on the dielectric substrate cross section. It is possible to obtain an effect of increasing the radiation effective area within a narrow area by re-copying the radio wave radiated from the radiation element or by the mutual coupling effect. By increasing the radiation effective area, it is possible to improve antenna performance in the low frequency band, return loss characteristics and gain, and to miniaturize the antenna.

13 is a front view of a multiple resonance broadband antenna according to another embodiment of the present invention.

Referring to FIG. 13, the antenna includes a dielectric substrate 1300, a ground 1310, a power supply 1320, a fractal radiation element 1330, and a conductor hole 1340. Although not shown in the drawing, the fractal substrate includes a parasitic radiating element on the back of the substrate 1300 and is connected to the fractal radiating element 1330 through three conductor holes 1340.

The fractal radiating element 1330 is a shape in which a cross-shaped fractal grid structure is arranged in an octagonal shape. The overall size of the fractal radiating element is preferably implemented in a microminiature within 40x40mm. Similarly, a fractal parasitic radiation element (not shown) on the back of the dielectric substrate 1300 corresponding to the fractal radiation element 1330 may also be configured as a cross-shaped fractal grid structure or another type of fractal grid structure. Conductor holes 1340 are located at the top and both ends of a cross-shaped fractal grid structure arranged in an octagonal shape. By separating the conductor hole 1340 from the power supply 1320 as far as possible, the antenna can be realized with the effect of increasing the effective antenna radiation area and multiple resonances and broadband.

14 and 22 illustrate fractal structures according to another embodiment of the present invention.

FIG. 14 is a diagram showing the detailed configuration of the fractal radiation element 1330 shown in FIG. The position of the conductor hole 1340 is more clearly shown in the figure.

Other embodiments of the multi-resonant broadband antenna according to still another embodiment of the present invention shown in Figs. 15 to 22 are all composed of a dielectric substrate, ground, feed section, fractal radiation element, or at least one fractal parasitic radiation Comprising elements and conductor holes, except for the stacking position, the number of stacking and the position of the conductor hole of the fractal radiation element or fractal parasitic radiation element functions and functions are the same as the configuration described in FIG. Detailed description of the configuration except for the position of the radiation element, the fractal parasitic radiation element, and the conductor hole is omitted.

FIG. 15 illustrates that the fractal radiating element 1500 is configured to reduce the size of the first fractal radiating element 1510 having the same shape as the fractal radiating element 1330 shown in FIG. 14. The third fractal radiation element 1530, which is disposed in the radiation element 1510 and smaller in size than the second fractal radiation element 1520, is disposed in the second fractal radiation element 920. That is, the fractal radiating element 900 according to the embodiment of FIG. 15 is a structure in which the size of the basic fractal radiating element 1330 illustrated in FIG. 14 is reduced in several units and arranged in layers. Of course, the fractal radiating element 1500 may be formed of a double structure and a quadrature structure in addition to the triple structure illustrated in FIG. 15. Each fractal radiating element 1510, 1520, and 1530 constituting the triple structure is connected to one feed line 1550. Also, the position of the conductor hole 1540 is the same as that shown in FIG.

The fractal radiating element according to the embodiment of FIG. 16 is a modified form of the fractal radiating element shown in FIG. 15. The fractal radiating element illustrated in FIG. 15 is in the form of a complete closed loop, but the fractal radiating element of the present embodiment is open in a portion 1610 in which a feeding part is located. In the present embodiment, the example in which the portion 1610 in which the feed portion is located is opened, but the open portion may be a portion other than where the feed portion is located.

The fractal radiating element 1700 according to the exemplary embodiment of FIG. 17 is a modified form of the fractal radiating element 1500 illustrated in FIG. 15. According to the present embodiment, a fractal lattice structure having a cross shape in four directions is attached to the fractal radiating element illustrated in FIG. 15 in a "B" shape 1710. The added “a” shape 1710 does not form a closed loop. In addition, unlike the positions of the conductor holes 1540 illustrated in FIG. 15, the conductors are located at the corners of the newly added “A” shape 1710. By doing so, it can be spaced apart from the power supply unit 1730.

The fractal radiating element 1800 according to the exemplary embodiment of FIG. 18 is a form in which the fractal lattice structure 1710 added by the letter “a” in the fractal radiating element 1700 illustrated in FIG. 17 is formed in a fully closed loop form 1810. . As in FIG. 17, the positions of the conductor holes 1820 are center and corner portions of the upper portion of the fractal radiation device 1800.

The fractal radiating element 1900 according to the exemplary embodiment of FIG. 19 is a form in which a cross-shaped fractal grid structure is arranged in a checkered pattern. As in FIG. 17, the positions of the conductor holes 1920 are center and corner portions of the upper portion of the fractal radiating element 1900.

The fractal radiating element 2000 according to the embodiment of FIG. 20 is arranged in a checkered pattern using a comb-like pattern or a lightning pattern and a cross-shaped fractal grid structure. The checkered line and the line where the line meets (2020) applies a cross-shaped fractal grid structure, the other portion 2010 applies a comb-shaped or lightning pattern fractal grid structure. On the other hand, the part where the line meets the comb pattern or the lightning pattern fractal lattice structure, the other part can be applied to the cross-shaped fractal lattice structure, other modifications are of course possible. As in FIG. 17, the positions of the conductor holes 2030 are the center and corner portions of the upper portion of the fractal radiating element 2000.

In the structure in which the fractal radiating element 2100 according to the embodiment of FIG. 21 is arranged in the shape of a checkered fractal lattice, the middle part of the checkered part, that is, the hollow in the middle of the checkered part in which the fractal lattice structure is not arranged Another cross-shaped fractal lattice structure is inserted in space, and the intersected fractal lattice structure is arranged to connect the checkered fractal lattice structure with the four-way plane. As in FIG. 17, the positions of the conductor holes 2110 are center and corner portions of the upper portion of the fractal radiation element 2100.

22 shows a fractal radiating element of a Hilbert fractal lattice structure. As in FIG. 17, the positions of the conductor holes 2210 are center and corner portions of the upper portion of the fractal radiation element.

FIG. 23 is a diagram illustrating return loss characteristics of a multi-resonant broadband antenna according to another exemplary embodiment of the present invention.

FIG. 23 measures return loss characteristics of a multi-resonant broadband antenna between 100 MHz and 2700 MHz. As shown, it can be seen that the return loss characteristic is improved over a wide frequency band.

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will understand that the present invention can be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown not in the above description but in the claims, and all differences within the scope should be construed as being included in the present invention.

The multi-resonant broadband antenna according to the present invention can implement a broadband and highly efficient micro antenna by stacking a fractal radiation element and a fractal parasitic radiation element and constructing a short circuit using conductor holes between the fractal radiation element and the fractal parasitic radiation element. .

Claims (3)

A first dielectric substrate; A fractal radiating element positioned over the first dielectric substrate and arranged in an arbitrary fractal lattice structure; A feeder positioned on the first dielectric substrate and configured to feed the fractal radiation element; A ground existing at a position corresponding to the power feeding portion of the lower portion of the first dielectric substrate; And And a fractal parasitic radiation element present at a position corresponding to the fractal radiation element in a lower portion of the first dielectric substrate. The method of claim 1, And a second dielectric substrate and at least one fractal parasitic radiating element further stacked on or above the fractal radiating element. The method of claim 2, And a conductor hole connecting between the fractal radiating element and the fractal parasitic radiating element or between the fractal parasitic radiating element and the fractal parasitic radiating element.

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