KR20090107736A - Multi-band antenna - Google Patents

Abstract

PURPOSE: A multi-band antenna is provided to implement a desired bandwidth and a resonance frequency through adjusting the interval between radiators. CONSTITUTION: A multi-band antenna includes a dielectric substrate(100), a first radiator(104), and a second radiator(106). The first radiators are arranged on the single-side of the dielectric substrate. The first radiators are composed of a straight part and a curved surface part extended from the end of the straight part, and the second radiators are arranged on the single-side of the dielectric substrate.

Description

Multiband Antenna {MULTI-BAND ANTENNA}

The present invention relates to a multi-band antenna, and more particularly to an antenna for implementing a multi-band using two or more radiators surrounded by a ground.

In general, since a small antenna mounted on a terminal, for example, a mobile terminal, changes according to the performance of the terminal, there is a problem in that the design of the antenna varies according to the model of the terminal in order to achieve optimal performance.

In addition, in the recent mobile communication service field requiring the implementation of a plurality of communication services through one terminal, a conventional antenna that satisfies only one band is not suitable. In particular, as the demand for terminals that can be used worldwide increases gradually, conventional antennas that satisfy only one band are difficult to meet the needs of consumers. Accordingly, there is a need for a multi-band antenna that can support various communication services and global standards.

It is a first object of the present invention to provide an antenna that is compact and implements multiple bands.

It is a second object of the present invention to provide a multiband antenna capable of realizing a desired resonance frequency.

In order to achieve the above object, a multi-band antenna according to an embodiment of the present invention comprises a dielectric substrate; A first radiator arranged on one surface of the dielectric substrate and having a straight portion and a curved portion extending from one end of the straight portion; And a second radiator arranged on one surface of the dielectric substrate and having a straight portion and a curved portion extending from one end of the straight portion. Here, the radiators are arranged spaced apart.

Multi-band antenna according to another embodiment of the present invention is a dielectric substrate; A grounding portion arranged on one surface of the dielectric substrate; And a first radiator and a second radiator surrounded by the ground portion on the dielectric substrate. Here, the first radiator and the second radiator, characterized in that spaced apart disposed.

Multi-band antenna according to another embodiment of the present invention is a dielectric substrate; A grounding portion arranged on one surface of the dielectric substrate; A first radiator positioned spaced apart from the ground portion on the dielectric substrate; And a termination unit coupled to the first radiator. Here, the bandwidth or the resonance frequency of the antenna is determined according to the resistance value of the termination part.

Since the multi-band antenna according to an embodiment of the present invention uses two or more radiators surrounded by the ground portion, there is an advantage that the multi-band can be implemented. In particular, since the radiators having a curved portion are connected by electromagnetic coupling, the antenna can be miniaturized. In addition, it is possible to implement a desired bandwidth and resonant frequency by adjusting the spacing between the radiators.

Multi-band antenna according to another embodiment of the present invention has the advantage that it is possible to implement the desired bandwidth and resonant frequency by appropriately selecting the resistance value of the termination unit coupled to one end of a particular radiator.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the drawings, similar reference numerals are used for similar elements.

When a component is said to be "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but other components may be present in the middle. It should be understood. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

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

1 is a perspective view showing a multi-band antenna according to a first embodiment of the present invention.

Referring to FIG. 1, the multi-band antenna according to the present embodiment includes a dielectric substrate 100, a ground portion 102, a first radiator 104, a second radiator 106, a power supply portion 108, and a termination portion 110. It includes.

The dielectric substrate 100 is an antenna body and is made of a dielectric material having a predetermined dielectric constant, and electrically separates the first radiator 104 and the second radiator 106.

As the dielectric substrate 100, for example, an FR-4 substrate (a dielectric constant of 4.4 and a height of 1.6 mm), which may be easily manufactured and lowers production cost, may be used. Of course, various substrates may be used as the dielectric substrate 100, and the shape and size of the dielectric substrate 100 may be variously modified according to the environment in which the antenna is used.

The ground portion 102 is formed on one surface, for example, an upper surface of the dielectric substrate 100, and is made of a conductive material to provide a ground voltage.

This ground portion 102 is spaced apart from the radiators 104 and 106 by a predetermined distance. Here, the outer line facing the radiators 104 and 106 among the outer lines of the ground portion 102 forms a circular shape as shown in FIG. 1. Of course, the shape formed by the outer line of the ground portion 102 is not limited to a circular shape, for example, may have a polygonal shape (such as a rectangular shape). That is, the shape formed by the outer line of the ground portion 102 may be variously modified according to the intention of the designer.

In addition, the ground portion 102 has a structure surrounding the radiators 104 and 106 as shown in FIG.

The first radiator 104 is manufactured by, for example, a printing method as a conductor and is formed on the dielectric substrate 100 on the same plane as the ground portion 102. In particular, the first radiator 104 is positioned in the space formed by the ground portion 102, that is, has a structure surrounded by the ground portion 102.

The first radiator 104 is connected to the feed line 108 and implements a specific frequency band in response to a signal fed through the feed line 108, that is, a current. For example, the first radiator 104 may implement WiMax bandwidth (3.4 GHz to 3.6 GHz). In this case, however, the length of the first radiator 104 should be appropriately adjusted to suit the implementation of the WiMAX bandwidth. That is, the antenna may implement a desired frequency band by adjusting the length of the first radiator 104.

According to one embodiment of the invention, a portion of the first radiator 104 has a curved shape, for example a circular shape, as shown in FIG. 1. In detail, the first radiator 104 includes a straight portion and a curved portion extending in a curved shape at one end of the straight portion. As a result, when trying to implement the same frequency band, an antenna made of a radiator having a curved portion may be miniaturized compared to an antenna made of a radiator implemented only in a straight shape.

The second radiator 106 is manufactured by, for example, a printing method as a conductor, and is formed on the dielectric substrate 100 on the same plane as the ground portion 102. In particular, the second radiator 106 has a structure surrounded by the ground portion 102. Preferably, both the first radiator 104 and the second radiator 106 are surrounded by the ground portion 102.

Unlike the first radiator 104 where a specific signal is fed directly from the feed line 108 to perform radiation, the second radiator 106 is electromagnetically coupled with the first radiator 104 without being coupled to the feed line 108. Radiation is carried out through electromagnetic coupling. Specifically, when a specific signal is fed to the first radiator 104, electromagnetic coupling occurs between the first radiator 104 and the second radiator 106, and as a result, the second radiator 106 The coupling operates in a specific resonance mode.

According to one embodiment of the invention, the second radiator 106 is composed of a straight portion and a curved portion extending with a curved shape at one end of the straight portion, as shown in FIG.

As mentioned above, electromagnetic coupling takes place between the first radiator 104 and the second radiator 106, resulting in a triple band impedance bandwidth and resonant frequency. However, the reason why such a triple band is implemented will be described in the reason why the quad band of the second embodiment to be described later is implemented.

According to an embodiment of the present invention, the bandwidth or resonant frequency may be changed through the spacing adjustment between the first radiator 104 and the second radiator 106, that is, the coupling adjustment.

Hereinafter, specific experimental results of the triple band and the resonance frequency will be described with reference to Table 1 below. Here, the lengths of the radiators 104 and 106 were set to 35.9 mm, and the length of the entire antenna including the ground portion 102 was set to 40 mm x 40 mm x 1.6 mm.

Spacing between radiators 104, 106 in mm Resonant frequency Bandwidth (BW, ㎓) 0.3 0.87, 1.76, 3.00 0.79-0.95, 1.69-1.82, 2.86-3.13 0.9 0.98, 1.87, 3.34 0.89-1.06, 1.78-1.95, 3.21-3.47 1.5 1.04, 1.91, 3.58 0.95-1.12, 1.81-2.01, 3.42-3.74

Referring to Table 1 above, it is confirmed that the resonant frequency and bandwidth change according to the spacing adjustment between the radiators 104 and 106. Specifically, as the spacing between the radiators 104 and 106 widened, the resonant frequency increased.

In addition, the above experiments can confirm that the bandwidth of the triple band is implemented, for example, WiMax (WiMax, 3.4㎓ to 3.6㎓), GSM900 (0.88㎓ to 0.96㎓) and DCS1900 (1.85) that can be used in the wireless terminal Is implemented to satisfy bandwidths of ㎓ to 1.99 GHz). Thus, the user can adjust the length of the first radiator 104, the length of the second radiator 106 and the spacing between the radiators 104 and 106 to achieve the desired bandwidth or resonant frequency.

In short, the bandwidth and resonant frequency of the triple band can be adjusted by the length of the first radiator 104, the length of the second radiator 106 and the spacing between the radiators 104 and 106.

Looking back at the radiators 104 and 106, the radiators 104 and 106 are symmetrically formed about the origin as shown in FIG. However, the radiators 104 and 106 may be formed symmetrically with respect to a specific axis (X-axis or Y-axis) or a diagonal line or the like rather than the origin symmetry.

In addition, although the curved portions of the radiators 104 and 106 are referred to as having a curved shape, they may have a polygonal shape, and the radiators 104 and 106 may have different lengths.

The feed line 108 serves to feed a specific signal to the first radiator 104, and for example, may be implemented with a coplanar waveguide (CPW) structure as shown in FIG. 1. According to one embodiment of the present invention, the distance between the feed line 108 and the ground portion 102 is 0.5 mm.

In addition, a power supply line such as an SMA connector may be inserted into the feed line 108.

The termination part 110 is coupled to one type of the second radiator 106. In this case, the bandwidth or the resonance frequency of the antenna may be determined according to the resistance value of the termination unit 110. This can be confirmed through Equation 1 below. In general, the bandwidth of an antenna is related to the Q value.

, 여기서 f_c는 공진 주파수이고, B는 대역폭이며, X는 리액턴스이고, R은 저항값이다.

Where f _c is the resonant frequency, B is the bandwidth, X is the reactance, and R is the resistance value.

As can be seen in Equation 1, the bandwidth is inversely proportional to the Q value, that is, the bandwidth is changed by adjusting the Q value. Here, since the Q value may be set as a ratio of reactance and input resistance as shown in Equation 1, the bandwidth may be changed by adjusting the reactance or the input resistance.

Also, since the resonant frequency is proportional to the Q value, the resonant frequency can be changed by adjusting the Q value, i.e., adjusting the reactance or the input resistance.

Therefore, the antenna of the present embodiment can determine the bandwidth or the resonance frequency by appropriately selecting the resistance value of the termination unit 110 based on the above-mentioned principle. Specific experimental examples for this will be described later.

In short, the antenna of this embodiment implements multiple bands using electromagnetic coupling of radiators 104 and 106 surrounded by ground 102. In particular, the antenna adjusts the distance between the radiators 104 and 106 or appropriately selects the resistance value of the termination unit 100 to implement the desired bandwidth and resonant frequency.

In such an antenna, the multi-band is implemented by electromagnetic coupling of the radiators 104 and 106 and a part of the radiators 104 and 106 has a curved shape, so that the antenna can be implemented small.

According to another embodiment of the present invention, the termination unit 110 is not limited to the structure shown in FIG. 1, but may be implemented in an antenna having a structure different from that shown in FIG. 1. That is, as long as the termination unit 110 is coupled to one end of a specific radiator to control the bandwidth or resonance frequency of the corresponding antenna, the use of the termination unit 110 is not limited to the specific antenna, and may be used for various antennas.

FIG. 2 is a perspective view illustrating a multi-band antenna according to a second embodiment of the present invention, and FIG. 3 is a diagram illustrating return loss characteristics measured by the antenna of FIG. 2. 4 is a diagram illustrating current distribution for each bandwidth.

Referring to FIG. 2, the antenna of this embodiment includes a ground portion 202, a first radiator 204, a second radiator 206, a third radiator 208, a feed line 210, and a termination portion 212. do.

Since the other components except for the third radiator 208 are similar to those of the first embodiment, detailed descriptions of similar components will be omitted.

The third radiator 208 is arranged as a conductor between the first radiator 204 and the second radiator 206, preferably between the bent portions of the radiators 204 and 206, and has a circular shape. Of course, the third radiator 208 may have various shapes such as a polygonal shape in addition to the circular shape.

A separate feed line is not connected to the third radiator 208, and radiates by electromagnetic coupling with the first radiator 204.

When implementing the radiators 204, 206 and 208 as described above, a quad band is implemented as shown in FIG. Specifically, when the return loss is 10 dB, the return loss characteristic of the antenna is divided into four bands (0.86 ㎓-0.99 ㎓, 1.77 ㎓-1.99 ㎓, 3.2 ㎓-3.65 ㎓, 5.05-5.36 ㎓). Satisfaction can be confirmed through FIG. 3. That is, the antenna satisfies the bandwidths of WiMAX (3.4 ㎓ to 3.6 ㎓), GSM900 (0.88 ㎓ to 0.96 ㎓), DCS1900 (1.85 ㎓ to 1.99 ㎓) and WLAN (5.15 ㎓ to 5.35 ㎓) that can be used in the wireless terminal Let's do it.

The implementation of this quad band can also be confirmed from the current distribution characteristics as shown in FIG. 4.

In detail, referring to FIG. 4 (a), a substantial portion of the first radiator 204 and the second radiator 206 is formed with a red band mainly contributing to resonance, and the red portion causes 0.94 kHz resonance. Frequency is implemented. Here, the first radiator 204 and the second radiator 206 are designed to a length for about 4 kHz resonance mode.

Referring to FIG. 4B, a red band is formed on a small portion of the first radiator 204 and the second radiator 206, and as a result, a 1.92 kHz resonance frequency is realized.

Referring to FIG. 4C, a red band is formed on a substantial portion of the first radiator 204, a portion of the second radiator 206, and a small portion of the third radiator 208, and consequently, 3.52 kHz resonance. Frequency is implemented.

Referring to FIG. 4 (d), red bands are formed on the curved portions of the first radiator 204 and the second radiator 206 and the outer portions of the third radiator 208, resulting in a 5.17 kHz resonance frequency. Is implemented.

That is, in the antenna of the present embodiment, the quadrature resonant frequency is generated by the electromagnetic coupling of the radiators 204, 206, and 208. In particular, since the high resonant frequency of 5.17 kHz and the low resonant frequency of 0.94 kHz can be realized, the antenna can be suitably used for various services.

Although not mentioned above, it can be seen from FIG. 4 (a) to FIG. 4 (d) that the current distribution is symmetrically distributed on the curved portions arranged symmetrically with each other.

Hereinafter, the actual experimental results for the resonant frequency and bandwidth of the antenna will be described in detail through Table 2 below. Here, the lengths of the first radiator 204 and the second radiator 206 were set to 35.9 mm, and the length of the entire antenna including the ground portion 202 was set to 40 mm × 40 mm × 1.6 mm.

Radius of third radiator 208 (mm) Resonant frequency Bandwidth (BW, ㎓) 5.0 0.94, 1.94, 3.46 5.21 0.86-1.02, 1.84-2.03, 3.32-3.59 5.05-5.37 5.2 0.94, 1.94, 3.52 5.17 0.86-1.02, 1.85-2.02, 3.38-3.65 5.01-5.32 5.4 0.94, 1.96, 3.55 5.13 0.86-1.01, 1.86-2.05, 3.41-3.68 4.98-5.27

Referring to Table 2 above, it is confirmed that the quadruple bandwidth and the resonant frequency are realized by arranging the third radiator 208 between the first radiator 204 and the second radiator 206. For example, bandwidths and resonant frequencies of WiMAX (3.4 GHz to 3.6 GHz), GSM900 (0.88 kHz to 0.96 GHz), DCS1900 (1.85 GHz to 1.99 GHz) and WLAN (5.15 GHz to 5.35 GHz) have been implemented.

Hereinafter, changes in resonance frequency and bandwidth according to resistance values of the termination unit 212 in the antenna will be described with reference to Table 3.

Resistance value (Ω) of the termination part 212 Resonant frequency Bandwidth (BW, ㎓) 30 0.91, 1.91, 3.50 5.03 0.85-0.97, 1.85-1.97, 3.38-3.62 4.87-5.18 50 0.94, 1.94, 3.52 5.17 0.86-1.02, 1.85-2.02, 3.38-3.65 5.01-5.32 70 1.00, 1.96, 3.65 5.27 0.89-1.11, 1.86-2.05, 3.48-3.81 5.11-5.42

Referring to Table 3 above, it can be seen that the resonance frequency and bandwidth change as the resistance value of the termination unit 212 coupled to the second radiator 206 is changed. Therefore, the antenna of the present embodiment can implement a desired bandwidth or resonant frequency by appropriately selecting the resistance value of the termination unit 212.

5 is a diagram illustrating a radiation pattern of a multi-band antenna according to an embodiment of the present invention.

As shown in Fig. 5, it is confirmed that the antenna of this embodiment forms an omnidirectional radiation pattern to be suitable for the antenna for the terminal, that is, has a radiation pattern similar to that of the monopole antenna.

The embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art having ordinary knowledge of the present invention may make various modifications, changes, and additions within the spirit and scope of the present invention. Should be considered to be within the scope of the following claims.

1 is a perspective view showing a multi-band antenna according to a first embodiment of the present invention.

2 is a perspective view illustrating a multi-band antenna according to a second embodiment of the present invention.

3 is a diagram illustrating return loss characteristics measured by the antenna of FIG. 2. 4 is a diagram illustrating current distribution for each bandwidth.

4 is a diagram illustrating current distribution for each bandwidth.

5 is a diagram illustrating a radiation pattern of a multi-band antenna according to an embodiment of the present invention.

Claims (19)

Dielectric substrates; A first radiator arranged on one surface of the dielectric substrate and having a straight portion and a curved portion extending from one end of the straight portion; And A second radiator arranged on one surface of the dielectric substrate and including a straight portion and a curved portion extending from one end of the straight portion, And the radiators are spaced apart from each other. The multi-band antenna according to claim 1, wherein the curved portion of the first radiator and the curved portion of the second radiator are symmetrically arranged about an origin, a specific axis or a diagonal. The method of claim 1, wherein the multi-band antenna, A third radiator arranged between the curved portion of the first radiator and the curved portion of the second radiator, And the third radiator has a circular shape or a polygonal shape. The method of claim 1, wherein the multi-band antenna, Further comprising a feed line coupled to one end of the first radiator, And the second radiator is electromagnetically coupled with the first radiator. The method of claim 1, wherein the multi-band antenna, Further comprising a termination portion coupled to the other end of the straight portion of the second radiator, Multi-band antenna, characterized in that the resonant frequency or bandwidth of the antenna is changed according to the resistance value of the termination unit. Dielectric substrates; A grounding portion arranged on one surface of the dielectric substrate; And A first radiator and a second radiator surrounded by the ground portion on the dielectric substrate, And the first radiator and the second radiator are spaced apart from each other. 7. The multi-band antenna of claim 6, wherein at least one of the first radiator and the second radiator is partially curved. The method of claim 7, wherein a portion of the first radiator has a curved shape and a portion of the second radiator has a curved shape, And the curved portions of the radiators are arranged symmetrically to each other. The method of claim 6, wherein the multi-band antenna, And a feeding part electrically coupled to the first radiator to feed a specific signal. The method of claim 9, wherein the multi-band antenna, Further comprising a termination unit coupled to one end of the second radiator, Multi-band antenna, characterized in that the resonant frequency or bandwidth of the antenna is changed according to the resistance value of the termination unit. The method of claim 6, wherein the multi-band antenna, Further comprising a third radiator having a circular or polygonal shape, A portion of the first radiator has a curved shape, a portion of the second radiator has a curved shape, and the third radiator is arranged between the curved portions. 12. The multi-band antenna of claim 11, wherein the resonant frequency and bandwidth of the antenna are determined by adjusting the spacing between the radiators. The multi-band antenna of claim 6, wherein the outer lines of the outer lines of the ground portion facing the radiator form a circular or polygonal shape. 7. The multi-band antenna of claim 6, wherein the radiators are formed symmetrically about the origin or a specific axis. In a multiband antenna, Dielectric substrates; A grounding portion arranged on one surface of the dielectric substrate; A first radiator positioned spaced apart from the ground portion on the dielectric substrate; And Including a termination portion coupled to the first radiator, The bandwidth or the resonant frequency of the antenna is varied according to the resistance value of the termination unit. The method of claim 15, wherein the antenna, A second radiator formed spaced apart from the first radiator by a predetermined distance; And Further comprising a feeder coupled to the second radiator to feed a specific signal, And the radiators are surrounded by the ground portion. The method of claim 16, wherein the antenna, Further comprising a third radiator arranged between the first radiator and the second radiator, And the third radiator has a circular shape or a polygonal shape. 17. The multi-band antenna according to claim 16, wherein the first radiator or the second radiator comprises a straight portion and a curved portion extending in length from the straight portion. 17. The multi-band antenna of claim 16, wherein outer lines of the outer lines of the ground portion facing the radiators form a circular or polygonal shape.

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