KR100544389B1 - Wide band chip antenna for wireless LAN - Google Patents

Abstract

The present invention discloses a WLAN broadband chip antenna having dual band operation characteristics and broadband characteristics in a frequency band of 4.9 GHz-5.85 GHz as an antenna used in a wireless LAN. The WLAN broadband chip antenna forms a radiation element on a radiation element and a feeder plate of an inverted-f type antenna only in one direction of the ceramic dielectric, so that the wireless broadband antenna may operate in different frequency bands as well as the power supply plate. The rear portion of the high frequency band radiating element and the ground is designed to be provided to transmit and receive signals in a wider frequency band.

The radiating element formed on the ceramic dielectric can be designed as a meander line, thereby reducing the overall size of the antenna.

WLAN, Broadband, Chip Antenna, Ceramic Dielectric

Description

Wide band chip antenna for wireless LAN             

1 is a perspective view showing that the WLAN broadband chip antenna mounted on a PCB board according to a preferred embodiment of the present invention,

2 is a plan view of FIG.

3 is an exploded perspective view illustrating a WLAN broadband chip antenna mounted thereon;

4 is a plan view of a PCB board on which the WLAN broadband chip antenna of the present invention is mounted;

5 is a rear view of FIG. 4;

6A and 6B illustrate a modified structure of the WLAN broadband chip antenna of the present invention;

7 is a graph showing the results of measuring the standing wave ratio (VSWR) of the antenna of FIG. 1 in the entire band from 2.3 GHz to 6 GHz;

8 is a view showing the radiation pattern of the antenna of FIG. 1 at 2.4 GHz, (a) shows a horizontal pattern, and (b) shows a vertical pattern;

FIG. 9 is a diagram illustrating the radiation pattern of the antenna of FIG. 1 at 4.9 GHz, in which (a) shows a horizontal pattern and (b) shows a vertical pattern.

* Description of the symbols for the main parts of the drawings *

10. PCB board 100. Ceramic dielectric block

102,104. Power feeding plate 110. Radiating element

100a low frequency radiating element 100b, 100c.high frequency radiating element

130. Feeding hole 140. Ground section

150. Feeding Line

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna of a wireless LAN device, and more particularly, to a WLAN broadband chip antenna having dual band operation characteristics and broadband radiation characteristics capable of operating in two different frequency bands.

In general, an antenna used in a mobile phone or the like is a whip antenna made of a straight metal wire or a helical antenna spirally wound around a metal wire, and a telescopic antenna. In accordance with the trend of miniaturization of the terminal to satisfy the consumer desire to have a has been switched to the internal antenna embedded in the terminal.

As the built-in antenna, an inverted F antenna (IFA) having a feed line formed at a predetermined position of a substantially '-' shaped metal element is used, but the inverted F antenna is used only in a single frequency band. In addition to the narrow band in operation, the antenna itself has a large size, and there are disadvantages in that there are processes and test procedures for maintaining the inherent characteristics of the antenna when the antenna is manufactured.

In other words, as the frequency band of mobile communication devices increases and various communication services are provided, miniaturization and multifunctionality are required for antennas. However, most antennas currently used are used only in a single frequency band.

Wireless Local Area Networks (WLANs), which are used to wirelessly transmit and receive digitally-formatted data between building interior areas, between buildings and other buildings, or between building and exterior areas using wireless communication devices. ) Is not suitable in the environment provided, and therefore, an antenna having a wide bandwidth and operating in multiple frequency bands is required for use in a wireless communication device under a wireless LAN system environment.

Here, the wireless LAN is divided into an IEEE802.11b system in which the use frequency is represented by 2.4 GHz and an IEEE802.11a system in which the use frequency is represented by 5.725 GHz, based on an international standard for use frequency.

Thus, two antennas are provided in a device currently being used in a wireless LAN system. That is, an antenna operating in a frequency band of 2 GHz and an antenna operating in a frequency band of 5 GHz are provided separately.

However, the two antenna systems allow wireless LAN devices to be used interchangeably in both systems, but have a very disadvantageous structural and economical structure. Therefore, there is an urgent need for the development of an antenna that can be used in both systems, that is, a dual band antenna capable of operating in all different frequency bands used in both systems.

Ceramic patch antennas have been disclosed to have dual band operating characteristics as the dual band antennas.

The patch antenna includes a ceramic substrate, a metalized patch formed on one surface of the ceramic substrate, and a ground plane disposed on an opposite surface of the ceramic substrate.

Such ceramic patch antennas can be miniaturized in practice, but are expensive compared to dipole antennas, and also require additional connectors and cables, which incur additional installation costs.

In addition, the conventional dipole antenna is designed to have a length of approximately [lambda] / 2, but the antenna cannot be made small due to the basic length characteristic.

In addition, since the ceramic patch antenna has a directional radiation characteristic, it is not suitable for use as an antenna for a wireless LAN that requires omnidirectional radiation characteristic.

Similarly, the chip pattern of most of the Planar Inverted F Antenna (PIFA) structures mounted inside the mobile communication device also requires omni-directional characteristics because the direct pattern is provided in the sky direction. Not suitable for antennas for wireless LAN.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, a wireless broadband broadband chip to use a wide frequency bandwidth by printing the antenna pattern of the inverted-f type only on one side of the ceramic dielectric mounted on a predetermined position of the PCB board The object is to provide an antenna.

In addition, another object of the present invention is to provide a WLAN broadband chip antenna that can be manufactured by minimizing the size of the chip antenna by applying a meander line (meander line).

A WLAN broadband chip antenna for use with a wireless communication device in a WLAN system is disclosed.

The WLAN broadband chip antenna of the present invention includes a ceramic dielectric block of a rectangular parallelepiped seated and fixed on a feeder plate formed at a predetermined position of a PCB board; It consists of a conductive pattern consisting of radiating elements arranged on one side of the ceramic dielectric block, preferably on two sides, and radiating elements arranged on a feeder plate on which the ceramic dielectric block is seated. The conductive pattern is double-resonated by two radiating elements having an inverted-f antenna pattern formed in the ceramic dielectric block, and the resonance is generated by the radiating element formed on the feeder plate, thereby causing triple resonance as a whole.

The WLAN broadband chip antenna of the present invention is designed so that the feeder on the PCB board is close to the radiating part for high frequency so that smooth radiation is achieved in the high frequency band. When the size of the WLAN broadband chip antenna mounted on the feeder plate is small, the radiating element is designed as a meander line.

Characteristics and effects of the WLAN broadband antenna according to the present invention not described above or described above will become more apparent through the preferred embodiments described below with reference to the drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a perspective view showing that the WLAN broadband chip antenna is mounted on a PCB board according to a preferred embodiment of the present invention, Figure 2 is a plan view of Figure 1, Figure 3 is an exploded perspective view of the WLAN broadband chip antenna is mounted.

As shown therein, the WLAN broadband chip antenna of the present invention includes a dielectric block 100 made of a substantially rectangular parallelepiped ceramic material mounted through a through hole (not shown) at a predetermined position of the PCB board 10. do.

The dielectric block 100 is provided with a radiating element 110 of a conductive pattern of an inverted-f antenna in one direction.

In the reverse F-type antenna pattern, a high frequency radiating element 110b extends in one direction on a side of the low frequency radiating element 110a at a position perpendicular to the top surface of the dielectric block 100. The low frequency radiating element 110a has a shape in which the dielectric block 100 surrounds an upper surface with a bent end portion having a substantially '7' shape when extended. In addition, a feed line for feeding power to the low frequency radiating element 110a and the high frequency radiating element 110b is connected in a vertical direction, and the feeding line on the feeder plate 102 on which the dielectric block 100 is mounted. The feeding hole 130 is formed at a point connected to the high frequency radiating element 110c extending in parallel in the direction in which the radiating elements 110a and 110b are formed.

The low frequency radiating element 110a and the high frequency radiating element 110b are designed to have the same width.

The low frequency radiating element 110a designed to operate in the low frequency band is actually designed to operate in 2.4-2.5 GHz, and the high frequency radiating elements 110b and 110c designed to operate in the high frequency band are actually 4.9-. It is designed to operate at 5.85GHz.

The end is grounded to the ground surface 140 to ground the pattern of the inverted-f antenna shape.

A feeding line 150 having an approximately 'b' shape is formed at the feeding hole 130.

On the other hand, the PCB board 10 is disposed in the vertical direction (90 °) and the direction in which the ceramic dielectric block 100 is disposed for diversity (Diversity) and the feeder plate 104 is formed in a predetermined spaced place .

Reference numeral 120 denotes a ground short state.

4 is a plan view of a PCB substrate on which the WLAN broadband chip antenna of the present invention is mounted, and FIG. 5 is a rear view of FIG. 4.

Referring to this, the high frequency radiating element 110c operating in the high frequency band in the range of 4.9 kHz to 5.85 kHz is designed to be close to the ground. In other words, since the ground portion protrudes in a plane (meaning to extend out of the pattern in a pattern) toward the radiating element 110c by a predetermined distance d, the ground portion protrudes from the bottom surface of the PCB board 10. The high frequency radiating element 110c is positioned directly above, and the high frequency radiating element 110c and the ground portion are patterned to be closest to the shortest distance.
Such a ground part can be implemented by a basic method of performing the work in consideration of the degree of protruding and bending the ground part when etching the ground pattern of the PCB board 10, in addition to attaching a conductive thin film or after etching the ground pattern It can be printed separately. The spacing between the radiating element 110c and the ground is equally applied to the modified structure (FIGS. 6A and 6B) of the antenna of the present invention described later.

As such, the low frequency radiating element 110a, the high frequency radiating element 110b, and the high frequency radiating element 110c of the power feeding plate 102 are formed in parallel with each other on the surface of the dielectric block 100, and the high frequency radiating element 110b is formed. When the device 110c and the ground plane are formed in close proximity, the signals of the low frequency band (2.4-2.5 GHz) and the high frequency band (4.9-5.85 kHz) can be transmitted and received.

On the other hand, as shown in Figure 6a and 6b showing a modified structure of the WLAN broadband chip antenna of the present invention, the pattern can be modified on the surface of the dielectric block 100 according to the antenna characteristics and printed.

That is, as shown in FIG. 6A, an inverted-f antenna pattern including a feed line is formed on the side of the dielectric block 100, and the topmost radiating element, that is, the low frequency radiating element, is formed at the end of the dielectric block 100. It extends to the upper surface of the dielectric block 100.

In addition, when the chip antenna of the present invention is small in size, a low frequency radiating element formed in the ceramic dielectric block 100 may be designed as a meander line 100a.

On the other hand, the conductive pattern formed on the dielectric block 100 is formed by etching a copper foil having a predetermined thickness on the surface of the dielectric block and then chemically corrodes and removes unnecessary portions and leaves only necessary patterns on the substrate. Of course, it can be arranged using a wire conductor.

FIG. 7 is a graph showing the results of measuring the standing wave ratio (VSWR) of the antenna of FIG. 1 in the entire band from 2.3 GHz to 6 GHz.

For reference, the markers are located at frequencies 2.40 Hz, 2.50 Hz, 5.725 Hz and 5.825 Hz, respectively, and have a standing wave ratio (VSWR) of 1.5: 1 in the frequency bands ranging from 2.40 Hz to 2.50 Hz and 5.725 Hz to 5.825 Hz. That was measured.

As a result of the measurement, the antenna of the present invention has omni-directional characteristics.

FIG. 8 is a diagram illustrating the radiation pattern of the antenna of FIG. 1 at 2.4 GHz, in which (a) shows a horizontal pattern and (b) shows a vertical pattern.

Referring to this, it can be seen that the horizontal pattern (FIG. 8A) is shown as an approximately circular pattern, and the vertical pattern (FIG. 8B) is shown as an 8-type pattern, which is an omnidirectional characteristic of the frequency-only antenna, thereby having omnidirectional characteristics. Can be.

FIG. 9 is a diagram illustrating the radiation pattern of the antenna of FIG. 1 at 4.9 GHz, in which (a) shows a horizontal pattern and (b) shows a vertical pattern.

Similarly, it can be seen that the horizontal pattern (FIG. 9A) is shown as a substantially circular pattern, and the vertical pattern (FIG. 9B) is shown as an 8-type pattern, which is the omnidirectional characteristic of the frequency-only antenna, thereby having omnidirectional characteristics. .

Referring to the standing wave ratio and the radiation pattern of the antenna as described above, it can be seen that a constant pattern shape appears in the range of about 1 dBi at 2.40 kHz and about -3 dBi at the frequency range of 4.9 kHz to 5.85 kHz. ) Appears small and 8-type pattern characteristics can be seen.

According to the WLAN broadband chip antenna of the present invention, it has a broadband characteristic of 4.9㎓-5.85㎓, and the standing wave ratio and the horizontal / vertical pattern are constantly measured, and the gain is excellent.

In addition, when the size of the ceramic dielectric is small, since the radiating element may be designed and provided as a meander line, the overall antenna size may be reduced.

In the above, the present invention has been described with reference to the preferred embodiments, but the present invention may be variously modified and changed without departing from the spirit and scope of the present invention described in the claims by those skilled in the art. There will be.

Claims (7)

A rectangular parallelepiped ceramic dielectric block seated and fixed on a feeder plate formed at a predetermined position of the PCB board; The radiation from a feed hole formed at a point connected to an upper surface of the dielectric block, two radiating elements of an inverted-f antenna pattern printed on a side orthogonal to each other, and a feed line on a feeder plate on which the dielectric block is mounted; Consists of a conductive pattern having a constant width consisting of a radiating element formed parallel to the direction in which the element is formed, The inverted F antenna pattern has radiating elements extending in one direction on the top and side surfaces of the dielectric block, and the radiating elements formed on the top surface have an approximately '7' shape surrounding the top surface, and the ends thereof are bent. WLAN broadband chip antenna, characterized in that formed. The method of claim 1, A WLAN broadband chip antenna, wherein the dielectric block includes an inverted-f antenna pattern including a feed line on a side thereof, and an end of the uppermost radiating element extends to an upper surface of the dielectric block in the pattern. . The method of claim 1, When the ceramic dielectric block is small in size, the WLAN broadband chip antenna, characterized in that the radiation element formed on the upper surface is designed as a meander line (meander line). The method according to any one of claims 1 to 3, And a part of the radiating element is designed to operate in a high frequency band and the other part in a low frequency band. The method of claim 4, wherein The high frequency band is 4.9-5.825GHz range, and the low-frequency band 2.4-2.5GHz range, WLAN broadband chip antenna. The method according to any one of claims 1 to 3, The WLAN broadband chip antenna, characterized in that the high frequency band radiating element formed in the PCB board and the ground portion adjacent to the design so that the ground portion is protruded by a predetermined distance in planar direction toward the radiating element side. The method of claim 1, The WLAN broadband chip antenna, characterized in that the feeder plate is disposed in a direction perpendicular to the direction in which the ceramic dielectric block mounted on the feeder plate of the PCB board (90 °).

Images