KR20070068182A - Antenna system for multi band - Google Patents

Abstract

A multi-band antenna system is provided to enhance the operation performance of the antenna at respective frequency bands by tuning a resonance frequency at a communication frequency. A multi-band antenna system includes a resonance frequency selector(10), a switching unit(20), and a high-frequency selector(30). The resonance frequency selector tunes the resonance frequency of the antenna to a communication frequency band by controlling first and second frequency select signals. The first frequency select signal is used to select one of high and low frequency bands. The second frequency select signal is used to select one of finely-tuned high frequency bands. The switching unit selects one of the high and low frequency bands based on the first frequency select signal. When the high frequency band is selected, the high-frequency selector manipulates antenna conductors to adjust a length of the antenna based on the second frequency select signal such that one of the finely-tuned high frequency bands is selected.

Description

Antenna system for multi-band {ANTENNA SYSTEM FOR MULTI BAND}

1 is a circuit diagram of a conventional antenna.

2 is a view showing the structure of the intenna.

3 is a view showing the operation characteristics of the conventional antenna.

4 and 5 schematically show the configuration of the multi-band antenna system according to an embodiment of the present invention.

6 is a diagram illustrating an antenna operating characteristic when a low frequency band is selected according to the present invention.

FIG. 7 is a diagram illustrating an antenna operation characteristic when a DCS band of a high frequency band is selected according to the present invention.

FIG. 8 is a diagram illustrating an antenna operation characteristic when a PCS band of a high frequency band is selected according to the present invention.

FIG. 9 is a diagram illustrating an antenna operation characteristic when a UMTS band of a high frequency band is selected according to the present invention.

*** Explanation of symbols for the main parts of the drawing ***

10. resonant frequency selection control unit, 20. switching unit, 30. high frequency band selection unit,

31. antenna connecting plate, 32. lever, 33. pedestal,

34. spring, 35. protruding member, 36. stepping motor

The present invention relates to a multi-band antenna system, and more particularly, to a multi-band antenna system to enable the resonance frequency of the antenna to match the current call band.

Currently, there is a growing number of terminals using multiple bands instead of single bands in the global telecommunications market. In other words, the transition from 2G to 3G adds 3G band to the existing 2G system, while the frequency of multiple bands is included in one terminal such as Bluetooth and GPS.

As described above, the characteristics of an antenna are important in a terminal using multiple bands. Since the antennas need to cover several bands with one antenna, they do not exhibit the same characteristics in all bands and the characteristics of the antennas are deteriorated in a specific frequency band. have.

1 is a circuit diagram of a conventional antenna and has a structure in which a signal path is determined to an antenna through an antenna switch module (ASM) and an RF mobile connector.

Figure 2 is a road showing the structure of the antenna, consisting of a micro strip (Intena) in the form of a micro strip covering both low and high frequencies, GSM (Global System for Mobile communication), DCS (Digital Cordless System), PCS (Personal) In the terminal using all 4 bands of communication system (UMTS) and universal mobile telecommunication system (UMTS), two poles (two resonance points) covering the low frequency coverage (GSM900) band and the high frequency coverage (DCS1800, PCS1900, UMTS2100) band Structure).

3 shows that one resonance point is generated in the GSM900 region on the road showing the operation characteristics of the conventional antenna, and a resonance frequency broadly generated in the DCS1800, PCS1900, and UMTS2100 is generated. This is because of parasitic components. Such an antenna is a PIAR (Planar Inverted F Antenna) type, and one port is connected to a feed point of GND and the other is provided with two ports.

As described above, the conventional antenna is a fixed antenna having a fixed resonance point, and exhibits good characteristics in a single band, but is multiband in three bands or four bands selected by ASM or FEM (Front End Module). There is a problem in that it is not possible to exhibit the full-range even characteristics. In other words, when one characteristic of a band is matched, it has a characteristic of a trade off type which loses in another band.

The present invention has been made to solve the above-described problem, by selecting any one of a low frequency band and a high frequency band using a switch, when the high frequency band is selected by varying the antenna length, the resonance point in the operating frequency band An object of the present invention is to provide an antenna system for a multi-band to be able to fit.

An antenna system for a multi-band according to an embodiment of the present invention for achieving the above object, the first frequency selection signal for selecting any one of a low frequency band and a high frequency band, and any one band of a high frequency band divided A resonant frequency selection controller for controlling a second frequency selection signal for selecting a signal to match the resonant frequency of the antenna to the talk frequency band; A switching unit for selecting any one of a low frequency band and a high frequency band based on the first frequency selection signal applied from the resonance frequency selection controller; When the high frequency band is selected by the switching unit, the antenna lengths are varied by connecting or disconnecting the antenna conductors separated from each other according to the second frequency selection signal applied from the resonance frequency selection control unit. It is preferable to comprise a high frequency band selecting section for selecting any one of the bands to match the resonant frequency.

Furthermore, the high frequency band selector is located between the separated antenna conductors and connects the separated antenna conductors to each other according to whether the two antenna conductors are separated from each other, or the connected antenna conductors. An antenna connecting plate for varying the antenna length by releasing the connection; An antenna connecting plate driver for contacting the antenna connecting plate with the antenna conductor or releasing contact of the antenna connecting plate in contact with the antenna conductor according to the second frequency selection signal applied from the resonance frequency selecting control unit; It is preferable to make.

In addition, the antenna connecting plate is preferably installed on one side of the lever to support the bar (bar) at a certain point to be able to rotate around the support point.

The antenna connecting plate driver may include a spring installed on the other side of the lever and pulling the other side of the lever in the opposite direction to the installation of the pedestal so that the antenna connecting plate installed on one side of the lever is in contact with the antenna conductor. ; An elliptic protrusion member having a radius difference is provided, wherein the protrusion member is rotated by a predetermined angle according to a second frequency selection signal applied from the resonance frequency selection controller, and the long axis of the protrusion member is rotated according to the rotation of the protrusion member. When the longitudinal axis is formed, it is preferable that a stepping motor is provided to release the contact between the antenna connecting plate and the antenna conductor by tensioning the spring while pressing the other axis of the lever.

The number of the second frequency selection signals is preferably varied according to the number of the high frequency bands.

In addition, the number of the antenna connecting plate and the antenna connecting plate driver is preferably varied according to the number of the high-frequency band is subdivided.

Hereinafter, a multi-band antenna system according to a preferred embodiment of the present invention with reference to the accompanying drawings will be described in detail.

Prior to the description of the present invention, in order to implement the present invention, the antenna conductor covering the high frequency band should be separated into three.

4 and 5 are diagrams schematically showing the configuration of the multi-band antenna system according to an embodiment of the present invention, Figure 4 is a diagram showing the electrical configuration of the multi-band antenna system according to the present invention, Figure 5 4 is a front view and a side view of the high frequency band selection unit of FIG. 4.

4 and 5, the multi-band antenna system according to an embodiment of the present invention, the resonance frequency selection control unit 10, the switching unit 20, the first antenna connecting plate 31a, It is provided with a high frequency band selector 30 composed of a second antenna connecting plate 31b, a first spring 34a, a second spring 34b, a first stepping motor 36a, and a second stepping motor 36b. Is done.

In such a configuration, the resonant frequency selection control unit 10 may include any one of a first antenna control signal (Antenna Control 1) for selecting one of a low frequency band and a high frequency band, a DCS band that is a high frequency band, a PCS band, and a UMTS band. The second antenna control signal (Antenna Control 2) and the third antenna control signal (Antenna Control 3) for selecting one band are controlled to adjust the resonance frequency of the antenna to the current talk frequency band. That is, by controlling the first antenna control signal (Antenna Control 1) applied to the switching unit 20 to select any one of the low frequency band and high frequency band to match the resonant frequency, the high frequency band is selected by the first antenna control signal In this case, the second antenna control signal (Antenna Control 2) and the third antenna control signal (Antenna Control 3) applied to the first and second stepping motor 36b are again controlled to control the high frequency band of the DCS band and the PCS band. In this case, one of the UMTS bands is selected to adjust the resonant frequency.

In order for the resonance frequency selection control unit 10 to adjust the resonance frequency of the antenna to the current talk frequency band, the first antenna control signal (Antenna Control 1), the second antenna control signal (Antenna Control 2) and the third antenna control signal (Antenna Control) The state of the signal applied to 3) is shown in Table 1.

First antenna control signal Second antenna control signal 3rd antenna control signal GSM L L H DCS H L L PCS H L H UMTS H H H

As described above, the resonance frequency selection control unit 10 may be made of ASM or FEM.

The switching unit 20 selects one of a high frequency band and a low frequency band based on the first antenna control signal applied from the resonance frequency selection control unit 10, and has a low level first antenna from the resonance frequency selection control unit 10. When a control signal is applied, a low frequency band is selected, and when a high level first antenna control signal is applied, a high frequency band is selected.

As described above, when the low frequency band is selected, the high frequency band is ignored and only the GSM900 band is in charge. On the contrary, when the high frequency band is selected, the low frequency band is ignored and the high frequency band (DCS band, PCS band, UMTS band) is in charge.

As described above, the switching unit 20 may be implemented with a PIN diode.

Meanwhile, as shown in FIG. 5, the first antenna connecting plate 31a and the second antenna connecting plate 31b are located between three separate antenna conductors, and are in contact with two separated antenna conductors. The antenna length is varied by connecting the separated antenna conductors to each other or by disconnecting the connected antenna conductors.

Each of the antenna connecting plates 31a and 31b described above is provided at one side of the lever 32 that supports the bar at a certain point and rotates about the supporting point, and is provided on the other side of the lever 32. The elliptical protrusion members 35a and 35b of the stepping motors 36a and 36b provided are in contact with the antenna conductor or are released from the contact.

The first spring 34a and the second spring 34b are provided on the other side of the lever 32 to which the first antenna connecting plate 31a and the second antenna connecting plate 31b are respectively connected, and each lever 32 The other side of each lever 32 is pulled in the opposite direction to the installation of the pedestal 33 so that each antenna connecting plate 31a, 31b provided at one side of the c) can contact the antenna conductor.

The first stepping motor 36a and the second stepping motor 36b are springs 34a provided on the other side of the lever 32 by pressing the other side of the lever 32 downward when the major axis forms a vertical axis due to the radial difference. And an elliptic protruding member 35a or 35b for tensioning 34b, and having an elliptic shape by a predetermined angle according to the second antenna control signal and the third antenna control signal applied from the resonance frequency selection control unit 10. The protruding members 35a and 35b are rotated.

The first stepping motor 36a and the second stepping motor 36b described above have an elliptic protrusion only when there is a change in the second antenna control signal and the third antenna control signal applied from the resonance frequency selection controller 10. The members 35a and 35b are rotated by a predetermined angle, for example 90 °. For example, when the mode of the mobile communication terminal is switched from the DCS mode to the PCS mode, the second antenna control signal applied to the first stepping motor 36a by the resonant frequency selection controller 10 is at a low level based on Table 1. And the third antenna control signal applied to the second stepping motor 36b is changed from the low level to the high level, and the first stepping motor (which is supplied with the low level signal in the PCS mode as in the DCS mode) Since 36a) does not perform the rotation operation, the long axis of the protruding member 35a continues to form the horizontal axis, and the first antenna connecting plate 31a contacts the antenna conductors to connect the antenna conductors separated from each other.

On the other hand, the second stepping motor 36b, which receives the low level signal and receives the high level signal, rotates the elliptical protrusion member 35b by 90 ° according to the change of the supplied control signal. Let's go. Accordingly, while the major axis of the elliptic protrusion member 35b provided in the second stepping motor 36b forms a vertical axis, the other axis of the lever 32 is pressed downward, and the first axis installed on one side of the lever 32 is provided. The two antenna connecting plate 31b is released from contact with the antenna conductor.

As described above, as the contact between the second antenna connecting plate 31b and the antenna conductor is released, two antenna conductors connected by the second antenna connecting plate 31b are separated and the length of the antenna is shorter than that of the DCS. You lose.

Hereinafter, an operation of a multi band antenna system according to an embodiment of the present invention will be described with reference to FIGS. 4 and 5.

First, when the mobile communication terminal mode is the GSM mode, the resonant frequency selection control unit 10 applies the low level first antenna control signal to the switching unit 20 to select the low frequency band. At this time, since the high frequency band is ignored, the second and third antenna control signals output to the first and second stepping motors 36a and 36b have no meaning.

FIG. 6 is a diagram illustrating an antenna operation characteristic when a low frequency band is selected in accordance with the present invention. In comparison with the prior art (see FIG. 3), the SWR (Standing Wave Ratio) characteristic is improved in the GSM900 band, and a broadband band is also used. It can be seen that the characteristics of.

On the other hand, when the mobile communication terminal mode is the DCS mode, the resonant frequency selection control unit 10 applies a high level first antenna control signal to the switching unit 20 to select a high frequency band, and to select a DCS band among the high frequency bands. In accordance with Table 1, the low level second antenna control signal is applied to the first stepping motor 36a and the low level third antenna control signal to the second stepping motor 36b.

As described above, in the first stepping motor 36a which receives the low level second antenna control signal from the resonance frequency selection control unit 10, the long axis of the protruding member 35a forms a horizontal axis, and the low level third antenna In the second stepping motor 36b receiving the control signal, the long axis of the protruding member 35b forms a horizontal axis so that both the first antenna connecting plate 31a and the second antenna connecting plate 31b come into contact with the antenna conductor. , The antenna is in the longest state. Accordingly, the resonant frequency is adjusted to the DCS band having the lowest frequency band even in the high frequency band.

FIG. 7 is a diagram illustrating an antenna operating characteristic when the DCS band of the high frequency band is selected according to the present invention, and it can be seen that the SWR characteristic is improved in the DCS1800 band as compared with the related art (see FIG. 3).

On the other hand, if the mobile communication short mode is the PCS mode, the resonant frequency selection control unit 10 applies a high level first antenna control signal to the switching unit 20 to select a high frequency band, according to Table 1 the first stepping motor A low level second antenna control signal is applied to the second stepping motor 36b at 36a.

As described above, in the first stepping motor 36a receiving the low level second antenna control signal from the resonance frequency selection control unit 10, the long axis of the protruding member 35a forms a horizontal axis, and the high level third antenna The second stepping motor 36b receiving the control signal also has a long axis of the protruding member 35b such that the first antenna connecting plate 31a is in contact with the antenna conductor, and the second antenna connecting plate 31b is The contact with the antenna conductor is released, which causes the resonance frequency to match the PCS band.

FIG. 8 is a diagram illustrating an antenna operation characteristic when the PCS band of the high frequency band is selected according to the present invention, and it can be seen that the SWR characteristic is improved in the PCS1900 band compared to the conventional (see FIG. 3).

On the other hand, if the mobile communication short mode is the UMTS mode, the resonant frequency selection control unit 10 applies a high level first antenna control signal to the switching unit 20 to select a high frequency band, according to Table 1 the first stepping motor At 36a, the high level second antenna control signal is applied to the second stepping motor 36b at the high level third antenna control signal.

As described above, in the first stepping motor 36a receiving the high level second antenna control signal from the resonance frequency selection control unit 10, the long axis of the protruding member 35a forms a vertical axis, and the high level third antenna In the second stepping motor 36b receiving the control signal, the long axis of the protruding member 35b forms a vertical axis so that both the first antenna connecting plate 31a and the second antenna connecting plate 31b release contact with the antenna conductor. The antenna is in the shortest state. Accordingly, the resonant frequency is matched to the UMTS band having the highest frequency band.

FIG. 9 is a diagram illustrating an antenna operation characteristic when the UMTS band of the high frequency band is selected according to the present invention, and it can be seen that the SWR characteristic is improved in the UMTS2100 band compared to the conventional (see FIG. 3).

The multi-band antenna system of the present invention is not limited to the above-described embodiments, and may be variously modified and implemented within the range allowed by the technical idea of the present invention.

According to the multi-band antenna system according to the present invention as described above, one of the low frequency band and the high frequency band is selected by using a switch, and when the high frequency band is selected, the antenna length is varied to talk the resonance frequency. By adjusting to the frequency, it is possible to improve the antenna characteristics in each frequency band.

Claims (6)

The first frequency selection signal for selecting any one of the low frequency band and the high frequency band and the second frequency selection signal for selecting any one of the subdivided high frequency bands are controlled to convert the resonance frequency of the antenna into the talk frequency band. A resonance frequency selection control unit for matching; A switching unit for selecting any one of a low frequency band and a high frequency band based on the first frequency selection signal applied from the resonance frequency selection controller; When the high frequency band is selected by the switching unit, the antenna lengths are varied by connecting or disconnecting the antenna conductors separated from each other according to the second frequency selection signal applied from the resonance frequency selection control unit. An antenna system for a multi-band comprising a high frequency band selection unit for selecting any one of the bands to match the resonant frequency. The method of claim 1, wherein the high frequency band selection unit, Located between the separated antenna conductors, the antenna length is varied by connecting the separated antenna conductors to each other or by disconnecting the connected antenna conductors according to whether the two antenna conductors are in contact with each other. An antenna connecting plate; An antenna connecting plate driver for contacting the antenna connecting plate with the antenna conductor or releasing contact of the antenna connecting plate in contact with the antenna conductor according to the second frequency selection signal applied from the resonance frequency selecting control unit; Multi-band antenna system, characterized in that made. The method of claim 2, wherein the antenna connecting plate, A multi-band antenna system, characterized in that it is installed on one side of the lever to support the bar (bar) at a certain point to rotate around the support point. The method of claim 2, wherein the antenna connecting plate driver, A spring installed on the other side of the lever and pulling the other side of the lever in the opposite direction to the installation of the pedestal so that the antenna connecting plate installed on one side of the lever is in contact with the antenna conductor; An elliptic protrusion member having a radius difference is provided, wherein the protrusion member is rotated by a predetermined angle according to a second frequency selection signal applied from the resonance frequency selection controller, and the long axis of the protrusion member is rotated according to the rotation of the protrusion member. When the vertical axis is formed, a stepping motor for tensioning the spring while pressing the other axis of the lever down to release the contact between the antenna connecting plate and the antenna conductor. The method of claim 1, wherein the number of the second frequency selection signal is And the high frequency band is varied according to the number of subdivisions. The method of claim 2, wherein the antenna connecting plate and the number of the antenna connecting plate driver, And the high frequency band is varied according to the number of subdivisions.

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