JP2019036822A - Phase difference feeding antenna device - Google Patents

Abstract

To realize a small-sized, wide-band, high-gain phase-difference feeding antenna device.SOLUTION: The phase difference feeding antenna device includes a first feeding element, a second feeding element, and a non-feeding element arranged in this order. When a free space wavelength of an electromagnetic wave to be transmitted and received is denoted as λ, a distance between the first feeding element and the second feeding element is λ/8, a distance between the second feeding element and the non-feeding element is 3λ/40, and a feed phase difference of the second feeding element with respect to the first feeding element is set to 40 degrees or more and 140 degrees or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a three-element high-gain phase difference feeding antenna apparatus.

FIG. 6 shows a configuration example of a conventional phase difference feeding antenna device (Non-Patent Document 1).
In FIG. 6, the phase difference feeding antenna device includes a first feeding element 11-1, a second feeding element 11-2, and a parasitic element 12. The interval between the two feeding elements is λ / 8 (λ: free space wavelength), and power is fed with a phase difference of 180 degrees. In order to realize the feed phase difference of 180 degrees, the phase is inverted by crossing the lines when connecting the two pairs of parallel feeders 13-1 and 13-2 to the feed element.

The Institute of Electronics, Information and Communication Engineers, “Antenna Engineering Handbook (Second Edition)”, 10.14.6 Phase Difference Feed Antenna, p.681 (July 25, 2008)

  The feeding part of the phase difference feeding antenna device can be easily realized by using two pairs of parallel feeders, but the configuration in which the lines are crossed using the parallel feeders makes the connecting parts unstable and resistant to aging degradation. There are weak issues. Further, since the interval between the two feeding elements is fixed (λ / 8) and the feeding to the two feeding elements is performed integrally, there is a problem of narrow band characteristics (specific bandwidth of 3% or less).

  An object of the present invention is to provide a phase difference feeding antenna device that is small, has a wide bandwidth, and has a high gain.

  In the phase difference feeding antenna device arranged in the order of the first feeding element, the second feeding element, and the parasitic element, the present invention provides the first feeding element and the second feeding element when the free space wavelength of electromagnetic waves to be transmitted and received is λ. Set the distance between the feed element to λ / 8, the distance between the second feed element and the parasitic element to 3λ / 40, and set the feed phase difference of the second feed element to the first feed element between 40 degrees and 140 degrees It is the structure to do.

  In the phase difference feeding antenna device according to the present invention, the first feeding element and the second feeding element are provided with a feeding phase difference of not less than 40 degrees and not more than 140 degrees by a line arranged on a dielectric substrate having a relative dielectric constant of 2 to 3. It is the structure which supplies electric power.

  In the phase difference feeding antenna device of the present invention, a feeding position is provided by a feeding line that is arranged at right angles and in a straight line with respect to the first feeding element and the second feeding element by utilizing the interval between the first feeding element and the second feeding element. In this configuration, a phase difference of 45 degrees is set.

  The present invention can realize a small-sized, wide-band, high-gain phase-difference feeding antenna device by limiting the intervals between the first feeding element, the second feeding element, and the parasitic element and the feeding phase difference.

It is a figure which shows the Example structure of the phase difference feeding antenna apparatus of this invention. It is a figure which shows the relationship between the electric power feeding phase difference and gain characteristic in an Example structure. It is a figure which shows the relationship between the electric power feeding phase difference in an Example structure, and a back lobe level characteristic. It is a figure which shows the relationship between the electric power feeding phase difference in an Example structure, and the input reflective characteristic of a 1st electric power feeding element. It is a figure which shows the structural example of the feeder in an Example structure. It is a figure which shows the structural example of the conventional phase difference electric power feeding antenna apparatus.

FIG. 1 shows a configuration of an embodiment of a phase difference feeding antenna device of the present invention.
In FIG. 1, the phase difference feeding antenna apparatus according to the present embodiment includes a first feeding element 11-1, a second feeding element 11-2, and a parasitic element 12. The spacing between the first feeding element 11-1 and the second feeding element 11-2 is λ / 8 (λ: free space wavelength), and the spacing between the second feeding element 11-2 and the parasitic element 12 is 3λ / 40. It is. At this time, the antenna length from the first feeding element 11-1 to the parasitic element 12 is λ / 5. For example, when transmitting and receiving electromagnetic waves in a 60 MHz band (wavelength 5 m), the antenna length is 1 m.

  In this way, the parasitic element 12 is arranged close to the feeding element, and by matching the feeding elements, the narrow band characteristic which is a demerit of the three-element phase difference feeding is improved, and a normal distribution circuit is used. Broadband characteristics (specific bandwidth of about 7%) can be ensured.

  Furthermore, the feeding phase difference (phase delay) of the second feeding element 11-2 with respect to the first feeding element 11-1 is set to 40 degrees or more and 140 degrees or less. The reason is shown below.

FIG. 2 shows the relationship between the feeding phase difference and the gain characteristic in the embodiment configuration.
In FIG. 2, if a gain equivalent to a 3-element Yagi-Uda antenna is 6 dBi or more, the feeding phase difference is 30 degrees or more, and even 200 degrees can ensure 6 dBi or more.

FIG. 3 shows the relationship between the feeding phase difference and the back lobe level characteristic in the embodiment configuration.
In FIG. 3, if a difference of 5 dB or more from the main lobe is appropriate as the back lobe level characteristic, the feeding phase difference is 20 degrees or more and 140 degrees or less.

  FIG. 4 shows the relationship between the feed phase difference and the input reflection characteristics of the first feed element in the configuration of the example. In FIG. 4, when the input reflection characteristic of the first feeding element is −6 dB or less (3/4 of the power is supplied), the feeding phase difference is 40 degrees or more and 160 degrees or less.

  From the AND condition of these three characteristics, it is appropriate that the feeding phase difference in the phase difference feeding antenna apparatus of the present embodiment is not less than 40 degrees and not more than 140 degrees.

  Here, when the feed phase difference is set to 45 degrees, as shown in FIG. 5, the first feed element 11-1 and the second feed element 11-2 arranged at λ / 8 intervals are perpendicular to each other. As feeder lines arranged in a straight line, parallel feeders 13-1 and 13-2 are configured using, for example, metal pipes. As a result, a power supply phase difference of λ / 8 = 45 degrees can be realized with a simple and robust configuration, and a configuration that can withstand aged deterioration can be obtained.

  Further, as a power feeding unit, a first power feeding element 11-1 and a second power feeding element 11- are provided with a power feeding phase difference of 40 degrees or more and 140 degrees or less by a line arranged on a dielectric substrate having a relative dielectric constant of 2 to 3. 2 may be configured to supply power.

11 Feeding element 12 Parasitic element 13 Parallel feeder

Claims (3)

In the phase difference feeding antenna device arranged in the order of the first feeding element, the second feeding element, and the parasitic element,
When the free space wavelength of the electromagnetic wave to be transmitted and received is λ, the distance between the first feeding element and the second feeding element is λ / 8, and the distance between the second feeding element and the parasitic element is 3λ / The phase difference feeding antenna device is configured to set the feeding phase difference of the second feeding element to 40 degrees or more and 140 degrees or less with respect to the first feeding element. In the phase difference feeding antenna device according to claim 1,
A structure in which a power supply phase difference of 40 degrees or more and 140 degrees or less is provided by a line arranged on a dielectric substrate having a relative dielectric constant of 2 to 3 to supply power to the first power supply element and the second power supply element. A characteristic phase difference feeding antenna device. In the phase difference feeding antenna device according to claim 1,
Using the distance between the first feed element and the second feed element, a feed phase difference of 45 degrees is set by a feed line arranged at right angles and in a straight line with respect to the first feed element and the second feed element. A phase difference feeding antenna device characterized by having a configuration.

Images