KR100292839B1 - Dual Band Ceramic Chip Antenna - Google Patents

Abstract

A dual band ceramic chip antenna is disclosed. The dual band ceramic chip antenna includes a main body formed of a rectangular parallelepiped using a ceramic dielectric material, and two helical conductors formed independently within the main body. Each helical conductor is formed in a helical shape and each spiral axis of rotation is parallel to the base and side of the body respectively. By forming the length of each helical conductor differently, the frequency band used for each helical conductor is changed. Therefore, two frequency bands can be used, and since the size is small, it can be embedded in a mobile terminal and has a relatively wide band width.

Description

Dual band ceramic chip antenna

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic chip antenna. More specifically, a dual band usable in two frequency bands by embedding a helical conductor operating in different frequency bands inside the ceramic chip. A) relates to a ceramic chip antenna.

In general, a small antenna is a starting point and end point of a signal that is mounted in a portable terminal and modulated in a microwave band and is a basic component in wireless communication, and the performance of the antenna itself depends on the performance of the entire portable terminal. Plays an important role.

Hereinafter, a conventional antenna will be described with reference to the accompanying drawings.

1 (a) is a diagram showing a conventional dipole antenna.

As shown in FIG. 1A, a conventional dipole antenna has two dipoles 1 and 3 connected to one-fourth the wavelength λ of the resonance frequency. Such a dipole antenna has a simple structure, which is easy to manufacture and can be used in a wide frequency range. However, since the length of the dipole antenna is very large, it is inconvenient to carry, and thus it is difficult to use in a portable terminal.

Figure 1 (b) is a view showing a conventional helical antenna.

As shown in FIG. 1 (b), the conventional helical antenna is formed by winding a spiral wire 7 in the form of a spiral coil on a support 5 of an insulating material, and by adjusting the number of coils, the interval and the length of the coil, and the like, and a resonance frequency. Determine the band. Such a helical antenna can be used in a portable terminal because its overall length is smaller than that of the dipole antenna.

Recently, various types of wireless communication services with different frequency bands such as Code Division Multiple Access (CDMA), Personal Communication Service (PCS), Group Special Mobile (GSM) and Digital European Cordless Tlelphone (DECT) have been supplied. Although subscribers use them, there is a disadvantage in that they are not compatible between services. Therefore, as a portable terminal, an antenna having a wide bandwidth that can be used in various frequency bands is required.

Figure 1 (c) is a diagram showing a conventional dual band helical antenna.

As shown in FIG. 1 (c), the conventional dual band helical antenna has a structure in which two helical antennas having different center frequencies of use are formed on the support 9 of the insulating material, and the upper end 11 of the support 9 Each of the lower ends 13 is wound with coils 15 and 17 to form two helical antennas. In addition, a coaxial line is formed inside the support 9, so that voltage can be supplied through the coaxial line so that it can be used in two frequency bands.

An antenna used in a general portable terminal is a retractable antenna that is a combination of a dipole antenna and a helical antenna. The antenna is stretched and formed at the upper end of the portable terminal, and used when the portable terminal is used. It is reduced and carried.

However, since the single-band and dual-band helical antenna and the retractable antenna are protruded at the upper end of the portable terminal, there is a problem such as breakage, portability, and the volume occupied by the antenna in the portable terminal There is a problem that is too large.

In order to solve this problem, a chip antenna using a ceramic chip manufacturing technology has been developed that can be embedded into a portable terminal.

FIG. 2 is a diagram illustrating a conventional ceramic chip antenna, and FIG. 3 is a diagram illustrating return loss for each frequency of the antenna of FIG. 2.

As shown in FIG. 2, the conventional ceramic chip antenna includes a helical conductor formed by spirally winding a coil inside the ceramic chip 19 using a chip stacking process. At this time, the helical conductor is formed by filling a thick film printed horizontal strip line 21 parallel to the bottom surface 25 and a conductive paste filled in a via hole formed perpendicularly to the bottom surface. It consists of a strip line 23.

On the other hand, one end of the helical conductor protrudes to the surface of the ceramic chip 19, the terminal for supplying voltage for applying a voltage to the helical conductor is formed on the end protruding loosely.

In the conventional ceramic chip antenna, as shown in Fig. 3, since the minimum value of the return loss is shown at a specific frequency fo, a frequency band centered on the specific frequency fo can be used.

These conventional ceramic chip antennas have been recently incorporated into portable terminals in the form of ultra small SMD (Surface Mounted Device), but since the frequency band used is used as a single band, wireless communication services of multiple frequency bands can be simultaneously performed. There is a problem that is difficult to do.

Accordingly, an object of the present invention is to provide a dual band ceramic chip antenna which has two usable frequency bands and is small in size and can be incorporated in a portable terminal.

Another object of this invention is to provide a dual band ceramic chip antenna having a relatively wide band width.

Figure 1 (a) is a diagram showing a conventional dipole antenna,

Figure 1 (b) is a view showing a conventional helical antenna (helical),

Figure 1 (c) is a diagram showing a conventional dual band helical antenna,

2 is a view showing a conventional ceramic chip antenna,

FIG. 3 is a diagram illustrating return loss by frequency of the antenna of FIG. 2;

4 is a perspective view of a dual band ceramic chip antenna according to an embodiment of the present invention;

5 is an exploded perspective view of the antenna of FIG. 4;

FIG. 6 is a diagram illustrating return loss by frequency of the antenna of FIG. 4.

As a means for achieving the above object, the present invention is to embed a helical conductor operating in different frequency bands in one ceramic dielectric chip.

Ceramic dielectric chips are manufactured through a ceramic chip manufacturing process in which a plurality of green sheets are stacked.

Strip lines and via holes are formed in a specific green sheet among a plurality of green sheets, and each helical conductor is formed by strip lines and via holes formed in a specific green sheet when a plurality of green sheets are stacked.

The end of each helical conductor protrudes out of the ceramic dielectric chip to form a voltage supply terminal, and when a voltage is applied to each helical conductor through the voltage supply terminal, each helical conductor resonates in two different frequency bands. .

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention may be easily implemented by those skilled in the art with reference to the accompanying drawings.

FIG. 4 is a perspective view of a dual band ceramic chip antenna according to an exemplary embodiment of the present invention, FIG. 5 is an exploded perspective view of the antenna of FIG. 4, and FIG. 6 is a diagram illustrating return loss for each frequency of the antenna of FIG. 4.

As shown in FIGS. 4 and 5, the dual band ceramic chip antenna according to the embodiment of the present invention includes a ceramic chip main body 100 formed by stacking dielectric ceramic green sheets 130 to 170 and having a rectangular parallelepiped shape. The first helical conductor 110 spirally formed inside the ceramic chip main body 100 and the second helical spirally formed separately from the first helical conductor 110 inside the ceramic chip main body 100. Conductor 120.

Here, the dielectric ceramic green sheets 130 to 170 have a high-frequency low temperature fired ceramic (LTCC) material based on glass ceramic as a main component.

Conductive strip lines 1401 to 1408 and 1701 to 1708 are printed on the surfaces of some green sheets 140 and 170 with conductive paste, and green sheets 140 are formed on both ends of strip lines 1401 to 1408 in the thickness direction. Via holes 1420 and 1430, which are small holes passing through the via holes, are formed, and the via holes 1420 and 1430 are filled with a conductive paste.

Here, the conductive paste is composed of a conductive phase, a binder, a vehicle and additives.

Meanwhile, some of the green sheets 150 and 160 are also formed with a plurality of via holes 1520, 1530, 1620, and 1630 corresponding to the positions of the via holes 1420 and 1430 formed in the green sheet 140. When the sheets 130 to 170 are laminated, the helical conductor 110 wound in a spiral shape is connected to each of the strip lines 1401 to 1408 and 1701 to 1710 through each of the via holes 1420, 1430, 1520, 1530, 1620, and 1630. 120 is formed.

For example, when the green sheets 130 to 170 are stacked, the strip lines 1701 of the green sheet 170 are connected to the strip lines 1401 of the green sheet 140 through via holes 1620, 1520, and 1420. The strip line 1401 is connected to the strip line 1702 of the green sheet 170 through the via holes 1430, 1530, and 1630.

On the other hand, the other end except for the end connected from the strip line 1701 of the green sheet 170 to the strip line 1401 of the other green sheet 140 protrudes to the surface of the ceramic chip body 100 to the first helical conductor A voltage supply terminal 1740 for applying a voltage to the 110 is formed.

Similarly, the other end except for the end connected to the strip line 1708 of the green sheet 170 to the strip line 1404 of the other green sheet 140 protrudes to the surface of the ceramic chip body 100 to form a second helical conductor. A voltage supply terminal 1760 for applying a voltage to the 120 is formed.

Here, the strip lines 1401 to 1408 and 1701 to 1708 printed on the surfaces of the green sheets 140 and 170 in a straight line are horizontal strip lines horizontal to the green sheet 170, and the green sheets 130 to 170 are stacked. The strip line formed perpendicular to the green sheet 170 by the sea via holes 1420, 1430, 1520, 1530, 1620, and 1630 is a vertical strip line.

The first helical conductor 110 is formed in a spiral form by a plurality of horizontal strip lines and a plurality of vertical strip lines, and the spiral rotation axis A of the first helical conductor 110 is the bottom surface 190 of the ceramic chip body 100. And parallel to the side face 180, respectively.

Similarly, the second helical conductor 120 is formed in a spiral form by a plurality of strip lines and a plurality of vertical strip lines, and the spiral axis B of the second helical conductor 120 is also formed on the bottom surface of the ceramic chip body 100 ( 190 and parallel to the side surfaces 180, respectively.

At this time, the first helical conductor 110 and the second helical conductor 120 are formed independently without being connected to each other, and the spiral rotation axes A and B of the respective conductors 110 and 120 are parallel to each other.

Meanwhile, strip lines and via holes in each of the green sheets 130 to 170 are three-dimensionally connected to form the first helical conductor 110 and the second helical conductor 120 through precise alignment.

The ceramic chip main body 100 is formed through a chip manufacturing process, such as pressing and sintering each of the green sheets 130 to 170 which are precisely aligned.

The frequency bands used for the first helical conductor 110 and the second helical conductor 120 are determined according to the lengths of the conductors 110 and 120, the distance between each strip line, the tilt angle of the horizontal strip line, and the length of the total conductor. do.

As a result, two different frequency bands may be used by adjusting the lengths of the conductors 110 and 120 such that the frequency bands of the first helical conductor 110 and the frequency bands of the second helical conductor 120 are different. Will be.

As shown in FIG. 6, when the center frequency of the first helical conductor 110 is f ″ o and the center frequency of the second helical conductor 120 is f′o, different center frequencies f′o and f ″ are provided. In o, the return loss value represents the minimum value, so that the ceramic chip antenna including the first helical conductor 110 and the second helical conductor 120 may use two different frequency bands, and thus, the frequency The band is also wider.

For example, when the center frequency f "o of the first helical conductor 110 is 1,800 MHz (1.8 GHz) and the center frequency f'o of the second helical conductor 120 is 900 MHz, the operating frequency of the ceramic chip antenna The band also becomes two frequency bands.

Meanwhile, the first helical conductor 110 and the second helical conductor 120 are not limited to being formed in a rectangular shape by a straight horizontal strip line and a vertical strip line, and are formed by winding in a circular shape or another shape. You may be.

In addition, although the first helical conductor 110 and the second helical conductor 120 are described as being formed inside the ceramic chip main body 100, each helical conductor may be formed by printing a strip line on the surface of the ceramic chip main body 100. 110 and 120 may be formed.

As described above, in the embodiment of the present invention, two frequency bands can be used by using helical conductors having different frequency bands, and because they are small in size, they can be embedded in a mobile terminal and have a relatively wide band width. To provide a band ceramic chip antenna.

Although this invention has been described with reference to the most practical and preferred embodiments, the invention is not limited to the embodiments disclosed above, but also includes various modifications and equivalents within the scope of the following claims.

Claims (7)

A chip body formed of a ceramic dielectric material, a first helical conductor spirally formed inside the chip body, and a second helical conductor disposed parallel to the first helical conductor inside the chip body and spirally formed; And one end of the first helical conductor and the second helical conductor protrudes from the surface of the chip main body to form a terminal for supplying a voltage for applying a voltage to the first helical conductor and the second helical conductor. Dual-band ceramic chip antenna. The dual band ceramic chip antenna of claim 1, wherein the chip main body is formed in a rectangular parallelepiped shape. The dual band ceramic chip antenna of claim 2, wherein the spiral rotation axis of the first helical conductor and the spiral rotation axis of the second helical conductor are parallel to the bottom and side surfaces of the chip body, respectively. The dual band ceramic chip antenna of claim 1, wherein the chip body is formed by stacking a plurality of green sheets. 5. The conductive sheet of claim 4, wherein a first strip line and a second strip line are respectively formed on the first and second green sheets of the plurality of green sheets, and the conductive sheet is formed on the green sheet between the first and second green sheets. The filled via hole is formed, and when the plurality of green sheets are stacked, the first strip line and the second strip line are electrically connected to each other through the via hole to form a first helical conductor, and among the plurality of green sheets, A third strip line and a fourth strip line are formed on the third and fourth green sheets, respectively, and a via hole filled with a conductive conductive material is formed in the green sheet between the third and fourth green sheets, and the plurality of green sheets are stacked. And the third strip line and the fourth strip line are electrically connected through the via hole to form a second helical conductor. 6. The dual band ceramic chip antenna of claim 5, wherein the first green sheet and the third green sheet are the same green sheet, and the second green sheet and the fourth green sheet are the same green sheet. 6. The dual band ceramic chip antenna of claim 5, wherein the first helical conductor and the second helical conductor have a rectangular shape wound around each spiral rotation axis.