JPH02224408A - Non-directional antenna shaped for polarized wave - Google Patents

Abstract

PURPOSE:To make the size of an antenna small by forming the antenna by using four pieces of 3dB 90 degree hybrid circuits each of which has an input/ output terminal and two pieces of output terminals and four pieces of monopole radiant elements each of which is connected to said output terminal. CONSTITUTION:A transmission signal supplied from the input/output terminal 1 is supplied to the monopole radiant elements 11 to 14 through a hybrid circuit and a 90 deg.-phase shifter, and a clockwise-rotational circularly polarized wave is radiated from the mopnopole radiant elements 11 to 14. Similarly, as for the transmission signal to be supplied from the input/output terminal 2, the signal phase of a feeding point D1 based on the signal of the feeding point D4 is delayed by 270 degrees behind the signal of the feeding point D4, and all the transmission signals of the feeding points D1 to D4 become equal. Accordingly, it can be radiated as a counter-clockwise-rotational circularly polarized wave from the monopole radiant elements 11 to 14. Consequently, the clockwise- rotational and the counter-clockwise-rotational circularly polarized waves can be transmitted simultaneously from the input/output terminals 1 and 2 respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an omnidirectional antenna used in a high frequency band on VHFHF, and more particularly to a dual polarization omnidirectional antenna that can share both polarizations.

(Prior Art) Conventionally, this type of dual-polarized omnidirectional antenna consists of three rat race circuits 51, 52, . . . as shown in FIG.
53, the rat race circuit 51 has an input/output terminal 1
, 2, and output one output from rat race 52.
, and the other output is supplied to the 90 degree phase shifter 10.
The signal is supplied to the single power of the rat race circuit 53 via. Here, the other input/output of the rat race circuits 52 and 53 is
A terminator is connected to the output terminal, and each output has a total of 4
Each of the monoball radiating elements 11 to 14 is connected to each of the monoball radiating elements 11 to 14.

(Problems to be Solved by the Invention) In the above-mentioned conventional omnidirectional antenna that can be used for both circular waves, each rat race circuit requires a line length of 3/4 wavelength in the rat race circuit section used. It had the disadvantage of being large.

(Means for Solving the Problems) A dual polarization omnidirectional antenna according to the present invention has first and second 3dB9 antennas each having an input/output terminal and two output terminals.
One output terminal of the 0 degree hybrid and the first 3 dB 90 degree hybrid are connected to one input terminal, and one output terminal of the second 3 dB 90 degree hybrid is connected to the 90 degree hybrid.
a third 3 dB 90 degree hybrid connected to the color input terminal via a degree phase shifter and having two output terminals, and one output terminal of the second 3 dB 90 degree hybrid connected to the one input terminal and having two output terminals; The other output terminal of one 3dB 90 degree hybrid is connected to the color input terminal through a 90 degree phase shifter, and the fourth 3dB having two output terminals
It includes a 90 degree hybrid and four monoball radiating elements each connected to each output terminal of the third and fourth 3 dB 90 degree hybrids.

(Example) The present invention will be explained below with reference to the drawings.

FIG. 1 is a configuration diagram showing an embodiment of a dual polarization omnidirectional antenna according to the present invention. In FIG. Monoball radiating elements 1 and 2 are input/output terminals for mutually counter-swirling circularly polarized feeding.

In this example, four 3dB 90 degree hybrids 3
1 to 34, and a terminator 8 is connected to the isolation boat of the hybrids 31 and 32. The terminal on the opposite side of the input/output terminal of each hybrid 31 to 34 is A
1-A4 and C1-C4. Terminal A2 of hybrid 31 and terminal A3 of hybrid 32 are connected to hybrids 33 and 34 via phase shifters 101 and 102, respectively, with a 90 degree phase delay. Further, D1 to D4 are monoball radiation elements 11 to 14, respectively.
Indicates the power feeding point.

Note that since the antenna is a reversible system, it operates in the same way as a transmitting antenna and as a receiving antenna, so in the following explanation, the operation as a transmitting antenna will be explained.

When transmit power is supplied to input/output terminal 1, it is divided into 1/2 to terminals A1 and A2 of hybrid 31, and the phase of the transmit signal output to A2 is different from that of the transmit signal output to A1. A signal appears with a phase delayed by 90 degrees.

The transmission signal supplied to the hybrid 33 through the terminal A1 is further equally distributed in the hybrid 33, and is sent to the terminals 01 and 0.
2, a signal appears which is further equally distributed and has a phase difference in which the phase of the signal output to C2 is delayed by 90 degrees with respect to C1. From terminal C1 to feeding point D1, from terminal C2 to feeding point D
2. From terminal 03 to power supply point D3, from terminal C4 to power supply point D4
If the electrical lengths of the lines up to The output signal of - is delayed by 90 degrees.

On the other hand, among the transmission signals supplied from input/output terminal 1,
Hybrid 3 via 90 degree phase detector 02 from terminal A2
The signal supplied to 4 is processed in the hybrid 34 in the same manner as in the hybrid 34, and the transmission signal power appearing at the feeding point D3 via the terminal C3 is equal to the power appearing at the feeding points Di and D2, and the phase is equal to that appearing at the feeding point D1. 180 degrees slower than the signal that appears.

Similarly, the signal from the terminal A2 of the hybrid 31 is supplied to the hybrid 34 via the 90-degree phase shifter 102. The power of the transmission signal that appears at the feeding point D4 via the terminal 04 of the hybrid 34 is equal to the signal power of D3, and the phase of the signal is 27 times smaller than the signal of feeding point D1.
It is clear that the delay is 0 degrees.

Therefore, the transmission signal supplied from input/output terminal 1 is
The light is supplied to the monoball radiating elements 11-14 through a hybrid 90-degree phase shifter with the phase relationship described above, and right-handed circularly polarized waves are radiated from the monoball radiating elements 11-14. Similarly, if the transmission signal supplied from the input/output terminal 2 is based on the signal at the feeding point D4, the transmission signal supplied from the input/output terminal 2 is
The phase of the signal at feeding point D2 is delayed by 90 degrees, the signal phase at feeding point D2 is delayed by 180 degrees from the signal at feeding point D4, and the signal phase at feeding point D1 is delayed by 270 degrees from the signal at feeding point D4. Since the transmission signal powers of D1 to D4 are all equal, the transmission signals supplied from the input/output terminal 2 can be radiated from the monoball radiating elements 11 to 14 as left-handed circularly polarized waves. As a result, it becomes possible to simultaneously transmit clockwise and counterclockwise circularly polarized waves from the input/output terminals 1 and 2, respectively.

(Effects of the Invention) As explained above, in the present invention, a 3 dB9
Since it uses a 0 degree hybrid, the conventional minimum is about 3
Whereas an electrical length of /4 wavelength was required, an electrical length of approximately 1/4 wavelength is sufficient, which has the effect of reducing the size of the antenna as a whole.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the shared omnidirectional antenna according to the present invention, and FIG. 2 is a block diagram of a conventional antenna. 1.2...Input/output terminal, 8...Terminator, 10゜101.102...Phase shifter, 31-34...3dB
90 degree hybrid, 51-53... rat race circuit section, 11-14... monoball radiation element.

Claims (1)

[Claims] The first and second terminals each have an input/output terminal and two output terminals.
3dB90 degree hybrid of the first 3dB90
One output terminal of the second 3 dB 90 degree hybrid is connected to one input terminal, and one output terminal of the second 3 dB 90 degree hybrid is connected to the other input terminal via a 90 degree phase shifter.
a third 3 dB 90 degree hybrid having two output terminals; one output terminal of the second 3 dB 90 degree hybrid is connected to one input terminal and the first 3 dB 90 degree hybrid has two output terminals;
The other output terminal of the 0 degree hybrid is connected to the other input terminal via a 90 degree phase shifter, and a fourth 3 dB 90 degree hybrid having two output terminals, and the third and fourth three
A dual polarization omnidirectional antenna comprising four monoball radiating elements each connected to each output terminal of a dB90 degree hybrid.