KR100541080B1 - Antenna for wireless-lan and wireless lan card with the same - Google Patents

Abstract

The present invention enables the transmission and reception of radio signals of the high band (5GHz) and low band (2.4GHz) required in the wireless LAN without increasing the size, and can be easily adjusted without a structural change WLAN antenna and implementation therefrom The present invention relates to a wireless LAN card, wherein an antenna according to the present invention has a predetermined area and has a radiation electrode for determining a transmission / reception frequency band of the antenna, a matching electrode having at least one open stub, and one end connected to the radiation electrode and the other end. Is connected to the matching electrode, and is composed of a feeding electrode having a feeding point to which a current is applied to an arbitrary position on the electrode, and the impedance and frequency can be adjusted by arbitrarily setting the feeding point and the ground point on the feeding electrode. .

PIFA antenna, radiating electrode, feeding, ground, open stub, slot

Description

Wireless LAN Antenna and Wireless LAN Card with the Same {ANTENNA FOR WIRELESS-LAN AND WIRELESS LAN CARD WITH THE SAME}             

1 is a perspective view showing an example of a conventional dual band antenna.

2 is a graph showing the characteristics of a conventional dual band antenna.

3 is a perspective view illustrating a dual band antenna according to the present invention.

4 is a graph showing the characteristics of a dual band antenna according to the present invention.

5 is a diagram illustrating an example of changing a feeding position in a dual band antenna according to the present invention.

6 is a view showing an example in which the dual-band antenna according to the present invention is modified into an inverted F type antenna.

7 is a perspective view showing another modified example of the antenna according to the present invention.

8 is a perspective view showing another modified variant of the antenna according to the present invention.

9 is an assembly state diagram of a diversity antenna implemented with a WLAN dual band antenna according to the present invention.

10 is another assembly state diagram of a diversity antenna implemented with a WLAN dual band antenna according to the present invention.

Explanation of symbols on the main parts of the drawings

30: dielectric block 31: radiation electrode

32: slot 33: feeding electrode

34: matching electrode

FP: feeding point

SP: short point

The present invention relates to an antenna embedded in a wireless LAN, and more particularly, it is possible to transmit and receive radio signals of a high band (5 GHz) and a low band (2.4 GHz) without increasing the size, and to easily adjust the characteristics of the antenna without a structural change. This relates to a possible WLAN antenna and a WLAN card implemented therein.

Recently, as a mobile communication device has become smaller and lighter, and a transmission / reception band is multiplexed in two or more bands, an antenna, which is an important component for wireless transmission / reception of a mobile communication terminal, is also converted from an external helical antenna to an F-type or inverse-F type antenna. It is developing.

In particular, in a wireless local area network, a dual band antenna capable of transmitting and receiving up to 5 GHz band is required to enable not only 2.4 GHz, which is the current band, but also a large amount of data transmission in the future. do.

1 shows a conventional dual band antenna, as shown, the antenna 11 is a radiation electrode 13 having a predetermined area, and the radiation electrode 13 is located inside the radiation electrode 13 Slot 14 for multiplexing the current path, a feeding electrode 16 for applying current to the radiation electrode 13, and a ground electrode 15 for grounding the radiation electrode 13.

In the above, one slot 14 forms two current paths connected in parallel on the radiation electrode 13 with respect to the feeding electrode 16, so that resonance occurs in two frequency bands corresponding to each current path. Get up. In addition, two frequency bands in which the resonance occurs are transmission / reception bands of the corresponding antenna. Therefore, the two transmission / reception bands are determined by the areas of the two radiation regions divided by the slots 14 of the radiation electrodes 13, respectively.

The antenna shown in FIG. 1 is called a Planar Inverted F Antenna (PIFA) because of its shape, and in addition, the antenna of the structure of FIG. 1 does not have a ground electrode, and a monopole type antenna is also used. do.

However, when the conventional dual band antenna shown in FIG. 1 is applied to a wireless LAN, the size of the wireless LAN itself is accompanied by constraints on height, length, area, etc. of the antenna.

Specifically, the antenna having the structure as shown in FIG. 1 has an appropriate center frequency, and in order to achieve a desired impedance matching, the radiation electrode 13 of the antenna should be as far away from the ground plane of the PCB as possible. In recent years, wireless LAN products have a card type such as a PCMCIA card or a CF card, and the maximum height between the antenna and the ground plane of the antenna is limited.

Therefore, in the case of a dual band antenna for WLAN, transmission and reception characteristics are not satisfactory in the 2.4 GHz and 5 GHz bands due to height and area limitations.

FIG. 2 is a graph illustrating characteristics of a 2.4 GHz / 5 GHz WLAN dual band antenna implemented with the conventional structure shown in FIG. 1.

Looking at the graph, it can be seen that the width of VSWR is very sharp in the 2.4 GHz band and the 5 GHz band of the conventional WLAN dual band antenna. Based on the markers P1 to P2 and the bands P3 to P4 shown in the graph, there is a problem that the signal characteristics of the 2.4 GHz band are deteriorated because the VSWR value in the 2.4 GHz band is higher than 2, and the signal characteristics are deteriorated. As a reference, since the width of the band that satisfies the VSWR value of 2 or less in the 2.4 GHz band is narrow, there is a disadvantage in that the characteristics of the antenna are easily changed according to the change in the set or the surrounding environment.

In order to improve this disadvantage, as described above, the area of the radiation electrode should be widened or the gap between the radiation electrode and the ground should be increased. In this case, there is a problem that the size of the antenna is increased. In the product, there is a problem that it is difficult to apply.

The present invention is a configuration means for achieving the above object, the object of the present invention can satisfy the characteristics of the antenna in the high band and low band without increasing the size, the WLAN antenna that can easily adjust the characteristics of the antenna without changing the structure and It is to provide a WLAN card implemented as this.

Another object of the present invention is to provide a dual band antenna for a wireless LAN capable of adjusting impedance matching and resonant frequency only by changing a feeding position without changing an antenna structure or pattern.

Still another object of the present invention is to provide a dual-band antenna for a wireless LAN that can be easily changed from a monopole type to an inverted-F type antenna without changing a pattern shape or structure, so that a change in a set can be appropriately and quickly.

As a constituent means for achieving the above object of the present invention, a wireless LAN antenna according to the present invention has a predetermined area and the radiation electrode for determining the transmission and reception frequency band of the antenna; A matching electrode having one or more open stubs; And a feeding electrode having one feeding end connected to the radiation electrode and the other end connected to the matching electrode, and having a feeding point at which a current is applied to an arbitrary position on the electrode.

In addition, the WLAN antenna according to the present invention is characterized in that it comprises at least one slot to form a current path connected in parallel to the feeding electrode by dividing the radiation electrode into two or more areas.

In addition, the WLAN antenna according to the present invention is characterized in that the impedance matching can be adjusted by adjusting the open stub length of the matching electrode.

In addition, the WLAN antenna according to the present invention is characterized in that the antenna resonant frequency and impedance matching can be adjusted by adjusting the feeding point position in the feeding electrode.

In addition, the WLAN antenna according to the present invention can further form a ground point on the feeding electrode, it characterized in that the change from the monopole type antenna to the inverted F type antenna according to the presence or absence of the ground point.

In addition, the present invention includes a printed circuit board mounted with a plurality of semiconductor chips and devices to process the WLAN signal; And a radiation electrode having a predetermined area on an upper surface of the rectangular parallelepiped dielectric block and having a transmission / reception frequency band of the antenna determined thereon, and a matching electrode of the open stub printed on the front surface of the dielectric block so as not to be in direct contact with the radiation electrode. First and second antennas mounted on the printed circuit board so that the feeding electrode connected to the matching electrode is printed on one end of the radiation electrode and the other end of the dielectric block on the rear and bottom surfaces of the dielectric block. Includes, in the first and second antennas by providing a wireless LAN card, by adjusting the impedance matching by adjusting the feeding point on the feeding electrode when mounted on the printed circuit board.

In addition, the present invention includes a printed circuit board mounted with a plurality of semiconductor chips and devices to process the WLAN signal; An antenna support member fixed at a predetermined height from a substrate at a predetermined position of the printed circuit board; And a radiation electrode having a predetermined area and having a transmission / reception frequency band of the antenna determined, a matching electrode having one or more open stubs, one end connected to the radiation electrode and the other end connected to the matching electrode, and an arbitrary position on the electrode. A feeding electrode having a feeding point to which a current is applied to each of the first and second radiation electrodes supported by the antenna support member, and each feeding electrode is soldered to the printed circuit board at the feeding point. Including an antenna, the present invention provides a WLAN card capable of achieving impedance matching by changing soldering feeding points of the first and second antennas.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation of the present invention.

3 is a perspective view showing an embodiment of a WLAN antenna according to the present invention.

Referring to FIG. 3, the wireless LAN antenna according to the present invention has a predetermined area, and a radiation electrode 31 for determining a transmission / reception frequency band of the antenna, and the radiation electrode 31 in parallel from the feed point FP. A slot 32 for dividing the two current paths connected to each other, a feeding electrode 33 having one end connected to a predetermined portion of the radiation electrode 31 and having a feeding point FP to which a current is applied at an arbitrary position; The matching electrode 34 is connected to the other end of the feeding electrode 33 and has at least one open stub having a predetermined distance from the radiation electrode 31.

The antenna having the above structure may be implemented by being printed on each side of the dielectric block having a predetermined volume made of dielectric ceramic or polymer, or formed by pressing, and then supporting member (for example, , Made of plastic or polymer and fixed on a printed circuit board) to maintain the shape of FIG. 3.

As described above, regardless of how the antenna of the present invention is implemented, the area, the distance, and the height of the radiation electrode 31, the slot 32, the feeding electrode 33, and the matching electrode 34 Its characteristics depend on it.

Similarly, the radiation electrode 31, the feeding electrode 33, and the matching electrode 34 are formed by printing and then heat-treating Ag, Cu, or other conductive material in a paste state on the surface of the dielectric block by screen printing or the like. It can be formed by a method such as, plating, and the like, and also, by cutting the Ag, Cu or other conductive electrode in the form of a sheet metal in the form shown in Figure 3, attached to the surface of the dielectric block, or placed on a printed circuit board It can be implemented to support the formation by the support member.

Alternatively, the antenna may form the electrodes 31, 33, 34 directly on a printed circuit board without using the above-described support.

In addition, the slot 32 forms two or more paths connected in parallel on the radiation electrode 31 through which the current input from the feeding point FP flows, and the resonance frequencies are different according to the electrical length in each radiation region. To form. Therefore, the slot 32 is not necessary when there is only one frequency band required by the corresponding antenna, and when the frequency band required by the corresponding antenna is two or more, a plurality of slots may be formed accordingly.

3 illustrates a wireless LAN antenna capable of transmitting / receiving in dual bands of 2.4 GHz and 5 GHz. One slot 32 is formed, and the radiation electrodes 31 divided by the slots 32. Resonance is generated in two bands by electrical lengths in two regions, and when there are radiation electrodes 31 having the same area, the resonance band varies depending on the length D1 of the slot 32. That is, the longer the length D1 of the slot 32, the longer the current path, and the lower the overall resonant frequency band. On the contrary, the shorter the length D1 of the slot 32, the shorter the current path and the overall resonant frequency band. Increases. That is, by adjusting the length of the slot D1, the resonance frequency in both the low frequency band and the high frequency band can be adjusted together.

The shape of the radiation electrode 31 and the slot 32 is not limited to the shape of FIG. 3, and any shape generally known can be used.

In addition, the matching electrode 34 is formed in a "b" shape, one end of which is connected to the radiation electrode 31 through the feeding electrode 33, and an open stub is formed on the other side, as means for adjusting impedance matching of the antenna. The antenna impedance is adjusted according to the length D2 of the open stub.

Specifically, when the length (D2) of the open stub is increased, the impedance circle of the antenna is increased, and the antenna impedance is lowered. On the contrary, when the length (D2) of the open stub is shortened, the antenna impedance can be increased. The electrode 34 allows antenna impedance matching.

In addition, by adjusting the length D1 of the slot 32 and the open stub length D2 of the matching electrode 34 together, the frequency characteristics and the band characteristics of the antenna can be adjusted together.

3 illustrates a basic configuration example of a wireless LAN antenna according to the present invention, and in this configuration, the number and shape of the open stubs of the slot 32 and the matching electrode 34 may be changed, and the optimal configuration therefrom. The antenna design value can be obtained.

For example, FIG. 7 illustrates a modification of the WLAN antenna of the present invention in which the “-” portion protruding from the open stub of the “a” shape is removed, and the matching electrode 34 ′ has a rod shape. In this case, impedance matching is performed by adjusting the length (ie, height) of the matching electrode 34 '.

As another modification of the present invention, Figure 8 shows a plurality of open stub WLAN antenna. As shown in FIG. 8, the WLAN antenna of the present invention may further include two matching electrodes 34 and 35 connected in parallel to the other end of the feeding electrode 33. In this case, the impedance depends on the sum of the lengths of the open stubs of the two matching electrodes 34 and 35. The number of matching electrodes 34 and 35 may be further increased as necessary.

The matching electrodes 34 and 35 are modified as necessary.

4 shows a dual band antenna for 2.4 GHz and 5 GHz wireless LAN as shown in FIG. 3, and measures the VSWR. The antenna size is the same as that of the conventional antenna measured in FIG.

In comparison with the conventional measurement shown in FIG. 2, the measurement result of FIG. 4 shows that the conventional antenna shows a high VSWR in the 2.4 to 2.484 GHz band between the markers P1 and P2. The standing wave ratio is less than 2 in the band wider than the 2.4 ~ 2.484 GHz band between P1 and P2.

In general, the wider the resonant frequency band satisfying the VSWR, the more stable the high performance of the antenna can be achieved without changing the characteristics of the antenna caused by the change of the environment around the set. Conventional WLAN antennas can not easily meet the required performance because the antenna characteristics are easily changed according to the set and the surrounding environment in the 2.4 GHz band, whereas the antenna according to the present invention exhibits a wide bandwidth characteristic in both bands. It has the advantage of exhibiting stable characteristics to changes in the surrounding environment.

In addition, the antenna according to the present invention shows a lower standing wave ratio in the 5GHz band (band between marker P3 and marker P4) than the conventional antenna, from which the dual-band wireless LAN antenna according to the present invention is not only 2.4GHz band Good signal characteristics can be obtained in all 5GHz bands.

In addition, in the WLAN antenna according to the present invention, the actual current is input on the feeding electrode 33 without the open stub length of the matching electrode 34 or the length of the slot 32 described above. By changing the position of the FP, antenna matching can be achieved.

5 (a) and 5 (b) show an example of changing the position of the feeding point (FP) in the WLAN antenna shown in FIG. First, FIG. 5A illustrates a case in which the feeding point FP is shifted toward the radiation electrode 31 in the WLAN antenna shown in FIG. 3. In this case, the open stub of the matching electrode 34 is relatively larger. The effect of lengthening becomes long. That is, as the feeding point FP is biased toward the radiation electrode 31, the length of the open stub of the matching electrode 34 becomes longer, and as a result, the impedance is adjusted to the side in which the antenna impedance is lowered (that is, the direction of the impedance circle becomes larger). It becomes possible. In addition, when viewed from the side of the radiation electrode 31, the feeding point (FP) is biased toward the radiation electrode 31, the effect is that the current path is shortened relatively, therefore, the center frequency of the resonance band is moved in a high direction do.

Next, FIG. 5B illustrates a case in which the feeding point FP is formed to be biased toward the matching electrode 34 in the WLAN antenna shown in FIG. 3. In this case, the electric warp path is lengthened and the open stub is The length is shortened, and the antenna impedance is adjusted in the direction of increasing, and the center frequency of the resonance band is shifted in the lower frequency direction.

Therefore, the WLAN antenna according to the present invention changes the impedance and the center frequency of the antenna only by changing the position of the feeding point (FP), thereby facilitating the implementation of an optimal antenna for each set.

In addition, the WLAN antenna according to the present invention can be changed from the monopole type antenna to the inverted F type antenna.

As described above, the inverted F-type antenna applies a current to the radiation electrode from one side and simultaneously grounds the radiation electrode. Therefore, the feeding point and the ground point appear at the same time, as shown in Figure 6, the wireless LAN antenna according to the present invention by grounding a predetermined point of the feeding electrode 33 having the feeding point (FP), inverted F type antenna It can be transformed into. The grounded portion on the feeding electrode 33 is called a ground point SP, and the ground conditions of the printed circuit board in the set are significantly different by adjusting the distance and the position of the feeding point FP and the ground point SP. Even if this occurs, it is easy to change the impedance matching and dual resonant frequency of the antenna.

The WLAN antenna of the present invention as described above may be particularly useful for implementing a diversity antenna using two antennas for vertical polarization and horizontal polarization.

9 and 10 illustrate an embodiment of implementing a diversity antenna using an antenna according to the present invention in a WLAN card.

First, FIG. 9 illustrates that the WLAN antenna according to the present invention is manufactured and used as a chip antenna type. After attaching the first antenna 92 in the vertical direction to the printed circuit board 91 of the WLAN card, The second antenna 93 is attached in a direction orthogonal to the first antenna 92. In this case, the characteristics of the second antenna 93 may be different for each set due to the interference with the first antenna 92. To this end, before soldering the second antenna 93 on the printed circuit board 91, the feeding point FP2 (i.e., the pattern and soldering of the printed circuit board) on the feeding electrode formed on the lower surface of the dielectric block 93a. The antenna characteristics can be adjusted to show the optimal characteristics while adjusting the position of the point.

Similarly, the first antenna 92 may also adjust antenna characteristics by adjusting the position of the feeding point FP1.

Next, FIG. 10 shows another type of diversity antenna implemented as a wireless LAN antenna according to the present invention, and a predetermined position on a printed circuit board 101 on which a plurality of circuits and elements for processing a wireless LAN signal are mounted. An antenna support member 102 formed of a polymer or plastic material is formed in the support member, and the first and second antennas 103 and 104 formed according to the present invention are supported by the antenna support member 102 so as to be perpendicular to each other.

In this case, the radiation electrodes of the first and second antennas 103 and 104 are positioned on the upper surface of the antenna support member 102, and the feeding electrodes of the first and second antennas 103 and 104 are positioned on the printed circuit board 101. A predetermined point on the image is soldered to the signal pattern and / or the ground pattern.

The antenna support member 102 supports the radiation electrodes of the first and second antennas 103 and 104 to be positioned at a predetermined height on the printed circuit board 101, and is not limited thereto.

In this case, the first and second antennas 103 and 104 are formed by forming a metal plate to have the radiation electrode 31, the slot 32, the feeding electrode 33, and the matching electrode 34 described above by pressing.

Also, as described above with reference to FIG. 9, the diversity antenna shown in FIG. 10 is controlled by changing the feeding point of the first and second antennas 103 and 104 to adjust the impedance, thereby causing the interference between the first and second antennas 103 and 104. The impact can be minimized.

As described above, the wireless LAN antenna according to the present invention is formed by connecting the matching electrode of the radiating electrode and the open stub on the basis of the feeding part, thereby realizing miniaturization and high performance of the antenna.

In addition, the wireless LAN antenna according to the present invention enables to adjust the antenna impedance and resonant frequency only by changing the feeding position without changing the length of the electrode, and it is possible to adjust the antenna characteristics by a simple method, and as a result, to reduce the antenna manufacturing cost. It can be effective.

In addition, in the WLAN antenna according to the present invention, by shorting a part of the fed feeding electrode to the ground, the antenna structure can be freely changed from the monopole type antenna to the inverted F type antenna, and the spacing and position of the feeding point and the ground point are also free. By adjusting the antenna characteristics by adjustment, there is an effect that the set change can be quickly responded.

Claims (12)

A radiation electrode having a predetermined area and determining a transmission / reception frequency band of the antenna; A matching electrode having one or more open stubs; And One end is connected to the radiation electrode and the other end is connected to the matching electrode, and includes a feeding electrode having a feeding point to which a current is applied to any position on the electrode, WLAN antenna, characterized in that for adjusting the antenna resonance frequency and impedance matching by adjusting the position of the feeding point in the feeding electrode. The method of claim 1, wherein the WLAN antenna And at least one slot for dividing the radiation electrode into two or more regions to form current paths connected in parallel with respect to a feeding electrode. The method of claim 1, wherein the WLAN antenna WLAN antenna, characterized in that for controlling the impedance matching by adjusting the length of the open stub of the matching electrode. delete The method of claim 1, wherein the WLAN antenna Wireless antenna having a feeding point and a ground point on the feeding electrode. The method of claim 1, The matching electrode having the open stub is a WLAN antenna, characterized in that the "b" shape. The method of claim 1, The matching electrode having the open stub is a WLAN antenna, characterized in that the rod shape. The method of claim 1, The matching electrode is a wireless LAN antenna, characterized in that it comprises two "a" shaped open stub connected in parallel to the feeding electrode. A radiation electrode having a predetermined area and determining a transmission / reception frequency band of the antenna; A matching electrode having one or more open stubs; And One end is connected to the radiation electrode and the other end is connected to the matching electrode, and includes a feeding electrode having a feeding point to which a current is applied to an arbitrary position on the electrode, and a ground point connected to the ground, An inverted F type WLAN antenna, by adjusting a feeding point position in the feeding electrode, thereby adjusting antenna resonance frequency and impedance matching. A rectangular parallelepiped dielectric block; A radiation electrode formed on an upper surface of the dielectric block to have a predetermined area and determining a transmission / reception frequency band of the antenna; A matching electrode formed in a "b" shape on the front surface of the dielectric block so as not to be in direct contact with the radiation electrode; And A WLAN antenna, which is formed over a rear surface and a lower surface of the dielectric block, and has one end connected to the radiation electrode, the other end connected to the matching electrode, and a feeding electrode having a feeding point formed on an electrode formed on the bottom surface. A printed circuit board on which a plurality of semiconductor chips and devices are mounted to process a WLAN signal; And A radiating electrode having a predetermined area on a top surface of a rectangular parallelepiped dielectric block having a predetermined area is determined, and a matching electrode of an open stub is printed on the front surface of the dielectric block so as not to be in direct contact with the radiating electrode. The first and second antennas are mounted on the printed circuit board so that the feeding electrodes connected to the matching electrodes are printed on one end of the radiation electrode and the other end of the dielectric block. Including, A wireless LAN card capable of adjusting impedance matching by adjusting a feeding point on a feeding electrode when mounted on a printed circuit board in the first and second antennas. A printed circuit board on which a plurality of semiconductor chips and devices are mounted to process a WLAN signal; An antenna support member fixed at a predetermined height from a substrate at a predetermined position of the printed circuit board; And A radiation electrode having a predetermined area and having a transmission / reception frequency band of the antenna determined, a matching electrode having one or more open stubs, one end of which is connected to the radiation electrode and the other end of which is connected to the matching electrode, at an arbitrary position on the electrode A feeding electrode having a feeding point to which a current is applied, and each of the radiation electrodes is supported to be perpendicular to each other by the antenna supporting member, and the feeding electrode is connected to the first and second antennas soldered to a predetermined position on the printed circuit board. Include, A wireless LAN card capable of adjusting impedance matching by adjusting a feeding point on a feeding electrode when mounted on a printed circuit board in the first and second antennas.

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