JPH04207702A - Primary radiator for circularly polarized wave - Google Patents

Abstract

PURPOSE:To realize the integral manufacture of a reflecting plate and a waveguide and to simplify the manufacture by forming the end of an opening part side of the waveguide in the reflecting plate to a mountain shape, so that an electric signal can be fetched in a state that an axial ratio and a characteristic of VSWR, etc., are cleared even if the reflecting plate is thickened. CONSTITUTION:In a primary radiator 1, as for a waveguide 2, that of a circular cross section is used, one end 3 is opened, and on the other hand, the other end 4 is closed by a reflecting wall 5 having a reflecting surface 5a. In the inside of the waveguide 2, a distance extending from a probe 7 provided in a position being near the opening end 3 to the opening end 3 is set so that a radio wave of a circularly polarized wave can exist stably in a space between both of them. A distance (h) extending from the axis center of the probe 7 to the reflecting surface 5a is set to 3/8 of guide wavelength lambdag. A reflecting plate 9 provided in a position of the inner part of the probe 7 is provided in a state that it runs along an axis of the waveguide 2, and also, is inclined at an inclination angle theta against the probe 7, and also, in a state that it is connected electrically and integrally to the reflecting surface 5a. The reflecting plate 9 is manufactured integrally with the waveguide 2. The end 10 of the opening part side of the waveguide 2 in the reflecting plate 9 is formed in a symmetrical, mountain shape.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a primary radiator for circularly polarized waves that receives circularly polarized radio waves and converts them into electrical signals.

[Conventional technology]

It has a waveguide that is open at one end to introduce circularly polarized radio waves and closed at the other end to reflect the introduced radio waves. A probe is provided in which an electrical signal is excited by the radio waves, and at a position deeper than the probe, the introduced circularly polarized radio waves are converted into linearly polarized radio waves at the position of the probe. There is a primary radiator for circularly polarized waves in which a reflecting plate is provided along the axis of the waveguide (for example, see Japanese Patent Laid-Open No. 1-277006). In such a primary radiator for circularly polarized waves, when a circularly polarized radio wave enters the waveguide, it can be converted into an electrical signal and taken out to the probe, and in this case, the presence of a reflector allows the axial ratio and Can receive with good characteristics such as VSWR.

[Problem to be solved by the invention]

However, in the conventional primary radiator for circularly polarized waves mentioned above, the reflector is thin and it is difficult to manufacture the primary radiator for circularly polarized waves integrally with the waveguide. manufactured in the body,
The separate reflecting plate must be incorporated into the waveguide, which poses a problem in that manufacturing is time-consuming. By making the reflector thicker so that it can be manufactured integrally with the waveguide, the axial ratio and V
There was a problem in that characteristics such as SWR could no longer meet standard values.

The present invention was made in order to solve the problems (technical problems) of the prior art described above, and by making the end of the reflecting plate on the side of the opening of the waveguide into a chevron shape, the reflecting plate can be thickened. This makes it possible to extract electrical signals while clearing characteristics such as axial ratio and VSW'R, and thereby enables integral manufacturing of the reflector and waveguide. The object of the present invention is to provide a primary radiator for circularly polarized waves that can be manufactured easily.

[Means to solve problems]

In order to achieve the above object, the primary radiator for circularly polarized waves according to the present invention has one end open so that circularly polarized radio waves can be introduced, and the other end closed so that the introduced radio waves can be reflected. Inside the waveguide, a probe is provided in which an electric signal is excited by linearly polarized radio waves, and at a position deeper than the probe, the above-mentioned introduced In the primary radiator for circularly polarized waves, the reflector plate is provided along the axis of the four-wave tube to convert the circularly polarized radio waves into linearly polarized radio waves at the position of the probe. The end on the waveguide side is formed into a chevron shape.

[Effect]

Incoming circularly polarized radio waves are introduced into the waveguide from the open end. The introduced circularly polarized radio waves pass through the position of the probe, are reflected at the closed end, and head toward the probe. In this case, the circularly polarized radio waves are converted into linearly polarized radio waves at the position of the probe by the reflector. The linearly polarized radio wave excites the probe and induces an electrical signal in the probe.

〔Example〕

The drawings showing the embodiments of the present application will be described below. In the primary radiation S1 shown in FIGS. 1 to 4, 2 is a waveguide with a circular cross section, -81a3 is open, and the other end 4 is provided with a reflecting wall 5. However, it is also blocked.

5a indicates a reflective surface of the reflective wall 5. The waveguide 2 is formed by cutting a metal rod, die-casting, or squeezing or pressing a metal plate. Aluminum, zinc, brass, etc. are used as the material. Reference numeral 6 denotes a conical horn connected to the open end 3, and is provided to provide directivity that matches the aperture angle of the antenna. Note that this conical horn 6 may not be used. A probe 7 is provided inside the waveguide 2 at a position close to the open end 3, is formed of a metal rod, and is fixed to the waveguide 2 via an insulator 8. The probe 7 from the open end 3
The distance is set to, for example, about z of the wavelength λg of the introduced radio wave in the waveguide 2 so that circularly polarized radio waves can stably exist in the space between them. Since the inner surface of the waveguide 2 is tapered, the inner wavelength λg is determined by the inner diameter f (for example, 18.4 mm) of the one end 3 and the other end 4, k
<For example, 17,5III11), it is preferable to find the inner wavelength at the center frequency of the received signal (for example, 11.7-12.0 GHz) and use the average value as the above-mentioned inner wavelength Jg (for example, 45.28 mm). . The distance from the axis of the probe 7 to the reflecting surface 5a is the tube wavelength zg.
Make it 378. Further, the dimension g of the portion of the probe 7 existing within the waveguide 2 is, for example, 6I. Above probe 7
The base part of the waveguide 2 extends outside through the tube wall of the waveguide 2, and serves as an output terminal 7a for transmitting the signal obtained by the probe 7 to the input end of the next stage, such as a converter or preamplifier. be. The probe 7 may be formed of a narrow metal plate or a microstrip line on a dielectric substrate.

Reference numeral 9 denotes a reflecting plate provided at a position deeper than the probe 7, which is inclined at an inclination angle θ with respect to the probe 7 along the axis of the waveguide 2, and is electrically integrated with the reflecting surface 5a. It is a continuous state of preparation. The reflecting plate 9 is manufactured integrally with the waveguide 2. It is also possible to attach it to the waveguide 2 after forming it separately. The end 10 of the waveguide 2 on the opening side at the reflection 1.9 is formed into a symmetrical chevron shape as clearly shown in FIG. The dimension a in the axial direction of the waveguide 2 in the central part of the reflection plate 9 is equal to the guide wavelength (47, 2
4mm) (for example, 11.81m+n), and the axial dimension of the waveguide 2 at both edges is equal to the guide wavelength (43, 52++n) of 174 (e.g. 10
．． 88+! +m). The thickness C of the base part and the thickness d of the top part of the reflector plate 9 are required to have a certain degree of thickness in order to allow the metal material to flow into the mold during molding, and also to be thicker than the former for demolding. It is also necessary to reduce the latter, and in this example, they are 2.4 m++w and 1 m-, respectively. In principle, the tilt angle θ is set to 45°, but when the circularly polarized wave has an elliptical component, the angle is set to around 45°.

Distance e between the probe 7 and the peak of the chevron on the reflection plate 9
is about 1/8 of the wavelength λg (for example, 5.17+*m)
be made into In the brief review, the reflector 9 is for left-handed circularly polarized waves. In the case of right-handed circularly polarized waves, it is arranged at an inclination as shown by an imaginary line of 9°. 14 shown in FIG.
is a camp, and a material with low dielectric loss, such as polycarbonate, is used. Reference numeral 15 denotes a circuit board, which is equipped with an amplifier circuit, a frequency conversion circuit, etc.
a is connected. A lid 16 is made of a metal plate with good conductivity.

Next, reception of circularly polarized radio waves by the primary radiator will be explained. When a right-handed circularly polarized radio wave is sent from a microwave transmission point such as a broadcasting satellite, the radio wave is reflected by a parabolic reflector and becomes a left-handed circularly polarized radio wave. A circularly polarized radio wave arrives toward the conical horn 6. The radio waves are introduced into the waveguide 2 from its open end 3 through the horn 6. The introduced circularly polarized radio wave passes through the position of the probe 7 and reaches the reflection plate 9 side. The reflecting plate 9 reflects the components of the circularly polarized radio waves parallel to the surface direction of the reflecting plate 9 at its end 10, and allows the perpendicular components to proceed toward the reflecting surface 5a. The vertical component that is allowed to proceed is reflected by the reflecting surface 5a and returns to the probe 7 side. As a result of these actions, at the position of the probe 7, the introduced circularly polarized radio waves are directed in a direction parallel to the direction of the probe 7 (the longitudinal direction of the probe 7, the vertical direction in Fig. 1.2). It becomes an oscillating linearly polarized radio wave. This linearly polarized radio wave excites the probe 7, and an electrical signal is generated in the probe 7. The signal thus obtained by the probe 7 is sent to the next stage through its output terminal 7a.

Next, with the structure shown in Figures 1 to 4, the G is 11.7 to 12.0G)
When the VSWR and axial ratio of the primary radiator designed and manufactured to the above-mentioned dimensions for receiving Iz circularly polarized radio waves were measured, the results shown in FIGS. 5 and 6 were obtained, respectively. Since the front end 1o of the reflector 9 is formed into a chevron shape as described above, even if the reflector 9 is thick as described above, the VSW is
The R satisfies the standard value of 1.3 or less, and the axial ratio satisfies the standard value of 1.7 dB or less.

〔Effect of the invention〕

As described above, in the present invention, when a left-handed or right-handed circularly polarized radio wave enters the waveguide 2, it is of course possible to extract it as an electric signal to the prologue 7. In the case of extracting an electric signal, the incoming circularly polarized radio wave is reflected by the probe 7 by a reflector 9 provided at the back of the waveguide 2.
Since the electric wave is converted into a linearly polarized radio wave at the position, the probe 7 has the effect of being able to extract the electric signal with good characteristics such as axial ratio and VSWR.

Moreover, even in the case where the reflector 9 is provided at the back of the waveguide 2 as described above, the end of the reflector 9 on the probe 7 side is formed in a chevron shape, so the thickness of the reflector 9 is Even if the reflector plate 9 is thin, it has the advantage that the above-mentioned electric signals can be extracted while the characteristics such as the above-mentioned axial ratio and VSWR clear the standard values regardless of the thickness.In this way, even if the reflector plate 9 is thick, it can be made thin. The fact that it is possible to meet the standard values even if the reflector plate 9 is made thick means that it can be manufactured integrally with the waveguide 2, which has the advantage of greatly simplifying the manufacture of the primary radiator. There is.

[Brief explanation of the drawing]

The drawings show an embodiment of the present application, and FIG. 1 is a longitudinal cross-sectional view;
Figure 2 is a front view, Figure 3 is a sectional view taken along the line IILIII in Figure 2, Figure 4 is a sectional view taken along the TV-IV line in Figure 2, Figure 5 is a graph showing the measurement results of VSWR, and Figure 6 is a sectional view taken along the line TV-IV in Figure 2. The figure is a graph showing the measurement results of the axial ratio. 2. Waveguide, 7... Probe, 9... Reflector.

Claims (1)

[Claims] It has a waveguide that is open at one end to introduce circularly polarized radio waves and closed at the other end to reflect the introduced radio waves. A probe is provided in which an electrical signal is excited by the radio waves, and at a position deeper than the probe, the introduced circularly polarized radio waves are converted into linearly polarized radio waves at the position of the probe. In the primary radiator for circularly polarized waves, the circularly polarized wave primary radiator is provided with a reflecting plate along the axis of the waveguide, wherein the end of the reflecting plate on the waveguide side is formed in a chevron shape. Primary radiator for polarization.