JP3668649B2 - Primary radiator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a primary radiator provided in a satellite broadcast reflection antenna or the like, and more particularly to a primary radiator suitable for converting circularly polarized waves into linearly polarized waves.
[0002]
[Prior art]
FIG. 7 shows a conventional example of this type of primary radiator, wherein FIG. 7 (a) is a left side view and FIG. 7 (b) is a cross-sectional view. The primary radiator includes a waveguide 1 having a horn portion 1a at one end and a closed surface 1b at the other end, a 90-degree phase shift plate 2 installed inside the waveguide 1, and a waveguide 1 The first and second probes 3 and 4 are inserted from the wall surface of the tube, and the distance between the probes 3 and 4 and the blocking surface 1a is about 1/4 wavelength of the guide wavelength. . The horn part 1a is opened in a conical shape, and the waveguide 1 including the horn part 1a is integrally formed by zinc die casting or the like. The 90-degree phase shift plate 2 is made of a dielectric plate having a predetermined thickness. The 90-degree phase shift plate 2 is inserted from the opening end of the horn 1a and fixed to the inner wall of the waveguide 1 by press-fitting or the like. Yes. Both the probes 3 and 4 are orthogonal to each other, and the 90-degree phase shift plate 2 is installed in a state inclined approximately 45 degrees with respect to the first and second probes 3 and 4.
[0003]
In the primary radiator configured as described above, the left-handed circularly polarized wave and the right-handed circularly polarized wave transmitted from the satellite are guided into the waveguide 1 from the horn portion 1a and linearly moved by the 90-degree phase shift plate 2. Converted to polarization. In the example shown in FIG. 7, since the left-handed circularly polarized wave is converted into the vertically polarized wave and the right-handed circularly polarized wave is converted into the horizontally polarized wave, the left-handed circularly polarized wave is installed vertically in the waveguide 1. The right-handed circularly polarized wave is received by the second probe 4 installed horizontally in the waveguide 1, and the received signal is converted into an IF frequency signal by a converter circuit (not shown). It is converted and output.
[0004]
[Problems to be solved by the invention]
By the way, in the conventional primary radiator configured as described above, the horn portion 1a protruding from the tip of the waveguide 1 needs to have a desired opening diameter and length, and continues to the horn portion 1a. Since it is necessary to fix the 90-degree phase shift plate 2 inside the waveguide 1, there is a problem that the primary radiator becomes longer in the axial direction of the waveguide 1. In particular, the 90-degree phase shift plate 2 fixed inside the waveguide 1 needs a sufficient length to convert circularly polarized light into linearly polarized light. The size increases due to the installation space of the 90-degree phase shift plate 2, and this is a major factor that hinders downsizing of the primary radiator. The 90-degree phase shift plate 2 is inserted from the horn 1a and fixed inside the waveguide 1. The 90-degree phase shift plate 2 is tilted by about 45 degrees with respect to the probes 3 and 4. Therefore, it is difficult to fix with high accuracy, and there is a problem that assembly workability is poor.
[0005]
[Means for Solving the Problems]
The present invention holds the dielectric feeder having a radiating portion on the open end of the waveguide, the radiation portion of the dielectric feeder intersect at an angle of about 45 degrees with respect to the probe at a site opposite A 90-degree phase shift portion extending in the radial direction of the waveguide is formed, and the 90-degree phase shift portion is configured by a stepped groove or a stepped projection having a step in the width direction . If comprised in this way, since a dielectric feeder has both functions as a horn part and a 90-degree phase shift plate, while being able to greatly shorten the full length of a primary radiator, it consists of a stepped groove | channel or a stepped protrusion. Impedance matching can be performed with respect to orthogonal polarization by the 90-degree phase shift section, and the 90-degree phase shift section can be accurately aligned with the probe.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
In the primary radiator of the present invention, a waveguide having an opening for introducing a radio wave at one end thereof, a dielectric feeder made of a dielectric material held at the opening end of the waveguide, and inserted into the waveguide. The dielectric feeder is provided with a radiating portion protruding from the open end of the waveguide and a holding portion fixed to the inner surface of the waveguide, and the probe is disposed on the end surface of the holding portion. A 90-degree phase shift portion extending in the radial direction of the waveguide is formed by crossing at an angle of about 45 degrees, and the 90-degree phase shift portion includes a plurality of concave grooves having different groove widths. Each groove has a depth of about ¼ wavelength of the radio wave .
[0007]
In the primary radiator of the present invention, a waveguide having an opening for introducing a radio wave at one end, a dielectric feeder made of a dielectric material held at the opening end of the waveguide, and the waveguide The dielectric feeder is provided with a radiation portion protruding from the open end of the waveguide and a holding portion fixed to the inner surface of the waveguide, and the end surface of the holding portion is provided with the A 90-degree phase shift portion extending in the radial direction of the waveguide is formed by crossing at an angle of about 45 degrees with respect to the probe, and the 90-degree phase shift portion guides the plurality of convex portions having different plate thicknesses to the waveguide. The projections are stepped projections continuous in the tube axis direction of the tube, and each of the convex portions has a height of about a quarter wavelength of the radio wave.
[0008]
If comprised in this way, since the circularly polarized wave input from the radiation | emission part of the dielectric feeder will be converted into a linear polarization | polarized-light by a 90 degree | times phase-shifting part, the full length of a primary radiator can be reduced significantly, and 90 Since the phase shift part is composed of a stepped groove or a stepped protrusion having a step in the width direction, impedance matching can be performed with respect to orthogonal polarized waves, and the 90 degree phase shift part is in the dielectric feeder. Since it is integrally formed, the 90-degree phase shift portion can be accurately aligned with the probe. At that time, the number of the concave grooves constituting the stepped groove and the number of convex parts constituting the stepped protrusion is not particularly limited, but the stepped groove is a two-stage having a narrow concave groove continuously on the bottom surface of the wide concave groove. It is preferable to use a two-step structure in which the stepped protrusion is formed on the end surface of the wide protrusion, or the length of the 90-degree phase shift portion can be effectively shortened. .
[0009]
Further, in the above configuration, when the radiating portion is formed in a trumpet shape extending in the protruding direction from the open end of the waveguide, and a plurality of annular grooves are formed on the end face of the radiating portion, Since the phase of the radio wave reflected by the end face of the portion and the bottom surface of the annular groove is reversed and canceled, there is almost no reflection component of the radio wave toward the radiating portion, and the radio wave can be efficiently converged on the dielectric feeder.
[0010]
【Example】
Embodiments will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a primary radiator according to a first embodiment of the present invention, FIG. 2 is a side view seen from the direction of arrow A in FIG. It is a perspective view of the dielectric material feeder with which a radiator is equipped.
[0011]
As shown in these drawings, the primary radiator according to the present embodiment is held by a waveguide 5 having a circular section with one end opened and the other end closed surface 5a, and the open end of the waveguide 5. A dielectric feeder 6 is provided, and a first probe 7 and a second probe 8 are installed inside the waveguide 5 so as to be orthogonal to each other. The distance between the probes 7 and 8 and the blocking surface 5a is about 1/4 wavelength of the guide wavelength λg, and both probes 7 and 8 are connected to a converter circuit (not shown).
[0012]
The dielectric feeder 6 is made of a dielectric material having a low dielectric loss tangent. In the case of the present embodiment, inexpensive polyethylene (dielectric constant ε = 2.25) is used in consideration of cost. The dielectric feeder 6 includes a holding portion 6a having a concave portion 9 as a 90-degree phase shift portion on one end surface, and a radiating portion 6b that continues in a conical shape from the other end of the holding portion 6a. 6 b protrudes from the open end of the waveguide 5 to the outside. The outer diameter of the holding portion 6 a is set to be substantially the same as the inner diameter of the waveguide 5. By pressing the holding portion 6 a into the inner surface of the opening end of the waveguide 5, the dielectric feeder 6 can be used as the waveguide 5. It is fixed to. The concave portion 9 is a stepped hole in which a narrow concave groove 9b is connected to the bottom surface of a wide concave groove 9a, and the depth of both concave grooves 9a and 9b is approximately the wavelength of the wave wavelength λε propagating in the dielectric feeder 6. The quarter wavelength is set. As shown in FIG. 2, the concave portion 9 (the concave grooves 9 a and 9 b) extends in the radial direction of the waveguide 5, and the extending direction is approximately 45 degrees with respect to the first and second probes 7 and 8, respectively. Crossing at an angle of
[0013]
In the primary radiator configured as described above, the left-handed circularly polarized wave and the right-handed circularly polarized wave transmitted from the satellite enter from the radiating portion 6b and propagate through the dielectric feeder 6, and reach the end face of the holding portion 6a. Due to the formed recess 9, the left-handed circularly polarized wave is converted into a vertically polarized wave, and the right-handed circularly polarized wave is converted into a horizontally polarized wave. At this time, since the depth of both concave grooves 9a and 9b constituting the concave portion 9 is set to about ¼ wavelength of the radio wave wavelength λε propagating in the dielectric feeder 6, the end surface and the width of the holding portion 6a are narrow. The phase of the radio wave reflected from the bottom surface of the concave groove 9b and the radio wave reflected from the bottom surface of the wide concave groove 9a are reversed and canceled. Thereby, the reflection component of the radio wave propagating through the dielectric feeder 6 and going into the waveguide 5 is almost eliminated, and impedance matching between the dielectric feeder 6 and the waveguide 5 is improved. Of the linearly polarized waves composed of the horizontally polarized waves and the vertically polarized waves input to the waveguide 5, the left-handed circularly polarized waves converted into the vertically polarized waves are received by the first probe 7 and converted into the horizontally polarized waves. The right-handed circularly polarized wave is received by the second probe 8, and the received signal is converted into an IF frequency signal by a converter circuit (not shown) and output.
[0014]
In the first embodiment described above, the concave portion 9 formed on the end surface of the holding portion 5a of the dielectric feeder 6 having the radiating portion 6b functions as a 90-degree phase shift portion that converts circularly polarized light into linearly polarized light. Therefore, the overall length of the primary radiator including the waveguide 5 and the dielectric feeder can be reduced. Further, even if a sufficient length is secured in the holding portion 6a, the total length of the dielectric feeder 6 does not become long, so that the posture of the dielectric feeder 6 can be stabilized, and the dielectric feeder 6 can be moved 90 degrees. Since the concave portion 9 as the phase portion is integrally formed, the concave portion 9 can be accurately aligned with the probes 7 and 8. Further, the concave portion 9 is formed by a stepped hole in which two concave grooves 9 a and 9 b are continuously arranged, and the depth of both concave grooves 9 a and 9 b is about 1 / wavelength λε propagating in the dielectric feeder 6. Since the four wavelengths are set, the phase of the radio wave reflected by the bottom surface and the open end of each concave groove 9a, 9b is reversed and canceled, and impedance matching between the dielectric feeder 6 and the waveguide 5 becomes good. .
[0015]
4 is a cross-sectional view of a primary radiator according to a second embodiment of the present invention, FIG. 5 is a side view seen from the direction of arrow B in FIG. 4, and parts corresponding to those in FIGS. It is attached.
[0016]
The second embodiment is different from the first embodiment described above in that a convex portion 10 as a 90-degree phase shift portion is formed on the end face of the holding portion 6a of the dielectric feeder 6, and the other configuration. Are basically the same. The convex portion 10 is a shape in which the concave portion 9 is reversed, that is, a stepped projection in which the narrow convex portion 10b protrudes from the end face of the wide convex portion 10a, and the height of both convex portions 10a and 10b is a dielectric. It is set to about ¼ wavelength of the radio wave wavelength λε propagating in the feeder 6. Therefore, among the radio waves propagating through the dielectric feeder 6 and traveling toward the end surface of the holding portion 6a, the phases of the radio waves reflected from the end surfaces and the bottom surface side of the both convex portions 10a and 10b are reversed and canceled. The reflection component of the radio wave propagating through the feeder 6 is almost eliminated, and the impedance matching between the dielectric feeder 6 and the waveguide 5 is improved.
[0017]
In the primary radiator configured as described above, the convex portion 10 formed on the end face of the holding portion 6a functions as a 90-degree phase shift portion that converts circularly polarized light into linearly polarized light. Therefore, compared to the first embodiment. Although the overall length of the dielectric feeder 6 is slightly longer, substantially the same effect can be achieved.
[0018]
In addition, the primary radiator by this invention is not limited to said each Example, A various modification can be employ | adopted. For example, the number of steps of the concave portion 9 and the convex portion 10 functioning as a 90-degree phase shift portion may be appropriately increased or decreased, or the cross-sectional shape of the holding portion 6a of the waveguide 5 or the dielectric feeder 6 may be changed to a square shape instead of a circular shape. possible Ru der.
[0019]
Further, the shape of the radiating portion of the dielectric feeder is not limited to the conical shape of each of the above embodiments, and the radiating portion 6b is expanded in a trumpet shape as shown in FIG. 6 in order to reduce the length of the radiating portion itself. Anyway. In this case, when a plurality of annular grooves 11 are formed on the end face of the radiating portion 6b and the depth of each annular groove 7 is set to about ¼ wavelength of the radio wave wavelength λ ₀ propagating in the air, the end face of the radiating portion 6b Since the phase of the radio wave reflected from the bottom surface of the annular groove 11 is reversed and canceled, the reflected component of the radio wave directed toward the radiating portion 6 b is almost eliminated, and the radio wave can be efficiently converged on the dielectric feeder 6.
[0020]
【The invention's effect】
The present invention is implemented in the form as described above, and has the following effects.
[0021]
Holds the dielectric feeder having a radiating portion on the open end of the waveguide, the radial direction of the dielectric crossover to waveguide at an angle of the probe and approximately 45 degrees at the site opposite to the radiating portion of the feeder If the 90-degree phase shift part is formed with a stepped groove or stepped protrusion having a step in the width direction, the circular deviation input from the radiating part into the dielectric feeder is formed. since the wave is converted into linear polarization with 90 degree phase shifting unit, Rutotomoni can greatly reduce the overall length of the primary radiator, stepped grooves 90 degree phase shifting unit to have a step in the width direction Alternatively, since it is composed of stepped protrusions, impedance matching can be satisfactorily performed with respect to orthogonally polarized waves, and since the 90-degree phase shift portion is integrally formed with the dielectric feeder, the 90-degree phase shift portion is It can be accurately aligned with the probe .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a primary radiator according to a first embodiment of the present invention.
FIG. 2 is a side view as seen from the direction of arrow A in FIG.
FIG. 3 is a perspective view of a dielectric feeder provided in the primary radiator.
FIG. 4 is a cross-sectional view of a primary radiator according to a second embodiment of the present invention.
5 is a side view seen from the direction of arrow B in FIG.
FIG. 6 is a cross-sectional view showing a modification of the dielectric feeder.
FIG. 7 is an explanatory diagram of a primary radiator according to a conventional example.
[Explanation of symbols]
5 Waveguide 5a Closed surface 6 Dielectric feeder 6a Holding portion 6b Radiating portion 7 First probe 8 Second probe 9 Recessed portions 9a, 9b Recessed grooves 10, 10a, 10b Protruded portion 11 Annular groove

Claims (5)

A waveguide having an opening for introducing a radio wave at one end thereof, a dielectric feeder made of a dielectric material held at the opening end of the waveguide, and a probe inserted into the waveguide; The body feeder is provided with a radiating portion protruding from the open end of the waveguide and a holding portion fixed to the inner surface of the waveguide, and the end surface of the holding portion crosses the probe at an angle of about 45 degrees. A stepped groove in which a 90-degree phase shift portion extending in the radial direction of the waveguide is formed, and the 90-degree phase shift portion has a plurality of concave grooves having different groove widths continuous in the tube axis direction of the waveguide. A primary radiator characterized in that each of the concave grooves has a depth of about ¼ wavelength of a radio wave . 2. The primary radiator according to claim 1, wherein the stepped groove is configured in two steps in which a narrow concave groove is continuously connected to a bottom surface of a wide concave groove . A waveguide having an opening for introducing a radio wave at one end thereof, a dielectric feeder made of a dielectric material held at the opening end of the waveguide, and a probe inserted into the waveguide; The body feeder is provided with a radiating portion protruding from the open end of the waveguide and a holding portion fixed to the inner surface of the waveguide, and the end surface of the holding portion is at an angle of about 45 degrees with respect to the probe. A step in which a 90-degree phase shift portion extending in the radial direction of the waveguide is formed by crossing, and the 90-degree phase shift portion has a plurality of convex portions having different plate thicknesses continuous in the tube axis direction of the waveguide. A primary radiator characterized by comprising protrusions, wherein each convex part has a height of about a quarter wavelength of a radio wave . 4. The primary radiator according to claim 3, wherein the stepped protrusion is configured in two steps in which a narrow convex portion protrudes from an end surface of the wide convex portion . 4. The radiating portion according to claim 1 or 3, wherein the radiating portion is formed in a trumpet shape extending in a protruding direction from the open end of the waveguide, and a plurality of annular grooves are formed on an end surface of the radiating portion. Primary radiator characterized by.

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