JP3104150U - Multiband monopole antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To support a plurality of frequency bands with a simple configuration.
A first element and a second element are both connected to a common element and can receive power from a power supply unit. As an example, the first element 4 and the second element 5 are linearly connected to each other and extend in different horizontal directions. In addition, by providing a curved or bent portion in the first and second elements 4 and 5, the shape of the monopole antenna 10 may be adapted to the shape of the housing of the terminal device. Further, the first element 4 and the second element 5 may be connected at a predetermined angle, for example, connected at a right angle to each other.
[Selection diagram] Fig. 1

Description

  The present invention relates to a multi-band monopole antenna that can be shared for a plurality of frequency bands.

  Strip antennas having a plurality of resonance frequency characteristics have been proposed as antennas for adapting to the increasing use of frequency bands with the diversification of wireless communication systems (for example, Yusuke Ukawa, “Dielectric Research on Multi-Frequency Strip Antenna Printed on Substrate ", [online], September 13, 2002, Tokai University, Faculty of Engineering, Research Committee on Electrical Engineering, [Search on March 17, 2004], Internet <http http://www.denkikei.u-tokai.ac.jp/yokou02%5CA%5CA2.pdf>, hereinafter referred to as “Non-Patent Document 1”).

  Further, in order to mount a plurality of quarter-wave monopole antennas having different resonance frequencies from each other, it is conceivable to arrange helical coils having different coil diameters and coil lengths on concentric circles. No. 6288681).

  In the technique described in Non-Patent Document 1, antenna elements are separately arranged on a dielectric substrate. For this reason, the antenna element has to be arranged on a substrate such as a dielectric substrate, and there has been a problem that design restrictions are increased.

  Further, when a plurality of helical coils having mutually different coil diameters and coil lengths are arranged on concentric circles, interference occurs between the coils. Such interference is difficult to predict at the design stage, and there is a problem that the performance is degraded due to the interference.

  The present invention has been made in view of the above situation, and has as its object to provide a multi-band monopole antenna that can be shared with a plurality of frequency bands with a simple configuration and that can be easily designed. .

  In order to achieve the above object, a multi-band monopole antenna according to a first aspect of the present invention has a power supply end for receiving power from a wireless communication system, a common element for transmitting a radio frequency signal, and a first element. A first element having one end connected to the common element and an open end at the other end, a second line length different from the first line length, and one end connected to the common element. And a second element, the other end of which is open, and at a connection portion between the first and second elements and the common element, a straight line is provided between the first element and the second element. Connected.

  According to such a configuration, the antenna can be shared for a plurality of frequency bands, for example, two different frequency bands. In addition, since both the first and second elements can be connected to the common element and receive power from the power supply end, it is possible to cope with a plurality of frequency bands with a simple configuration, thereby reducing the mounting area and the device. Can be reduced in size. Since the first and second elements are linearly connected to each other, interference generated between the elements can be suppressed, and the difficulty in designing can be eliminated.

  The common element may extend vertically upward from the power supply end, and the first and second elements may extend in different horizontal directions.

  At least one of the first and second elements may have a curved or bent portion.

  At least one of the first and second elements may be formed in a meander shape.

  At least one of the first and second elements may be arranged at least partially on the surface or inside of a substrate made of a dielectric material.

  A multiband monopole antenna according to a second aspect of the present invention has a feeding end receiving power from a wireless communication system, has a common element for transmitting a radio frequency signal, has a first line length, and has one end. Is connected to the common element, has a first element whose other end is open, a second line length different from the first line length, one end is connected to the common element, and the other end is open A second element, wherein at a connection portion between the first and second elements and the common element, the first element and the second element are connected at a right angle. I do.

  According to the present invention, it is possible to support a plurality of frequency bands with a simple configuration. In addition, it is possible to eliminate difficulty in designing.

  Hereinafter, a multi-band monopole antenna according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration example of a monopole antenna 10 corresponding to a multi-band as one embodiment of the present invention. As shown in FIG. 1, the monopole antenna 10 includes a plane conductor ground plane (ground plane) 1, a feeding unit 2, a common element 3, and first and second elements 4 and 5.

  The ground plane 1 is a planar conductor plate having a predetermined shape, for example, a rectangle. The power supply unit 2 is disposed at one end of the common element 3 and includes a center conductor 2A and an insulator 2B formed coaxially with the center conductor 2A between the center conductor 2A and the ground plane 1. Is done. For example, the power supply unit 2 is connected to a wireless communication system, receives power, and transmits a radio frequency (RF) signal.

  The common element 3 is connected to the first and second elements 4 and 5 at the other end different from the one end where the power supply unit 2 is arranged. For example, the common element 3 extends vertically upward with the power supply unit 2 as a lower end. The first and second elements 4 and 5 are linearly connected between the first element 4 and the second element 5 at a connection portion with the common element 3. For example, the first and second elements 4 and 5 extend in different horizontal directions in the monopole antenna 10. The other end of the first and second elements 4 and 5, which is different from the one end connected to the common element 3, is open. The first and second elements 4 and 5 have different line lengths corresponding to a frequency band used in a wireless communication system to which the monopole antenna 10 is connected.

  As a specific example, the line length of the common element 3 is 18 mm (millimeter), and the line lengths of the first and second elements 4 and 5 are 40 mm and 55 mm, respectively. In this case, resonance occurs in the 1.5 GHz band which is a band used by the GPS (Global Positioning System) due to the path length of the common element 3 and the first element 4. Also, due to the path length of the common element 3 and the second element 5, resonance occurs in the 900 MHz band which is a band used by the cellular system for mobile telephone devices. FIG. 2 shows the impedance characteristics of the monopole antenna 10 having the configuration shown in FIG.

  Due to such characteristics of the monopole antenna 10, the monopole antenna 10 can be shared for a plurality of frequency bands, for example, two different frequency bands. Further, since both the first and second elements 4 and 5 are connected to the common element 3 and can receive power from the power supply unit 2, even when the first and second elements 4 and 5 are shared corresponding to a plurality of frequency bands. The power supply circuit in the wireless communication system can be configured with a single circuit, and can support a plurality of frequency bands with a simple configuration. Further, by disposing the common element 3 as a configuration that can be shared corresponding to a plurality of frequency bands, the overall mounting area can be reduced, and the device can be downsized. In addition, since the first element 4 and the second element 5 are linearly connected to each other and extend in different horizontal directions, it is possible to suppress interference occurring between the elements, and to obtain antenna characteristics due to mutual interference. Thus, it is possible to reduce the difference between the design value and the actually measured value, thereby eliminating the difficulty of the design.

  FIG. 3 is a diagram illustrating an example of a specific configuration in a case where the monopole antenna 10 is applied to a mobile communication terminal such as a mobile telephone device. Here, FIG. 3A is a front view of the monopole antenna 10, and FIG. 3B is a left side view of the monopole antenna 10.

  When mounted on a mobile communication terminal, by adapting the shape of the monopole antenna 10 to the shape of the housing of the terminal device, it becomes possible to mount the monopole antenna 10 inside the terminal. Can be achieved. Therefore, for example, as shown in FIG. 3, by providing curved or bent portions in the first and second elements 4 and 5, the shape of the monopole antenna 10 is adapted to the housing shape of the terminal device, and Enable implementation to In the example shown in FIG. 3, one bending portion 4A and one bending portion 4B are formed in the first element 4, and one bending portion 5A is formed in the second element 5. FIG. 4 shows the impedance characteristics of the monopole antenna 10 configured as shown in FIG. According to the impedance characteristics shown in FIG. 4, it can be seen that the monopole antenna 10 configured as shown in FIG. 3 has resonance frequencies around 870 MHz and 1.6 GHz.

  As described above, according to the present invention, the monopole antenna 10 having a simple configuration can be shared for a plurality of frequency bands. Further, since the first and second elements 4 and 5 are linearly connected to each other at the connection portion with the common element 3 and extend in different horizontal directions, it is possible to suppress interference between the respective elements. And the difficulty of design can be eliminated.

  The present invention is not limited to the above embodiment, and various modifications and applications are possible. For example, at least one of the first and second elements 4 and 5 may be formed in a meander shape. FIG. 5 shows an example in which both the first and second elements 4 and 5 are formed in a meander shape.

  In at least one of the first and second elements 4 and 5, part or all of the element conductors may be arranged on the surface or inside the base made of a dielectric material. In this case, the propagation speed of the electromagnetic wave becomes slow inside the dielectric material and on the surface of the dielectric material, and the wavelength is shortened. Thereby, the effective line length of the first and second elements 4 and 5 can be reduced, and the entire monopole antenna 10 can be further reduced in size. FIG. 6 shows an example in which both the first and second elements 4 and 5 are disposed on the surfaces of the bases 41 and 51 each partially made of a dielectric material. FIG. 7 shows an example in which the entire first and second elements 4 and 5 are disposed inside a base 61 made of a dielectric material.

  Here, the substrate made of a dielectric material may be formed in a plate shape, or may be formed by inserting one of the first and second elements 4 and 5 into a hollow portion formed in a rod shape. It may be something. Further, a film made of a dielectric material may be formed on at least one of the first and second elements 4 and 5. Further, as a dielectric material used as the base, barium oxide, aluminum oxide, those containing silica as a main component, for example, lead oxide, lead oxide glass containing boron oxide, bismuth oxide, zinc oxide, boron oxide, Bismuth oxide glass or the like containing calcium oxide, or a high dielectric constant resin such as an epoxy resin containing a dielectric filler, a phenoxy resin, a phenol resin, a vinyl ester resin, or the like, and titanium oxide and neodymium oxide may be used. A dielectric material having a main component, a magnetic material having nickel, cobalt, or iron as a main component, or a combination of a dielectric material and a magnetic material may be used.

  In the above-described embodiment, the connection between the first and second elements 4 and 5 and the common element 3 is described as being linearly connected between the first and second elements 4 and 5. However, the present invention is not limited to this, and the first and second elements 4, 5 are connected at a predetermined angle, for example, the first element 4 and the second element 5 are connected at a right angle. May be done.

  FIG. 8 shows an example of a configuration in which the first element 4 and the second element 5 are connected at a right angle at the connection between the first and second elements 4 and 5 and the common element 3. Here, FIG. 8A is a front view of the monopole antenna 10, FIG. 8B is a top view of the monopole antenna 10, and FIG. It is the perspective view seen.

  That is, the first and second elements 4 and 5 only need to be connected to the common element 3 in an arbitrary arrangement while considering the degree of interference generated between the elements.

FIG. 3 is a diagram illustrating a configuration example of a monopole antenna according to an embodiment of the present invention. FIG. 2 is a diagram illustrating impedance characteristics of the monopole antenna illustrated in FIG. 1. FIG. 9 is a diagram illustrating an example of a specific configuration when a monopole antenna is applied to a mobile communication terminal. FIG. 4 is a diagram illustrating impedance characteristics of a monopole antenna configured as shown in FIG. 3. It is a figure showing an example in which both the 1st and the 2nd element were formed in meandering. FIG. 4 is a view showing an example in which both of the first and second elements are arranged on the surface of a base partially made of a dielectric material. FIG. 4 is a diagram showing an example in which the entire first and second elements are arranged inside a base made of a dielectric material. It is a figure showing an example of 1 composition where the 1st and the 2nd element were connected at right angles.

Explanation of reference numerals

  DESCRIPTION OF SYMBOLS 1 ... Planar conductor ground plane (ground plane), 2 ... Power supply part, 2A ... Central conductor, 2B ... Insulator, 3 ... Common element, 4 ... First element, 5 ... Second element, 10 ... Monopole antenna, 41 ... Substrate, 51: Substrate, 61: Substrate

Claims (6)

A common element having a power supply end for receiving power supply from the wireless communication system and transmitting a radio frequency signal,
A first element having a first line length, one end connected to the common element, and the other end open;
A second element having a second line length different from the first line length, one end of which is connected to the common element, and the other end of which is open;
At a connection portion between the first and second elements and the common element, the first element and the second element are linearly connected,
A multi-band monopole antenna, characterized in that: The common element extends vertically upward from the power supply end,
The first and second elements extend in different horizontal directions from each other,
The multi-band monopole antenna according to claim 1, wherein: At least one of the first and second elements has a curved or bent portion,
The multi-band monopole antenna according to claim 1 or 2, wherein: At least one of the first and second elements is formed in a meander shape.
The multiband monopole antenna according to claim 1, 2 or 3, wherein: In at least one of the first and second elements, at least a part is disposed on a surface or inside a base made of a dielectric material.
The multi-band monopole antenna according to any one of claims 1 to 4, wherein: A common element having a power supply end for receiving power supply from the wireless communication system and transmitting a radio frequency signal,
A first element having a first line length, one end connected to the common element, and the other end open;
A second element having a second line length different from the first line length, one end of which is connected to the common element, and the other end of which is open;
At a connection portion between the first and second elements and the common element, the first element and the second element are connected at a right angle,
A multi-band monopole antenna, characterized in that:

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