JP2003101305A - Satellite broadcast receiving converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a satellite broadcast receiving converter which is reduced in manufacturing cost and size and capable of improving a dielectric feeder in dimensional accuracy. SOLUTION: A synthetic resin dielectric feeder 3 held at a waveguide 1 is composed of a first split body 3a equipped with a radiation part 10 protruding from the open end of the waveguide 1, and a second split end 3b equipped with a phase conversion part 12 fixed to the inside of the waveguide 1. A projection 13 provided to the second split body 3b is inserted into a through-hole 10a provided at the center of the first split body 3a, so as to form the first split body 3a and the second split body 3b into one piece.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a satellite broadcast receiving converter for receiving radio waves transmitted from satellites, and particularly to satellite broadcast reception suitable for receiving circularly polarized radio waves transmitted from satellites. For converters.

[0002]

2. Description of the Related Art A satellite broadcast receiving converter mounted on an outdoor antenna device includes a hollow-structured waveguide for injecting radio waves transmitted from a satellite, a probe for detecting radio waves propagating in the waveguide, and a probe. It is equipped with a circuit board equipped with a processing circuit that appropriately processes (amplifies, frequency converts, etc.) the signals detected by the. For example, right-handed circularly polarized waves or left-handed circularly polarized waves transmitted from satellites. If you want to receive
It is necessary to convert the circularly polarized wave that has entered the inside of the waveguide into a linearly polarized wave by the phase conversion unit, and combine this linearly polarized wave with the probe to receive it.

Conventionally, in such a satellite broadcast receiving converter, a waveguide having a horn portion is die-cast with an alloy such as aluminum or zinc, and a phase conversion called a ridge is formed on the inner wall surface of the waveguide. It is known that a circularly polarized wave that enters the waveguide from the horn section is converted into a linearly polarized wave by a ridge by integrally molding the section. That is, since the circularly polarized wave is a polarized wave in which a combined vector of two linearly polarized waves having a phase difference of 90 degrees at equal intervals is rotating, the circularly polarized wave passes through the ridge,
The phases shifted by 90 degrees become the same phase and are converted into linearly polarized waves.

However, in the conventional satellite broadcast receiving converter described above, a horn portion having a desired opening diameter and length is integrally formed at the tip of the waveguide, and extends in the axial direction on the inner wall surface of the waveguide. Since the ridge of a specified length is integrally molded, the waveguide becomes longer in the axial direction, which hinders miniaturization, and the ridge that is the phase conversion part has an undercut shape. There is a problem that the mold becomes complicated and the manufacturing cost rises.

Therefore, in recent years, a dielectric feeder in which a radiation portion and a phase conversion portion are integrally molded is used, and the radiation portion is projected forward from the opening end of the waveguide, and the phase is inserted and fixed inside the waveguide. A satellite broadcast receiving converter has been proposed in which the converting unit intersects the probe at an angle of about 45 degrees. In this type, when circularly polarized waves transmitted from a satellite enter from the radiating part of the dielectric feeder, the circularly polarized waves are converted into linearly polarized waves by the phase converter when propagating inside the dielectric feeder. The linearly polarized wave enters the inside of the waveguide and is coupled to the probe.

Therefore, according to the satellite broadcast receiving converter using such a dielectric feeder, it is not necessary to integrally form a horn portion or a ridge (phase conversion portion) on the waveguide, and thus the shape of the waveguide is formed. Can be simplified to reduce the manufacturing cost, and the total length of the waveguide itself can be shortened because the phase difference with respect to the linearly polarized wave is large even if the total length of the dielectric feeder is relatively short.

[0007]

By the way, in the case of a satellite broadcast receiving converter using a dielectric feeder, since a waveguide having a simple shape and a short length can be used, the manufacturing cost can be reduced and the size can be reduced. Although it has the advantage that it can be achieved, it is not without problems. That is, the dielectric feeder is formed by injection-molding a synthetic resin material. Generally, the synthetic resin causes a large number of sink marks and bubbles at the time of contraction as the volume (volume) increases. As in the conventional example described above, it is impossible to obtain high dimensional accuracy in a dielectric feeder integrally formed with a radiation portion and a phase conversion portion. In particular, when polyethylene (PE), which is inexpensive and has a low dielectric loss tangent, is used as the material for the dielectric feeder, the shrinkage after injection molding is large and the occurrence of sink marks and bubbles is remarkable, so the dimensional accuracy of each part of the dielectric feeder is There was a problem in that the reception efficiency of the radio waves transmitted from the satellites deteriorates because it becomes very bad.

The present invention has been made in view of the circumstances of the prior art as described above, and an object thereof is to be suitable for reduction of manufacturing cost and miniaturization, and to improve dimensional accuracy of a dielectric feeder. It is to provide a converter for receiving satellite broadcasts.

[0009]

In order to achieve the above object, the present invention provides a waveguide having one end closed and the other end open;
The waveguide is provided with a probe protruding in the direction of the central axis of the waveguide, and a dielectric resin-made dielectric feeder held by the waveguide, the dielectric feeder radiating from the open end of the waveguide. A first divided body having a portion and a second divided body having a phase conversion portion fixed inside the waveguide, and the through hole provided at the center of the first divided body is The first and second divided bodies are integrated by inserting a protrusion provided on the second divided body.

In the satellite broadcast receiving converter configured as described above, the dielectric feeder is composed of the first divided body and the second divided body which are divided and integrated with each other. The volume (volume) of the second divided body alone is reduced, and accordingly, the occurrence of sink marks and bubbles can be reduced. Moreover, this dielectric feeder is divided at the portion where the through hole and the protrusion are joined, and the division surface is located away from the center of the first divided body having the highest electric field strength, so that the electric field caused by the division is The adverse effect can be suppressed.

In the above structure, the second split body is provided with the impedance conversion portion that narrows in an arc shape from the open end of the waveguide toward the phase conversion portion, and a projection is provided on the end face of the impedance conversion portion. It is preferable to join the first and second divided bodies at the end face of the impedance conversion section. When such an impedance converter is provided, it is possible to significantly reduce the reflection component of the radio wave propagating from the radiation unit to the phase converter through the impedance converter, and moreover, from the impedance converter to the phase converter. Even if the length is shortened, the phase difference with respect to the linearly polarized wave becomes large, so that the total length of the waveguide can be significantly shortened.

In this case, the projection may be tightly fitted in the through hole, but a fitting convex portion is formed on the inner wall surface of the through hole and a fitting concave portion is formed on the outer wall surface of the projection. It is preferable that the fitting convex portion and the fitting concave portion are snap-connected. If such a snap connection is adopted, even if there is some dimensional variation in the projection and the through hole, they can be easily and reliably connected. At that time, if the length from the rear end face of the radiating part to the fitting convex part is A and the length from the end face of the impedance conversion part to the fitting concave part is B, and these are set to the relationship of A> B, It is preferable that the convex portion and the fitting concave portion can be securely snap-coupled without rattling.

In the above structure, it is preferable that the radiating portion has a conical shape that spreads forward from the open end of the waveguide in a trumpet shape, and the end face of the impedance conversion portion is joined to the rear end face of the radiating portion. In this way, the division plane perpendicular to the traveling direction of the radio wave propagating in the dielectric feeder becomes small, so that the reflection of the radio wave on this division plane can be reduced.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention will be described with reference to the drawings. FIG. 1 is a sectional view of a satellite broadcast receiving converter according to the embodiment, and FIG. 3 is a perspective view of the waveguide, FIG. 4 is a front view of the waveguide, FIG. 5 is a perspective view of the dielectric feeder, FIG. 6 is a front view of the dielectric feeder, and FIG. 7 is a dielectric. FIG. 8 is an exploded view of the body feeder, FIG. 8 is an explanatory view showing a state in which the dielectric feeder is attached to the waveguide, FIG. 9 is an explanatory view showing the difference between the two dielectric feeders, and FIG. 10 is a shield case. 11 is an exploded perspective view of the circuit board and the short cap, FIG. 11 is a rear view of the shield case, FIG. 12 is an explanatory view showing a state in which the circuit board is attached to the shield case, and FIG. 13 is a line AA of FIG. FIG. 14 is a sectional view taken along the line of the first circuit board. FIG. 15 is a view showing a mounting surface, FIG. 15 is an explanatory view showing a positional relationship between a phase conversion part of a dielectric feeder and a minute radiation pattern, FIG. 16 is a cross-sectional view showing a mounting state of a waveguide, a circuit board and a short cap, FIG. Is an explanatory view showing the relationship between the correction unit of the waterproof cover and the radiation pattern, FIG. 18 is an explanatory view showing a modification of the correction unit, FIG. 19 is a block diagram of the converter circuit, and FIG. 20 is an explanatory view showing the layout state of circuit components. FIG. 21 is an explanatory view showing an enlarged joint portion of two circuit boards.

The satellite broadcast receiving converter according to the present embodiment is composed of first and second waveguides 1 and 2, and waveguides 1 and 2.
First and second dielectric feeders 3 and 4 respectively held at the tip of 2, a shield case 5, and first and second circuit boards 6 and 7 mounted inside the shield case 5, The waveguides 1 and 2 are composed of a pair of short caps 8 for closing the rear open ends of the waveguides, a waterproof cover 9 for covering these components, and the like.

As shown in FIGS. 3 and 4, the first waveguide 1
Is a metal flat plate wound in a cylindrical shape and joined, and the joined portions are fixed by a plurality of caulking portions 1a. The distance between the caulking portions 1a is set to about 1/4 wavelength of the guide wavelength λg. There is. Although the first waveguide 1 has a substantially circular cross-sectional shape, four parallel portions 1b are formed on the circumferential surface of the first waveguide 1 at intervals of approximately 90 degrees in the circumferential direction. Each parallel portion 1b extends in the longitudinal direction parallel to the central axis of the first waveguide 1,
A snap claw 1c is provided at the rear end of each of them. In addition, the stopper claw 1d is provided in the middle of the two parallel portions 1b facing each other.
Are formed, and these stopper claws 1d project inside the first waveguide 1. The second waveguide 2 is constructed exactly the same as the first waveguide 1, and the duplicated description is omitted here, but the second waveguide 2 has a caulking portion 2a, a parallel portion 2b, a snap claw 2c and a stopper claw 2d. is doing.

Both the first dielectric feeder 3 and the second dielectric feeder 4 are made of a synthetic resin material having a low dielectric loss tangent, and in the case of the present embodiment, an inexpensive polyethylene (dielectric The rate ε≈2.25) is used.
As shown in FIGS. 5 to 7, the first dielectric feeder 3 is
The first divisional body 3a having the radiation portion 10, the impedance conversion portion 11 and the phase conversion portion 12 are provided as the second divisional body 3b.
It consists of and. The radiating part 10 has a conical shape that spreads like a trumpet, and a circular through hole 10a is formed at the center thereof. The fitting protrusion 10 is formed on the inner peripheral surface of the through hole 10a.
b is provided, and the first divided body 3a is designed to be opened by using the fitting convex portion 10b as a parting line during injection molding. Further, an annular groove 10c is formed on the end face of the radiating portion 10 which is widened forward, and the annular groove 10c is formed.
The depth of c is about 1/4 of the radio wave wavelength λ propagating in the annular part.
It is set to the wavelength.

The impedance converter 11 is the phase converter 1.
The curved surface 11a has a pair of curved surfaces 11a which are narrowed in an arc shape toward 2, and the cross-sectional shapes of these curved surfaces 11a are approximate quadratic curves. Although the end surface of the impedance conversion section 11 is substantially circular, four flat mounting surfaces 11b are formed on the peripheral edge thereof at intervals of approximately 90 degrees. Further, a cylindrical projection 13 is provided at the center of the end surface of the impedance conversion section 11, and the fitting recess 13 is provided on the outer peripheral surface of the projection 13.
a is formed. Then, the protrusion 13 is formed in the through hole 10a.
The end face of the impedance converter 11 into the radiator 1
When it is abutted against the rear end surface of 0, the fitting concave portion 13a and the fitting convex portion 10b snap-fit inside the through hole 10a, whereby the first divided body 3a and the second divided body 3b are integrated. It has become so.

At this time, if the length from the rear end surface of the radiation portion 10 to the fitting convex portion 10b is A and the length from the end surface of the impedance conversion portion 11 to the fitting concave portion 13a is B, the A dimension is the B dimension. Is set to be slightly longer than. Therefore, when the fitting concave portion 13a and the fitting convex portion 10b are snap-coupled to each other, a force is generated in the direction in which the rear end surface of the radiating portion 10 is pressed against the end surface of the impedance conversion portion 11, and the first split body 3a The second divided body 3b is integrated without play. An annular groove 13b is also formed on the tip surface of the protrusion 13, and when the first divided body 3a and the second divided body 3b are integrated, both annular grooves 10c and 13b are arranged concentrically. It

The phase converter 12 is the impedance converter 1
It functions as a 90-degree phase shifter that is continuous with the first tapered portion and converts the circularly polarized wave that has entered the first dielectric feeder 3 into a linearly polarized wave. The phase converter 12 is a plate-shaped member having a substantially uniform thickness, and has a plurality of notches 1 at its tip.
2a is formed. The depth of each notch 12a is set to about ¼ wavelength of the guide wavelength λg, and the phase converter 1
The end surface of 2 and the bottom surface of the notch 12a are two reflecting surfaces orthogonal to the traveling direction of the radio wave. Further, long grooves 12b are formed on both side surfaces of the phase conversion portion 12.

As shown in FIG. 8, the first dielectric feeder 3 thus constructed is held by the first waveguide 1.
The radiation portion 10 of the first divided body 3a and the protrusion 13 of the second divided body 3b protrude from the open end of the first waveguide 1, and the impedance conversion portion 11 and the phase conversion portion 12 of the second divided body 3b.
Is inserted and fixed inside the first waveguide 1. that time,
Four parallel portions 1b formed on the inner peripheral surface of the first waveguide 1
On the other hand, each mounting surface 11b of the impedance conversion section 11 is press-fitted into the corresponding four parallel sections 1b, and both side surfaces of the phase conversion section 12 are press-fitted into the two parallel sections 1b facing each other by 180 degrees. The divided body 3b can be easily attached to the first waveguide 1 with high positional accuracy. Further, the stopper claw 1d formed on the two parallel portions 1b bites into the long groove 12b of the phase conversion portion 12, thereby
It is possible to reliably prevent the split body 3b from coming off from the first waveguide 1.

The second dielectric feeder 4 has a first division body 4a having a radiation portion 14, and an impedance conversion portion 15
And the phase converter 16 is composed of the second divided body 4b, and the basic configuration of inserting and fixing the protrusion 17 of the second divided body 4b into the through hole 14a of the first divided body 4a is It is the same as the first dielectric feeder 3 but differs from the first dielectric feeder 3 in the following two points. The first difference is that the lengths of both phase conversion units 12 and 16 are changed, and the length L of the phase conversion unit 12 of the first dielectric feeder 3 is changed.
1 and length L of the phase converter 16 of the second dielectric feeder 4
Comparing 2 and 2, the relationship is set to L1> L2.
The second difference is that the colors of both the second divided bodies 3b and 4b are changed, and for example, the second dielectric body 3 of the first dielectric feeder 3 is changed.
The divided body 3b of 1 is injection-molded in the color of the raw material, and the second divided body 4b of the second dielectric feeder 4 is injection-molded by coloring the raw material in red or blue.

That is, the first dielectric feeder 3 and the second dielectric feeder 3
Among the respective components of the dielectric feeder 4 of FIG. 1, both first divided bodies 3a and 4a are common components, and both second divided bodies 3b and 4b are the same as the lengths of the phase conversion parts 12 and 16, respectively. It is a separate part with different colors. Both phase converters 12,
The reason for changing the length of 16 will be described later, but both second
When the colors of the divided bodies 3b and 4b of FIG. 9 are changed, the first and second dielectric feeders 3 and 4 are held in the corresponding first and second waveguides 1 and 2, respectively, as shown in FIG. At this time, the projection 1 exposed on the end faces of both the first divided bodies 3a and 4a
By visually observing the colors of 3, 17
It is possible to easily and surely check erroneous insertion of b and 4b.

As shown in FIGS. 10 to 13, the shield case 5 is formed by pressing a flat metal plate, and a pair of connectors 18 are attached to the inclined surface 5a formed on one side thereof. A pair of through holes 19 and a plurality of through holes 20 are formed in the flat top plate of the shield case 5, and a plurality of supporting portions 2 are provided on the periphery of each circular through hole 19.
1 is bent and formed at a right angle toward the outside of the shield case 5. Further, a plurality of crosspieces 5b surrounded by each through hole 20 are formed on the top plate of the shield case 5, and a plurality of locking claws 22 are formed on the outer edges of the crosspieces 5b at right angles toward the inside of the shield case 5. It is bent and formed. Further, a plurality of recesses 23 are formed on the back surface of the cross section 5b of the shield case 5, and these recesses 23 are formed in an elongated shape along the outer edge of the through hole 20.

The first circuit board 6 is made of a material such as fluororesin-based polytetrafluoroethylene having a low dielectric constant and a small dielectric loss, and its outer shape is larger than that of the second circuit board 7, and is appropriately formed. A plurality of through holes 6a are provided at the locations. The second circuit board 7 is made of a material having a Q value lower than that of the first circuit board 6 such as epoxy resin containing glass,
One through hole 7a is provided. Also, the first and second
Ground patterns 24, 25 on one side of the circuit boards 6, 7 of
Are provided respectively, and these ground patterns 2
4 and 25 are soldered to the shield case 5 using the solder 26 filled in the recesses 23. In this case, the ground patterns 24 and 25 of both circuit boards 6 and 7 are superposed on the back surface of the top plate of the shield case 5 in a state where each recess 23 is filled with cream solder in advance, and then the cream solder is placed in a reflow oven or the like. If melted, both circuit boards 6,7
Can be easily and surely grounded to the shield case 5. At that time, as shown in FIG. 12 and FIG.
If a part of 3 is exposed to the outside of the outer edge portions of both circuit boards 6 and 7, it is possible to easily visually check for defects such as insufficient solder, and easily replenish the insufficient solder. it can.

The first and second circuit boards 6 and 7 are not only soldered to the shield case 5, but also locked to the back surface of the top plate of the shield case 5 using the locking claws 22. . In this case, the through holes 6a of both circuit boards 6 and 7,
After inserting 7a into each locking claw 22 of the shield case 5,
By bending the locking claws 22 toward the plate surface side of the first circuit board 6, both circuit boards 6 and 7 can be locked to the shield case 5. In particular, looking at the first circuit board 6 which is larger than the second circuit board 7, appropriate portions including the central portion and the peripheral portion are pressed against the back surface of the top plate of the shield case 5 by the plurality of locking claws 22. Therefore, the first circuit board 6
The warp can be reliably corrected.

As shown in FIGS. 14 and 15, a pair of circular holes 27 is formed in the first circuit board 6, and the first to third bridging portions are formed in the circular holes 27, respectively. 27
a to 27c are formed. In the state where the first circuit board 6 is fixed inside the shield case 5, both circular holes 27 are aligned with the through holes 19 of the shield case 5, respectively. The first bridging portion 27a and the second bridging portion 27b intersect at an angle of approximately 90 degrees, and the third bridging portion 27c is different from the first and second bridging portions 27a and 27b. They intersect at an angle of about 45 degrees. However, each bridge 2 on the left side of the figure
7a to 27c and the respective bridging portions 27a to 27c on the right side of the drawing are in line-symmetrical positions with respect to a straight line P passing through the center of the first circuit board 6. The side opposite to the ground pattern 24 of the first circuit board 6 is a component mounting surface, and on this component mounting surface, an annular ground pattern 28 is formed around both circular holes 27. These ground patterns 28 are electrically connected to the ground pattern 24 through through holes, and four mounting holes 29 are formed in each ground pattern 28 at intervals of approximately 90 degrees in the circumferential direction. . Each of the mounting holes 29 is formed in a rectangular shape, and the four mounting holes 29 on the left side of the drawing and the four mounting holes 29 on the right side of the drawing are also line symmetrical with respect to the straight line P.

Further, on the component mounting surface of the first circuit board 6, a pair of first probes 30a and 30b located on both the first bridging portions 27a and on both the second bridging portions 27b. A pair of second probes 31a and 31b located at
Pair of minute radiation patterns 3 located on the bridging portion 27c of
2a and 32b are patterned respectively. Therefore, each pair of the first and second probes 30a and 30b, the second probes 31a and 31b, and the minute radiation patterns 32a and 32b on the left and right sides are also in line symmetry with respect to the straight line P, and in the following description, in FIG. The minute radiation pattern 32a on the right side of the drawing is called a first minute radiation pattern, and the minute radiation pattern 32b on the left side of the figure is called a second minute radiation pattern.

The short cap 8 is formed by pressing a metal flat plate, and as shown in FIG. 10, a flange 8a is formed on the open end side of the bottomed shape. The collar portion 8a is provided with four mounting holes 33 at intervals of approximately 90 degrees in the circumferential direction, and each mounting hole 33 is formed in a rectangular shape.
The short cap 8 functions as a terminating surface that closes the rear open ends of both the waveguides 1 and 2, and as shown in FIG. 15, the short cap 8 and the first and second waveguides 1 and 2 are different from each other. They are integrated via the first circuit board 6. That is,
Snap claws 1c, 2 of the first and second waveguides 1, 2
c is inserted into each mounting hole 29 of the first circuit board 6 and protrudes to the back side. By snapping each mounting hole 33 of the short cap 8 into these snap claws 1c and 2c, the first circuit is formed. The substrate 6 is sandwiched and fixed between the waveguides 1 and 2 and the pair of short caps 8. At that time, the cream solder is applied in advance on the ground pattern 28 of the first circuit board 6, and after the short cap 8 is snapped in, the cream solder is melted in the reflow furnace.
The short cap 8 is adapted to be soldered to the ground pattern 28 of the first circuit board 6.

As described above, the first circuit board 6 is fixed inside the shield case 5, and each of the first waveguide 1 and the second waveguide 2 has the first circuit. Board 6
It is fixed vertically with respect to the first circuit board 6 and is inserted through the through hole 19 of the shield case 5 from the first circuit board 6 to project to the outside. In this case, the two waveguides 1 and 2 are in contact with the respective support portions 21 formed on the peripheral edge of the through hole 19, and the support portions 21 cause undesired deformation such as inclination of the two waveguides 1 and 2. Is prevented. The opening of the shield case 5 on the side opposite to the protruding direction of the waveguides 1 and 2 is covered with a cover (not shown).

Returning to FIG. 1 and FIG. 2, both the above-mentioned waveguides 1,
Each of the components such as 2, the dielectric feeders 3, 4 and the shield case 5 is housed inside the waterproof cover 9, and the pair of connectors 18 projects from the waterproof cover 9 to the outside. The waterproof cover 9 is made of a dielectric material having excellent weather resistance such as polypropylene or ASA resin, and the radiating parts 10 and 14 of both dielectric feeders 3 and 4 face the front part 9a of the waterproof cover 9. A pair of projecting walls 34 is provided substantially in the center of the front face portion 9a, and both projecting walls 34 extend so as to cross between the first and second waveguides 1 and 2. These protruding walls 34
Serves as a correction unit, and since the phase of the radio wave that passes through the waterproof cover 9 is delayed by the projecting wall 34, the radiation pattern of the radio wave that enters both the waveguides 1 and 2 depends on the volume ratio of the projecting wall 34. Can be corrected. Therefore, FIG.
As shown in FIG. 5, the radiation pattern can be corrected from a broken line shape (when there is no protruding wall 34) to a solid line shape, and a miniaturized reflecting mirror (dish) can be used. Note that, as shown in FIG. 18, it is also possible to use the thick portion 35 in which the front surface portion 9a of the waterproof cover 9 is thickened substantially at the center as a correction portion.

The satellite broadcast receiving converter according to the present embodiment receives radio waves transmitted from two adjacent satellites (first satellite S1 and second satellite S2) that are launched into the sky. , First and second satellites S1, S2
Respectively, the left-handed circularly polarized signal and the right-handed circularly polarized signal are transmitted, and these circularly polarized signals are converged by the reflecting mirror and then pass through the waterproof cover 9 to pass through the first and second waveguides 1 and 2. It is input inside. For example, the left-handed and right-handed circularly polarized signals transmitted from the first satellite S1 are emitted by the radiation unit 10 and the protrusions 13.
From the end surface of the first dielectric feeder 3 to the inside of the first dielectric feeder 3 and propagates from the radiating section 10 to the phase converting section 12 via the impedance converting section 11 and then to the phase converting section 12 Is converted into a linearly polarized wave and enters the inside of the first waveguide 1. That is, since the circularly polarized wave is a polarized wave in which the combined vector of two linearly polarized waves having the same amplitude and a phase difference of 90 degrees from each other is rotated, the circularly polarized wave propagates in the phase conversion unit 12. The phases shifted by 90 degrees become the same phase, for example, the left-handed circularly polarized wave is converted into the vertical polarized wave, and the right-handed circular polarized wave is converted into the horizontal polarized wave.

At this time, a plurality of annular grooves 10c, 13 having a depth of about λ / 4 wavelength are formed on the end surface of the first dielectric feeder 3.
Since b is formed, the end face of the radiating portion 10 and the annular groove 1 are formed.
The phases of the radio waves reflected by the bottom surfaces of 0c and 13b are reversed and cancelled, and the reflection components of the radio waves traveling toward the end surface of the radiation unit 10 are significantly reduced. Moreover, this radiating unit 10 is the first
Since it has a trumpet shape that spreads from the front opening end of the waveguide 1, the radio waves can be efficiently converged in the first dielectric feeder 3 and the length of the radiation portion 10 in the axial direction is shortened. can do.

Further, the radiation portion 1 of the first dielectric feeder 3
0 and the phase converter 12 between the impedance converter 11
Is provided and the cross-sectional shapes of the pair of curved surfaces 11a formed in the impedance conversion section 11 are continued by an approximate quadratic curve, whereby the thickness of the first dielectric feeder 3 changes from the radiation section 10 to the phase conversion section 12. Since it is converged so as to become gradually thinner toward, the reflection component of the radio wave propagating in the first dielectric feeder 3 can be effectively reduced, and the impedance conversion unit 11 changes the phase conversion unit 12 to the phase conversion unit 12. Even if the length of all the parts is shortened, the phase difference with respect to the linearly polarized wave becomes large, and from this point as well, the total length of the first dielectric feeder 3 can be significantly shortened.

Further, the end surface of the phase conversion portion 12 has approximately λg /
Since the notch 12a having a depth of four wavelengths is formed, the phase of the radio wave reflected by the bottom surface of the notch 12a and the end face of the phase conversion unit 12 is reversed and canceled, and the impedance of the end face of the phase conversion unit 12 becomes unbalanced. Matching can also be resolved.

The left-handed and right-handed circularly polarized signals transmitted from the first satellite S1 are thus converted into vertical and horizontal polarized signals by the phase converter 12 of the first dielectric feeder 3. After that, the light propagates in the first waveguide 1 toward the short cap 8, the vertically polarized wave is detected by the first probe 30a, and the horizontally polarized wave is detected by the second probe 31a. Similarly, the left-handed and right-handed circularly polarized signals transmitted from the second satellite S2 are radiated by the radiating section 14 and the protrusions 17.
Enters the inside of the second dielectric feeder 4 from the end face of the, and the left-hand circular polarization is converted to the vertical polarization by the phase converter 16 of the second dielectric feeder 4, and the right-hand circular polarization is horizontal. Converted to polarized waves. Then, these vertically polarized waves and horizontally polarized waves are
Traveling in the waveguide 1 toward the short cap 8,
The vertically polarized wave is detected by the first probe 30b, and the horizontally polarized wave is detected by the second probe 31b.

Here, the first and second minute radiation patterns 32a and 32b are formed on the first circuit board 6, and the first minute radiation pattern 32a is the first and second probes 30a and 31a. Of the second microscopic radiation pattern 32b intersects with each axis of the first and second probes 30b and 31b by approximately 4 degrees.
Since they intersect at an angle of 5 degrees, the disturbance of the electric fields of the vertically polarized wave and the horizontally polarized wave in the waveguides 1 and 2 is suppressed by the first and second minute radiation patterns 32a and 32b, respectively, and Isolation between polarized waves and horizontal polarized waves is ensured. In addition, the first and second minute radiation patterns 32a and 32b are provided in the respective probes 30a, 31a and 3a.
Since it is a rectangle asymmetric with respect to the axes of 0b and 31b, and its size (area) is set to be relatively small,
After ensuring the isolation between the vertically polarized wave and the horizontally polarized wave, the first and second minute radiation patterns 32a, 3
The reflection at 2b can be reduced.

However, since the first and second minute radiation patterns 32a and 32b are line symmetrical with respect to the straight line P on the first circuit board 6, as is apparent from FIG. The pattern 32a is substantially orthogonal to the phase converter 12 of the first dielectric feeder 3, and the second minute radiation pattern 32b is substantially parallel to the phase converter 16 of the second dielectric feeder 4. In this case, compared with the electric field distribution in the second waveguide 2 in which the second minute radiation pattern 32b is substantially parallel to the phase converter 16, the first minute radiation pattern 32a is substantially orthogonal to the phase converter 12. Since the electric field distribution in the first waveguide 1 becomes worse, the deterioration of the electric field distribution is corrected by increasing the dimension of the phase conversion unit 12 in the axial direction. That is, as described above, the length L1 of the phase conversion unit 12 of the first dielectric feeder 3 and the length L2 of the phase conversion unit 16 of the second dielectric feeder 4 are L1>
The relationship is set to L2 (see FIG. 9), and by making the phase conversion unit 12 long, the phase shift of the linearly polarized wave traveling in the first waveguide 1 does not occur. There is.

The reception signals detected by the first probes 30a and 30b and the second probes 31a and 31b are
The converter circuit mounted on the first and second circuit boards 6 and 7 frequency-converts the IF frequency signal and outputs the IF frequency signal. As shown in FIG. 19, this converter circuit has a first
Satellite broadcast signal input end 100 for receiving the satellite broadcast signals transmitted from the satellite S1 and the second satellite S2 and deriving them to a subsequent circuit, and amplifying the received signal for amplifying and outputting the input satellite broadcast signals. Circuit section 101 and filter section 102 for attenuating the image frequency band of the input satellite broadcast signal
A frequency converter 103 for frequency-converting the satellite broadcast signal output from the filter 102, and a frequency converter 10.
3, an intermediate frequency amplification circuit section 104 for amplifying the signal output from the signal No. 3, signal selection means 105 for selecting and outputting the satellite broadcast signal amplified by the intermediate frequency amplification circuit section 104, a reception signal amplification circuit section 101 and a filter. It is provided with first and second regulators 106 and 107 for supplying a power supply voltage to each circuit section such as the section 102 and the signal selection means 105.

From the first satellite S1 and the second satellite S2,
12.2 GHz to 1 for left-handed and right-handed circularly polarized waves, respectively
A 2.7 GHz satellite broadcast signal is transmitted, and these satellite broadcast signals are converged by the reflector of the outdoor antenna device and input to the satellite broadcast signal input end 100. The satellite broadcast signal input terminal 100 is transmitted from the first and second probes 30a and 31a for detecting the left-handed and right-handed circularly polarized signals transmitted from the first satellite S1 and the second satellite S2. It has first and second probes 30b and 31b for detecting left-handed and right-handed circularly polarized signals. As mentioned above, the first
The left-handed and right-handed circularly polarized signals transmitted from the satellite S1 are converted into vertically polarized waves and horizontally polarized waves and detected by the first and second probes 30a and 31a, respectively, and the first probe 30a is left-handed. The circularly polarized signal SL1 is output, and the second probe 31a outputs the right circularly polarized signal SR1. On the other hand, the left-handed and right-handed circularly polarized waves transmitted from the second satellite S2 are converted into the vertically polarized waves and the horizontally polarized waves, and the first and second
Are detected by the respective probes 30b and 31b, and the first probe 30b outputs the left-hand circularly polarized signal SL2,
Probe 31b outputs a right-handed circularly polarized signal SR2.

The reception signal amplifying circuit section 101 has first to fourth amplifiers 101a, 101b, 101c and 101d. The first amplifier 101a has a right-hand circularly polarized signal S
R1 and the second amplifier 101b are left-hand circularly polarized signals SL1
The third amplifier 101c outputs the left-hand circularly polarized signal SL2,
The fourth amplifier 101d inputs the right-handed circularly polarized signals SR2, amplifies these signals to a predetermined level, and outputs them to the filter unit 102.

The filter section 102 includes the first to fourth band-eliminated filters 102a, 102b, 102.
c, 102d. The first and fourth band-elluminate filters 102a and 102d have the image frequency bands of the first intermediate frequency signal FIL1 and the fourth intermediate frequency signal FIL2 of 9.8 GHz to 10.3 GHz.
Of the second intermediate frequency signal FIH1 and the third intermediate frequency signal FIH2 of 16.0 GHz to 16.5 GHz, which are the image frequency bands of the second intermediate frequency signal FIH1 and the third intermediate frequency signal FIH2. Attenuate the frequency band of. The right-hand circularly polarized signal SR1 is the first
Of the left-hand circularly polarized signal SL1 to the second band-elimated filter 102a.
b, the left-handed circularly polarized signal SL2 passes through the third band-elimated filter 102c, and the right-handed circularly polarized signal SR2 passes through the fourth band-elimated filter 102d, respectively, and then are guided to the frequency conversion unit 103.

The frequency converter 103 has first to fourth mixers 103a, 103b, 103c and 103d, a first oscillator 108 and a second oscillator 109. The first oscillator 108 (oscillation frequency = 11.25G
Hz) is the first mixer 103a and the fourth mixer 103d
And the satellite broadcast signal output from the first band-elimination filter 102a is connected to the first mixer 103a at a first frequency of 950 MHz to 1450 MHz.
Of the intermediate frequency signal FIL1 of the satellite broadcasting signal output from the fourth band erasing filter 102d at 950 MHz in the fourth mixer 103d.
The frequency is converted into the fourth intermediate frequency signal FIL2 of 1450 MHz. In addition, the second oscillator 109 (oscillation frequency =
(14.35 GHz) is connected to the second mixer 103b and the third mixer 103c, and the satellite broadcast signal output from the second band erasing filter 102b is 1650 MHz in the second mixer 103b. 215
The satellite broadcast signal frequency-converted into the 0 MHz second intermediate frequency signal FIH1 and output from the third band erminating filter 102c is converted into a third intermediate frequency signal FIH2 of 1650 MHz to 2150 MHz in the third mixer 103c. To be converted.

The intermediate frequency amplifier circuit section 104 includes the first to fourth intermediate frequency amplifiers 104a, 104b, 104c,
The first to fourth intermediate frequency signals output from the frequency conversion unit 103 are input, the signals are amplified to a predetermined level and output to the signal selection unit 105.
That is, the first intermediate frequency signal FIL1 is fed to the first intermediate frequency amplifier 104a, the second intermediate frequency signal FIH1 is fed to the second intermediate amplifier 104b, and the third intermediate frequency signal FIH.
2 is input to the third intermediate frequency amplifier 104c and the fourth intermediate frequency signal FIL2 is input to the fourth intermediate frequency amplifier 104d, and their output signals are led to the signal selecting means 105.

The signal selecting means 105 has a first and a second one.
10 and 111 and a signal switching control circuit 112. The first signal synthesis circuit 110 synthesizes the input first intermediate frequency signal FIL1 and second input intermediate frequency signal FIH1 and outputs the synthesized signal to the signal switching control circuit 112. Similarly, the second signal synthesis circuit 110 111 synthesize | combines the 3rd intermediate frequency signal FIH2 and the 4th intermediate frequency signal FIL1 which were input, and it guide | induces to the signal switching control signal 112. The signal switching control circuit 112 determines which of the combined signal of the first intermediate frequency signal FIL1 and the second intermediate frequency signal FIH1 and the combined signal of the third intermediate frequency signal FIH2 and the fourth intermediate frequency signal FIL2. Select one of the first output terminal 10
5a and the second output terminal 105b. This switching control will be described later.

Then, the first and second output terminals 105
Separate satellite broadcast receiving televisions (not shown) are connected to a and 105b, respectively, and each satellite broadcast receiving television operates each circuit unit together with a control signal for controlling the signal selecting means 105. Voltage is supplied for this purpose. 22kH for DC 15V
By superimposing the z control signal, it is possible to distinguish whether the composite signal of the intermediate frequency signals FIL1 and FIH1 or the composite signal of the intermediate frequency signals FIL2 and FIH2 is selected. That is, the television for receiving satellite broadcasting is the first
The right-hand circularly polarized signal SR1 and the left-hand circularly polarized signal SL1 transmitted from the satellite S1 of
When selecting between the case of receiving the right-handed circularly polarized signal SR2 and the left-handed circularly polarized signal SL2 transmitted from No. 2, the control signal to be superimposed on the supply voltage is output terminal 10 respectively.
5a, 105b. These voltages are input to the signal switching control circuit 112 from the first output terminal 105a via the high frequency blocking choke coil 113, and similarly from the second output terminal 105b via the high frequency blocking choke coil 114. Signal switching control circuit 11
Entered in 2.

On the other hand, the first voltage and the second voltage are input to the first and second regulators 106 and 107 via the high frequency blocking choke coils 113 and 114, respectively, and the first and second regulators 106 and 107 are input. , 107
Supplies a power supply voltage (for example, 8 V) to each circuit unit. Therefore, the first and second regulators 106 and 107 have the same configuration, and the integrated circuit constitutes a voltage stabilizing circuit. The output terminals of the first and second regulators 106 and 107 are connected to the power supply voltage output terminal 117 via backflow prevention diodes 115 and 116, respectively.
It is connected to the. Therefore, even when only one of the satellite broadcasting receiving televisions is operating, the power supply voltage is supplied to each circuit portion. Further, since the first and second output terminals 105a and 105b are connected to the power supply voltage output terminal 117 via the regulators 106 and 107, respectively, the isolation between elements included in the first and second regulators 106 and 107 is isolated. By utilizing, the control signal supplied from the first output terminal 105a is prevented from being input to the signal switching control circuit 112, for example. Similarly, the second output 1
The control signal supplied from 05b is not input to the signal switching control circuit 112.

As shown in FIG. 20, in the converter circuit configured as described above, the RF circuit components preceding the frequency conversion unit 103 are mounted on the first circuit board 6 and the intermediate frequency amplification is performed. The IF circuit components subsequent to the circuit unit 104 are mounted on the second circuit board 7,
Moreover, the first circuit board 6 and the second circuit board 7 are partially overlapped and joined and integrated.

In this case, the signal lines of the right-handed circularly polarized signals SR1 and SR2 of the first satellite S1 and the second satellite S2 are provided on the outermost side of the first circuit board 6, and the first satellite is provided on the inner side thereof. Left-handed circularly polarized signals SL1 and S of S1 and the second satellite S2
The signal lines of L2 are laid out respectively, and the first and fourth mixers 103a and 103d in which the outer right-hand circularly polarized signals SR1 and SR2 are connected to the first oscillator 108 are first and fourth 950 MHz to 1450 MHz. Second intermediate frequency signals FIL1 and FIL2, and second and third mixers 103b, 103b in which the inner left-hand circularly polarized signals SL1 and SL2 are connected to the second oscillator 109.
The frequency conversion is performed by 103c into second and third intermediate frequency signals FIH1 and FIH2 of 1650 MHz to 2150 MHz. That is, the first oscillator 108 and the second oscillator 1 are provided in the central portion of the first circuit board 6.
09 is arranged, and the first oscillator 108 is connected to the outer first mixer 103a and the fourth mixer 108a via the oscillation signal line 36.
And the second oscillator 109 is connected via the oscillation signal line 37 to the inner second mixer 103b and the third mixer 103c.

As shown in FIG. 21, the intermediate frequency signal lines 38 of the intermediate frequency signals FIL1, FIL2, FIH1 and FIH2 output from the mixers 103a to 103d on the first circuit board 6 are connected to the connection pins 39, respectively. Is connected to the intermediate frequency amplification circuit section 104 on the second circuit board 7 via the first circuit board 6 and the second circuit board 7
In the overlapping portion of, the ground pattern 24 formed on the first circuit board 6 and the ground pattern 25a formed on the component mounting surface of the second circuit board 7 are in contact with each other. Further, the ground pattern 25 is formed on the second circuit board 7.
Lead-out patterns 40 facing a are formed, and these lead-out patterns 40 are connected to the intermediate frequency amplification circuit section 104 of the second circuit board 7 through the through holes 41, and both ends of the connection pin 39 have the intermediate frequency signal. It is soldered to the line 38 and the lead-out pattern 40. Therefore, the first oscillator 108 is connected to the outer first and fourth mixers 103a, 103a,
The oscillation signal line 36 connected to 103d and each mixer 1
Intermediate frequency signals FIL1 to FIL from 03a to 103d
The intermediate frequency signal line 38, which leads 4 to the intermediate frequency amplifier circuit section 104, can be made to intersect at the overlapping portion of the first circuit board 6 and the second circuit board 7 while having the ground.

According to the satellite broadcast receiving converter according to the above-described embodiment, the synthetic resin dielectric feeders 3 and 4 held by the waveguides 1 and 2 are opened from the open ends of the waveguides 1 and 2. A first divided body 3a having projecting radiating parts 10 and 14,
4a and the phase converter 1 fixed inside the waveguides 1 and 2.
A through hole 10 formed in the center of the first divided body 3a, 4a
a and 14a, the protrusions 13 and 17 of the second divided bodies 3b and 4b
By inserting the first divided body 3a, 4a
Since the second divided bodies 3b and 4b are integrated with each other, the volume of each of the first divided bodies 3a and 4a and the second divided bodies 3b and 4b is reduced. Can be reduced. Moreover, the dielectric feeders 3 and 4 are divided at the portions where the through holes 10a and 14a and the protrusions 13 and 17 are joined, and the divided surfaces are separated from the centers of the first divided bodies 3a and 4a having the highest electric field strength. Since it is at the position, it is possible to suppress an adverse electrical effect due to the division.

Further, impedance conversion portions 11 and 15 which are narrowed in an arc shape from the open ends of the waveguides 1 and 2 toward the phase conversion portions 12 and 16 are provided in the second divided bodies 3b and 4b,
Protrusions 1 are formed on the end faces of the impedance converters 11 and 15.
3, 17 are provided, and the first divided bodies 3a, 4a and the second divided bodies 3b, 4b are connected to the impedance conversion section 11,
Since the end faces of 15 are joined, the radiating parts 10, 14 pass through the impedance converting parts 11, 15 and then the phase converting parts 12,
The reflected component of the radio wave propagating to 6 can be significantly reduced, and even if the length from the impedance converters 11 and 15 to the phase converters 12 and 16 is shortened, the phase difference with respect to the linearly polarized wave is reduced. Is large, the total length of the waveguides 1 and 2 can be significantly shortened.

In the first dielectric feeder 3, the fitting convex portion 10b is formed on the inner wall surface of the through hole 10a, and the fitting concave portion 13a is formed on the outer wall surface of the protrusion 13.
Since the fitting convex portion 10b and the fitting concave portion 13a are configured to be snap-coupled and the same snap coupling is adopted for the second dielectric feeder 4, the projections 13 and 17 are also provided.
Even if there is some dimensional variation in the through holes 10a and 14a, the two can be easily and reliably joined together. At that time, regarding the first dielectric feeder 3, the length from the rear end surface of the radiation portion 10 to the fitting convex portion 10b is A, and the length from the end surface of the impedance conversion portion 11 to the fitting concave portion 13a is B. Since these are set to have the relationship of A> B, the fitting convex portion 10b and the fitting concave portion 13a can be securely snap-coupled without rattling. The same applies to the second dielectric feeder 4.

Further, the radiating portions 10 and 14 are connected to the waveguides 1 and 2.
With a conical shape that spreads like a trumpet from the open end of
Since the end faces of the impedance conversion units 11 and 15 are joined to the rear end faces of the radiating units 10 and 14, the dielectric feeder 3,
The division plane perpendicular to the traveling direction of the radio wave propagating in 4 becomes small, and the reflection of the radio wave on this division plane can be reduced.

In the above embodiment, the two-satellite broadcast receiving converter including the first and second waveguides 1 and 2 and the first and second dielectric feeders 3 and 4 has been described. It goes without saying that the present invention can be applied to a single satellite broadcast receiving converter in which one dielectric feeder is held in one waveguide.

[0056]

The present invention is carried out in the form as described above, and has the following effects.

A dielectric resin feeder made of synthetic resin is divided into a first divided body having a radiating portion protruding from the open end of the waveguide and a second divided body having a phase conversion portion fixed inside the waveguide. The first divided body and the second divided body are integrated by inserting a protrusion provided in the second divided body into a through hole provided in the center of the first divided body. Therefore, the volume (volume) of each of the first and second divided bodies alone is reduced, and accordingly, the occurrence of sink marks and bubbles can be reduced. Moreover, this dielectric feeder is divided at the portion where the through hole and the protrusion are joined, and the division surface is located away from the center of the first divided body having the highest electric field strength, so that the electric field caused by the division is The adverse effect can be suppressed.

[Brief description of drawings]

FIG. 1 is a sectional view of a satellite broadcast receiving converter according to an embodiment.

FIG. 2 is a cross-sectional view of the satellite broadcast receiving converter viewed from another direction.

FIG. 3 is a perspective view of a waveguide.

FIG. 4 is a front view of a waveguide.

FIG. 5 is a perspective view of a dielectric feeder.

FIG. 6 is a front view of a dielectric feeder.

FIG. 7 is an explanatory view showing the dielectric feeder in a disassembled state.

FIG. 8 is an explanatory diagram showing a state in which a dielectric feeder is attached to a waveguide.

FIG. 9 is an explanatory diagram showing a difference between two dielectric feeders.

FIG. 10 is an exploded perspective view showing a shield case, a circuit board, and a short cap.

FIG. 11 is a rear view of the shield case.

FIG. 12 is an explanatory diagram showing a state in which the circuit board is attached to the shield case.

13 is a cross-sectional view taken along the line AA of FIG.

FIG. 14 is a diagram showing a component mounting surface of a first circuit board.

FIG. 15 is an explanatory diagram showing a positional relationship between a phase conversion portion of a dielectric feeder and a minute radiation pattern.

FIG. 16 is a cross-sectional view showing a mounted state of a waveguide, a circuit board, and a short cap.

FIG. 17 is an explanatory diagram showing the relationship between the correction unit of the waterproof cover and the radiation pattern.

FIG. 18 is an explanatory diagram showing a modified example of the correction unit.

FIG. 19 is a block diagram of a converter circuit.

FIG. 20 is an explanatory diagram showing a layout state of circuit components.

FIG. 21 is an explanatory view showing an enlarged joint portion of two circuit boards.

[Explanation of symbols]

1 1st waveguide 2 2nd waveguide 1a, 2a Caulking part 1b, 2b Parallel part 1c, 2c Snap claw 1d, 2d Stopper claw 3 1st dielectric feeder 4 2nd dielectric feeder 3a, 4a 1st division body 3b, 4b 2nd division body 5 Shield case 5b Crosspiece part 6 1st circuit board 6a Through hole 7 2nd circuit board 8 Short cap 9 Waterproof cover 10,14 Radiating part 10a Through hole 10b Fitting convex part 10c Annular groove 11,15 Impedance converting part 12,16 Phase converting part 13,17 Protrusion 13a Fitting concave part 19 Through hole 20 Through hole 21 Support part 22 Locking claw 23 Recessed part 24,25 Ground pattern 25a Grand pattern 26 Solder 27 Circular Hole 28 Ground Pattern 29 Mounting Holes 30a, 30b First Probes 31a, 31b Second Probe 32a First Micro Radiation Pattern 32b Second minute radiation pattern 34 Projection wall 35 Thick portion 36 Oscillation signal line 38 Intermediate frequency signal line 39 Connection pin 40 Derivation pattern 41 Through hole 103 Frequency converter 103a, 103b, 103c, 103d First to fourth mixture Unit 104 Intermediate frequency amplifier circuit section 104a, 104b, 104c, 104d First to fourth intermediate frequency amplifier 108 First oscillator 109 Second oscillator S1 First satellite S2 Second satellite

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor's string pearl             1-7 Aki, Otsuka-cho, Yukiya, Ota-ku, Tokyo             Su Electric Co., Ltd. F-term (reference) 5J012 FA03                 5J045 AA11 AB05 CA02 CA03 CA04                       DA01 EA07 GA04 HA03 JA15                       KA02 MA04 NA08                 5J046 AA04 AA07 AB09 RA03 RA06                 5K016 AA01 AA08 BA18 EA04 EA07                       EA09                 5K062 AA09 AB10 AE01 AE02 BF03                       BF07

Claims (5)

[Claims] 1. A waveguide having one end closed and the other end open,
A probe protruding in the central axis direction of the waveguide and a dielectric feeder made of synthetic resin held by the waveguide are provided, and the dielectric feeder radiates from the opening end of the waveguide. A first split body having a portion and a second split body having a phase conversion portion fixed inside the waveguide, and a through hole provided in a central portion of the first split body. By inserting the protrusions provided on the second divided body, these first
And a satellite broadcast receiving converter characterized by integrating the second divided body. 2. The impedance conversion section according to claim 1, wherein the second divided body is provided with an impedance conversion section that narrows in an arc shape from the open end of the waveguide toward the phase conversion section. While providing the protrusion on the end face,
A satellite broadcast receiving converter characterized in that the first and second divided bodies are joined together at an end face of the impedance conversion section. 3. The fitting convex portion is formed on the inner wall surface of the through hole and the fitting concave portion is formed on the outer wall surface of the protrusion, and the fitting convex portion and the fitting concave portion are formed. A satellite broadcast receiving converter characterized by snap-linking and. 4. The length from the rear end surface of the radiating portion to the fitting convex portion is A, and the length from the end surface of the impedance conversion portion to the fitting concave portion is B. At this time, the relationship is set such that A> B, and the satellite broadcast receiving converter is characterized. 5. The radiating portion according to claim 2, wherein the radiating portion has a conical shape that spreads forward in a trumpet shape from the open end of the waveguide, and the impedance conversion is performed on a rear end surface of the radiating portion. A satellite broadcast receiving converter characterized by joining the end faces of the parts.