KR20040077632A - Wideband Yagi-antenna using solid type dipole - Google Patents

Abstract

PURPOSE: A wideband Yagi antenna is provided, in which elements of a radiation unit are formed by bending a single metal plate in a direction, to thereby allow for ease of manufacture and reduce costs since. CONSTITUTION: A wideband Yagi antenna comprises a radiation unit(11); a waveguide(12) arranged in front of the radiation unit; and a reflector(13) arranged in rear of the radiation unit. The radiation unit includes a square C-shaped dipole(17); and a C-couple element(18) extended from a positive dipole element(17a) and bent toward a negative dipole element(17b). The feeding operation is performed through the C-couple element. The radiation unit is interposed between the positive and negative dipole elements. The wideband Yagi antenna further includes a frequency tuning element(20) for supplementing the necessary capacitance value between the positive and negative dipole elements.

Description

Wideband Yagi Antenna using solid dipole {Wideband Yagi-antenna using solid type dipole}

The present invention relates to an outdoor Yagi antenna used in a repeater of a wireless communication (PCS, IMT-2000) system, and more particularly, to a Yagi antenna implementing wideband characteristics using a three-dimensional bent dipole element and a C-couple element. .

Figure 1a shows an outdoor Yagi antenna for repeaters according to the prior art. The illustrated Yagi antenna 100, like a typical Yagi antenna, a radiator 101 for transmitting and receiving radio waves, a waveguide 102 provided in front of the radiator 101 to induce radio waves, and A radiation directing reflector (103) provided at the rear of the radiator (101) for reflecting radio waves, the feeder cable for supplying predetermined power to the radiator (101), and antenna elements (101, 102, 103) Radom 105 for protecting them to the external environment. In particular, the antenna 100 is in the form of a planar antenna using the microstrip substrate 106. Specifically, the radiator 101 is a planar radiator using the microstrip substrate 106. The radiator 101 includes a dipole 107 for transmitting and receiving radio waves, and a feed transmission line 108 including a power distribution circuit and a matching circuit. It is printed on the substrate 106 and formed.

1B is a standing wave ratio measurement result graph showing band characteristics of the antenna 100.

In general, a microstrip antenna is a planar antenna using a pattern implemented on a printed circuit board. The antenna can be miniaturized and reduced in weight, and therefore, it is known to be suitable for use in a device such as a portable terminal or a computer. There is a trend that is widely used in all antenna applications.

However, microstrip antennas have narrow frequency bandwidths of several percent or less and low gains. In fact, the conventional antenna 100 has a narrow bandwidth and is used only for PCS, and as a result of measuring at the IMT-2000 (1920 to 2170 MHz) with the antenna 100, both the horizontal and vertical patterns have been messed up. For example, high gain may be obtained through the antenna array, but in this case, the design and manufacturing conditions are difficult and the size of the antenna increases. In addition, the microstrip antenna is not only expensive in itself, but also very disadvantageous in terms of manufacturing cost due to the printing cost of the antenna elements.

The present invention is to solve the above problems of the antenna according to the prior art, an object of the present invention is to provide a Yagi antenna obtained experimentally broadband effect, excellent electrical characteristics through a specially designed dipole radiator.

1A is a partially cut away perspective view of a yagi antenna according to the prior art;

Figure 1b is a graph showing the standing wave ratio characteristics of Figure 1a.

2 is a perspective perspective view of a yagi antenna according to the present invention;

3 is an exploded perspective view of the antenna of FIG. 3;

4 is a graph showing the standing wave ratio characteristics of the antenna of FIG.

5A and 5B are vertical and horizontal pattern views of the antenna of FIG.

<Description of the symbols for the main parts of the drawings>

10. Yagi antenna 11. Radiator

12. Waveguide 13. Reflector

14. Base 15. Cover

16. Support 17. Dipole

18. C-couple element 19. Insulator

20. Tuning Elements

Like the usual, the Yagi antenna according to the present invention comprises a radiator, a waveguide provided in front of the radiator, and a reflector provided behind the radiator. Characteristically, the radiating portion comprises a "c" bent dipole and a C-couple element extending from the positive dipole element and bent towards the negative dipole element, wherein feeding is via the C-couple element.

For reference, the present invention has been made experimentally for the purpose of developing an antenna having a bandwidth (1750 ~ 2170 MHz) that can be used in common for PCS and IMT-2000, and thus the configuration of the present invention is an experiment for satisfying the commonality. The results are obtained in advance.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the Yagi antenna according to the present invention. 2 and 3 is a view showing the configuration of the Yagi antenna according to the present invention, Figures 4 and 5a, b is a view showing the electrical performance of the Yagi antenna according to the present invention.

2 and 3, a Yagi antenna implemented in accordance with the present invention is indicated by reference numeral 10. The antenna 10 includes a radiator 11, a waveguide 12 provided in front of the radiator 11, and a reflector 13 provided at the rear of the radiator 11, An antenna fixing base 14 and an antenna protective cover 15 are included.

The radiator 11 comprises: an impedance matching support 16 for maintaining a gap between the dipole 17 and the reflector 13, a dipole 17 composed of a positive element 17a and a negative element 17b, and the positive A capacitor (C) -couple element (18) extending from the element (17a) to face the negative element (17b).

These elements 16, 17, 18 are formed by bending one metal (brass) plate in a constant direction, respectively. The dipole 17 is horizontally bent with respect to the vertical support 16, and each element 17a, 17b of the dipole 17 is bent in a "c" shape. The bent form of the dipole elements 17a and 17b is advantageous in that the size of the dipole elements 17a and 17b can be reduced as well as the bandwidth is wider than in the flat or straight form. Further, the C-couple element 18 for compensating the C value between the feed solder and the dipole elements 17a and 17b is bent upward from the positive element 17a and then bent back toward the negative element 17b.

The radiator 11 further includes a frequency tuning element 20 disposed between the dipole elements 17a and 17b to further compensate for a required C (capacitance) value between the dipole elements 17a and 17b. As shown in the figure, the tuning element 20 may be provided as a pattern on the insulator 19.

Between the radiator 11 and the front waveguide 12, an insulator 19 is provided as a medium for mutual coupling, and the radiator 11 and the waveguide 12 are connected through the insulator 19. Respectively pinned or bolted. The radiator 11 is coupled to the back reflector 13. The bracket 13a is integrally formed on the reflector 13, and the support 16 of the radiator 11 is fixed to the bracket 13a with a pin or bolt.

A coaxial cable 21 for power supply is provided through the connector 14a on one side of the base 14 so that the core wire of the cable 21 is soldered to the C-couple element 18 and fed to the positive element 17a. The outer shell (ground) of the cable 21 is soldered to the negative element 17b.

Referring to FIG. 4, the Yagi antenna 10 has excellent standing wave ratio characteristics of 1.5 or less in all bands of 1750 to 2170 MHz. 5A and 5B, the Yagi antenna 10 exhibited a stable vertically polarized radiation pattern in the entire frequency band, and showed excellent electrical characteristics of 15 dB or more in front and rear ratio and 12 dBi in gain.

According to the invention, each of the elements 16, 17, 18 forming the radiating part 11 is formed by bending one metal plate in a constant direction, respectively. Therefore, it is easy to manufacture and advantageous in cost. At the same time, broadband characteristics and excellent electrical characteristics can be obtained by appropriately using the "c" bent dipole 17, the C-couple 18, the tuning element 20, and the like.

Claims (4)

In the radiation part 11, the waveguide 12 provided in front of the said radiation part 11, and the reflector 13 provided in the back of the said radiation part 11, The said radiation part 11 ) Includes a "c" bent dipole 17 and a C-couple element 18 extending from the positive dipole element 17a and bent towards the negative dipole element 17b, the feed being the C-couple Broadband Yagi antenna using a three-dimensional dipole, characterized in that made through the element (18). The method of claim 1, The radiating part 11 is formed by bending one metal plate for each element, and the dipole 17 is horizontally bent with respect to the vertical support part 16, and each element 17a, 17b of the dipole 17 is " And a C-couple element (18) is bent upward from the positive element (17a) and then bent to face the negative element (17b) again. The method according to claim 1 or 2, The radiator 11 further includes a frequency tuning element 20 disposed between the dipole elements 17a and 17b to further compensate for the required C (capacitance) value between the dipole elements 17a and 17b. Wideband Yagi antenna using a three-dimensional dipole. The method of claim 3, The tuning element (20) is a wideband cause antenna using a three-dimensional dipole, characterized in that formed on an insulator (19) provided for mutual coupling between the radiator (11) and the waveguide (12).