KR200268498Y1 - Mobile handset antenna with coupling slots - Google Patents

Abstract

The present invention relates to an antenna, and more particularly, to an antenna for a wireless communication terminal having a coupling slot fixedly installed in a portable terminal and capable of operating in a dual band and exhibiting sufficient gain characteristics in operation in each band .

An antenna for a wireless communication terminal having a coupling slot according to the present invention includes a fixed portion, a helical element, an insulator, and a coupling slot. The fixing part is fixed on the terminal and is electrically connected to the terminal internal circuit, and the helical element is connected to the fixing part to serve as the first radiation body. The insulator has a hollow portion formed in a vertical direction along the center of the shaft, and the first radiation is inserted into the hollow portion. A hollow portion is formed in the outer periphery of the insulator in a direction perpendicular to the axis, Slots are alternately interlaced in opposite directions to form a coupling slot in which a conductor radiation pattern is arranged in a zigzag pattern, the coupling slot serving as a second radiation body.

Description

[0001] The present invention relates to an antenna for a wireless communication terminal having a coupling slot,

The present invention relates to an antenna device, and more particularly to an antenna device for a portable terminal.

[Background Art] [0002] A conventional antenna device for a portable terminal includes a whip antenna formed by a straight metal wire, a helical antenna formed by spirally winding a metal wire, a helical antenna operated when the whip antenna is inserted, And a stretchable antenna in which the whip antenna is operated in a state where the antenna is in a state where the antenna is in a state where the antenna is in a closed state However, in the case of a whip antenna or a stretchable antenna employing the antenna, there is a problem in that it is troublesome to take out and use the whip antenna, and the mechanical strength is not high so that the antenna can be caught by a user or other objects, And an antenna that is fixedly installed in the terminal is getting attention again.

Meanwhile, as a wireless communication service and a system for implementing the wireless communication service are diversified, a terminal manufacturer must secure an antenna corresponding to each system and service having different frequencies. Here, in order to facilitate the assembly while facilitating the inventory management, a dual band antenna capable of operating in two different frequency ranges is required. In the future, a hybrid terminal capable of receiving communication services from a plurality of systems may also be expected. In such a terminal, a dual band antenna is essential. However, the antenna fixedly installed in the terminal generally has no dual band characteristic, or the impedance is not properly matched in operation in each band, and the gain may be low.

It is an object of the present invention to provide an antenna which is fixed to a portable terminal and can operate in a dual band and exhibits sufficient gain characteristics in operation in each band.

1 is an exploded perspective view of a preferred embodiment of an antenna for a wireless communication terminal having a coupling slot according to the present invention;

2 is a view showing a voltage standing wave ratio according to the frequency of the antenna of FIG. 1;

FIG. 3A is a diagram showing a radiation pattern in the first frequency band of the antenna of FIG. 1; FIG.

FIG. 3B is a view showing a radiation pattern in the second frequency band of the antenna of FIG. 1; FIG.

FIG. 4 is a diagram showing SAR measurement results for the antenna of FIG. 1; FIG.

5 is an exploded view of a coupling slot according to another embodiment of the present invention;

[Description of Drawings]

10. Coupling slot 12. Fixing

16a. First conductor pattern 16b. The second conductor pattern

20, 32. Hollow part 22. Slot

30. Insulator 36. Flange

40. Helical element

According to an aspect of the present invention, there is provided an antenna for a portable terminal, the antenna including a fixed portion, a helical element, an insulator, and a coupling slot. The fixing part is fixed on the terminal and is electrically connected to the terminal internal circuit, and the helical element is connected to the fixing part to serve as the first radiation body. The insulator has a hollow portion formed in a vertical direction along the center of the axis, and the first radiation is inserted into the hollow portion. The slots penetrating the inner and outer sides of the insulator are alternately formed in the opposite direction, The coupling slot is disposed in the zigzag shape, and the coupling slot functions as a second radiation body.

In one embodiment, the coupling slots are alternately interlaced from the upper and lower sides so that the conductor radiation pattern is arranged in a zigzag shape along the circumference. On the other hand, in another embodiment, the second radiation body includes two conductor radiation patterns having different shapes in the traveling direction. The first conductor radiation pattern is arranged in a zigzag form along the circumference by alternately forming the first slot from the upper side and the lower side and the second conductor radiation pattern is formed by alternately interlacing the second slots from the left side and the right side, Direction and are connected to the first conductor radiation pattern.

The lower end of the helical element 40 as a first radiation acts in the first frequency band by being directly contacted with the fixing portion and operated at the first frequency band, and the lower end of the coupling slot 10 is spaced apart from the fixing portion by a predetermined distance And is operated by the electromagnetic coupling from the fixed portion to operate in the second frequency band.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. 1 is an exploded perspective view of a preferred embodiment of an antenna for a wireless communication terminal having a coupling slot according to the present invention. The antenna according to this embodiment is suitable for use in a portable terminal such as a mobile phone and includes a helical element 40, an insulator 30 covering the outer circumferential surface of the helical element 40, 30). On the other hand, in the assembled state, a case (not shown) is formed on the outer peripheral surface of the coupling slot 10 by molding.

The helical element 40 is in the form of a coil and acts as a first radiation body. Here, it is preferable that the pitch is not easily changed by processing the helical element 40 using a material having a high elastic modulus. The helical element 40 is fixed to the portable terminal body, and is connected to the fixing portion 12, which is electrically connected to an internal circuit of the terminal.

The insulator 30 is formed in a cylindrical shape in the vertical direction along the center of the axis of the insulator 30. In the preferred embodiment, the insulator 30 is formed in a cylindrical shape, And a flange (36) for supporting the coupling slot (10) at a predetermined distance from the fixing portion (12) at the lower side. The outer diameter of the insulator 30 is approximately the same as the inner diameter of the hollow portion 20 of the coupling slot 10. Such an insulator 30 prevents the coupling slot 10 from contacting the helical element 40 directly.

The coupling slot 10 has a hollow portion 20 formed in a vertical direction along the center of the shaft and has a cylindrical shape as a whole. The side surface of the coupling slot 10 has slots 22, which extend outwardly and inside the hollow portion 20, Are alternately interlaced from the upper side and the lower side. Accordingly, the coupling slot 10 has a shape in which band-shaped conductor radiation patterns are arranged in a zigzag form along the circumference, and acts as a second radiation body. The coupling slot 10 is provided on the outer periphery of the insulator 30 and has a flange 36 which is supported at a predetermined distance from the fixing portion 12 in the downward direction as described above, And is operated by electromagnetic coupling without directly contacting the portion 12 and the helical element 40.

By forming the cover by molding the outer circumferential surface of the assembly in which the helical element 40, the insulator 30 and the coupling slot 10 are sequentially assembled on the upper end of the fixing portion 12 with a sealing material made of a plastic material as described above, So that the portion from the remaining portion except for the thread portion to be engaged with the terminal to the upper end of the coupling slot 10 is protected by the cover.

The antenna shown in Fig. 1 operates as follows. A signal supplied from the terminal main body to the fixed portion 12 is supplied to the helical element 40 as a first radiation. Thus, the first radiation element radiates radio waves corresponding to the signal to be fed. On the other hand, a part of the signal fed to the fixing portion 12 is also fed to the coupling slot 10, which is the second radiation, by the electromagnetic coupling, so that the coupling slot 10 also receives the radio wave corresponding to the signal to be fed Copy. In one embodiment, the lower end of the helical element 40 is in direct contact with the fixed portion 12, and thus is directly fed through the contact portion. However, the lower end of the coupling slot 10 is spaced apart from the fixed portion 12 by a predetermined distance, and is fed from the fixed portion by electromagnetic coupling. In the preferred embodiment, the helical element 40 and the coupling slot 10 have different electrical lengths and exhibit resonance characteristics in different frequency bands, and thus the antenna of the present invention operates as a dual band antenna. As an example, the first copy operates primarily in a first frequency band (e.g., the PCS band) and the second copy operates primarily in a second frequency band (e.g., the frequency band of a cellular network). On the other hand, the signal reception process is the opposite of the above-mentioned copy process.

FIGS. 2 to 4B show measurement results of the actual operation characteristics of the antenna of FIG. 2 shows the voltage standing wave ratio according to the frequency of the antenna of FIG. As shown, the antenna exhibits resonance characteristics in two frequency bands, 900 MHz band and 1.9 GHz band. In particular, it exhibits wide resonance characteristics in the 1.9 GHz band, and thus operates as a wideband antenna in this band.

FIG. 3A shows a radiation pattern in the 1.9 GHz band of the antenna of FIG. 1, and FIG. 3B shows a radiation pattern in the 900 MHz band. Referring to FIG. 3A, the antenna of FIG. 1 forms a beam peak at about 180 degrees in the 1.9 GHz band. Meanwhile, referring to FIG. 3B, the antenna exhibits a uniformly high gain over all directions in the 900 MHz band. 3A, the radiating pattern of the antenna is distorted unlike the case of FIG. 3B because it is mounted on the 900 MHz terminal. When the radiating pattern is actually mounted on the terminal for 1.9 GHz, a uniform radiating pattern can be obtained as shown in FIG. 3B .

In order to confirm the effect of improving the Specific Absorption Rate (SAR) in the antenna shown in FIG. 1, the SAR in the 900 MHz band was measured using SPIS (SchmidPartner Engineering AG) DAISY3 Professional System. This equipment consists of a robot, a robot controller, a phantom, and a probe. To measure the SAR, a phantom is filled with a solution of a permittivity similar to that of a human brain, At a predetermined position of the model, while setting the transmission mode, a maximum 500 mW of power is generated, and the head of the human body is automatically scanned with a probe connected to the robot to measure the absorption rate of electromagnetic waves. In general, the SAR varies depending on the size and shape of the terminal. The measurement conditions are measured with a flip-type terminal at an inclination of 59 ° from the vertical axis of the human head.

FIG. 4 shows the SAR measurement result for the antenna of FIG. 1, and it can be seen that the SAR measurement value of the antenna according to the present invention is 0.875 mW / g at 900 MHz band as shown in FIG.

5 shows a coupling slot in another embodiment of the antenna according to the present invention. According to the present embodiment, the coupling slot 10 is formed in the shape of a cylinder as a whole with a hollow portion formed in the vertical direction along the center of the axis thereof. In the same manner as in the embodiment shown in Fig. 1, It is preferable to roll after winding.

In addition, slots formed through the outside of the coupling slot 10 and the inside of the hollow portion are formed on the side surface of the coupling slot 10 so that a band-shaped conductor radiation pattern is arranged in a zigzag pattern. In this embodiment, It can be divided into two parts. That is, in the first conductor pattern 16a, the slots are alternately formed from the upper side and the lower side so that the conductor patterns in the form of strips are arranged in a zigzag form along the circumference. On the other hand, in the second conductor pattern 16b, the slots are formed alternately from left and right sides so that the band-shaped conductor patterns are arranged in a zigzag fashion from the upper side to the lower side.

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive. The scope of the present invention is defined by the claims of utility model registration described below rather than the above detailed description, and all modifications or variations derived from the meaning and scope of the utility model registration claims and equivalents thereof are included in the scope of the present invention Should be interpreted as being.

As described above, the antenna according to the present invention operates in a dual band and has broadband characteristics in at least one operating band, and thus can be used, for example, in both cellular phones and PCS phones. It also exhibits a sufficiently high gain in both operating bands. Accordingly, terminal manufacturers can reduce costs such as inventory costs through the common use of components. Especially, according to the present invention, the SAR measurement value is significantly lower than that of the conventional antenna, and since the electromagnetic waves are absorbed less by the human body, the concern about harmful electromagnetic waves and the side effects can be reduced.

Claims (4)

An antenna for installation in a portable terminal, A fixing unit installed on the terminal and electrically connected to the terminal internal circuit; A helical element connected to an upper side of the fixing portion and connected in a vertical direction along a center of the axial direction to serve as a first radiation body; An insulator having a cylindrical shape and having a hollow portion formed in a vertical direction along a center of the shaft, the first radiation member being inserted into the hollow portion, and the flange being formed in the outer radial direction at the lower end; And A coupling slot formed on the outer periphery of the insulator, the slots passing through the inner and outer sides of the insulator, alternately interlaced in the opposite direction, and the conductor radiation pattern being arranged in a zigzag shape to act as a second radiator; . The method according to claim 1, And a lower end portion of the coupling slot is spaced apart from the fixed portion by a predetermined distance, and is fed from the fixed portion by electromagnetic coupling. 2. The connector according to claim 1, Wherein the slots are alternately interlaced from the upper side and the lower side, and the conductor radiation patterns are arranged in a zigzag shape along the circumference. 2. The connector according to claim 1, A first conductor radiation pattern arranged in a zigzag form along the circumference by alternately forming the first slots alternately from the upper side and the lower side; A second conductor radiation pattern arranged in a zigzag fashion in an up and down direction and connected to the first conductor radiation pattern, wherein the second slots are alternately formed from left and right sides, .