JPH0342737Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The purpose of this invention is to transmit or receive radio waves in a wide wavelength range using a single dipole antenna.

[Conventional technology]

Conventional dipole antennas transmit or receive radio waves in a wide range of wavelengths using a common feeding point, so they use multiple resonant wavelengths to transmit or receive radio waves with high sensitivity. It was difficult to do so.

[Problems that this invention attempts to solve]

Vertical or horizontal dipole fixed to a post
In order to cause the antenna to resonate with radio waves, it is suitable that the total length of the dipole is one wavelength or half the wavelength of the radio waves, or an integral multiple thereof. Although one dipole antenna can be divided into multiple lengths and resonated with multiple radio waves, it has been difficult to divide and set the feeding points.

The present invention provides a structure in which a plurality of the above-mentioned feeding points can be set.

[Means for solving problems]

In this invention, each of the dipole antennas divided into two parts in the supporting part is further divided into two to transmit or receive radio waves in the short wavelength band and long wavelength band, and the feeding point of the two wavelength bands is A dipole antenna capable of transmitting and receiving radio waves in a wide wavelength band with high sensitivity is obtained by connecting the antenna to a feeder line using a matching coil made of a coaxial line formed into a coil shape.

〔Example〕

FIG. 1 shows the main parts of the present invention, part of which shows the structure of the main parts in sectional and perspective views.

The pillar 20 is a rod-shaped hollow member that supports the present invention, and has a base 19 fixed to one end thereof.

One end of the lower antennas 21 and 22 forming a pair of dipoles is fixed in a straight line so as to pass through the base 19, and the other end thereof has a folded part 3.
There are 1,32.

The upper antennas 11 and 12 have connection parts 41 and 42
It is connected to the folded portions 31 and 32 while maintaining insulation.

Coaxial lines 51, 52 are connected to the lower antennas 21, 22.
is pulled in, and the inner conductor 61 of the coaxial line,
62 is the upper antenna 1 inside the connecting parts 41 and 42.
It is connected to 1 and 12.

The coaxial wires 51, 52 drawn into the base 19 are formed into a coil shape to form matching coils 71, 72, and the lead wires 91, 92 of the internal conductors of the coaxial wires 51, 52 that pass through the matching coils 71, 72 are formed with short wavelengths. Belt feeder line 1
6 and 18 to transmit or receive short wavelength radio waves.

The matching coils 71 and 72 are connected at the neutral point 8 to the outer conductors of the long wavelength band feed lines 15 and 17 and the short wavelength band feed lines 16 and 18. Reference numeral 81 is a connection line of the neutral point.

Long wavelength band lead wires 101, 102 connected to intermediate portions of the outer conductors of matching coils 71, 72 are connected to long wavelength band feed lines 15, 17 to transmit or receive long wavelength band radio waves. .

As shown in the figure, the short wavelength band leader lines 91, 9
2 has an impedance equivalent to the sum of the impedances of the coaxial lines 51 and 52, but the leader line 101,
The impedance of 102 is the matching coil 71, 7
The closer the connection point to neutral point 8 is located, the lower it becomes.

In order to transmit or receive waves with high sensitivity, it is necessary to provide the connection point of the lead wires 101 and 102 so as to match the impedance of the power supply lines 15 and 17.

When using coaxial feeder lines for the lead wires 16 and 18, a transformer must be inserted between the inner conductor lead wires 91 and 92 and the coaxial feeder line to convert the balanced circuit into an unbalanced circuit. Bye.

This means that the lead wires 101, 102 and the feeder line 1
The same applies to between 5 and 17.

In order to increase the coupling coefficient of the matching coils 71 and 72, inserting a ferrite magnetic core is effective in improving the sensitivity of wave transmission and reception.

Stabilizing resistor 201, 202, 203, 204
are the reduction in insulation resistance of the base 19 and the connecting parts 41 and 42, the inner conductors 61 and 62 of the coaxial line at the resonant wavelength of the antenna and feeder line of the present invention, and the lower antennas 21 and 22 and the matching coils 71 and 72. A resistor inserted to limit the sudden increase in impedance at the connection point, with a value on the order of several kilohms.

It goes without saying that the outside of the present invention is assembled to have a waterproof structure so that there is no leakage of water into the inside of the base 19 and the inside of the connecting parts 41 and 42.

Assuming that the shortest wavelength of radio waves transmitted and received in the short wavelength part of the present invention is 2 meters, the sum of the lengths of the upper antenna 11 and the folded part 31 is 1 meter, and the upper antenna has a wavelength of 2 meters. 2 on the radio wave
By resonating at a wavelength of 1/4 of a wavelength, and resonating at a quarter wavelength of a radio wave with a wavelength of 4 meters,
It is capable of transmitting and receiving radio waves with high sensitivity to wavelengths in and around meters.

In addition, by setting the sum of the lengths of the upper antenna 11 and the lower antenna 21 to one quarter of the longest wavelength of the radio waves for transmission and reception in the long wavelength band, it is possible to It is possible to transmit and receive radio waves with a wavelength of one-half of the wavelength of 1/2, and radio waves with wavelengths close to that wavelength with high sensitivity.

The lower antenna 21 and the upper antenna 11 exhibit substantially the same characteristics when connected in series for radio waves having the leader wire 101 as the feeding point.

Therefore, when the sum of the lengths of the upper antenna 11 and the folded part 31 is 1 meter as described above, that is, when the length of the upper antenna 11 is set to 0.5 meters, the length of the lower antenna 21 is set to 1.5 meters. If set to meters, the long wavelength band leader line 101
is a radio wave whose total wavelength of 2 meters, which is the total length of the lower antenna 21 and the upper antenna 11, is 1/4 wavelength.
It is possible to transmit and receive waves with high sensitivity within the range of radio waves that is one-tenth of the wavelength.

One quarter of the antenna with a total length of 2 meters above corresponds to a wavelength of 8 meters, and one half corresponds to a wavelength of 4 meters.

Therefore, the above embodiment provides a dipole antenna for use with radio waves having a wavelength of 2 meters to 8 meters.

Since the present invention has the configuration described above, by combining multiple antennas of the present invention,
In addition to normal wave transmitting and wave receiving antennas, it is possible to provide antennas for radio direction finders for measuring the arrival direction of radio waves.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional view showing the main parts of the present invention. 11, 12... Upper antenna, 21, 22...
Lower antenna, 15, 17... Long wavelength band feed line, 16, 18... Short wavelength band feed line, 19...
Base, 20... Support, 31, 32... Turned part,
41, 42... Connection portion, 51, 52... Outer conductor of coaxial line, 61, 62... Inner conductor of coaxial line, 7
1, 72...Matching coil, 91, 92...Leader wire of internal conductor for short wavelength band, 101, 102...
... External conductor lead line for long wavelength band, 8 ... Neutral point, 81 ... Neutral point connection line, 201, 20
2,203,204...Stabilizing resistor.

Claims (1)

[Claims for Utility Model Registration] The outer ends of dipole-type lower antennas 21 and 22 into which coaxial lines 51 and 52 are drawn and the upper antenna 1
At the connection parts 41 and 42 for connecting the antennas 1 and 12, a folded parts 31 and 3 of the lower antennas 21 and 22
b) connecting the outer ends of the upper antennas 11 and 12 to the outer conductors of the coaxial lines 51 and 52;
The lower antennas 21, 22 are connected to the inner conductors 61, 62 of
In the base 19 to which c is fixed, the coaxial wires 51 and 52 are formed as matching coils 71 and 72, and d the internal conductor 6 passing through the matching coils 71 and 72 is formed.
Connecting the lead wires 91 and 92 of Nos. 1 and 62 to the short wave band feed lines 16 and 18, and e Connecting the lead wires 101 and 102 provided on the outer conductors of the matching coils 71 and 72 to the long wave band feed lines. A two-wavelength band dipole antenna featuring the following.