KR102586064B1 - Antenna apparatus - Google Patents

Abstract

An antenna device that provides multi-frequency band characteristics while miniaturizing and lightweighting an electronic device by using a metal frame that forms the exterior of the electronic device as a radiator is disclosed. An antenna device for an electronic device according to one aspect includes a circuit board on which a power feeder and a ground plane are formed; a T-shaped first radiator spaced apart from the ground plane, one end of which is connected to the power feeder, and the other end of which is bifurcated; a first conductive member that is indirectly supplied with power from the first radiator, forms a border exterior of the electronic device, and is segmented into one slit; and a second conductive member branched from the first conductive member and operating as a second radiator together with the first conductive member.

Description

Antenna device {ANTENNA APPARATUS}

The present invention relates to an antenna device, and more specifically, to an antenna device that uses a metal frame of an electronic device as a radiator.

Electronic devices with communication functions are becoming smaller and lighter, and are required to support mobile communication services in different frequency bands. Accordingly, a built-in antenna device with multi-frequency band characteristics is installed in the electronic device.

Recently, the number of cases of applying metal frames to the exterior of electronic devices is increasing, and consumer demand for them is also increasing. However, when a metal frame is applied to the exterior of an electronic device, there is a problem in that the radiation performance of the antenna device built into the electronic device deteriorates. To overcome this, antenna devices are designed to avoid metal frames applied to the exterior of electronic devices or to be separated from the metal frames. However, in this case, the size of the electronic device must be increased, which goes against the trend of miniaturization and lightweighting.

The present invention was proposed to solve the above-mentioned problems, and its purpose is to provide an antenna device that provides multi-frequency band characteristics while miniaturizing and lightweighting the electronic device by using a metal frame that forms the exterior of the electronic device as a radiator. there is.

An antenna device for an electronic device according to one aspect includes a circuit board on which a power feeder and a ground plane are formed; a T-shaped first radiator spaced apart from the ground plane, one end of which is connected to the power feeder, and the other end of which is bifurcated; a first conductive member that is indirectly supplied with electricity from the first radiator, forms a border exterior of the electronic device, and is segmented into one slit; and a second conductive member branched from the first conductive member and operating as a second radiator together with the first conductive member.

The two branches of the first radiator may have different lengths.

The antenna device may further include a capacitor installed between the ground plane and an end of a relatively short branch of the two branches of the first radiator.

The capacitor may compensate for the electrical length for forming the resonant frequency of the short branch.

Of the two parts from the second conductive member to the slit of the first conductive member, the shorter part may operate as the second radiator.

The antenna device may further include a capacitor installed in the slit to compensate for the electrical length of the second radiator.

The antenna device may further include an inductor installed between the second conductive member and the ground plane to switch the frequency band.

The separation distance between the first radiator and the first conductive member may be 2 mm.

The present invention can achieve miniaturization and weight reduction of an electronic device by using the first conductive member that forms the outer edge of the electronic device as an radiator.

In addition, the present invention branches and extends the second conductive member from the first conductive member to the inside of the electronic device and uses it as a radiator to form a minimal slit on the outer edge of the electronic device, thereby minimizing damage to the outer edge of the electronic device. .

In addition, the present invention can shorten the electrical length of the branch by installing a capacitor between the branch operating in the high frequency band of the two branches of the T-shaped radiator and the ground plane, thereby achieving miniaturization and weight reduction of the electronic device.

In addition, the present invention can shorten the electrical length of the radiator operating in a low frequency band by installing a capacitor in the slit of the first conductive member forming the outer edge of the electronic device, thereby achieving miniaturization and weight reduction of the electronic device. .

In addition, the present invention can implement a wide bandwidth in the low-frequency band by installing an inductor between the ground plane and a second conductive member that branches off and extends from the first conductive member that forms the outer edge of the electronic device to switch the low-frequency band.

1 is a diagram showing the configuration of an antenna device according to an embodiment of the present invention.
FIG. 2 is a diagram showing the frequency band of the antenna device of FIG. 1.
Figure 3 is a diagram showing the resonant frequency of the antenna device when the separation distance between the first radiator and the first conductive member is greater than 2 mm according to an embodiment of the present invention.
Figure 4 is a diagram showing the resonant frequency of the antenna device when the separation distance between the first radiator and the first conductive member is less than 2 mm according to another embodiment of the present invention.

Hereinafter, with reference to the attached drawings, preferred embodiments will be described in detail so that those skilled in the art can easily practice the present invention. However, when describing preferred embodiments of the present invention in detail, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. In addition, the same symbols are used throughout the drawings for parts that perform similar functions and actions.

FIG. 1 is a diagram showing the configuration of an antenna device according to an embodiment of the present invention, and FIG. 2 is a diagram showing the frequency band of the antenna device of FIG. 1.

Referring to FIG. 1, the antenna device 100 according to one embodiment includes a first conductive member 110 that forms the outer edge of the electronic device, and a second conductive member that branches off and extends from the first conductive member 110. It includes a member 120, a T-shaped first radiator 130, a circuit board 140, an inductor 150, and capacitors 160 and 170.

The first conductive member 110 may surround the outside of the housing of the electronic device as a metal frame that forms the outer edge of the electronic device. In this embodiment, the first conductive member 110 is shown as having a square shape, but it is not limited thereto and its shape may change depending on the external shape of the electronic device. The electronic device is a communication terminal that requires the antenna device 100 and may include, but is not limited to, a smartphone, navigation device, or tablet PC. The first conductive member 110 does not have a continuous strip shape as shown in FIG. 1, but is segmented into one slit 160.

The second conductive member 120 branches off from the first conductive member 110, extends inside the electronic device, and operates as a radiator together with the first conductive member 110. As shown in FIG. 1, since the first radiator 130 exists, the second conductive member 120 and the first conductive member 110 operate as a second radiator. Since the second conductive member 120 branches off and extends from the first conductive member 110, the branch point 120a of the second conductive member 120 separates the first conductive member 110 into two parts. Based on the branch point 120a, the first conductive member 110 is divided into a short first part 110-1 and a longer second part 110-2, and the first part 110-1 ) and the second conductive member 120 operates as a second radiator. The first part 110-1 and the second conductive member 120 resonate in a low frequency band among the frequency bands covered by the antenna device 100. Here, the low frequency band is 699MHz to 960MHz as shown in Figure 2.

The first conductive member 110 is divided into two parts 110-1 and 110-2 using the second conductive member 120, and the first part 110-1, which is relatively short in length, is used as a radiator. By doing so, the space A in the upper left corner of FIG. 1 surrounded by the second conductive member 120 and the second part 110-1 of the first conductive member 110 can be used for other types of antennas (e.g., GPS antennas, It can be used to place a Wi-Fi antenna). In addition, by extending the second conductive member 120 from the first conductive member 110, only one slit is formed in the first conductive member 110, thereby reducing the number of slits and minimizing damage to the external design of the electronic device. .

The circuit board 140 is installed in the internal space formed by the first conductive member 110. The circuit board 140 is equipped with circuits and elements for operating an electronic device, and includes a power supply unit 140a and a ground plane 140b, as shown in FIG. 1 .

The first radiator 130 has a T-shape with one end electrically connected to the power feeder 140a and the other end branched into two branches 130a and 130b. As shown in FIG. 1, the lengths of the two branches 130a and 130b of the first radiator 130 are different from each other, and specifically, the first branch 130a is longer than the second branch 130b. The first radiator 130 resonates in the high frequency band and the intermediate frequency band among the frequency bands covered by the antenna device 100. Preferably, because the first prong 130a is longer than the second prong 130b, the first prong 130a resonates in a mid-frequency band and the second prong 130b resonates in a high frequency band. Here, the high frequency band (High Band) is 2300MHz to 2690MHz, as shown in Figure 2, and the middle frequency band (Middle Band) is 1710MHz to 2170MHz. Preferably, the first prong 130a has an electrical length of about 25 mm.

As shown in FIG. 1, a capacitor 150 exists between the second prong 130b of the first radiator 130 and the ground plane 140b of the circuit board 140. The capacitor 150 is used to couple the current flowing from the power supply unit 140a to the second branch 130b of the first radiator 130 to the ground plane 140b, and determines the electrical length of the second branch 130b. Compensate. In general, the antenna should have an electrical length of 1/4 of the wavelength (λ). However, due to limitations in the internal space of the electronic device, the second prong 130b in this embodiment has an electrical length shorter than the required electrical length. Therefore, the capacitor 150 is installed between the second branch 130b and the ground plane 140b to compensate for the short electrical length of the second branch 130b to adjust the resonance frequency and bandwidth. By shortening the length of the second prong 130b of the first radiator 130, miniaturization and weight reduction of the electronic device can be achieved. For example, the electrical length of the second branch 130b should be about 10 mm, but the length can be reduced by about 3 mm by adjusting the capacity (capacitance) of the capacitor 150.

As described above, the first conductive member 110 does not have a continuous strip shape but is segmented into one slit 160. And as shown in FIG. 1, a capacitor 160 is installed in the slit 160. The capacitor 160 adjusts the resonance frequency and bandwidth by compensating the electrical lengths of the first part 110-1 and the second conductive member 120 of the first conductive member 110, which operates as a second radiator. For example, the electrical length of the first part 110-1 and the second conductive member 120 of the first conductive member 110 should be about 50 mm, but the length can be reduced by about 5 mm by adjusting the capacity (capacitance) of the capacitor 160. You can.

As shown in FIG. 1, the power supply portion 140a of the circuit board 140 is directly connected to the first radiator 130, but is not directly connected to the first conductive member 110. The first part 110-1 of the first conductive member 110 is not directly connected to the first radiator 130 but is arranged horizontally at a certain distance. Accordingly, the first part 110-1 of the first conductive member 110 is indirectly coupled to the first radiator 130 and is indirectly supplied with electric power from the first radiator 130 through electrical coupling.

Meanwhile, as shown in FIG. 1, an inductor 170 is installed between the second conductive member 120 and the ground plane 140b of the circuit board 140. The inductor 170 is used to switch the frequency band of the first part 110-1 of the second conductive member 120 and the first conductive member 110, which operates as a second radiator. As described above, the second conductive member 120 and the first part 110-1 of the first conductive member 110 operate in a low frequency band of 699 MHz to 960 MHz, and the inductor 170 operates at a desired frequency among these low frequency bands. Select a band to enable use. For example, the inductor 170 can be used by selecting one of the 700 MHz band, 800 MHz band, and 900 MHz band.

As described above, the first radiator 130 and the first conductive member 110, specifically the first part 110-1 of the first conductive member 110, are arranged horizontally at a predetermined distance, The first part 110-1 of the first conductive member 110 is indirectly supplied with power from the first radiator 130. The first part 110-1 of the first conductive member 110 must have an optimal separation distance from the first radiator 130 to form optimal resonance in the low frequency band. The separation distance between the first part 110-1 of the first conductive member 110 and the first radiator 130 according to this embodiment is preferably 2 mm.

Figure 3 is a diagram showing the resonant frequency of the antenna device when the separation distance between the first radiator 130 and the first conductive member 110 according to an embodiment of the present invention is greater than 2 mm, and Figure 4 is a diagram showing the resonant frequency of the antenna device according to another embodiment of the present invention. This diagram shows the resonant frequency of the antenna device when the separation distance between the first radiator 130 and the first conductive member 110 according to the embodiment is less than 2 mm. As shown in FIG. 3, when the separation distance between the first radiator 130 and the first conductive member 110 is greater than 2 mm, the quality factor (Q) value of resonance deteriorates, making it difficult to form resonance. And as shown in FIG. 4, when the separation distance between the first radiator 130 and the first conductive member 110 is less than 2 mm, the bandwidth in the low frequency band is reduced. Therefore, it cannot exhibit broadband characteristics in the low frequency band.

The antenna device according to the embodiment described above can achieve miniaturization and weight reduction of the electronic device by using the first conductive member that forms the outer edge of the electronic device as a radiator. In addition, the antenna device according to the embodiment branches and extends the second conductive member from the first conductive member to the inside of the electronic device and uses it as a radiator to form a minimal slit on the outer edge of the electronic device, thereby reducing the outer edge of the electronic device. Minimize damage. In addition, the antenna device according to the embodiment can shorten the electrical length of the branch by installing a capacitor between the branch operating in the high frequency band of the two branches of the T-shaped radiator and the ground plane, thereby achieving miniaturization and weight reduction of the electronic device. can do. In addition, the antenna device according to the embodiment can shorten the electrical length of the radiator operating in the low frequency band by installing a capacitor in the slit of the first conductive member that forms the outer edge of the electronic device, thereby miniaturizing and lightweighting the electronic device. It can be achieved. In addition, the antenna device according to the embodiment switches the low-frequency band by installing an inductor between the ground plane and a second conductive member branching and extending from the first conductive member forming the outer edge of the electronic device, thereby providing a wide bandwidth in the low-frequency band. It can be implemented. Additionally, the antenna device according to the embodiment can increase the degree of freedom of the internal ground environment of the electronic device by minimizing the antenna pattern.

As described above, although the present invention has been described with limited examples and drawings, the present invention is not limited thereto, and the technical idea of the present invention and the following will be understood by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalence of the patent claims to be described.

100: antenna device
110: first conductive member
120: second conductive member
130: first emitter
140: circuit board
150: inductor
160, 170: Capacitor

Claims (8)

In the antenna device of an electronic device,
A circuit board on which a power feeder and a ground plane are formed;
a T-shaped first radiator spaced apart from the ground plane, one end of which is connected to the power feeder, and the other end of which is bifurcated;
a capacitor installed between the end of a relatively short branch of the first radiator and the ground plane to compensate for the electrical length for forming a resonance frequency of the short branch;
a first conductive member that is indirectly supplied with electricity from the first radiator, forms a border exterior of the electronic device, and is segmented into one slit;
a second conductive member branching from the first conductive member, extending inside the electronic device, and operating as a second radiator together with the first conductive member; and
It includes an inductor installed between the second conductive member and the ground plane to switch the frequency band,
Of the two parts from the second conductive member to the slit of the first conductive member, the shorter part operates as the second radiator,
The antenna device further includes a capacitor installed in the slit to compensate for the electrical length of the second radiator. delete delete delete delete delete delete According to claim 1,
The antenna device is characterized in that the separation distance between the first radiator and the first conductive member is 2 mm.

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