KR101862060B1 - Compact Quasi-isotropic Antennas with Multiband Operation - Google Patents

Abstract

An antenna according to the present invention includes a first folded split ring resonator (FSRR) operating as an electric dipole; and a second FSRR disposed perpendicular to the first FSRR and operating as a magnetic dipole. It is possible to implement a compact antenna which radiates in a quasi-isotropic pattern in multiple bands with high efficiency. Since an equivalent electrical dipole and a magnetic dipole are generated simultaneously in a single structure, the complexity of structure can be reduced.

Description

[0001] The present invention relates to a compact quasi-isotropic antenna that operates in a multi-

[0001] The present invention relates to a multi-band isotropic antenna, and more particularly to a multi-band isotropic antenna which is compact and highly efficient in use such as radio frequency identification (RFID), wireless access points (APs), radio frequency energy harvesting It is a multi-band isotropic antenna.

An isotropic antenna is an antenna that exhibits a spherical radiation pattern due to polarization in all directions. Since a perfect isotropic antenna can not be implemented, a quasi-isotropic antenna is used, and researches on it have been actively conducted recently.

 The isotropic antenna can be used in various ways because the radiated field spreads uniformly. First, in RFID, the recognition distance can be securely secured in all directions, and in a wireless router, even energy can be transmitted to all users in all directions. In the case of electromagnetic energy harvesting, it is preferable that an isotropic antenna is used because an incident radio wave enters in a random direction, and an isotropic antenna can be used for signal sensing.

In order for the isotropic antenna to be utilized as described above, it must be miniaturized according to the characteristics of the terminal, and it must operate at high efficiency in multiple bands. In the prior art, attempts were made to implement isotropy using a plurality of dipoles and loops. Therefore, there is a limitation that the electrical size is large or the pattern imbalance occurs and the operation can be performed only in a single band.

Accordingly, in order to solve the above-mentioned problems, the present invention has implemented a wide band or dual band characteristic by vertically arranging a folded SRR (Folded Split Ring Resonator), which is a small isotropic antenna. In addition, a parasitic antenna is applied to the folded SRR or a split ring resonator (SRR) is added to realize a small isotropic antenna that operates at high efficiency in multiple bands.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a compact high-efficiency pseudo-isotropic antenna that operates in multiple bands by modifying a folded SRR structure.

According to an aspect of the present invention, there is provided an antenna including: a first folded SRR (Folded Split Ring Resonator) operating as an electric dipole; And a second folded SRR disposed perpendicularly to the first folded SRR and operating as a magnetic dipole and capable of implementing an antenna that radiates in a pseudo-isotropic pattern in multiple bands with small, high efficiency, The electric dipole and the magnetic dipole are generated at the same time, so that the complexity of the structure can be reduced.

In one embodiment, the first folded SRR comprises: a first lower conductor formed in a metal pattern on one surface of the first dielectric; And a first upper conductor disposed on one side of the first dielectric in parallel with the first lower conductor. The second folded SRR may include: a second lower conductor formed on the other surface of the second dielectric body in a metal pattern; And a second upper conductor disposed on the other side of the second dielectric in parallel with the second lower conductor.

In one embodiment, one end and the other end of the first lower conductor and the first upper conductor are interconnected by a metal pattern perpendicular to the first lower conductor and the first upper conductor, A first gap may be formed between one end of the first upper conductor and the other end of the first upper conductor. In addition, one end and the other end of the second lower conductor and the second upper conductor are mutually connected by a metal pattern perpendicular to the second lower conductor and the second upper conductor, and the second lower conductor and the second upper conductor, There may be a second gap between the one end and the other end of the first electrode, where no metal pattern is formed.

In one embodiment, the first folded SRR and the second folded SRR cross each other vertically, and the first gap and the second gap may be on the same area.

In one embodiment, since the second folded SRR is disposed inside the first folded SRR, the second folded SRR can operate in a high frequency band as compared to the first folded SRR because the resonant length is reduced have.

In one embodiment, the apparatus may further include a third folded SRR disposed coplanar with the first folded SRR. The third folded SRR may include a third lower conductor connected to the first lower conductor and disposed perpendicularly to the first lower conductor; And a third upper conductor connected to the first upper conductor and disposed perpendicular to the first upper conductor.

In one embodiment, the first folded SRR and the second folded SRR may be electrically connected at both ends of the feed portion using vias.

By using the structure proposed in the present invention, it is possible to realize an antenna which radiates in a quasi-isotropic pattern in a multi-band with a high efficiency, and the complexity of the structure can be reduced since the equivalent electric dipole and the magnetic dipole are simultaneously generated in a single structure.

Also, in the present invention, the resonance point can be easily adjusted by parameters such as the length of the parasitic element, the radius, the thickness, and the interval of the folded SRR.

1 is an analysis of an isotropic radiation pattern of SRR, in relation to the present invention.
2 shows a folded dipole structure according to the present invention.
FIG. 3 is a wideband small-sized high-efficiency isotropic antenna structure that extends the operating band by utilizing a single folded SRR.
Fig. 4 is a simulation result of the antenna structure shown in Fig. 3, where (a) shows the reflection coefficient, and (b) shows the total radiation efficiency and realized gain.
Fig. 5 is a simulated radiation pattern of the antenna structure shown in Fig. 3, wherein (a) is a radiation pattern at a relatively low resonance point and (b) is a radiation pattern at a relatively high resonance point.
6 is a dual-band compact high-efficiency isotropic antenna implementing a dual band utilizing a single folded SRR.
FIG. 7 shows simulation results of the antenna structure shown in FIG. 6, where (a) shows the reflection coefficient, and (b) shows the total radiation efficiency and realized gain.
Fig. 8 is a simulated radiation pattern of the antenna structure shown in Fig. 6, wherein (a) is a radiation pattern at a low resonance point and (b) is a radiation pattern at a high resonance point.
Figure 9 is a dual-band isotropic antenna implementation utilizing a single folded SRR.
Fig. 10 is a simulation result of the antenna structure shown in Fig. 9, in which (a) represents the reflection coefficient, and (b) represents the total radiation efficiency and realized gain.
Fig. 11 is a simulated radiation pattern of the antenna structure shown in Fig. 9, wherein (a) shows a radiation pattern at a low resonance point and (b) shows a radiation pattern at a high resonance point.
12 is a structure designed to operate in a dual band by implementing a parasitic element in a single folded SRR.
FIG. 13 shows simulation results of the antenna structure shown in FIG. 12, where (a) represents the reflection coefficient, and (b) represents the total radiation efficiency and realized gain.
Fig. 14 is a simulated radiation pattern of the antenna structure shown in Fig. 12, in which (a) is a radiation pattern at a low resonance point and (b) is a radiation pattern at a high resonance point.
FIG. 15 shows a structure in which a wide band characteristic and a dual band characteristic are implemented using a basic folded SRR structure.
FIG. 16 shows simulation results of the antenna structure shown in FIG. 15, in which (a) represents the reflection coefficient, and (b) represents the total radiation efficiency and realized gain.
17 is a simulated radiation pattern of the antenna structure shown in Fig.
FIG. 18 shows a structure in which a quadband is implemented by using a parasitic element in a conventional FSRR structure and a dual band technique. FIG.
19 shows the simulation results of the antenna structure shown in Fig.
20 is a simulation radiation pattern of the antenna structure shown in Fig.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, It will be possible. The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Like reference numerals are used for similar elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The term " and / or " includes any combination of a plurality of related listed items or any of a plurality of related listed items.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Should not.

The suffix " module ", " block ", and " part " for components used in the following description are given or mixed in consideration of ease of specification only and do not have their own distinct meanings or roles .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Hereinafter, a small quasi-isotropic antenna operating in multiple bands according to the present invention will be described. The present invention relates to designing a compact high-efficiency multi-band isotropic antenna from a structure having a single band isotropic antenna with a folded split ring resonator (SRR) structure.

 1 is an analysis of an isotropic radiation pattern of SRR, in relation to the present invention. It can be assumed that the SRR has a minimum current in the gaps at both ends and a sinusoidal current at its maximum. This current distribution can be thought of as dividing the current flowing in a short direction in the same direction as the current having a uniform size and direction as shown in the right side of FIG. At this time, the electrons generate an equivalent electric dipole in the direction of penetrating the drawing and the latter generate an equivalent electric dipole in the horizontal direction. The magnetic dipole and the electric dipole emit in an omnidirectional pattern as in Fig. When two equivalent dipoles are generated at the same time, the fields emanating from each dipole have a phase difference of 90 degrees, so they can emit without interfering with each other. Thus, an omni-directional radiation pattern of each dipole is added to form an isotropic radiation pattern as shown in the left side of Fig.

 However, with SRR single structure, the radiation resistance is low and the radiation characteristics such as impedance matching and radiation efficiency are very low. Therefore, a structure in which a folded dipole structure is applied to utilize the SRR as an antenna is the structure shown in FIG. The SRR to which the folded dipole structure is applied is referred to as folded SRR. The folded SRR operates in the transmission line mode (FIG. 2A) and the antenna mode (FIG. 2B) as shown in FIG. In this case, when the folded SRR has a half-wave length, the input resistance of the transmission line mode diverges and only the antenna mode is generated. This is because the two SRRs emit simultaneously, thereby improving the radiation characteristics while maintaining the SRR isotropic pattern. . In particular, it is possible to easily adjust the radiation resistance by adjusting the thickness ratio of the two SRRs, thus improving the radiation characteristics such as radiation efficiency and impedance matching.

FIG. 3 is a wideband small-sized high-efficiency isotropic antenna structure that extends the operating band by utilizing a single folded SRR. The structure can be printed on a flexible substrate in a developed format and then folded into an octagonal structure. The folded SRR 310 of the xy plane and the folded SRR 320 of the xz plane are printed on different surfaces and are electrically connected to both ends of the feeder 300 by using the vias 330. In this paper, we have implemented octagonal shape, but it can be designed variously such as circle or polygon. the wide band characteristic is realized by differently designing the resonance points of the respective folded SRRs by making a difference between the gap 313 of the folded SRR 310 of the xy plane and the gap 323 of the folded SRR 320 of the xz plane, A capacitive component can be added by separately implementing a distributing element such as an interdigital capacitor or a lumped element such as a capacitor. If the folded SRR of the xy plane resonates, the equivalent electric dipole in the y direction and the equivalent magnetic dipole in the z direction can be generated at the same time, and the dual polarization characteristic and the isotropic pattern can be realized in the xy plane. When the folded SRR of the xz plane resonates, an equivalent electrical dipole in the z-direction and an equivalent magnetic dipole in the y-direction are generated so that a dual polarization and an isotropic pattern can be realized in the xz plane. At this time, the equivalent electrical dipoles (or magnetic dipoles) generated by the folded SRRs in the xy plane are perpendicular to the equivalent electrical dipoles (or magnetic dipoles) generated by the folded SRRs in the xz plane, Can be reduced, and even when each resonance point is very close, it can resonate at the original resonance point without any interference. In the folded SRR 310 of the xy plane, the lower conductor 311 and the upper conductor 312 may have the same thickness or different thicknesses, and the thickness ratio may be adjusted to improve the radiation characteristic. This applies equally to the folded SRR 320 of the xz plane. Meanwhile, the folded SRR 310 in the xy plane and the folded SRR 320 in the xz plane may be referred to as a first folded SRR 310 and a second folded SRR 320, respectively. That is, the first folded SRR 310 is disposed on the xy plane, and the second folded SRR 320 is disposed on the xz plane.

The first folded SRR 310 includes a first lower conductor 311 formed in a metal pattern on one side of the first dielectric and a first upper conductor 312 disposed in parallel with the first lower conductor 311, . At this time, one end and the other end of the first lower conductor 311 and the first upper conductor 312 may be connected to each other by a metal pattern perpendicular to the first lower conductor 311 and the first upper conductor 312. Also, a first gap 313 in which no metal pattern is formed exists between one end and the other end of the first lower conductor 311 and the first upper conductor 312.

Similarly, the second folded SRR 320 includes a second lower conductor 321 formed on the other surface of the second dielectric body in a metal pattern, a second upper conductor 322 disposed in parallel with the second lower conductor 321, . At this time, one end and the other end of the second lower conductor 321 and the second upper conductor 322 may be connected to each other by a metal pattern perpendicular to the second lower conductor 321 and the second upper conductor 322. In addition, a second gap 323 is formed between one end of the second lower conductor 321 and the other end of the second upper conductor 322, in which no metal pattern is formed. Meanwhile, the first folded SRR 310 and the second folded SRR 320 cross each other vertically, and the first gap 313 and the second gap 323 may exist in the same area.

FIG. 4 shows simulation results of the antenna structure shown in FIG. 3. FIG. 4 (a) shows the reflection coefficient, and FIG. 4 (b) shows the total radiation efficiency and realized gain. As a result of FIG. 4, it can be seen that the broadband small high-efficiency isotropic antenna designed as described above operates as intended.

FIG. 5 shows a simulation radiation pattern of the antenna structure shown in FIG. 3, wherein FIG. 5 (a) is a radiation pattern at a relatively low resonance point and FIG. 5 (b) is a radiation pattern at a relatively high resonance point. It can be seen that the broadband small high efficiency isotropic antenna shown in FIG. 5 actually operates with a pseudo-isotropic pattern. In this case, the gain deviation at the first resonance point is 4.6 dB and the gain deviation at the second resonance point is 4 dB.

6 is a dual-band compact high-efficiency isotropic antenna implementing a dual band utilizing a single folded SRR. This structure is similar to the structure shown in FIG. 3, but operates at a relatively high frequency by increasing the difference in radii of the folded SRRs of the xz plane, so that the dual band can be implemented. The folded SRR 610 in the xy plane resonates in the low band because of its relatively long resonance length, and the folded SRR 620 in the xz plane resonates in the high band. The resonance frequency can be easily adjusted by adjusting the respective gaps 613 and 623, and a dispersive element or a lumped element can be implemented at the corresponding position, so that a capacitive component can be more effectively applied.

 The basic operation characteristics are substantially similar to those of FIG. 6 mentioned above, and detailed description is as follows. The folded SRR 610 on the xy plane and the folded SRR 620 on the xz plane are printed on different surfaces and electrically connected to both ends of the feeder 600 using vias 630. In this paper, we have implemented octagonal shape, but it can be designed variously such as circle or polygon. If the folded SRR of the xy plane resonates, the equivalent electric dipole in the y direction and the equivalent magnetic dipole in the z direction can be generated at the same time, and the dual polarization characteristic and the isotropic pattern can be realized in the xy plane. When the folded SRR of the xz plane resonates, an equivalent electrical dipole in the z-direction and an equivalent magnetic dipole in the y-direction are generated so that a dual polarization and an isotropic pattern can be realized in the xz plane. At this time, the equivalent electrical dipoles (or magnetic dipoles) generated by the folded SRRs in the xy plane are perpendicular to the equivalent electrical dipoles (or magnetic dipoles) generated by the folded SRRs in the xz plane, Can be reduced. Therefore, the folded SRRs 610 and 620 of the xy plane and the xz plane can operate as a dual-band isotropic antenna while resonating without interfering with each other. In the folded SRR 610 of the xy plane, the lower conductor 611 and the upper conductor 612 may have the same thickness or different thicknesses, and the thickness ratio may be adjusted to improve the radiation characteristic. This applies equally to the folded SRR 620 of the xz plane. Meanwhile, the folded SRR 610 in the xy plane and the folded SRR 620 in the xz plane may be referred to as a first folded SRR 610 and a second folded SRR 620, respectively. That is, the first folded SRR 310 is disposed on the xy plane, and the second folded SRR 320 is disposed on the xz plane.

The first folded SRR 610 includes a first lower conductor 611 formed on one surface of the first dielectric material in a metal pattern and a first upper conductor 612 disposed in parallel with the first lower conductor 611, . At this time, one end and the other end of the first lower conductor 611 and the first upper conductor 612 may be connected to each other by a metal pattern perpendicular to the first lower conductor 611 and the first upper conductor 612. A first gap 613 is formed between one end of the first lower conductor 311 and the other end of the first upper conductor 612 so that no metal pattern is formed.

Similarly, the second folded SRR 620 includes a second lower conductor 621 formed on the other surface of the second dielectric body in a metal pattern, a second upper conductor 622 disposed in parallel with the second lower conductor 621, . At this time, one end and the other end of the second lower conductor 621 and the second upper conductor 622 may be connected to each other by a metal pattern perpendicular to the second lower conductor 621 and the second upper conductor 622. In addition, a second gap 623 in which no metal pattern is formed is present between one end and the other end of the second lower conductor 621 and the second upper conductor 622. Meanwhile, the first folded SRR 610 may be disposed inside the second folded SRR 620. At this time, the first folded SRR 610 operates in a higher frequency band than the second folded SRR 620 because the resonance length is reduced. Alternatively, the second folded SRR 620 may be disposed within the first folded SRR 610. At this time, the second folded SRR 620 operates in a higher frequency band than the first folded SRR 610 because the resonance length decreases.

FIG. 7 shows simulation results of the antenna structure shown in FIG. 6. FIG. 7 (a) shows the reflection coefficient, and FIG. 7 (b) shows the total radiation efficiency and realized gain. As a result of Fig. 7, it can be confirmed that the dual band small high efficiency isotropic antenna designed as above operates as intended.

Fig. 8 is a simulated radiation pattern of the antenna structure shown in Fig. 6, Fig. 6 (a) is a radiation pattern at a low resonance point, and Fig. 6 (b) is a radiation pattern at a high resonance point. 8 shows that the dual-band compact high-efficiency isotropic antenna actually exhibits a pseudo-isotropic pattern. In this case, the gain deviation at the first resonance point is 4.42 dB and the gain deviation at the second resonance point is 5.76 dB.

Figure 9 is a dual-band isotropic antenna implementation utilizing a single folded SRR. This structure can be produced by printing on a flexible substrate and can be printed on a single plane. The operation at the low frequency is operated by the folded SRR 910 and the SRR 920 is further implemented around the feeding portion of the upper conductor 910 and the lower conductor 920 to implement the operation in the high frequency band. In this case, SRR is implemented in both the upper and lower conductors in FIG. 9, but it can be operated in a dual band even if only one region is selectively implemented. The shape of the SRR can be variously changed from circular to polygonal. Both the folded SRR 910 in the xy plane and the SRR 920 in the upper and lower conductors can emit an isotropic pattern because they are SRR-based resonators. In the folded SRR 910 of the xy plane, the lower conductor 911 and the upper conductor 912 may have the same thickness or different thicknesses, and the thickness ratio may be adjusted to improve the radiation characteristic. Both the folded SRR 910 and the SRR 920 can adjust the resonance frequency by adjusting the gaps 913, 923 and 924 and the radius. On the other hand, the folded SRRs 920 disposed on the same plane as the folded SRRs 910 in the xy plane may be referred to as a first folded SRR 910 and a third folded SRR 920, respectively. That is, the first folded SRR 910 and the third folded SRR 920 may all be disposed on the same plane. 3 and 6, the first folded SRR 910 and the third folded SRR 920 are separated from the first folded SRR 910 and the third folded SRR 920, And may be disposed perpendicular to the third folded SRR 920.

The first folded SRR 910 includes a first lower conductor 911 formed on one surface of the first dielectric material in a metal pattern and a first upper conductor 912 disposed in parallel with the first lower conductor 911, . At this time, one end and the other end of the first lower conductor 911 and the first upper conductor 912 may be connected to each other by a metal pattern perpendicular to the first lower conductor 911 and the first upper conductor 912. A first gap 613 is formed between one end of the first lower conductor 911 and the other end of the first upper conductor 912 so that no metal pattern is formed.

Likewise, the third folded SRR 920 includes a third bottom conductor 921 connected to the first bottom conductor 911 of the first folded SRR 910 and a third bottom conductor 921 connected to the first top side 911 of the first folded SRR 910. [ And a third upper conductor 922 connected to the conductor 912. At this time, the third lower conductor 921 and the third upper conductor 922 are disposed perpendicular to the first lower conductor 911 and the first upper conductor 912. That is, the first lower conductor 911 and the first upper conductor 912 are disposed on the xz plane, while the third lower conductor 921 and the third upper conductor 922 are disposed on the xy plane. On the other hand, a gap 923 is formed in the third lower conductor 921, and a gap 924 is formed in the third upper conductor 922 as well.

FIG. 10 shows simulation results of the antenna structure shown in FIG. 9, and FIG. 10 (a) shows the reflection coefficient and FIG. 10 (b) shows the total radiation efficiency and realized gain. By confirming the results shown in FIG. 10, it can be confirmed that the double-band compact high-efficiency isotropic antenna designed as described above operates as intended.

Fig. 11 is a simulated radiation pattern of the antenna structure shown in Fig. 9, in which Fig. 11 (a) is a radiation pattern at a low resonance point and Fig. 11 (b) is a radiation pattern at a high resonance point. 11 shows that the dual-band compact high-efficiency isotropic antenna actually exhibits a pseudo-isotropic pattern.

12 is a structure designed to operate in a dual band by implementing a parasitic element in a single folded SRR. This structure can be realized by printing the developed surface on a flexible substrate and printed on a single plane. The parasitic element 1220 is symmetrically implemented at the upper and lower ends of the upper conductor 1212 and the lower conductor 1211 of the folded SRR 1210 and designed to operate in a dual band. And is resonated by the folded SRR 1210 in the low frequency band and resonated by the parasitic element 1220 in the high frequency band. The overall antenna structure may vary from circular to polygonal and the resonance frequency of the low frequency band is easily adjustable to the radius and gap 1213 of the folded SRR 1210 and the resonance frequency of the high frequency band is controlled by the parasitic element 1220 ) Length, thickness, and spacing. At this time, the thickness of the upper conductor 1212 and the lower conductor 211 of the folded SRR 1210 may be the same or different, and the radiation property may be improved by adjusting the thickness ratio.

FIG. 13 shows simulation results of the antenna structure shown in FIG. 12. FIG. 13 (a) shows the reflection coefficient, and FIG. 13 (b) shows the total radiation efficiency and realized gain. By confirming the results shown in FIG. 13, it can be confirmed that the dual-band compact high-efficiency antenna previously designed operates as intended.

Fig. 14 is a simulated radiation pattern of the antenna structure shown in Fig. 12, Fig. 14 (a) is a radiation pattern at a low resonance point, and Fig. 14 (b) is a radiation pattern at a high resonance point. It can be seen from the results of FIG. 14 that the proposed antenna operates in a quasi-isotropic pattern in a dual band with a small high efficiency.

FIG. 15 shows a structure in which a wide band characteristic and a dual band characteristic are implemented using a basic folded SRR structure. This combines the broadband antenna of FIG. 3 with the dual band antenna structure of FIG. 9 and exhibits a dual band characteristic that operates at high frequencies while exhibiting broadband characteristics at low frequencies. The operation in the low frequency band is the same as that shown in Fig. 3, and the operation in the high frequency band is the same as that shown in Fig.

FIG. 16 shows simulation results of the antenna structure shown in FIG. 15. FIG. 16 (a) shows the reflection coefficient, and FIG. 16 (b) shows the total radiation efficiency and realized gain. By confirming the results shown in FIG. 16, it can be seen that the above-described antenna operates as a compact high-efficiency antenna having broadband and dual-band characteristics.

Fig. 17 is a simulation radiation pattern of the antenna structure shown in Fig. 15, Fig. 17 (a) is a radiation pattern at a first resonance point in a low frequency band, Fig. 17 (b) is a radiation pattern at a second resonance point in a low- to be. 17 (c) is a radiation pattern of a high frequency band. It can be seen from the result of FIG. 17 that the proposed antenna operates in a quasi-isotropic pattern in a dual band with a small high efficiency.

FIG. 18 shows a structure in which a quadband is implemented by using a parasitic element in a conventional FSRR structure and a dual band technique. FIG. This combines the dual band structure of FIG. 6 with the dual band structure of FIG. 12 and operates in a total of four bands. The folded SRR 1810 in the xy plane and the folded SRR 1850 in the xz plane may be electrically connected to each other via a via 1830 As shown in Fig. At this time, the first operating band is divided by the folded SRR 1810 of the xy plane, the second operating band is divided by the parasitic element 1820 of the xy plane, and the third band is divided by the folded SRR 1850 of the xz plane , And the fourth band is generated by the parasitic element 1860 in the xz plane. The two folded SRRs 1810 and 1850 can adjust the resonant frequency by its radius and gaps 1813 and 1853 and the two parasitic elements 1820 and 1860 can adjust the length, Can be adjusted. The two folded SRRs 1810 and 1850 and the two parasitic elements 1820 and 1860 are arranged perpendicular to each other, so that there is little interference at each resonance point and four bands can be formed. The basic operation is the same as that shown in FIG. 6 and FIG.

FIG. 19 shows simulation results of the antenna structure shown in FIG. 18. FIG. 19 (a) shows the reflection coefficient, and FIG. 19 (b) shows the total radiation efficiency and realized gain. By confirming the results shown in FIG. 19, it can be confirmed that the above-mentioned antenna operates at a small and high efficiency in a quad band.

Fig. 20 is a simulation radiation pattern of the antenna structure shown in Fig. 18, Fig. 20 (a) is the radiation pattern at the first resonance point, Fig. 20 (b) is the radiation pattern at the second resonance point, The radiation pattern at the third resonance point, Fig. 20 (d) is the radiation pattern at the fourth resonance point. It can be seen from the result of FIG. 20 that the proposed antenna operates in a quasi-isotropic manner in a quadrupole with a small high efficiency.

By using the structure proposed in the present invention, it is possible to realize an antenna which radiates in a quasi-isotropic pattern in a multi-band with a high efficiency, and the complexity of the structure can be reduced since the equivalent electric dipole and the magnetic dipole are simultaneously generated in a single structure.

Also, in the present invention, the resonance point can be easily adjusted by parameters such as the length of the parasitic element, the radius, the thickness, and the interval of the folded SRR.

According to a software implementation, the design and parameter optimization for each component as well as the procedures and functions described herein may be implemented as separate software modules. Software code can be implemented in a software application written in a suitable programming language. The software code is stored in a memory and can be executed by a controller or a processor.

Claims (7)

A first folded SRR (Folded Split Ring Resonator) for simultaneously generating an electric dipole and a magnetic dipole perpendicular to the electric dipole; And
And a second folded SRR disposed perpendicular to the first folded SRR and operating as an electrical dipole and a magnetic dipole perpendicular to the electrical dipole,
Wherein the second folded SRR is disposed within the first folded SRR so that the second folded SRR operates in a higher frequency band than the first folded SRR due to a reduced resonant length. . The method according to claim 1,
Wherein the first folded SRR comprises:
A first lower conductor formed in a metal pattern on one surface of the first dielectric; And
And a first upper conductor disposed on one side of the first dielectric and arranged parallel to the first lower conductor,
Wherein the second folded SRR comprises:
A second lower conductor formed on the other surface of the second dielectric body in a metal pattern; And
And a second upper conductor disposed on the other side of the second dielectric and disposed parallel to the second lower conductor. 3. The method of claim 2,
One end and the other end of the first lower conductor and the first upper conductor are connected to each other by a metal pattern perpendicular to the first lower conductor and the first upper conductor, There is a first gap in which no metal pattern is formed,
One end and the other end of the second lower conductor and the second upper conductor are connected to each other by a metal pattern perpendicular to the second lower conductor and the second upper conductor, And a second gap is formed between the other end of the first electrode and the other end of the second electrode, in which no metal pattern is formed. The method of claim 3,
Wherein the first folded SRR and the second folded SRR cross each other perpendicularly and the first gap and the second gap are on the same area. delete 3. The method of claim 2,
Further comprising a third folded SRR disposed on the same plane as the first folded SRR,
The third folded SRR includes:
A third lower conductor connected to the first lower conductor and disposed perpendicularly to the first lower conductor; And
And a third upper conductor connected to the first upper conductor and disposed perpendicularly to the first upper conductor. The method according to claim 1,
Wherein the first folded SRR and the second folded SRR are electrically connected at both ends of the feed portion using vias.

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