KR20120105681A - Antenna device and electronic apparatus including the same - Google Patents

Abstract

PURPOSE: An antenna device and an electronic apparatus including the same are provided to easily control a resonant frequency regardless of a length of a conductive pattern by using zero resonance of a conductive pattern having a CRLH-TL(Composite Left/Right Handed Transmission Line) structure. CONSTITUTION: A second radiator(21) is electrically connected to a feeding unit formed on a part of an upper side. The feeding unit includes a feeding pad(27a) connected to a feeding point(24). A grounding terminal(28b) is formed in the second radiator. The grounding terminal is electrically connected to a grounding pad(27b). A conductive pattern(22) is formed into a CRLH-TL structure. An inductor is interposed between the conductive pattern and a ground surface(32).

Description

ANTENNA DEVICE AND ELECTRONIC APPARATUS INCLUDING THE SAME}

The present invention relates to an antenna device and an electronic device including the same, and more particularly, to a technique for suppressing interference between antennas.

Recently, with the development of the electronics industry, communication technology has rapidly developed. In particular, with the development of wireless communication technology including mobile communication, various electronic devices capable of performing voice and data communication with anyone, anytime, anywhere have been spread.

In order to improve the portability of the electronic device, the electronic device has been miniaturized. Accordingly, various components included in the electronic device have been miniaturized. In particular, antennas, which are essential parts for wireless communication, have also been miniaturized.

As electronic devices and antennas are miniaturized, a problem arises in that the antenna is interfered with by other components and its performance is degraded. In particular, as a diversity antenna or a multi-in-multi-antenna (MIMO) antenna has recently appeared, deterioration in performance due to interference between the antenna and the antenna has been a problem.

In addition, as the performance of electronic devices is diversified, in order to implement various performances, many antennas satisfying various frequency bands are often included in one electronic device. Accordingly, deterioration of performance due to interference between antennas is increasing as an important problem, and a technique for solving the problem is required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art, and an object of the present invention is to provide a technique for suppressing interference between antennas in an antenna device including at least two antennas.

According to an embodiment of the present invention for achieving the above object, a first antenna having a first radiator for transmitting and receiving radio signals; And a second antenna having a second radiator for transmitting and receiving a wireless signal, and a conductive pattern for controlling interference between the first radiator and the second radiator to adjust radiation efficiency of the second radiator. do.

Here, the conductive pattern may have a composite right / left handed transmission line (CRLH-TL) structure.

According to one embodiment of the invention, the ground plane and the non-grounded surface formed substrate; A first antenna having a first radiator for transmitting and receiving a radio signal and coupled to the substrate; And a second antenna for transmitting and receiving a wireless signal, and a conductive pattern for controlling interference between the first radiator and the second radiator by adjusting the radiation efficiency of the second radiator, wherein the second antenna is coupled to the substrate. An antenna device is provided that includes.

Here, the feed portion of the second radiator is formed on a portion of the upper surface of the substrate,

The conductive pattern may be formed on the rear surface of the feeding part of the second radiator to provide coupling coupling, and an inductor may be interposed between the conductive pattern and the ground plane.

Meanwhile, an inductive component in the longitudinal direction of the conductive pattern becomes a series inductor, and a capacitive component formed between the conductive pattern and the ground plane becomes a parallel capacitor, and an inductor interposed between the conductive pattern and the ground plane. The inductive component of is a parallel inductor, and the capacitive component formed between the conductive pattern and the feed part of the second radiator is a series capacitor, and the conductive pattern is CRLH-TL (Composite Right / Left Handed Transmission Line). It could be a structure.

Meanwhile, an inductive component in the longitudinal direction of the second radiator becomes a series inductor, and a capacitive component formed between the second radiator and the ground plane becomes a parallel capacitor, interposed between the conductive pattern and the ground plane. The inductive component of the inductor becomes a parallel inductor, and the capacitive component formed between the conductive pattern and the feed portion of the second radiator becomes a series capacitor, and the second antenna is a composite right / left handed. Transmission Line) structure.

According to an embodiment of the present invention, an electronic device including the antenna device described above is provided.

According to an embodiment of the present invention, an antenna device including at least two antennas has an effect of suppressing interference between antennas.

In addition, according to an embodiment of the present invention, interference between antennas can be suppressed through zero order resonance of a conductive pattern having a composite left / right handed transmission line (CRLH-TL) structure. There is an advantage that can easily adjust the resonant frequency irrespective of the length of.

1 is an equivalent circuit diagram of a composite left / right handed transmission line (CRLH-TL) structure.
2 is a view showing the top of the antenna device according to an embodiment of the present invention.
3 is a view showing the back of the antenna device according to an embodiment of the present invention.
4 is an enlarged view of a second antenna of an antenna device according to an embodiment of the present invention.
FIG. 5 is an enlarged view of a second antenna of an antenna device according to an embodiment of the present invention, and is a view illustrating a conductive pattern formed on a rear surface of the antenna device.
6 is an enlarged view of a conductive pattern of an antenna device according to an embodiment of the present invention.
7 is a graph showing a change in antenna efficiency according to the presence or absence of a conductive pattern in the antenna device according to an embodiment of the present invention.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the detailed description of the well-known technology and its configuration which are determined to obscure the gist of the present invention will be omitted. In addition, in describing the present invention, the criteria such as up, down, left, and right are not absolute but are merely described with reference to the drawings in order to easily describe the present invention. And mathematical expressions such as 'parallel' or 'vertical' as used herein are not meant to mean theoretically exact parallel or vertical, but are to be understood to mean substantially parallel or vertical in the actual configurable range. In addition, in describing the present invention with reference to the drawings, components that perform the same function will be described with the same reference numerals.

CRLH - TL ( Composite Right Of Left Handed Transmission Line )rescue

Hereinafter, the structure of the composite right / left handed transmission line (CRLH-TL) will be described. The CRLH-TL structure is also known as metamaterial theory, which has recently been studied in relation to the resonant structure of an antenna.

Metamaterial refers to a material or electromagnetic structure that is artificially designed to have special electromagnetic properties not commonly found in nature. In general, and in this specification, metamaterial refers to permittivity. Refers to materials or such electromagnetic structures that are both negative and permeability negative.

Such materials are also called double negative (DNG) materials in the sense of having two negative parameters. In addition, metamaterials have a negative reflection coefficient due to their negative dielectric constant and permeability, and thus are also called NRI (Negative Refractive Index) materials. Metamaterial was first researched by Soviet physicist V. Veselago in 1967, but recently, a concrete implementation method has been studied and its application has been attempted.

It is possible to implement a zero-order resonator (ZOR) using metamaterials. Unlike the conventional resonant structure, the zero-order resonator has a resonant frequency determined regardless of the electrical length of the resonant structure. The zero-order resonator has substantially the same resonant structure as the LC resonant circuit, so that the inductance and capacitance of the inductor and capacitor included in the circuit determine the resonant frequency. Therefore, the resonant frequency can be changed by adjusting the inductance and capacitance, and the size of the antenna does not increase even if the resonant frequency is lowered.

1 shows an equivalent circuit diagram of a DNG unit cell in a CRLH-TL structure. As shown in FIG. 1, the DNG unit cell exhibits a RH (Right Handed) characteristic through a series inductor L _R and a parallel capacitor C _R , and the series capacitor C _L and the parallel inductor L _L are represented. Left Handed (LH) characteristics. The RH and LH properties combine to have the properties of CRLH-TL. That is, a general transmission line has an RH characteristic, and thus, an additional series capacitor C _L and a parallel inductor L _L are inserted into the transmission line so that the transmission line has an LH characteristic, thereby operating as a CRLH-TL circuit.

Antenna device and electronic device including same

Hereinafter, an antenna device according to an embodiment of the present invention will be described with reference to FIGS. 2 to 7.

2 is a view showing the top of the antenna device according to an embodiment of the present invention. According to an embodiment of the present invention, a first antenna having a first radiator 11 for transmitting and receiving a wireless signal and a second antenna having a second radiator 21 for transmitting and receiving a wireless signal are included. The first antenna and the second antenna may operate independently of each other, but may also operate as a diversity antenna or a MIMO antenna. In this case, the first antenna may be used as the main antenna and the second antenna may be used as the sub antenna, or the roles thereof may be changed.

As an example, the first antenna is used as the main antenna and designed to satisfy the LTE (Rx / Tx) band, the DCN (Rx / Tx) band, and the WCDMA band, and the second antenna is used as the sub antenna to form a DCN single band. Can only be designed to work. However, even if the second antenna is designed to be operated only in the DCN single band, radiation may occur in other bands, which may affect the performance of the first antenna. That is, even if the second antenna is designed to operate in the DCN single band, for example, radiation may occur in the LTE band, thereby affecting the LTE band of the first antenna.

In order to solve this problem, the second antenna may include a conductive pattern 22. The conductive pattern 22 adjusts the radiation efficiency of the second radiator 21 to suppress interference between the first radiator 11 and the second radiator 21. The conductive pattern 22 may emit electromagnetic waves. The electromagnetic waves emitted from the conductive patterns 22 may cause a destructive interference with the electromagnetic waves emitted from the second radiator 21, thereby reducing the radiation efficiency of the second radiator 21. It becomes. At this time, the band causing the destructive interference is a band emitted even though not intended by the second radiator 21. That is, according to the example described above, although the second radiator 21 is designed to operate only in the DCN single band, since the radiation occurs in the LTE band, it causes cancellation interference in the unintended LTE band.

On the other hand, according to the antenna device according to an embodiment of the present invention, an antenna device in which the first antenna and the second antenna are coupled to one substrate 30 may be provided. The ground planes 32 and 32 and the non-contact plane 31 are formed in the substrate 30. The ground planes 32 and 32 may be formed of a metal component so as to be conductive. In addition, the substrate 30 may include a circuit (not shown) for implementing various functions of the electronic device.

The first antenna has a base frame 13 supporting the first radiator 11 and the first radiator 11, and the second antenna has a base frame supporting the second radiator 21 and the second radiator 21. 23 can be provided. The first and second antennas may be coupled to the top surface of the substrate 30, but the first and second antennas do not always have to be formed on the top surface. In addition, the first antenna and the second antenna may be formed on different surfaces, respectively.

Hereinafter, the structure of the second radiator 21 and the conductive pattern 22 included in the antenna device according to an embodiment of the present invention will be described in detail with reference to FIGS. 3 to 6.

The second radiator 21 is electrically connected to a power supply unit formed in a part of the upper surface. The feeder may be configured of only the feed point 24 or may include a feed pad 27a connected to the feed point 24. When the feed pad 27a is included, the feed side terminal 28a formed at one end of the second radiator 21 is electrically connected to the feed pad 27a to transmit current. When the second radiator 21 operates as an inverted-F antenna, the second radiator 21 is further provided with a ground terminal 28b, and the ground terminal 28b is electrically connected to the ground pad 27b. The ground pad 27b is connected to the ground plane 32 formed on the upper surface of the substrate, and an element 26 for impedance matching may be interposed between the ground pad 27b and the ground plane 32. Although the structure of the second radiator 21 has been described with reference to the inverted-F antenna, the second radiator 21 may have a radiator structure other than the inverted-F antenna.

The conductive pattern 22 may have a composite right / left handed transmission line (CRLH-TL) structure. When the conductive pattern 22 has a CRLH-TL structure, the resonance frequency of the conductive pattern 22 may be easily adjusted regardless of the shape and length of the conductive pattern 22.

An example for forming the conductive pattern 22 in the CRLH-TL structure will be described below.

The conductive pattern 22 is formed on the rear surface of the feed portion of the second radiator 21. The feed section may be a concept including a feed point 24 and a feed pad 27a, or may mean only the feed point 24. The region where the conductive pattern 22 is formed is the non-contact surface 31 formed on the rear surface of the substrate 30. If the conductive patterns 22 are formed on the back side of the feed section, they are not electrically connected directly, but may be coupled fed and electromagnetically connected. According to this structure, a capacitive component, that is, a capacitance component, may be formed between the conductive pattern 22 and the second radiator 21.

An inductor 25 is interposed between the conductive pattern 22 and the ground plane 32. In this way, an inductive component, that is, an inductance component can be formed.

Through the above-described structure, a transmission line having an LH characteristic is implemented. The CRLH-TL structure described with reference to FIG. 1 and the corresponding structure can be described in the following two viewpoints.

As the structure of the first aspect, the inductive component in the longitudinal direction of the conductive pattern 22 becomes a series inductor, and the capacitive component formed between the conductive pattern 22 and the ground plane 32 becomes a parallel capacitor, and the conductive pattern The inductive component of the inductor 25 interposed between the 22 and the ground plane 32 becomes a parallel inductor, and the capacitive component formed between the conductive pattern 22 and the feed portion of the second radiator 21 Being a series capacitor, the conductive pattern 22 can be a CRLH-TL structure.

As the structure of the second aspect, the inductive component in the longitudinal direction of the second radiator 21 becomes a series inductor, and the capacitive component formed between the second radiator 21 and the ground plane 32 becomes a parallel capacitor, The inductive component of the inductor 25 interposed between the conductive pattern 22 and the ground plane 32 becomes a parallel inductor and is a capacitive formed between the conductive pattern 22 and the feed portion of the second radiator 21. The component becomes a series capacitor so that the second antenna can be a CRLH-TL structure.

On the other hand, the structure of the first aspect and the structure of the second aspect may be interpreted as a result of the CRLH-TL structure.

According to the above-described antenna device, the interference between the second radiator 21 and the first radiator 11 can be suppressed by controlling the radiation efficiency caused by the interference of the conductive pattern 22 and the second radiator 21. have. Referring to FIG. 7, the antenna efficiency change according to the presence or absence of the conductive pattern 22 will be described.

According to FIG. 7, the average gain of the first antenna and the average gain of the second antenna are shown depending on the presence or absence of the conductive pattern 22. In the graph shown in FIG. 7, the X axis represents frequency, and the unit is (MHz), and the Y axis represents average gain, and the unit is (dBi). The first antenna main gain ZOR when there is no conductive pattern 22 is not significantly different from the first antenna main gain ZOR when there is a conductive pattern 22. However, the average gain (Sub wo ZOR) of the second antenna when there is no conductive pattern 22 is different from the second gain (Sub w ZOR) when the conductive pattern 22 is present. In particular, in the 746-794 MHz band, since the second antenna average gain (Sub w ZOR) of the conductive pattern 22 is lowered, the interference between the first antenna and the second antenna is suppressed in the 746-794 MHz band. It is proved that there is. Of course, the frequency band can be adjusted according to the intention of the user.

Meanwhile, the above-described antenna device may include any device as long as it is an electronic device to which wireless communication is applied, including a mobile communication terminal. In particular, it is suitable for a device including an antenna that must satisfy various bands. In addition, the effect is doubled in the device using the LTE service band spotlighted in the 4G MIMO antenna and the existing mobile communication service.

In addition, such an effect can be realized by including a passive element such as the conductive pattern 22 without using an active element such as a band blocking filter to reduce the LTE band efficiency of the second antenna.

In the foregoing, preferred embodiments of the present invention have been described with reference to the accompanying drawings. Here, the terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings, but should be construed as meaning and concept consistent with the technical idea of the present invention.

Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention, and not all of the technical ideas of the present invention are described. Therefore, It is to be understood that equivalents and modifications are possible.

11: first radiator 13: base frame of first antenna
21: second radiator 22: conductive pattern
23: base frame of the second antenna 24: feed point of the second antenna
25: inductor 26: element for impedance matching
27a: power pad 27b: ground pad
28a: feed terminal 28b: ground terminal
30: substrate
31: Ungrounded 32: Grounded

Claims (7)

A first antenna having a first radiator for transmitting and receiving radio signals; And
A second antenna having a second radiator for transmitting and receiving a radio signal, and a conductive pattern for controlling the radiation efficiency of the second radiator to suppress the interference between the first radiator and the second radiator
.
The method of claim 1,
The conductive pattern has a CRLH-TL (Composite Right / Left Handed Transmission Line) structure.
A substrate having a ground plane and a non-ground plane formed thereon;
A first antenna having a first radiator for transmitting and receiving a radio signal and coupled to the substrate; And
A second antenna coupled to the substrate, having a second radiator for transmitting and receiving a wireless signal, and a conductive pattern for controlling interference between the first radiator and the second radiator by adjusting radiation efficiency of the second radiator
.
The method of claim 3, wherein
A feed part of the second radiator is formed on a portion of an upper surface of the substrate,
The conductive pattern is formed on the rear surface of the feeding portion of the second radiator is coupled coupling power,
And an inductor interposed between the conductive pattern and the ground plane.
The method of claim 4, wherein
The inductive component in the longitudinal direction of the conductive pattern is a series inductor,
The capacitive component formed between the conductive pattern and the ground plane becomes a parallel capacitor,
The inductive component of the inductor interposed between the conductive pattern and the ground plane becomes a parallel inductor,
The capacitive component formed between the conductive pattern and the feed portion of the second radiator becomes a series capacitor,
The conductive pattern is an antenna device having a CRLH-TL (Composite Right / Left Handed Transmission Line) structure.
The method of claim 4, wherein
The inductive component in the longitudinal direction of the second radiator becomes a series inductor,
The capacitive component formed between the second radiator and the ground plane becomes a parallel capacitor,
The inductive component of the inductor interposed between the conductive pattern and the ground plane becomes a parallel inductor,
The capacitive component formed between the conductive pattern and the feed portion of the second radiator becomes a series capacitor,
The second antenna has a CRLH-TL (Composite Right / Left Handed Transmission Line) structure.
An electronic device comprising the antenna device according to any one of claims 1 to 6.

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