KR100649492B1 - Multi band internal antenna in mobile handset - Google Patents

Abstract

The present invention relates to an antenna configured in a mobile communication terminal to process a multi-band signal.

The present invention provides a multi band internal antenna embedded in a mobile communication terminal and processing a multi band signal, comprising: a feed line for supplying current to the antenna; And a radiation unit winding one or more coils having different pitch intervals connected in series to the feed line in a rectangular shape, thereby implementing the multi-band internal antenna of the present invention in a coil type helical antenna structure. It can be implemented as, the size can be reduced compared to the conventional PIFA type planar antenna can reduce the product cost, there is an advantage that can implement the improved multi-band characteristics.

Mobile communication terminal, built-in antenna, multi band, coil, rectangular parallelepiped, case, surface mount

Description

MULTI BAND INTERNAL ANTENNA IN MOBILE HANDSET}             

1 is a structure of a conventional flat inverted antenna (PIFA),

2 is a structure of a conventional built-in dual band antenna,

3 is a view showing the basic structure of a multi-band internal antenna according to the present invention;

4 is a view showing an installation example of a multi-band internal antenna according to the present invention;

5a to 5c is a case structure of a multi-band internal antenna according to the present invention,

6 is a diagram showing the voltage standing wave ratio (VSWR) characteristics of a multi-band antenna according to an embodiment of the present invention;

7A to 7J are diagrams illustrating radiation pattern characteristics according to embodiments of the multi-band antenna according to the present invention.

Explanation of symbols on the main parts of the drawings

30: multiband internal antenna 31: feedline

32: radiating part 321: the first coil part

322: 2nd coil part 52 ~ 54: case

The present invention relates to an antenna provided in a mobile communication terminal for transmitting and receiving wireless signals, and more particularly, to a multi-band internal antenna which is configured inside a mobile communication terminal and can process a multi-band signal.

Currently, mobile communication terminals are required to have various service providing functions, while being miniaturized and lightweight. In order to satisfy these demands, embedded circuits and components employed in mobile communication terminals are becoming more versatile and at the same time gradually becoming smaller. This trend is equally required in the antenna, which is one of the main components of the mobile communication terminal.

Commonly used antennas of a mobile communication terminal include a helical antenna and a planar inverted F antenna (hereinafter referred to as PIFA). Here, the helical antenna is used together with the monopole antenna as an external antenna fixed to the top of the terminal. When the helical antenna and the monopole antenna are used together, the antenna operates as a monopole antenna when the antenna is extended from the terminal body, and when the antenna is extended, the helical antenna and the monopole antenna operate as ?? / 4 helical antennas.

 These antennas have the advantage of obtaining high gain, but due to their omni-directional, SAR characteristics, which are harmful to the human body of electromagnetic waves, are not good. In addition, since the helical antenna is configured to protrude to the outside of the terminal, it is difficult to design the exterior suitable for the aesthetics and the portable function of the terminal, the internal structure of this has not been studied yet.

On the other hand, the PIFA antenna as having a low profile structure, in order to overcome this disadvantage. As shown in FIG. 1, it basically consists of a planar radiating part 2, a shorting pin 4 connected to the radiating part 2, a coaxial line 5, and a ground plate 9. As shown in FIG. The radiating part 2 is fed through the coaxial line 5, and short-circuited with the ground plate 9 by the shorting pin 4 to achieve impedance matching. The PIFA should be designed in consideration of the length L of the radiating part 2 and the height H of the antenna according to the width W _p of the shorting pin 4 and the width W of the radiating part 2. do.

The PIFA regenerates the beam directed toward the ground plane of the entire beams generated by the current induced by the radiator 2 to attenuate the beam directed toward the human body, thereby improving the SAR characteristics and simultaneously radiating the beam directed toward the radiator. It is possible to realize a low profile structure by acting as a rectangular microstrip antenna with a reinforcing directivity and the length of the rectangular flat radiating portion reduced by half. In addition, since the PIFA is configured inside the terminal as a built-in antenna, the appearance of the terminal can be designed beautifully and has excellent characteristics against external impact.

The PIFA is being improved in accordance with the trend of multifunctionalization, of which multi-band antenna is applied as shown in Figure 2a.

Referring to FIG. 2A, a conventional built-in dual band antenna includes a radiator 20, a power supply pin 25, and a ground pin 26. The radiator 20 of the conventional built-in antenna has a low band spaced apart by a predetermined distance along the outer circumferential surface and the high band radiator 21 for processing a high band signal therein. It consists of low-band radiators 22, 23, and 24 that process the signal of. That is, the high band radiator 21 and the low band radiator 22, 23, 24 are connected in parallel. The feed pin 25 and the ground pin 26 are connected to one end of the radiator 20.

However, the conventional built-in dual band antenna has a problem that the radiator is all formed on one plane, and because the size and the cost are high, the recent mobile phone terminal that requires miniaturization has a disadvantage in that the competitiveness is low.

The present invention has been proposed to solve the above problems, and an object of the present invention is to provide a first and second helical antennas having different pitch intervals using one coil to transmit and receive a multiband radio signal. The present invention provides a multi-band internal antenna having a coil structure and structured in a built-in structure in which the first and second coils are implemented in the form of a rectangular bent wire.

According to an aspect of the present invention, there is provided a multi-band internal antenna, a multi-band internal antenna for processing a multi-band signal embedded in a mobile communication terminal, comprising: a feed line for supplying current to the antenna; And two or more coil parts connected in series to the feed line and having different pitch intervals using one coil, wherein each coil part has a rectangular shape, and a central axis of each coil part is Characterized in that arranged in series on the same line.

In addition, the multi-band internal antenna according to the present invention is made of a dielectric and by combining two dielectric cases formed with the insertion hole and the insertion member in a position opposite to each other, the case in which the rectangular parallelepiped-shaped receiving space for receiving the radiation portion is formed It may further include.

DETAILED DESCRIPTION A detailed description of preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be noted that reference numerals and like elements among the drawings are denoted by the same reference numerals and symbols as much as possible even though they are shown in different drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

3 is a diagram illustrating a basic structure of a multi band internal antenna according to the present invention.

Referring to FIG. 3, the multi-band internal antenna of the present invention includes a radiator 32 and a radiator 32 formed of coils wound at one or more pitch intervals in a rectangular shape so as to radiate or receive signals of two or more set frequency bands. It is connected to the) is composed of a feed line 31 for drawing / applying the electrical signal.

The radiator 32 is composed of first and second coil parts 321 and 322 that are wound at different pitch intervals using one coil and connected in series. That is, the first coil portion 321 is wound at a first pitch interval, and the second coil portion 322 is disposed between the first coil portion 321 and the other feed line 31 than the first pitch interval. It is wound at a second pitch interval with a wide gap. In addition, the first coil part 321 and the second coil part 322 are formed by arranging their central axes in series on the same line, and the wound form is processed into a substantially rectangular parallelepiped shape rather than a circular shape.

The radiator 32 can obtain two or more desired resonant frequency bands by appropriately adjusting the pitch, the number of turns, and the overall length of the first and second coil parts 321 and 322. In FIG. 3, the pitch spacing of the first coil part 321 located at the upper end of the radiating part 32 is small, and the pitch spacing of the second coil part 322 located at the lower part is made large. By appropriately adjusting the pitch spacing of the coil unit 321, a very high impedance is achieved in a predetermined high frequency band, for example, the first frequency band (1.575 GHz = GPS band). Therefore, in the high frequency band, the lower portion of the second coil portion 32 having a large pitch operates as an antenna.

On the contrary, since the impedance of the first coil part 321 is not so large in a predetermined low frequency band, for example, the second frequency band (800 MHz to 900 MHz = CDMA band), both the first and second coil parts 321 and 322 are antennas. Acts as.

Therefore, by appropriately designing the pitch, winding portion, and length of the first and second coil portions 321 and 322 in the radiating portion 32, two desired resonant frequency bands such as GPS, CDMA, DCS, and GSM can be obtained. .

In addition, since the first and second coil parts 321 and 322 are wound in a rectangular parallelepiped shape, the radiating part 32 may be mounted like a chip component inside a case of a mobile communication terminal or on a circuit board, which is advantageous for an embedded type.

The radiating part 32 may be formed by winding the first and second coil parts 321 and 322 on a non-conductive base having a rectangular parallelepiped shape, and after winding the coils at respective pitch intervals, the radiating part 32 may be predetermined up, down, left, and right. It can also be formed by processing into a rectangular parallelepiped shape having the desired width * length * height by applying a pressure of.

In the case of the radiator 32 as described above, since the resonance frequency is determined according to the total length of the coils, and the capacitance value is changed by the pitch of each coil, the first coil part 321 reduces the bandwidth characteristic due to miniaturization. And the pitch of the second coil portion 322 can be adjusted appropriately.

4 is a view showing the mounting position of the mobile communication terminal to the antenna according to the present invention, the antenna 42 according to the present invention can be mounted on the printed circuit board 41 of the mobile communication terminal, as shown Likewise, it may be coupled to the upper end of the printed circuit board 41.

The multi-band internal antenna according to the present invention further includes a predetermined case surrounding the radiator 32 shown in FIG. 3 to obtain a coil-shaped protection and a fastening structure to a mobile communication terminal.

5A to 5C are views illustrating various embodiments of a case in the multi-band internal antenna according to the present invention. FIG. 5A is a surface mount type, FIG. 5B is a hook type, and FIG. 5C is a screwing type, respectively. In the figure, 51 shows the feed line 31 and the radiating portion 32 implemented by the present invention as shown in Figure 3, 52 to 54 can protect the radiating portion 51 therein It is formed in the form and each case 52 to 54 having a fastening structure.

The cases 52 to 54 may be formed of a dielectric having a predetermined dielectric constant (for example, ?? = 3) to reduce the size of the antenna by reducing the wavelength of the use frequency. By further including the cases 52 to 54, the resonant frequency can be moved to about 100 MHz.

Next, when divided into each type to be described, the surface-mounted case 52 shown in Figure 5a is made of a dielectric and by combining two dielectric cases formed with the insertion hole and the insertion member in a position opposite to each other, rectangular parallelepiped A shape receiving space is formed, and a bonding padding part electrically connected to a feed line connected to the radiator 51 is formed on one surface, and is mounted by a surface mounting method on a main board of the mobile communication terminal.

Next, the hook type case 53 illustrated in FIG. 5B is implemented as such to form a rectangular parallelepiped storage space by combining two dielectric cases in which insertion holes and insertion members are formed at opposite positions. And a means for electrically drawing a feed line connected to the radiator 51 to be received in the inner storage space to the outside, and having a hook structure formed at a position corresponding to a mounting location of the mobile communication terminal. The hook is detachable from a predetermined position of the mobile communication terminal. In addition, the electrical connection can be realized by wire bonding the feed line with the corresponding pattern of the circuit board.

Finally, the screw fastening type case 54 in FIG. 5C is similarly implemented by combining two dielectric cases in which insertion holes and insertion members are formed at opposite positions, thereby forming a rectangular parallelepiped storage space. And a means for electrically drawing a feed line connected to the radiator 51 to be accommodated in the inner storage space to the outside, and having a screwing structure at a corresponding position of the circuit board.

In this case, the electrical connection may be implemented through a wire bonding method, as in the hook type described above.

These cases 52 to 53 can improve the convenience of mounting on the mobile communication terminal set.

The case structure of the antenna according to the present invention can be modified and applied in various forms in addition to the structure described above.

As described above, the multi-band internal antenna of the present invention implemented by the feed line 51, the radiator 32, and the cases 52 to 54 can achieve satisfactory antenna characteristics while miniaturizing.

FIG. 6 is a diagram illustrating a voltage standing wave ratio (VSWR) characteristic in an embodiment of a multi-band internal antenna according to the present invention, in which the vertical axis represents a standing voltage ratio (VSWR), the value of which is the bottom value. Is 1, and increases by 1 for each division toward the upward direction. And the horizontal axis represents frequency. The frequency and VSWR measured at the point marked "??" appear on the right and top.

Referring to FIG. 6, the multi-band internal antenna of the present invention secures a bandwidth of about 17% (150 MHz) in the low frequency band of the 800 MHz band by the first and second coil parts 321 and 322, and the second coil part 322. By, it can be seen that the bandwidth of about 16% (320MHz) is secured in the high frequency band of 1800MHz.

Next, FIGS. 7A to 7J illustrate E-CDMA, E-GSM, E-DCS, E-KPCS, E-US PCS, H-CDMA, and H in free space for the multi-band internal antenna according to the present invention. -GSM, H_DCS, H-KPCS, and H-US PCS shows the result of measuring antenna radiation pattern for each band. The bottom of each diagram shows the characteristic conditions of each antenna.

Referring to the diagrams of FIGS. 7A to 7J, the multi-band internal antenna according to the present invention is 360-degree omnidirectional with respect to the antenna in the H-CDMA, H-GSM, H_DCS, H-KPCS, and H-US PCS bands. It shows uniform radiation characteristics at, and the radiation characteristics of E-CDMA, E-GSM, E-DCS, E-KPCS, and E-US PCS bands are better in front and rear.

From the above results, it can be seen that the multiband internal antenna according to the present invention exhibits sufficiently satisfactory antenna characteristics as compared with the conventional PIFA antenna.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims below, but also by those equivalent to the claims.

 According to the present invention as described above has the advantage of improving the high frequency band characteristics of the multi-band internal antenna.

In addition, according to the present invention there is an advantage to reduce the degradation occurring in the high frequency band of the multi-band internal antenna.

In addition, according to the present invention there is an advantage that can implement an improved broadband characteristics or improved multi-band characteristics in the built-in antenna.

Claims (6)

In the multi-band internal antenna embedded in the mobile communication terminal to process a multi-band signal, A feed line for supplying current to the antenna; And Two or more coil parts connected in series to the feed line and having different pitch intervals using one coil; Including; The cross section of each coil portion is rectangular in shape, and the central axis of each coil portion is multi-band internal antenna, characterized in that arranged in series on the same line. The method of claim 1, And a case in which a rectangular parallelepiped receiving space is formed by combining two dielectric cases formed of a dielectric material and having an insertion hole and an insertion member formed at positions facing each other. The method of claim 1, The radiating part includes a first coil having a predetermined pitch and wound in a rectangular parallelepiped shape, and a second coil connected to the first coil and having a pitch interval greater than that of the first coil. And a first pass band is set by the entire length of the first and second coils, and a second pass band is set by the second coil. The method of claim 2, The case has a surface mount type mounting structure, characterized in that the multi-band internal antenna. The method of claim 2, The case has a multi-band internal antenna, characterized in that the screw fastening structure at a position corresponding to the predetermined mounting position of the mobile communication terminal. The method of claim 1, The case has a multi-band internal antenna, characterized in that having a hook (hook) structure in a position corresponding to the predetermined mounting position of the mobile communication terminal.

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