KR20030008613A - Short antenna element with broadband and antenna using the same - Google Patents

Abstract

PURPOSE: A broadband shortened antenna element and antenna using the same is provided to reduce weight and size of the antenna element, while preventing deterioration of antenna efficiency at the grounding surface. CONSTITUTION: A broadband shortened antenna element comprises a top-shaped member(201) formed of a conductor, and which has a lower end disposed at a feeder(204) of a co-axial connector arranged at a grounding surface(205); a central member(202) arranged upright onto the top-shaped member, and which has a diameter smaller than the diameter of the top-shaped member and is formed of a conductor; an end cap member(203) arranged at the top of the central member and formed of a conductor having a diameter larger than the diameter of the central member. The end cap member forms a resonance frequency at the state where the electrical length of the end cap member is short.

Description

Broadband shortened antenna element and antenna using same {SHORT ANTENNA ELEMENT WITH BROADBAND AND ANTENNA USING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wideband antenna, and more particularly, to a wideband shortened antenna element having an electrically small length and thickness while maintaining widebandability and an antenna using the same.

In general, in a wireless device that must have a thinner and smaller structure, such as an antenna for a mobile phone or an antenna for an earthquake prevention device for wireless theft, development of an antenna element having a small length and a thickness is a very important problem. As an antenna element applied to a conventional monopole antenna or dipole antenna, a linear antenna element having a constant length and thickness, a tunable antenna element that can be freely adjusted for a length that is frequently used for a vehicle or a radio, and an end of the head An end cap element with a conductor, an element for a sleeve antenna having a wide cylindrical shape by placing a thick cylindrical conductor inside a cylindrical pipe conductor, and the like are used.

Since the sleeve antenna has to be manufactured by putting a thick cylindrical conductor inside the cylindrical pipe conductor, there is a problem in that there is always a difficulty in manufacturing, and to produce a monopole antenna using a straight element and a tunable antenna element having the above-described length and thickness. In this case, the length and diameter are increased because the length close to the quarter wavelength of the used radio wave must be maintained.

1 is a front view of a conventional head antenna element capable of operating with a length shorter than a quarter wavelength of a used radio wave.

As shown in Fig. 1, the conventional head antenna element has a structure in which the head conductor 101 is attached to the top of the center element 102 connected to the feeder. That is, when the diameter of the head conductor 102 is formed to be larger than the diameter of the center conductor 102 by a predetermined ratio (about 2 times or more), the resonant frequency characteristics are less than 1/4 wavelength of the used electric wave. All. However, since the broadband characteristics are determined by the radius of the center conductor 102 rather than the diameter of the shoulder conductor 101, in order to have broadband characteristics, as in the conventional shoulder antenna element shown in FIG. ) Has to be thickened, and accordingly, there was a problem that the radius of the head conductor 101 should be increased by a corresponding amount.

In addition, when the conventional antennas are mounted on a mobile phone having a thin thickness, it is difficult to secure an image plane of the antenna element, which causes a problem that the antenna radiation efficiency is extremely reduced.

Accordingly, an object of the present invention is to provide a broadband shortened antenna element which can maintain a wide bandwidth while having a small size in electrical length and thickness to solve the above problems.

Another object of the present invention is to provide an antenna that, when mounted on a mobile phone, maintains a high radiation efficiency of the antenna even when mounted on a thinner mobile phone, and reduces radio wave absorption (SAR) induced in the head of the human body. There is this.

1 is a front view showing a conventional broadband antenna.

2A and 2B are a perspective view and a front view showing one embodiment configuration of a broadband shortened antenna element according to the present invention;

Figures 3a to 3c is a perspective view, a side cross-sectional view and a front sectional view showing a state where the broadband shortened antenna according to the present invention is applied to a flip-type mobile phone.

Figure 4 is an exploded perspective view showing an example of implementing the SAR reduction and the ground plane secured by mounting the broadband shortened antenna element directly to the PCB of the flip-type mobile phone according to the present invention.

Figures 5a to 5c is a perspective view, a side cross-sectional view and a front sectional view showing a state where the broadband shortened antenna according to the present invention is applied to a clamshell mobile phone.

Figure 6 is an exploded perspective view showing an example of implementing the SAR reduction and the ground plane secured by mounting the broadband shortened antenna element directly to the PCB of the clamshell mobile phone according to the present invention.

* Explanation of symbols for main parts of the drawings

201: top element 202: center element

203: head element 204: coaxial connector feed part

205: element ground plane

In order to achieve the above object, the present invention is a top-shaped member made of a conductor, the lower end is disposed on the feed side of the ground plane to have a broadband characteristics; A center member provided upward from the top of the top member and having a diameter smaller than that of the top member, the center member including a conductor; And provided on the top of the center material, and consists of a conductor having a diameter larger than the diameter of the center material provides a shortened antenna element comprising a head member so that the resonant frequency appears even in a short electrical length.

In addition, the present invention is a top-shaped member made of a conductor, the lower end is disposed on the feed side of the ground plane to have a broadband characteristics; A center member provided upward from the top of the top member and having a diameter smaller than that of the top member, the center member including a conductor; And a head member provided at an upper end of the center member, the conductor having a diameter greater than the diameter of the center member, so that a resonant frequency appears even in a state in which the electrical length is short. It is disposed in a position adjacent to at least one side of the front and rear of the provided circuit board, the head member provides a wide band shortened antenna, characterized in that disposed outside the side end of the circuit board.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2a is a perspective view showing an embodiment configuration of a broadband shortened element according to the present invention, Figure 2b is a sectional view thereof.

2A and 2B, the broadband shortened element of the present invention is made of a conductor such as copper, brass, aluminum, iron, and the like, and has a top member 201 for having broadband characteristics; The center member 202 is formed upright on the top surface of the top member 201, having a diameter smaller than the diameter of the top member 201, made of a conductor such as copper, brass, aluminum, iron, etc. Wow; It is provided on the upper end of the core member 202, and is composed of a head member 203 made of copper, brass, aluminum, iron, etc. so that the resonance frequency appears even in a short electrical length.

Here, the lower end of the top member 201 is in contact with the coaxial connector feeding portion 204 provided on the ground surface 205.

In addition, the top-shaped member 201, the center member 202 and the head member 203 are screwed to enable separation and coupling to each other. Accordingly, the length of the core member 202 is variable to adjust the resonant frequency.

In addition, the top-shaped member 201 and the center member 202 are integrated with each other, and the head member 203 and the center member 202 are screwed together, or the head member 203 and the center member 202 are screwed together. The top member 201 and the center member 202 may be screwed together so that the length of the center member 203 is variable.

Referring to the state of use of the broadband shortened antenna element according to the present invention configured as described above are as follows.

3A to 3C are perspective, sectional and front sectional views showing an example in which the wideband shortened antenna element of the present invention is used as a monopole antenna and applied to a flip phone.

As shown in Figs. 3A to 3C, when the antenna element of the present invention is used as a monopole antenna, the top of the coaxial connector feeder 204 is provided on an element ground plane 205 made of a conductor inside a mobile phone. The lower end of the member 201 is mounted on the upper side of the mobile phone while generating a radiated electromagnetic wave according to the image effect.

In addition, as shown in Figure 4, the "a" shaped reflector plate 221 made of a conductor is provided on the PCB 220 of the mobile phone, the inner pin 207 of the connector at the bottom of the top member 201 The ground plane 205 is provided with a connector 208 into which the connector inner pin 207 is inserted. In addition, the outside of the center member 202 is provided with a dielectric 226 for preventing a characteristic change due to the hand contact of the antenna element when using a mobile phone, and fixing the antenna element to the mobile phone case, the dielectric 226 is the center It is made of a structure surrounding the member 202.

At this time, the top-shaped member 201 is formed in a form that the diameter is larger toward the upper side from the feed portion 204 to have a broadband characteristics, the center member 202 has a small diameter, so The diameter of the member 203 can be made small and the overall length of the antenna element can be reduced.

According to the experimental results to verify this, it can be seen that the wideband characteristic can be maintained more than the frequency bandwidth (up to 150MHz) that the existing whip antenna has secured. For example, when the top member 201 has a thickness of 0.6 mm, it was measured to have a bandwidth of 350 MHz with a standing wave ratio of 1.2 or less at 2 GHz. In particular, it has a structure that can support wideband transmit / receive bandwidth (300MHz) such as IMT-2000, and because the electrical length becomes small, when a 1 / 4-wavelength whip antenna is pulled out in a general mobile phone without an antenna pulled out. Antenna efficiency and gain can be kept similar. In addition, the surface area through which current flows in the top member 201 is secured to increase the capacitance coupling amount between the PCB 220 and the reflecting plate 221, so that the radiation efficiency is increased even when a mobile phone is made thin. There is a number.

In addition, the electrical coupling with various elements (resistors, capacitors, chips, etc.) installed on the PCB 220 by the reflector 221 is minimized, and at the same time, the PCB 220 shields electromagnetic waves generated from the antenna feeder. It has a function to reduce the SAR of the head.

5A to 5C are a perspective view, a side cross-sectional view, and a front sectional view showing an example in which a broadband shortened antenna element according to the present invention is installed in a monopole antenna of a clamshell-type cellular phone for SAR reduction, which has recently been developed.

As shown, the monopole antenna of the SAR-type cellular phone is generated from the antenna by installing a radio wave absorber 241 and a thin wave absorber reflector 242 made of a conductor in the clamshell mobile phone cover 240 in which the speaker is installed. It is possible to shield the electromagnetic wave heading to the middle of the radiated electromagnetic waves in the middle, thereby exhibiting a very large SAR reduction effect. By separating and mounting the PCB 231 and the antenna, in which the element reflector plate 232 is installed, the clamshell-type mobile phone main body 230 can be manufactured to have a thin thickness of the mobile phone, and a broadband member mounting technology is possible in a narrow space. Even if the antenna is not removed, the same antenna radiation efficiency can be obtained. As in the above-described flip-type cell phone, a contact preventing dielectric 226 is provided to prevent a change in electrical characteristics due to the hand contact of the antenna element and to fix the member to the cell phone case at the same time, and the contact preventing dielectric 226 is used. The center member 202 and the head member 203 are simultaneously wrapped. Here, in the case of the head member 203, the diameter of the head part is large, so that it is preferable to process the coating thinly with a dielectric material.

6 is an exploded perspective view showing an example in which the broadband shortened antenna element according to the present invention is directly mounted on the PCB 231 of a clamshell mobile phone to reduce SAR and secure a ground plane. It is the same as, so it is omitted.

On the other hand, the wideband shortened antenna element of the present invention is applied to a dipole antenna as well as a monopole antenna. In this case, it is possible to provide an antenna which has a wide band characteristic and is electrically small in length and width in the same manner as in the case of the monopole antenna described above.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be apparent to those of ordinary knowledge.

According to the present invention as described above, when manufacturing a monopole antenna or a dipole antenna with a wide band shortened antenna member, it is possible to form a resonant frequency even with a small head, it is possible to provide a lighter, smaller width and length antenna element. When mounted on a mobile phone, when the clamshell phone and the flip phone are made thin, there is an effect that the ground plane antenna efficiency caused by failing to secure the ground plane can be prevented.

In addition, it is possible to implement an electrically short antenna, it is possible to provide an antenna having the same characteristics as the radiation efficiency of the general monopole antenna without removing the antenna from the body of the mobile phone, when applied to the PCS band antenna length protruding from the case of the mobile phone Since it can be maintained to 1.5 cm or less, it is possible to obtain the same radiation efficiency as the existing dipole antenna while minimizing the protrusion of the antenna.

In addition, it is possible to manufacture a very thin mobile phone, there is an effect that can increase the battery life of the mobile phone.

Claims (9)

A top member made of a conductor, the bottom end of which is disposed on the feed side of the ground plane to have a wide band characteristic; A center member provided upright on an upper surface of the top member and having a diameter smaller than that of the top member, the center member including a conductor; And Is provided on the top of the center material, made of a conductor having a diameter larger than the diameter of the center material to the head member so that the resonance frequency appears even in a short electrical length state Broadband shortened antenna element comprising a. The method of claim 1, The top member and the center member is detachable with respect to each other, the broadband short axis antenna element consisting of a structure that is screwed to adjust the coupling length. The method of claim 1, The central member and the head member is detachable with respect to each other, the broadband shortened antenna element made of a structure that is screwed to adjust the coupling length. The method of claim 1, And the top member, the center member, and the head member are detachable with respect to each other, and are configured to be screwed to adjust the coupling length thereof. The method of claim 1, And said top member, said center member and said head member are in one-piece structure. A top member made of a conductor, the bottom end of which is disposed on the feed side of the ground plane to have a wide band characteristic; A center member provided upward from the top of the top member and having a diameter smaller than that of the top member, the center member including a conductor; And Is provided on the top of the center material, made of a conductor having a diameter larger than the diameter of the center material to the head member so that the resonance frequency appears even in a short electrical length state And the top member is disposed at a position adjacent to at least one of a front side and a rear side of a circuit board provided in the communication device, and the head member is disposed outside the side end of the circuit board. The method of claim 6, And a ground plate provided perpendicular to the bottom of the top member and made of a conductor, the ground plate being connected to the ground plane of the circuit board of the communication device. The method of claim 7, wherein And a reflector plate formed of a conductor and vertically provided at one end of the ground plate to shield the antenna and the driving element mounted on the circuit board. The method of claim 6, Broadband short-axis antenna made of a non-conductive material, further comprising a contact preventing dielectric attached to the outer surface of the center member and the head member to prevent a change in antenna characteristics due to contact with an external object.