KR20100106164A - Antenna using reactive element - Google Patents

Abstract

PURPOSE: An antenna using a reactive element is provided to secure a desired resonance point and bandwidth by properly selecting the feedback of a reactive element and a reactive component. CONSTITUTION: A feeding point(100) is combined with an RF transmission line to supply a feed signal. A radiator(102) radiates a fed radio frequency signal to the outside. The radiator is electrically connected to the feed point. A reactive element(104) is combined with the end(A) and a certain part of the radiator. The reactive component includes an inductive element or a capacitive element.

Description

Antenna Using Reactive Element

The present invention relates to an antenna, and more particularly, to an antenna for securing a desired bandwidth and resonance characteristics by applying a reactive element.

Recently, a mobile terminal has been required to have a small size and a light weight, and to receive a mobile communication service having a different frequency band using a single terminal. Accordingly, miniaturization of the antenna radiator and broadband characteristics were required, and various types of built-in antennas were researched.

Representative small antennas include a planar inverted-F antenna (PIFA), a small monopole antenna, and a high dielectric antenna.

Techniques applied to the antennas as described above may be classified into a miniaturization technique and a multi-band technique. The miniaturization technique is a technique for reducing the size of the antenna, and the method of increasing the electrical length of the antenna in a limited physical length includes various methods such as using a radiator such as meander and helical or using a high dielectric material. In addition, the multi-band technique has a method of securing multiple resonances by diversifying the current path of the antenna or securing multiple resonance characteristics by coupling using parasitic radiating elements.

Most of the antennas used in recent years are designed using the above-described miniaturization technique and multi-band technique, and no additional technique for securing a desired resonance point and bandwidth is used.

In order to solve the problems of the prior art as described above, the present invention proposes an antenna that can efficiently secure a desired resonance point and bandwidth by using a reactive element.

Another object of the present invention is to propose an antenna capable of adaptively adjusting the resonance point and the bandwidth by appropriately selecting the feedback and reactive components of the reactive element.

It is still another object of the present invention to propose an antenna using a reactive element capable of effectively miniaturizing and widening an antenna.

Other objects of the present invention will be readily apparent to those skilled in the art through the following examples.

In order to achieve the object as described above, according to an aspect of the present invention, the radiator electrically connected to the power supply before the radiator having a predetermined length to emit an RF signal; An antenna using a reactive element coupled to an end of the radiator and including a reactive element connected to a predetermined portion of the radiator in a feedback form is provided.

The reactive element may include an inductive element or a capacitive element.

The inductive element may include a chip inductor, and the capacitive element may include a chip capacitor.

The resonance point and the bandwidth change according to the type of the reactive element and the size of the reactant component.

The end of the radiator has an open structure. In this case, when the inductive element is coupled to the reactive element, the resonance point increases, and the bandwidth is extended. When the capacitive element is coupled to the reactive element, the resonance point decreases.

 The end of the radiator has a structure connected to the ground, and when the reactive element is coupled to the end of the radiator in a feedback form, the resonance point is maintained while the bandwidth is extended.

The reactive element may further include a resonator.

The reactive element may be connected in the form of a feedback to the end of the radiator and a point away from the beginning or the beginning of the radiator.

According to another aspect of the invention, the feed point; At least one radiator electrically coupled to the feed point; An antenna using a reactive element comprising at least one reactive element connected in parallel to two predetermined points of the at least one radiator is provided.

According to the present invention, according to the present invention, it is possible to efficiently secure a desired resonance point and bandwidth by using a reactive element, and there is an advantage that the miniaturization and widening of the antenna can be effectively realized.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the antenna using a reactive element according to the present invention.

1 is a perspective view showing an antenna using a reactive element according to a first embodiment of the present invention.

Referring to FIG. 1, an antenna using a reactive element according to a first embodiment of the present invention may include a feed point 100, a radiator 102, a reactive element 104, and a ground plane 106. .

The feed point 100 feeds an RF signal and the feed point is combined with an RF transmission line such as a coaxial cable to provide a feed signal.

The radiator 102 is electrically connected to the feed point 100 and functions to radiate the supplied RF signal to the outside. The length of the radiator corresponds to the frequency band used, and in the case of the monopole antenna, the length of the radiator may be set to about 1/4 of the wavelength. Figure 1 is shown in the form of '' ', but the shape of the radiator is not limited to this, it can be used to those skilled in the art that various kinds of radiators such as meander shape, line shape, spiral shape, helical shape can be used It will be self-evident.

In addition, although an antenna using one radiator is shown in FIG. 1, a multiple radiator (described as a third embodiment in FIG. 7) in which multiple current paths are formed for multi-band formation may be used.

As shown in FIG. 1, the end of the radiator 102 is open, the reactive element 104 is coupled in parallel with the radiator, and preferably the reactive element 104 is the end A of the radiator and the radiator. Bound to a predetermined site (B). That is, according to a preferred embodiment, the reactive element 104 is coupled to another portion of the radiator in feedback form from the end of the radiator and the portion where the reactive element is coupled in feedback form may be the beginning of the radiator, from the beginning It may be a site having a predetermined distance.

The reactive element 104 may be an inductive element such as an inductor or a capacitive element such as a capacitor. Substantially, when coupling the reactive element to the antenna, a device such as a chip inductor or chip capacitor may be used as the reactive element.

 2 is a perspective view showing an antenna using a reactive element according to a second embodiment of the present invention.

2, the antenna using the reactive element according to the second embodiment of the present invention includes a feed point 200, a radiator 202, a reactive element 204, and a ground plane 206. The components are the same as those of the antenna of the first embodiment shown in FIG. 1, but the terminals of the radiator 202 are connected to ground rather than open.

In the second embodiment, the connecting manner of the reactive element 204 is the same as that of the first embodiment shown in FIG. Referring to FIG. 2, the reactive element 204 is connected in parallel to the radiator 202, preferably in feedback form at the end A of the radiator and a predetermined portion B of the radiator. As in the above-described first embodiment, the portion where the reactive element fed back from the end A of the radiator 202 is coupled may be the beginning of the radiator or a portion having a predetermined distance from the beginning.

When the reactive element is connected in the form of feedback at the open antenna end as in the first embodiment of FIG. 1 and the feedback element is connected in the form of feedback at the end coupled to ground as in the second embodiment of FIG. The effect is different, and the effect is different depending on the type of reactive element. By using this phenomenon, it is possible to adjust the resonance point and the bandwidth.

Hereinafter, the operation of the antenna using the reactive element according to the present invention will be described in detail.

FIG. 3 is a diagram showing reactance curves when the end of the radiator is opened and an inductive element is used as the reactive element as in the first embodiment.

Referring to FIG. 3, a reactance curve is shown when no reactive element is fed back and when the inductance of the inductive element is 5 nH and 10 nH. In FIG. 3, when there is no inductive element fed back, the first resonance point (zero reactance point) is formed at about 1.1 GHz, but when the inductive element is used, it is confirmed that it is formed at about 2 GHz. However, it can be seen that the slope of the reactance curve at the first resonance point is more gentle when the reactive element is used.

That is, when the inductive element is coupled to the radiator with the open end in the form of a feedback, the resonance point increases, but the reactance curve is gentle to secure a wider bandwidth.

Therefore, when bandwidth is more important than the size of the radiator, a wide bandwidth can be secured by connecting an inductive element to the antenna end in a feedback form.

4 is a diagram showing reactance curves when the end of the radiator is opened and a capacitive element is used as a reactive element as in the first embodiment.

Referring to FIG. 4, there is shown a reactance curve when no reactive element is fed back and when the capacitance of the capacitive element is 0.1 pF and 0.5 pF. In FIG. 4, when no capacitive element is fed back, a first resonance point (zero reactance point) is formed at about 1.1 GHz, but when a 0.1 pF capacitive element is used, a resonance point is formed at about 1 GHz and a capacitive capacitance of 0.5 pF is shown. When the device is used, it can be seen that a resonance point is formed at about 0.8 GHz. When the capacitive element is coupled in a feedback form, the reactance curve at the first resonance point is slightly steep, so that the bandwidth is narrow.

In other words, when the capacitive element is coupled to the radiator with the open end in the form of a feedback, the bandwidth is narrowed but the resonance point is lowered, thereby miniaturizing the antenna.

Therefore, when the size of the radiator is more important than the bandwidth, the size of the radiator can be further reduced by coupling the capacitive element to the end of the radiator in a feedback form.

Meanwhile, referring to FIG. 4, in the case of the second resonance point, when the inductive elements connected in the form of feedback are coupled, the resonance point is lowered and the bandwidth is increased. Thus, feedback coupling of the capacitive element can benefit both in bandwidth and size when the resonance band at the second resonance point is used.

FIG. 5 is a diagram illustrating a reactance curve when an end of a radiator is connected to ground and an inductive element is used as a reactive element as in the second embodiment.

Referring to FIG. 5, there is shown a reactance curve when no reactive element is fed back and when the inductance of the inductive element is 5nH and 10nH. In FIG. 5, it can be seen that the first and second resonant points do not change when compared with the case where there is no inductive element fed back, and the first and second resonant points do not change, but the inductive element is in the feedback form. When combined, the reactance curves can be seen to be gentle. That is, when the inductive element is connected in the feedback form in the antenna in which the radiator terminal is connected to the ground, the resonance point can be maintained while improving the bandwidth.

In addition, when the inductive element is coupled in the form of feedback, the pseudo resonance point (F, the point where the reactance curve is vertically formed and the reactance is 0) is closer to the first resonance point in the band lower than the first resonance point, thereby causing the The bandwidth at the first resonance point can be extended to include the lower band.

FIG. 6 is a diagram illustrating reactance curves when the end of the radiator is connected to ground and a capacitive element is used as a reactive element, as in the second embodiment.

Referring to FIG. 6, there is shown a reactance curve when no capacitive element is fed back and when the capacitance of the capacitive element is 0.1 pF and 0.5 pF. In FIG. 6, even when the capacitive element is used, it can be seen that the first and second resonance points do not change when there is no capacitive element fed back. In addition, although the first and second resonance points do not change, it can be seen that the reactance curve becomes smooth when the capacitive elements are coupled in the feedback form. That is, when the capacitive element is connected in feedback form in the antenna in which the radiator end is connected to the ground, the resonance point can be maintained while the bandwidth can be improved.

In addition, when the capacitive element is coupled in the form of feedback, the pseudo resonance point (F, the point where the reactance curve is vertically formed and the reactance is 0) is closer to the first resonance point in the band higher than the first resonance point, thereby causing the The bandwidth at the first resonance point can be extended to include the higher bandwidth band.

7 is a diagram illustrating a perspective view of an antenna using a reactive element according to a third exemplary embodiment of the present invention.

Referring to FIG. 7, an antenna using a reactive element according to a third embodiment of the present invention may include a feed point 700, a first radiator 702, a second radiator 704, and a first reactive element 706. And a second reactive element 708 and a ground plane 710.

The feed point 700 feeds an RF signal and the feed point is combined with an RF transmission line such as a coaxial cable to provide a feed signal.

The first radiator 702 and the second radiator 704 are electrically connected to the feed point 100 and radiate the supplied RF signal to the outside. FIG. 7 illustrates a case in which a reactive element is applied to an antenna that resonates for multiple bands by using two radiators 702 and 704.

In FIG. 7, the first radiator 702 is vertically raised after having progressed in a '-' shape, and has a meander shape, and the terminal is opened. The first reactive element 706 is coupled to the end of the first radiator 702 and the first reactive element is coupled to the end of the first radiator 702 and a predetermined portion of the first radiator 702 in a feedback form. .

The second radiator 704 has a 'c' shape and the end of the radiator is open. The second radiator 7040 has a shorter electrical length than the first radiator 702. A second reactive element 708 is coupled to the end of the second radiator 704, and the second reactive element 708 is connected. Is coupled in the form of a feedback to the end of the second radiator 704 and a predetermined portion of the second radiator.

In FIG. 7, the first radiator 702 and the second radiator 704 radiate an RF signal in a band corresponding to each length, and have a first radiator 702 having a longer length than the second radiator 704. Radiates an RF signal in a low frequency band compared to the second radiator 704.

8 is a diagram illustrating VSWR when no reactive element is coupled in the antenna according to the third embodiment of the present invention.

Referring to FIG. 8, two resonance bands are formed when the reactive elements are not coupled and operate as a general antenna. The first resonance band of the low frequency is the resonance band of the first radiator 702, and the relatively high frequency The second resonance band is a resonance band by the second radiator 704. In FIG. 8, it can be seen that the first resonance band is formed at about 1.4 GHz and the second resonance band is formed at about 1.8 GHz.

When there is no reactive element, the antenna according to the third embodiment operating as shown in FIG. 8 may adjust the bandwidth and the resonance band by coupling the reactive elements to the first radiator and the second radiator.

FIG. 9 is a view showing VSWR when reactive elements are coupled to an antenna according to the third embodiment. In FIG. 9, a solid line shows an inductive element having an inductance of 2.7 nH as a first reactive element. The VSWR curve and the dotted line show the case where an inductive element having an inductance of 2.7 nH is coupled to the first reactive element, and a capacitive element having a capacitance of 0.2 pF is coupled to the second reactive element.

In FIG. 9, when only the inductive element is coupled to the first radiator as the first reactive element in a feedback form, the first resonance point is moved to near the second resonance point, thereby forming a wider resonance band in the second resonance band. You can check it.

In addition, in FIG. 9, when the inductive element is coupled to the first radiator in the form of feedback and the capacitive element is coupled to the second radiator in the form of feedback, an additional resonance band is formed at about 1.7 GHz as shown by the dotted line of FIG. 9. You can see that. In Fig. 9, the resonance band of 1.7 GHz is generated by dropping the resonance band of the second radiator into the capacitive element.

As can be seen in FIG. 9, by appropriately coupling the reactive elements to the first radiator and the second radiator, it is possible to expand the bandwidth and adjust the resonance point even in the multi-band antenna.

FIG. 10 illustrates another VSWR when reactive elements are combined in an antenna according to a third embodiment of the present invention.

In FIG. 10, the solid line indicates that an inductive element having an inductance of 2.7 nH corresponding to the dotted line in FIG. 2 is coupled to the first reactive element, and a capacitive element having a capacitance of 0.2 pF is coupled to the second reactive element. The dotted line shows the case where an inductive element having an inductance of 2.7 nH is coupled to the first reactive element, and a capacitive element having a capacitance of 0.4 pF is coupled to the second reactive element. .

As shown in FIG. 10, when the capacitance of the capacitive element is changed from 0.2pF to 0.4pF while maintaining the inductive element, the resonance point is further lowered to form a resonance point at about 1.6 GHz. That is, it can be seen that the resonance point also decreases when the capacitance of the capacitive elements to be coupled increases.

Meanwhile, in the above-described embodiment, a case in which one of an inductive element or a capacitive element is coupled to a reactive element has been described, but a resonator in which the inductive element and the capacitive element are coupled in parallel may be combined.

1 is a perspective view showing an antenna using a reactive element according to a first embodiment of the present invention.

2 is a perspective view showing an antenna using a reactive element according to a second embodiment of the present invention.

Fig. 3 shows a reactance curve when the end of the radiator is open as in the first embodiment and an inductive element is used as the reactive element.

4 shows a reactance curve when the end of the radiator is open and a capacitive element is used as the reactive element as in the first embodiment;

FIG. 5 shows a reactance curve when an end of a radiator is connected to ground and an inductive element is used as a reactive element as in the second embodiment; FIG.

FIG. 6 shows a reactance curve when the end of the radiator is connected to ground and a capacitive element is used as a reactive element as in the second embodiment; FIG.

7 is a perspective view of an antenna using a reactive element according to a third embodiment of the present invention;

FIG. 8 illustrates VSWR when no reactive elements are coupled in the antenna according to the third embodiment of the present invention. FIG.

9 illustrates VSWR when reactive elements are coupled to an antenna according to the third embodiment;

FIG. 10 illustrates another VSWR when reactive elements are combined in an antenna according to a third embodiment of the present invention. FIG.

Claims (15)

A radiator electrically connected to the power point before the radiator having a predetermined length to emit an RF signal; And a reactive element coupled to an end of the radiator and connected to a predetermined portion of the radiator in a feedback form. The method of claim 1, The reactive element is an antenna using a reactive element, characterized in that it comprises an inductive element or a capacitive element. The method of claim 2, The inductive element includes a chip inductor, and the capacitive element comprises a chip capacitor. The method of claim 2, And a resonance point and a bandwidth are changed according to the type of the reactive element and the size of the reactive component. The antenna using a reactive element according to claim 2, wherein the end of the radiator is open. The method of claim 5, When the inductive element is coupled to the reactive element, the resonance point is increased and the bandwidth is expanded. When the capacitive element is coupled to the reactive element, the resonance point is reduced. The method of claim 2,  Termination of the radiator is an antenna using a reactive element, characterized in that connected to the ground. The method of claim 7, wherein When the reactive element is coupled to the end of the radiator in the form of a feedback, the antenna using a reactive element, characterized in that the bandwidth is extended while maintaining the resonance point. The method of claim 2, And the reactive element further comprises a resonator. The method of claim 1, The reactive element is an antenna using a reactive element, characterized in that connected to the end of the radiator and the start or start of the radiator a predetermined distance from the start form. Feed point; At least one radiator electrically coupled to the feed point; And at least one reactive element connected in parallel to two predetermined points of said at least one radiator. The method of claim 11, The reactive element is an antenna using a reactive element, characterized in that it comprises an inductive element or a capacitive element. The method of claim 12, And a resonance point and a bandwidth are changed according to the type of the reactive element and the size of the reactive component. The method of claim 11, An antenna using a reactive element, characterized in that the resonance point and the bandwidth is changed according to the type of the reactive element and the size of the reactive component. The method of claim 11, And the reactive element is coupled to each of the plurality of radiators in parallel when the radiators are plural.

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