KR20040081615A - Wideband Characterized Dual Band Omni-Antenna having Step-Structured Radiation Element - Google Patents

Abstract

PURPOSE: A dual band omni antenna is provided to uniformly form an omni directional beam pattern in a horizontal direction by arranging a first radiator, a second radiator, a reflector, and a radome unit symmetrically with each other centering from a connector. CONSTITUTION: A dual band omni antenna comprises a connecting unit(11) for inputting/outputting an RF signal; a first radiator(14) for resonating the high frequency signal input from the connecting unit, and matching the low frequency signal input from the connecting unit; a second radiator(15) electrically connected to the first radiator, and which resonates the low frequency signal input from the connecting unit; a reflector(16) for radiating the wave radiated from the first and second radiators in the radiation pattern same as that of a symmetric dipole antenna, by reflecting the wave; a dielectric unit(13) for spacing apart the first and second radiators from the reflector; and a radome unit(17) for forming a uniform omni directional beam pattern in a horizontal direction, from the wave radiated from the first and second radiators and the wave reflected from the reflector.

Description

Wideband Characterized Dual Band Omni-Antenna having Step-Structured Radiation Element

The present invention relates to a broadband multi-band omni antenna having a two-stage radiating element, and more particularly, the first radiator unit resonates a signal of a high frequency band and operates as an impedance matching circuit for a signal of a low frequency band. The two radiator section relates to an omni antenna having a two-stage structure radiating element exhibiting a dual band characteristic of a wide band characteristic by resonating a signal of a low frequency band.

In general, various wireless communication relay antennas are installed in each service area of a wireless communication system, and omni antennas that can be attached to a ceiling or the like for wireless communication service are used in a shaded area such as a building.

On the other hand, the conventional omni-directional antenna for wireless communication is capable of relaying only a single frequency band, so that the frequency bands are different for each frequency band, such as cellular, personal communication service (PCS), and IMT-2000. An antenna is being used.

However, as the IMT-2000 project is recently performed, the service providers who have provided services in a single single frequency band must simultaneously provide services for other frequency bands. In this case, when using a conventional omni-directional antenna of a single frequency band, operators have to install an omni antenna suitable for each frequency band in each service area, and therefore, it is very expensive to manufacture, purchase, and install the antenna. There is a problem.

On the other hand, the omni antenna has a problem that a non-uniform omnidirectional horizontal beam pattern occurs due to an asymmetry of the current distribution formed in the antenna by reducing the size of the antenna, and also decreases the efficiency of the antenna caused by impedance mismatch. In addition, there is a problem of reducing the efficiency of the RF system by the power reflected back from the antenna input portion.

The present invention has been proposed to solve the above problems, and the first radiator resonates a signal of a high frequency band and operates as an impedance matching circuit for a signal of a low frequency band, and the second radiator resonates a signal of a low frequency band. It is an object of the present invention to provide an omni antenna having a two-stage structure radiating element exhibiting a dual band characteristic.

1 is an exploded perspective view of a broadband multi-band omni antenna having a two-stage structure radiating element according to the present invention.

2 is a cross-sectional view of a combination of a wide band dual antenna omni antenna having a two-stage structure radiating element according to the present invention.

3A and 3B are coupling diagrams of a first radiator portion and a second radiator portion of a broadband dual-band omni antenna having a two-stage structure radiating element according to the present invention;

4A is a cross-sectional view of a broadband dual band omni antenna having a two-stage structure radiating element according to the present invention;

4B is an explanatory diagram for explaining current flow in a high frequency band inside a dual band omni antenna having a broadband characteristic having a two-stage structure radiating element according to the present invention;

4C is an explanatory diagram illustrating surface currents and propagating electric fields flowing in a first radiator unit by applying image theory to a dual band omni antenna having a broadband characteristic having a two-stage structure radiating element according to the present invention;

5A is a cross-sectional view of a broadband dual band omni antenna with a two-stage structure radiating element in accordance with the present invention.

5B is an explanatory diagram for explaining current flow in a low frequency band inside a dual band omni antenna having a broadband characteristic having a two-stage structure radiating element according to the present invention;

Fig. 5C is an explanatory diagram illustrating the surface current and the electric field flowing through the radiator part by applying image theory to the dual band omni antenna having the broadband characteristic having the two-stage structure radiating element according to the present invention.

6A is a diagram showing a horizontal beam pattern in an 800 MHz band of a broadband dual band omni antenna according to the present invention;

Figure 6b is a view showing a vertical beam pattern in the 800MHz band of the broadband dual-band omni antenna according to the present invention.

FIG. 7A illustrates a horizontal beam pattern in a 2 GHz band of a wide band omni antenna according to the present invention; FIG.

7b illustrates a horizontal beam pattern in a 2 GHz band of a wide band omni antenna according to the present invention;

8 is a view showing a standing wave ratio for a broadband dual-band omni antenna according to the present invention.

* Explanation of symbols for the main parts of the drawings

11 connector part 12 connector part inner core

13 dielectric part 14 first radiator part

15: second radiator 16: reflector

17: radome portion 18: radome coupling portion

In order to achieve the above object, the present invention provides a broadband dual band omni antenna having a two-stage radiating element used in a wireless communication system, comprising: connecting means for inputting and outputting an RF signal, and a high frequency signal inputted from the connecting means. A first radiating means for resonating, the low frequency signal being impedance matched, a second radiating means electrically coupled with the first radiating means to resonate a low frequency signal input from the connecting means, and radiating from the first and second radiating means Reflecting means for radiating in a radiation pattern such as a symmetrical dipole antenna by reflecting a radio wave, a dielectric part composed of a dielectric material spaced apart from the reflecting means at regular intervals, and the first and second means Radio waves radiated from the radiating means and the reflecting means Provided is a wideband dual-band omni antenna having a two-stage structured radiating element comprising a radome portion for uniformly forming an omnidirectional radiation pattern horizontally with respect to radio waves reflected from the same.

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.

1 is an exploded perspective view of a broadband dual band omni antenna having a two-stage radiating element according to the present invention, and FIG. 2 is a combination of a broadband dual band omni antenna having a two-stage radiating element according to the present invention. 3A and 3B are combined views of a first radiator portion and a second radiator portion of a broadband multi-band omni antenna having a two-stage structure radiating element according to the present invention.

1 to 3B, a dual band omni antenna having a broadband characteristic having a two-stage structure radiating element according to the present invention will be described in detail as follows.

The dual band omni antenna having a broadband structure having a two-stage radiating element according to the present invention has a connector portion 11 connected to a transmitting and receiving end of a system, and a high frequency signal input through the connector portion 11 (for example, 2 GHz IMT-2000 signal) and the low frequency band signal is electrically coupled with the first radiator unit 14 and the first radiator unit 14 to operate as an impedance matching circuit. 11) radiation from the second radiator unit 15, the first radiator unit 14 and the second radiator unit 15 for resonating a low frequency signal (for example, a digital cellular signal of 800 MHz band) input through the Reflector section 16, reflector section 14 and 15, for reflecting radio waves that are formed as if another radiator is virtually present so that the monopole antenna behaves in the same radiation pattern as a symmetrical dipole antenna A dielectric portion 13 for maintaining and supporting the base 16 at regular intervals and a radome portion 17 for protecting the radiator from the natural environment.

The connector portion 11 is a portion connected to the transmission / reception system, and is fixed to a central portion of the reflector portion 16. The inner core 12 of the connector portion fixed in this way is treated with bolts for coupling with the radiators 14 to 15, and the lower end portions of the radiators 14 to 15 are treated with nuts as shown in FIG. 3B. The dielectric part 13 serves to maintain and support the radiator parts 14 and 15 at regular intervals from the reflector part 16 when the connector part 11 and the radiator parts 14 and 15 are coupled.

The first radiator section 14 and the second radiator section 15 are designed to be integrally connected in series. Therefore, when the high frequency signal of the 2 GHz band is input, the first radiator unit 14 resonates the input high frequency signal. When the low frequency signal of the 800 MHz band is input, the first radiator unit 14 operates as an impedance matching circuit. This simplifies and unifies the structure of the antenna, reducing labor costs and time required to assemble the antenna, as well as material costs for the antenna. In particular, spinnerets 14 to 15 plated on aluminum or plastic are used to reduce the weight. Detailed operations of the first radiator 14 and the second radiator will be described later.

On the other hand, the reflector portion 16 is made of a metal material with good conductivity in order to form a radiation pattern such as a dipole antenna in which the monopole antenna is symmetrical by image theory.

In addition, the radome portion 17 serves to protect the integral radiator portions 14 and 15, the reflector portion 16, and the radiator portions 14 and 15 from the natural environment, and the radiation pattern has a horizontal omnidirectional pattern. In order to be uniformly formed, the connector 12 is symmetrically formed.

The operation characteristics in the high frequency band of the broadband dual-band omni antenna having the two-stage structure radiating element according to the present invention having the above structure will be described in detail with reference to FIGS. 4A to 4C.

4A to 4C are cross-sectional views of a broadband dual-band omni antenna having a two-stage radiating element according to the present invention, an explanatory diagram illustrating current flow in a high frequency band inside the antenna, and an image theory on the first radiator. It is explanatory drawing explaining the surface current and the electric field applied to this.

First, the power input through the connector portion 11 is fed to the first radiator portion 14, which is a high frequency element, and according to the image theory, an electric field as shown in FIG. 4C is formed by the reflector portion 16 and radiated into free space. do. At this time, the first radiator portion 14 is designed to have a resonant length (1/4 times the wavelength) of the high frequency band so that the current hardly flows to the second radiator portion 15 as shown in FIG. 4A. In order to form a discontinuity point between the radiator portion 14 and the second radiator portion 15, the diameter of the cylinder is designed to be different. Therefore, when operating as a high frequency antenna, although the first radiator unit 14 and the second radiator unit 15 are connected in series, almost all power is radiated from the first radiator unit 14.

4A to 4C, the power radiating process of the first radiator unit 14 which is the high frequency device as described above will be described.

The current flowing in the first radiator unit 14 flows as shown in FIG. 4B, and may be represented as an electric field as shown in FIG. 4C by applying image theory as a signal source for calculating a radiation pattern. 4C shows a propagating electric field formed in the space by the current flowing on the surface of the first radiator section 14.

The operation principle of the low frequency band is more complicated than the operation principle in the high frequency band, but since the basic operation characteristics are similar, the following description will be given with reference to FIGS. 5A to 5C.

5A to 5C are cross-sectional views of a broadband dual-band omni antenna having a two-stage structure radiating element according to the present invention, an explanatory diagram for explaining current flow in a low frequency band inside the antenna, and an image radiator part applied thereto. It is explanatory drawing explaining the surface current and the electric field which flow through.

As shown in FIG. 5A, the power input through the connector portion 11 is fed to the integral radiator portion, which is a low frequency element, in which the first radiator portion 14 and the second radiator portion 15 are connected in series, and radiate. The bases 14 to 15 are applied to image theory by the reflector unit 16 to form an electric field as shown in FIG. 5C and radiate to free space. When operating as a low frequency antenna, all currents flowing through the first radiator unit 14 through the first radiator unit 14 and the second radiator unit 15 are radiated integrally with the first radiator unit 14 and the second radiator unit 15 connected in series. . As shown in FIG. 4A, the electrical length of the integrated radiator parts 14 to 15 in which the first radiator part 14 and the second radiator part 15 are connected in series is a resonance length of a low frequency band (1/4 times the wavelength). In the low frequency band, the first radiator unit 14 is designed to serve as an impedance matching circuit in the low frequency band.

On the other hand, the conventional monopole antenna has broadband characteristics when the size of the reflector portion 16 is electrically much larger (diameter is larger than the wavelength length), but since the size of the reflector portion 16 is limited to reduce the overall size of the antenna, low frequency Impedance matching in the band becomes very difficult. Therefore, in the present invention, by adjusting the diameter and length of the first radiator portion 14 to use the first radiator portion 14 as an impedance matching circuit in the low frequency band, it is possible to provide broadband characteristics even in a low frequency band.

The power radiation process of the low frequency device as described above will be described with reference to FIGS. 5B and 5C.

The current flowing through the first radiator unit 14 through the second radiator unit 15 flows as shown in FIG. 5B, and an image theory is applied as a signal source for calculating a radiation pattern to be represented by an electric field such as 5c. Can be. FIG. 5C shows a propagating electric field formed in the space by a current flowing on the surface of the radiators 14 to 15.

The embodiment of the present invention described above has been described with respect to the broadband dual-band omni antenna consisting of the first radiator portion and the second radiator portion, the radiator portion structure by adding another radiator portion to the first radiator portion and the second radiator portion It will be apparent to those skilled in the art that the present invention can be operated by a multi-band antenna by forming in multiple stages.

FIG. 6A is a diagram illustrating a horizontal beam pattern in an 800 MHz band of a dual band omni antenna having a broadband characteristic according to the present invention, and it may be seen that the omnidirectional beam pattern is uniformly horizontally.

6B is a view showing a vertical beam pattern in the 800 MHz band of the broadband dual-band omni antenna according to the present invention. Since the bidirectional beam pattern is symmetrically vertically, the transmit / receive radio wave power of the omni antenna is uniform, It can be seen that the quality is improved.

FIG. 7A is a diagram illustrating a horizontal beam pattern in a 2 GHz band of a broadband dual band omni antenna according to the present invention, and it may be seen that the omnidirectional beam pattern is uniformly horizontally.

FIG. 7B is a diagram illustrating a horizontal beam pattern in a 2 GHz band of a broadband dual band omni antenna according to the present invention, and it can be seen that the bidirectional beam pattern is vertically symmetrical.

FIG. 8 is a diagram illustrating a standing wave ratio for a dual band omni antenna having a broadband characteristic according to the present invention, and it can be seen that the bandwidth is improved as compared with the conventional omni antenna.

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 clear to those of ordinary knowledge.

In the present invention as described above, the first radiator portion, the second radiator portion, the reflector portion, and the radome portion are symmetrically formed around the connector portion, so that the current, the electric field, and the magnetic field are symmetrically formed around the connector portion so that the omnidirectional beam is horizontal. There is an effect that the pattern is formed uniformly.

In addition, the present invention provides a wideband characteristic because the reflector portion is larger than the resonance length in the high frequency band, and the first radiator portion serves as an impedance matching circuit in the low frequency band, thereby providing the wideband characteristic.

In addition, the present invention has the effect of reducing the labor cost and time required to assemble the antenna, as well as material costs of the antenna by designing and simplifying and unifying the first radiator and the second radiator in series.

Claims (9)

A broadband wide band omni antenna having a two-stage radiating element for use in a wireless communication system, Connecting means for inputting and outputting an RF signal; First radiating means for resonating a high frequency signal inputted from said connecting means and for impedance matching a low frequency signal; Second radiating means electrically coupled with the first radiating means to resonate a low frequency signal input from the connecting means; Reflecting means for radiating in a radiation pattern such as a symmetrical dipole antenna by reflecting radio waves radiated from said first and second radiating means; A dielectric part spaced apart from the reflecting means by the first and second radiating means at a predetermined interval and composed of a dielectric material; And A radome part for uniformly forming an omnidirectional radiation pattern horizontally with respect to radio waves radiated from the first and second radiating means and radio waves reflected from the reflecting means. Dual band omni antenna having a wideband characteristic having a two-stage radiating element comprising a. The method of claim 1, The first spinning means The electrical length being one quarter of the wavelength of the high frequency signal A broadband dual-band omni antenna having a two-stage structure radiating element characterized in that. The method of claim 1, The first and second radiating means The electrical length of the whole being 1/4 of the low frequency signal wavelength A broadband dual-band omni antenna having a two-stage structure radiating element characterized in that. The method according to any one of claims 1 to 3, The first spinning means and the second spinning means, Consisting of integral two-stage cylindrical structures having different diameters A broadband dual-band omni antenna having a two-stage structure radiating element characterized in that. The method of claim 4, wherein The first spinning means is. The diameter of which is smaller than the diameter of the second spinning means A dual band omni antenna having a broadband structure having a two-stage radiating element. The method according to any one of claims 1 to 3, The high frequency signal, Substantially an IMT-2000 signal in the 2 GHz band A dual band omni antenna having a broadband structure having a two-stage radiating element. The method according to any one of claims 1 to 3, The low frequency signal, Practically a digital cellular signal in the 800 MHz band Broadband dual band omni antenna with two-stage radiating element The method according to any one of claims 1 to 3, The first and second radiating means, the reflecting means and the radome portion, Each configured to be symmetrical about said connecting means A dual band omni antenna having a broadband structure having a two-stage radiating element. The method of claim 1, Radiating means coupled to the second radiating means in multiple stages and electrically coupled to the first radiating means for resonating signals of bands other than high frequency and low frequency input from the connector portion. The dual band omni antenna of the broadband characteristic further comprising.