JPH0224242Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention consists of an offset parabolic antenna that receives radio waves arriving from a broadcasting satellite, specifically a reflector and an arm attached to the tip of the arm that extends forward from the bottom of the reflector. The present invention relates to an offset parabolic antenna consisting of a primary radiator.

In this type of parabolic antenna, if snow falls during reception and the snow accumulates on the arm or primary radiator as shown by reference numeral 31 in Figure 1, it will be reflected by the reflector and focused toward the primary radiator. The drawback was that the radio waves were blocked by the snow, resulting in extremely low reception efficiency or no reception at all.

In order to eliminate the above-mentioned drawbacks, there are conventionally known means, such as a means for heating the opening of the primary radiator (see Utility Model Application Publication No. 133604/1983) and a means for heating the entire rear surface of the reflector ( However, the former is limited to localized snow melting around the primary radiator and is not effective in melting snow in front of the reflector, and in addition, it is difficult to blow air. The disadvantage is that snow accumulates on the pipes. Although the latter method is effective in melting snow on the reflective mirror surface, it has a fatal drawback of poor thermal efficiency and requiring a large amount of electric power. To reiterate, it is not possible to heat the surface by placing a heating wire directly in front of the reflector, whereas heating the surface indirectly from the back has poor heat transfer efficiency and requires a large amount of power. There is a big drawback.

In order to solve the above technical problem, the present invention aims to provide an offset parabolic antenna that uses low power and can efficiently melt the snow that accumulates in front of the reflector.

In order to achieve the above object, the invention of the present application,
It consists of a reflector, an arm whose base is attached to the lower part of the reflector and whose tip is brought out in front of the reflector, and a primary radiator body attached to the tip of the arm,
The radio waves arriving towards the reflector are reflected by the reflector, converged towards the primary radiator, input through the opening of the primary radiator, and sent from the primary radiator to the next receiving equipment. In the parabolic antenna, a part of the upper surface of the arm facing the space between the reflecting mirror and the opening of the primary radiator and a part of the periphery of the opening of the primary radiator are provided with a Each of the mirrors is equipped with an electric heating element for snow melting, which melts the snow that is about to accumulate on the mirror and prevents the snow from blocking the space between the reflecting mirror and the opening.

The drawings showing the embodiments of the present application will be described below. 1 is the foundation, 2 is the pole fixed to the foundation 1, 3
A supporting device is attached to the upper end of the pole, and a parabolic antenna (offset parabolic antenna) 4 is supported by the supporting device 3 so as to be able to adjust its direction and angle of elevation. In this antenna, reference numeral 5 denotes a reflecting mirror, and the back surface thereof has well-known reinforcing ribs 6.
The rib is fixed to the support device 3. 7
is an arm, the base of which is attached to the lower part of the reflecting mirror 5, and the tip of which is provided with a mounting part 8 for a primary radiator. 9 indicates an auxiliary arm. Next, 10 is the mounting part 8
11 is an opening for receiving radio waves provided at the tip of the radiator 10, 12 is a converter attached to the rear end of the radiator 10, and 13 is an output terminal. Reference numeral 14 denotes a power supply line using a coaxial cable, one end of which is connected to the output terminal 13 using a connector 15. In addition, the above-mentioned power supply line 14
The part on the way toward the support device 3 is inserted into the hollow arm 7, and the further end thereof is connected to an indoor receiving facility. Reference numeral 16 indicates a portion fixed to the pole 2.

Next, numerals 21 and 22 indicate snow accumulation prevention devices, respectively. First, in the preventer 21, 23 is a base material made of epoxy,
It is formed using a thermosetting resin material such as melamine, phenol, or urea. The base material 23 is made to have a slight elasticity so that the arm 7 is clamped by a biasing force as shown by the arrow in FIG. 5, and thereby is fixed thereto. Reference numeral 24 denotes an electric heating element made of nichrome wire, which is embedded in the base material 23 in a meandering manner so that the entire upper surface of the base material 23 is heated. Reference numeral 25 indicates a power supply terminal, and reference numeral 26 indicates a connection terminal. Next, the preventer 22 is made of the same material as the preventer 21 and is formed into an annular shape. That is, 27 represents a base material, and 28 represents an electric heating element.
Note that the electric heating body 28 may be provided only in the portion located above the opening 11. Reference numeral 29 is a through hole formed in a size that does not block the opening 11 of the primary radiator 10. 30 indicates a connection terminal. Next, 31 is a power supply device, which uses a transformer that reduces AC of 100 V to about 20 to 30 V2 to 3 A, for example. 3
2 represents a power cord, and 33 represents a connection cord.

In the configuration described above, when a microwave radio wave, for example, a radio wave of 11.71398 to 12.0095 GHz arrives from a broadcasting satellite, the radio wave is reflected by the reflecting mirror 5 and focused toward the primary radiator 10. The focused radio waves are introduced into the interior of the radiator 10 through the opening 11, and are further converted into intermediate frequency (1.03598 to 1.33150 GHz) signals through the high frequency amplification section, frequency conversion section, etc. provided in the converter 12. Further, the converted intermediate frequency signal is sent out from the output terminal 13 to a feeder line (for example, a coaxial cable) 14, and sent to an indoor receiving facility via the cable.

If snowfall is likely in the above reception state, power is supplied from the power supply device 31 to the electric heating bodies 24 and 28 of the snow prevention devices 21 and 22, causing them to generate heat. In this state, even if snow falls around the opening 11 of the primary radiator 10 or on the arm 7, the snow will be melted by the heat from the electric heating element. When snow melts in a small amount, it melts completely and drips down as water. Also, if there is a lot of snow, some of the snow will melt and the remaining snow will slide off along with the water that is created. As a result, snow accumulates in those areas,
The accumulated snow is reflected in the reflecting mirror 5 and the opening 11 of the radiator.
This prevents a situation in which the connection between the Therefore, the above-mentioned reception can be continued stably. The electric heating bodies 24 and 28 may be used as long as they can prevent snow from accumulating in a state that blocks the space between the reflecting mirror 5 and the opening 11 of the primary radiator 10. Therefore, it is only necessary to melt the snow to such an extent that such a situation does not occur, and a small amount of snow may remain on the arm 7. Also, preventive tool 2
1, the arrangement state of the electric heating body 24 is as follows:
Instead of being provided over the entire surface of the arm 7, only one may be provided at an intermediate position in the width direction of the arm 7 in the longitudinal direction of the arm 7, as shown in FIG.

Furthermore, even when the cross-sectional shape of the arm 7 is circular as shown in FIG. 9, it may be provided at the same location.

As described above, in the present invention, the parabolic antenna 4 is of an offset type so that the reflector 5 can stand upright, so that snow does not accumulate above the reflector 5, as can be assumed from FIG. In this respect, it is effective in preventing radio wave interference due to snow accumulation.

Moreover, the arm 7 for supporting the primary radiator 10
is attached to the bottom of reflector 5, so this arm 7
There is no fear of blocking the radio waves from the broadcasting satellite to the reflector 5, and it is effective in receiving high quality radio waves.

Moreover, since the upper surface of the arm 7 provided to support the primary radiator 10 is provided with an electric heating element 24, the electric heating element 24 disposed on the upper surface of the arm 7
4 has the effect of melting the snow that falls directly on the upper surface of the arm 7 even if it uses a small amount of electricity.In addition, the rising warm air melts the snow that falls directly on the upper surface of the arm 7 (as shown by reference numeral 31 in Fig. 1). This has the effect of melting snow in the area (parts near the reflecting mirror 5). This means that even if a large amount of snow adheres to the lower surface of the reflector 5, where snow is most likely to adhere, the large amount of snow will be transferred to the electric heating element 2 in the arm 7.
Since it is directly above the electric heating element 24, the warm air rising from the electric heating element 24 is utilized, which has the effect of melting snow.

In this way, the present invention not only has a structure in which no radio wave obstruction is structurally interposed between the reflector 5 and the primary radiator 10, but also prevents snow from accumulating on the arm 7 disposed below. To deal with the danger of becoming an obstruction to radio waves, an electric heating element 24 is placed on top of the snow to melt the snow, and the warm air rising upward from the electric heating element 24 is utilized to prevent the reflection mirror 5 from becoming a radio wave obstruction. It also has the effect of melting snow that accumulates on the lower front side of the reflector 5 and preventing radio wave interference caused by snow accumulating on the lower front side of the reflecting mirror 5.

Moreover, even if the electric heating element 24 is used to melt the snow on the lower front surface of the reflector 5, it is placed in a very small area on a part of the upper surface of the arm 7 and a part around the radiator opening. It also has an energy-saving effect in that it requires only a small amount of electric power in terms of area, and can achieve the above-mentioned large snow melting effect even with a small amount of electrical energy.

[Brief explanation of drawings]

The drawings show an embodiment of the present application, in which Fig. 1 is a side view of the antenna in a state of receiving radio waves, Fig. 2 is a plan view thereof, Fig. 3 is an enlarged partial view showing the arm tip and the primary radiator, and Fig. Figure 4 is a perspective view showing the state in which the electric heating element for snow melting is to be installed, Figure 5 is a sectional view taken along the - line, Figure 6 is a sectional view taken along the line - Figure 7 is a circuit diagram of the electric heating element, and Figures 8 and FIG. 9 is a sectional view showing different examples of the arrangement locations of the electric heating elements. 5... Reflector, 7... Arm, 10... Primary radiator, 24, 28... Electric heating element.

Claims (1)

[Scope of utility model registration request] Consisting of a reflector, an arm whose base is attached to the bottom of the reflector and whose tip is brought out in front of the reflector, and a primary radiator body attached to the tip of the arm, the radiator is directed toward the reflector. A parabolic parabolic device that reflects radio waves from a reflecting mirror, converges them toward a primary radiator, inputs them through the opening of the primary radiator, and sends them out from the primary radiator toward the next receiving equipment. In the antenna, a portion of the upper surface of the arm facing the space between the reflecting mirror and the opening of the primary radiator and a portion of the periphery of the opening of the primary radiator are covered with snow that is about to accumulate there. An offset parabolic antenna characterized in that each of the offset parabolic antennas is equipped with an electric heating element for snow melting to prevent snow from blocking the space between the reflecting mirror and the opening.