JPH05299928A - Primary radiator in common use for circularly polarized wave and linearly polarized wave - Google Patents

Abstract

PURPOSE:To receive a polarized wave without deterioration in the reception sensitivity even when a deviation takes place between horizontal and vertical directions being reference directions of the primary radiator and a polarized wave front of a horizontally or vertically polarized wave made incident in the primary radiator. CONSTITUTION:The primary radiator consists of a circular waveguide 2 having an aperture 1 introducing an electromagnetic wave at one end and having a termination face 3 at other end, a ferrite rod 4 with a 1st exciting coil 5 wound around whose lengthwise direction is formed in parallel with a guide axis toward the aperture 1 of the circular waveguide 2 and arranged in the center of the circular waveguide 2, four sets of 2nd-5th exciting coils (6, 7 and others are not shown) provided to an outer circumference of the circular waveguide 2 with the ferrite rod 4 located thereto at an equal interval vertically, and a probe 8 inserted in the inside of the circular waveguide 2 from the side face of the circular waveguide 2 between the ferrite rod 4 and the termination face 3 at an angle bisecting the angle formed by the adjacent exciting coils among the four exciting coils.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a satellite broadcasting (BS) using circular polarization and a communication satellite (CS) using linear polarization (horizontal polarization and vertical polarization). , And a primary radiator for both circularly polarized waves and linearly polarized waves that can be received together.

[0002]

2. Description of the Related Art A conventional primary radiator for both circularly polarized waves and linearly polarized waves has an opening 21 of a circular waveguide 22 as shown in FIG.
On the side, the 90-degree phase difference plate 23 is arranged so that the longitudinal direction is parallel to the tube axis, and the ferrite polarizer 24 is arranged on the end face 27 side of the circular waveguide 22.
The angle of attachment of the 90-degree phase difference plate 23 as viewed from the side of the opening 21 is set to be parallel to the electric field of the horizontal polarization or the vertical polarization introduced into the circular waveguide 22, and the ferrite polarizer 24 and the termination surface. When a probe 26 for signal output is provided on the side surface of the circular waveguide 22 between the two and is inserted into the circular waveguide 22 to receive horizontal polarization or vertical polarization, a current is passed through the ferrite polarizer 24. When the circularly polarized wave is received by rotating the electric field direction of the horizontal polarized wave or the vertical polarized wave by rotating the electric field, coupling the polarized wave desired to be received with the probe 26 and converting it into an electric signal. The 90-degree phase plate 23 is oriented parallel to the Y-axis, and the left-hand circularly polarized wave is
Degree phase difference plate 23 converts the linearly polarized wave, and the electric current is passed through the ferrite polarizer 24 to rotate the direction of the electric field of the linearly polarized wave, which is coupled to the probe 26 and converted into an electric signal. Was taken out so that circular polarization and linear polarization could be received. When receiving a right-handed circularly polarized wave, it is necessary to change the direction of the 90-degree phase difference plate 23 so that it is parallel to the X-axis. Therefore, a single primary radiator makes a left-handed circularly polarized wave and a right-handed circularly polarized wave. It could not be used commonly for circular polarization.

9 viewed from the side of the opening 21 of the circular waveguide 22
When the mounting angle of the 0-degree phase difference plate 23 is deviated from the plane of polarization of the horizontal polarization or the vertical polarization, the horizontal polarization and the vertical polarization are respectively perpendicular to the 90-degree phase difference plate 23. Since there is a propagation state having a component and a horizontal component, a phase difference occurs between the vertical component and the horizontal component, and horizontal polarization,
Alternatively, the vertically polarized wave becomes an elliptically polarized wave when passing through the 90-degree phase difference plate 23, and there is a problem that the reception sensitivity is reduced. Communication satellites are launched at different positions, and the polarization plane of horizontal polarization or vertical polarization that reaches the ground is slightly deviated from the horizontal or vertical direction for each satellite. When receiving linearly polarized waves of multiple satellites with a single antenna, the actuators direct the antennas toward the respective satellites, so the horizontal and vertical directions that are the reference of the primary radiator attached to the antenna are also tilted. Therefore, there is a problem in that a deviation occurs between the polarization plane of the horizontally polarized wave or the vertically polarized wave that is incident on the primary radiator, which lowers the reception sensitivity.

[0004]

According to the present invention, by removing the 90-degree phase difference plate 23 and using a ferrite rod, horizontal polarization or vertical polarization is incident on the primary radiator at an arbitrary angle. In this case, the reception can be performed without lowering the reception sensitivity, and even if circularly polarized waves (left-handed and right-handed circularly polarized waves) are incident, they can be converted to linearly polarized waves and received. An object is to provide a primary radiator for both wave and linear polarization.

[0005]

FIG. 1 is a partially cutaway perspective view of a primary radiator for circular polarization and linear polarization, showing an embodiment of the present invention. As shown in FIG. A circular waveguide 2 having an opening 1 for introducing an electromagnetic wave at one end and a terminating surface 3 at the other end, and the longitudinal direction on the side of the opening 1 of the circular waveguide 2 is parallel to the tube axis. The ferrite rod 4 having the first exciting coil 5 wound around it and arranged at the center of the circular waveguide 2 is perpendicular to the outer circumferential portion of the circular waveguide 2 where the ferrite rod 4 is located. Four second to fifth exciting coils (6 and 7, other not shown) provided at even intervals
And the mounting angle viewed from the opening of the circular waveguide is an angle that bisects the angle formed by the adjacent exciting coils among the four exciting coils, and between the ferrite rod 4 and the terminal surface 3. The probe 8 inserted inside the circular waveguide 2 from the side.

[0006]

By applying a DC current to the exciting coil 5, a DC magnetic field along the axial direction is applied to the ferrite rod 4 so that the polarization planes of the horizontal polarization and the vertical polarization introduced into the circular waveguide 2 are made relative to each other. The desired signal to be received and coupled to the probe 8 to convert it into an electric signal, which is provided at equal intervals vertically on the outer circumference of the circular waveguide 2 where the ferrite rods 4 are located. Of the four exciting coils (6 and 7, others not shown), two facing each other, for example, exciting coils 6 and 7
By applying a DC current to the ferrite rod 4, a DC magnetic field in the Y-axis direction is applied to convert the circularly polarized wave introduced into the circular waveguide 2 into a linearly polarized wave. When circularly polarized waves are received, a DC magnetic field in the X-axis direction is applied to the ferrite rod 4 by applying a DC current to the opposing exciting coils (not shown) other than the exciting coils 6 and 7, and the circular waveguide The circularly polarized wave introduced into the tube 2 is converted into a linearly polarized wave, the linearly polarized wave is coupled with a probe to be converted into an electric signal, and the signal can be taken out through the probe, at an arbitrary angle. It enables horizontal polarization and vertical polarization incident on the primary radiator to be received without deteriorating the receiving sensitivity, and linear even when circular polarization (left-handed and right-handed circularly polarized) is incident. It is converted to polarized waves so that it can be received.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a partially cutaway perspective view of a primary radiator for both circular polarization and linear polarization, showing an embodiment of the present invention.
In the figure, an axis extending upward from the tube axis of the circular waveguide is defined as a Y-axis, an axis extending leftward is defined as an X-axis, and opposite axes are defined as -Y-axis and -X-axis (not shown). ) (Hereinafter the same in FIGS. 2 and 3). One end of the circular waveguide 2 is formed as a horn-shaped opening 1 so that an electromagnetic wave can be efficiently introduced, and a terminal surface 3 for reflecting the introduced electromagnetic wave is provided at the other end. Reference numeral 4 denotes a ferrite rod, which is arranged at the center of the circular waveguide 2 so that the longitudinal direction of the ferrite rod 4 is parallel to the tube axis on the side of the opening 1 of the circular waveguide 2. Wrap the excitation coil 5 around the
The exciting coil 5 is sandwiched between the inner walls of the circular waveguide 2 so that the ferrite rod 4 is held at a predetermined position inside the circular waveguide 2. The ferrite rod 4 is put in a metal tube (not shown), an exciting coil 5 is wound around the metal tube, and ceramic pieces (not shown) for matching with the circular waveguide 2 are provided at both ends of the metal tube. No) may be attached.

Exciting coil 5 provided in the circular waveguide 2
Through the opening (not shown) provided on the side surface of the circular waveguide 2, and is connected to the DC power source by connecting to the DC power source so that a DC current flows through the exciting coil 5. Thus, a predetermined DC magnetic field can be applied in the longitudinal direction of the ferrite rod 4. Reference numeral 8 denotes a probe, which is inserted into the circular waveguide 2 from the side surface of the circular waveguide 2 between the ferrite rod 4 and the termination surface 3. The electric field distributions of the horizontal polarization and the vertical polarization of CS introduced in the circular waveguide 2 are linear polarizations of TE11 mode orthogonal to each other, and when the CS is received, the horizontal polarization or the vertical polarization introduced. By selecting the desired one for the polarized wave and controlling the current flowing through the exciting coil 5, the ferrite rod 4
By rotating the phase angle of the electric field of the horizontally polarized wave or the vertically polarized wave which is relatively introduced by (1), the desired polarized wave is coupled to the probe 8 so that the maximum signal can be extracted. Therefore, unlike the conventional example, since the phase difference plate is not used, even if the horizontally polarized wave or the vertically polarized wave is incident on the primary radiator at an arbitrary angle, by controlling the current flowing through the exciting coil 5, Since the phase angle of the electric field of the electromagnetic wave incident on the ferrite rod 4 can be controlled, a desired polarized wave signal can be extracted from the probe 8.

FIG. 2 is a front view of the circular polarization and linear polarization primary radiator of FIG. Four exciting coils (6, 7, 11, and 12) are provided vertically equidistantly on the outer circumferential portion of the circular waveguide 2 where the ferrite rods 4 are located. Each of the exciting coils (6, 7, 11 and 12) uses an iron core or the like (not shown), and the exciting coil (6, 6,
7, 11 and 12) are respectively wound,
The exciting coils 6 and 7 attached to the outer circumferential portion of the circular waveguide 2 facing each other are arranged so that a direct-current magnetic field in the Y-axis direction is applied to the ferrite rod 4, and the exciting coils 6 and 7 are similarly excited. The coils 11 and 12 are adapted to apply a DC magnetic field in the X-axis direction to the ferrite rod 4.
The probe 8 is inserted into the circular waveguide 2 from the side surface of the circular waveguide 2 between the ferrite rod 4 and the termination surface 3 at an angle that bisects the angle formed by the adjacent excitation coils 7 and 11. ing.

The circularly polarized wave is a state in which the amplitudes of two orthogonal linearly polarized waves are equal and their phases are deviated from each other by 90 degrees, and the electric field of the circularly polarized wave of BS bisects the -X axis and the -Y axis. Is introduced into the circular waveguide 2. When the circularly polarized wave is the left-handed circularly polarized wave, the linearly polarized wave in the −Y-axis direction is 90 degrees in phase ahead of the linearly polarized wave in the −X-axis direction, and the excitation coils 6 and 7 are provided. By applying a current to the ferrite rod 4 to apply a magnetic field in the Y-axis direction, the phase velocity of the linearly polarized wave in the -Y-axis direction can be delayed with respect to the linearly polarized wave in the -X-axis direction. If the currents flowing through the exciting coils 6 and 7 are controlled so that the phases of the linearly polarized wave in the -X axis direction and the linearly polarized wave in the -Y axis direction are matched when passing through 4,
Since it can be converted into a linearly polarized wave having an electric field in a direction that bisects the −X axis and the −Y axis, the same linearly polarized wave is coupled to the probe 8 and a signal of a left-handed circularly polarized wave is passed through the probe 8. Can be taken out. Reference numeral 10 is an input terminal of the DC power supply, one end of the exciting coil 6 is connected to one end of the input terminal 10, the other end of the exciting coil 6 is connected to one end of the exciting coil 7, and the other end of the exciting coil 7 is an input terminal. 10 is connected to the other end of the input terminal 10, and a DC power source is connected to both ends of the input terminal 10 so that a DC current can flow through the exciting coils 6 and 7 so that a predetermined DC magnetic field can be applied to the ferrite rod 4. ing.

When the circularly polarized wave is a right-handed circularly polarized wave, the linearly polarized wave in the -Y-axis direction is 90 times that in the -Y-axis direction.
Excitation coils 11 and 1
By applying a current to the ferrite rod 4 and applying a magnetic field in the X-axis direction to the ferrite rod 4, the linear polarization in the -Y-axis direction becomes -X.
The phase velocity of the linearly polarized wave in the axial direction can be delayed, and when passing through the ferrite rod 4, the exciting coil is set so that the phase of the linearly polarized wave in the −X axis direction and the linearly polarized wave in the −Y axis direction match. By controlling the currents flowing through 11 and 12, it is possible to convert into a linearly polarized wave having an electric field in a direction that bisects the -X axis and the -Y axis. Therefore, by coupling the linearly polarized wave to the probe 8, A right-handed circularly polarized signal can be taken out via the probe 8. Reference numeral 13 is an input terminal of the DC power supply, one end of the exciting coil 11 is connected to one end of the input terminal 13, and the other end of the exciting coil 11 is connected to one end of the exciting coil 12.
The other end of the exciting coil 12 is connected to the other end of the input terminal 13, a DC power source is connected to both ends of the input terminal 13, and a DC current is caused to flow through the exciting coils 11 and 12 to generate a predetermined DC magnetic field. It is possible to add it to the rod 4. Therefore, unlike the conventional example, left-handed and right-handed circularly polarized waves can be received by the same primary radiator. Of the circular polarization,
When receiving only left-handed circularly polarized waves, exciting coils 11 and 1
2 may be omitted, or the excitation coils 6 and 7 may be omitted when only right-handed circularly polarized waves are received.

[0012]

As described above, according to the present invention,
By applying a DC magnetic field to the ferrite rod along the axial direction, the polarization planes of horizontal polarization and vertical polarization are relatively rotated, and the desired reception is selected and coupled to the probe to convert it to an electrical signal. Then, by applying a DC magnetic field in the diameter direction to the ferrite rod, the circularly polarized wave is converted into a linearly polarized wave, the linearly polarized wave is coupled to the probe, converted into an electric signal, and the signal can be taken out through the probe. Unlike the conventional example, since the 90-degree phase difference plate is not used, it is possible to eliminate the directivity such as the horizontal direction and the vertical direction, which are the reference of the primary radiator, and the primary radiator can have an arbitrary angle. It is possible to provide a primary radiator for both circularly polarized waves and linearly polarized waves that can be received without lowering the sensitivity even when horizontally polarized wave or vertically polarized wave is incident.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a primary radiator for both circular polarization and linear polarization, showing an embodiment of the present invention.

FIG. 2 is a front view of the primary radiator for circular polarization and linear polarization, which is the same as the above.

FIG. 3 is a partially cutaway perspective view of a primary radiator for both circular polarization and linear polarization, showing a conventional example.

[Explanation of symbols]

 1 Opening 2 Circular Waveguide 3 End Surface 4 Ferrite Rod 5 Excitation Coil 6 Excitation Coil 7 Excitation Coil 8 Probe 9 Leader Wire 10 Input Terminal 11 Excitation Coil 12 Excitation Coil 13 Input Terminal 21 Opening 22 Circular Waveguide 23rd Position Phase difference plate 24 Ferrite polarizer 26 Probe 27 End surface

Claims (1)

[Claims] 1. An opening for introducing an electromagnetic wave is provided at one end,
A circular waveguide with a terminating surface at the other end and the circular waveguide at the center of the circular waveguide with the longitudinal direction parallel to the tube axis on the opening side of the circular waveguide. A ferrite rod around which the first excitation coil is wound, four second to fifth excitation coils provided at equal intervals vertically on the outer circumferential portion of the circular waveguide where the ferrite rod is located, and the circular shape. The mounting angle viewed from the opening of the waveguide is an angle that bisects the angle formed between the adjacent exciting coils of the four exciting coils, and the circular waveguide between the ferrite rod and the end face. A primary radiator for both circularly polarized waves and linearly polarized waves, characterized in that it comprises a probe inserted inside from the side surface of.