JP2666602B2 - Dipole antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dipole antenna, and more particularly to a dipole antenna capable of changing a beam direction in an asymmetrically fed dipole antenna.

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional dipole antenna has a main conductor rod 2 having a length of 1/2 wavelength, and is disposed in parallel with the main conductor rod 2 and has a center. The conductor bar 10 is arranged from the first end to the one end. Here, the coaxial outer conductor 1 of the coaxial feeder is connected to the center position of the main conductor bar 2 by short wiring. Further, one end of the conductor bar 10 was connected to the coaxial center conductor 3 and the other end was connected to the main conductor bar 10 by short wiring.

[0003] A conventional dipole antenna is asymmetrically fed by γ (gamma) matching, and its radiation pattern is a pattern that is biased toward the matching side as shown in FIG.

[0004]

However, this conventional dipole antenna has a drawback that the dipole antenna itself must be physically moved or a large number of array type antenna elements must be provided in order to change the direction of the radiated electric field. is there. Therefore, there is a drawback that the structure is complicated or large because the movable mechanism of the entire antenna or the array system is used.

[0005]

According to the present invention, there is provided a dipole antenna in which an outer conductor of a coaxial feeder is connected to a center position.
And a first and second main conductor rod having a length of / 2 wavelengths, and first and second symmetrically disposed from the center position of the main conductor rod and arranged in parallel with a slight distance from the main conductor rod. A conductor bar, first and second diodes connected to respective ends of the first and second conductor bars with different polarities from a center conductor of the coaxial feeder line, and the first and second conductor bars And third and fourth diodes connected in forward direction with the first and second diodes, respectively, between the other end of each of the first and second conductors and the main conductor bar.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of one embodiment of the present invention. The coaxial outer conductor 1 of the coaxial feed line is a main conductor rod 2 having a length of about 1/2 wavelength.
And the coaxial center conductor 3 is a diode 4,
5 are connected to short conductor rods 6 and 7 respectively.
At this time, the diodes 4 and 5 are connected to polarities opposite to each other. Diodes 8, 9 are provided between the outer ends of the first and second conductor bars 6, 7 and the main conductor bar 2.
Are respectively connected. The polarity of the diodes 8 and 9 is connected to the diodes 4 and 5 in the forward direction so that the first and second conductor bars 6 and 7 are energized.

Next, the electrical operation will be described. In the dipole antenna of FIG. 1, when a positive DC voltage is applied to the coaxial center conductor 3, the diodes 4 and 8 are turned on,
This means that γ (gamma) matching is performed in the path of the diode 4, the conductor bar 6, and the diode 8, and the radiation pattern characteristic at this time is as shown in FIG. 2A. Similarly, when a negative DC voltage is applied to the coaxial center conductor 3, the diodes 5, 9 are turned on, and γ matching is performed in the path of the diode 5, the conductor bar 7, and the diode 9, and the horizontal plane The radiation pattern inside is as shown in FIG.
In both cases of FIGS. 2A and 2B, the pattern is γ
(Gamma) The characteristic is shifted to a direction with matching. FIG. 2 (c) shows a superposition of these characteristics. FIG.
As shown in (c), by superimposing a positive or negative DC voltage on the coaxial center conductor 3 and turning on and off the diodes 4, 8 or the diodes 5, 9, the direction of the radiation pattern in the horizontal plane of the antenna is changed. Can be changed.

[0008]

As described above, the dipole antenna of the present invention has two γ matching circuits that can be switched by applying a bias voltage to four diodes.
This has the effect that the direction of the radiation pattern in the horizontal plane of the antenna can be changed. That is, in the conventional dipole antenna, since the direction of the radiation pattern cannot be changed by itself, it is necessary to form an array, and it is necessary to add a variable phase shifter to each antenna.
However, if this antenna is used, it is possible to change the direction of the radiation pattern by itself, and it is not necessary to add a variable phase shifter even in the case of an array. realizable.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a dipole antenna according to one embodiment of the present invention.

FIG. 2 is a characteristic diagram of the embodiment of the present invention.

FIG. 3 is a configuration diagram of a conventional dipole antenna.

FIG. 4 is a characteristic diagram of a radiation pattern of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coaxial outer conductor 2 Main conductor bar 3 Coaxial center conductor 4,5,8,9 Diode 6,7 First and second conductor bar

Claims (2)

(57) [Claims] 1. A main conductor rod having a length of 波長 wavelength and having an outer conductor of a coaxial feed line connected to a center position thereof, the main conductor rod being arranged in parallel with a slight distance from the main conductor rod, and First and second symmetrically arranged from the center position of the body rod
And a first and second diode connected to one end of each of the first and second conductor bars at a different polarity from a center conductor of the coaxial feeder line, and the first and second conductors A dipole, further comprising third and fourth diodes connected between the other end of each rod and the main conductor rod in a forward direction with each of the first and second diodes. antenna. 2. A method according to claim 1, wherein a bias voltage is applied through a center conductor of said coaxial feeder to make said first and third diode pairs conductive and said second and fourth diode pairs nonconductive. The dipole antenna according to claim 1, wherein the pair of first and third diodes is turned off and the pair of second and fourth diodes is turned on.