MXPA99002877A - Converter receiving transmissions by satel - Google Patents

Abstract

In accordance with the present invention, a converter is provided that receives satellite transmissions comprising a waveguide in which the transmission wave traveling therein travels as a first wave of linearly polarized TEW11 mode and as a second wave of transmission. linearly polarized TE mode intersecting a right angle to each other, a first probe disposed at a predetermined position within this waveguide to detect the first linearly polarized wave, a first reflective conductor disposed about 1/4 of the wavelength separated from the first probe in the direction in which the electrical wave travels to reflect the first linearly polarized wave, a second probe disposed in the vicinity of the first reflective conductor to detect the second linearly polarized wave, and a second reflective conductor disposed about 1/4 of the wavelength separated from the second probe in the direction in which the electric wave travels to reflect the second linearly polarized wave, on the second reflective conductor, an electrically conductive columnar portion protruding is provided, so that it may be in the vicinity of the inner peripheral surface of the waveguide on the line axial of the

Description

CONVERTER RECEIVING SATELLITE TRANSMISSIONS BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to a converter that receives satellite transmissions that has a waveguide that is loaded on an outdoor antenna apparatus to receive two types of polarized linear wave signals.

DESCRIPTION OF THE RELATED TECHNIQUE A conventional converter receiving satellite transmissions is described in relation to figures 6 to 9. There, figure 6 is a cross-sectional side view of the conventional converter receiving satellite transmissions, figure 7 is a front view thereof, Figure 8 is a back view illustrating the internal construction thereof, and Figure 9 is an external view thereof. In these figures, a waveguide 30 is formed in a cylindrical shape, the two ends of which are open. A circuit board 31 formed with a microtire line is provided at the rear end of the extension opening 30a for extension, while a metal bottom cover 32 having a jaw portion 32a is disposed in a position, where the the opening 30a is closed with a cover, by means of the circuit board 31. Furthermore, within the waveguide 30, it is disposed about 1/4 wavelength of the received electrical wave (the frequency bandwidth varies approximately from 10.7 GHz to 12.75 GHz) in front of the rear circuit board 31, there is a first probe 33 for detecting a first linearly polarized wave (e.g., a horizontally polarized wave). This first probe 33 is substantially L-shaped, and its proximal terminal portion is connected to the circuit board 31, while its portion extending linearly from the proximal terminal portion is covered with an insulating member 34 made of, for example, Teflon, to be incorporated into a depressed groove 30b of the waveguide 30, such that its tip end portion can protrude in the waveguide 30 by a predetermined size. From both surfaces (front and rear) intersecting at a right angle with the axial line of the waveguide 30, on the side surface of the first probe 33, a short circuit pattern 35 is provided to make the first probe 33 detects the first reflected linearly polarized wave while, on the other surface, a second probe 36 is molded to detect a second linearly polarized wave (e.g., a perpendicularly polarized wave) intersecting a right angle with the first linearly polarized wave . Here, since the circuit board 31 is negligibly thin compared to the wavelength of the received electrical wave, after all, either the short circuit pattern 35 and the second probe 36 is located approximately in wavelength separated from the wavelength. first probe 33 in the direction in which the electric wave travels (in the direction of arrow A). Further, in this embodiment, the inner bottom surface of the metal cover 32 is formed with a short circuit surface 32b for detecting the second linearly polarized reflective wave by the second probe 36. Incidentally, within the circuit board 31, it is provided a processing circuit in which the signal detected by the first probe 33 and the second probe 36 is processed appropriately (amplified or converted into frequency), and the first probe 33 and the second probe 36 are each connected to first transistors amplifiers of stage 41, 42 by means of separation patterns 39, 40 on the circuit board 31, as shown in figure 8. Furthermore, provided on the metal cover 32 are exhaust ducts 32c, 32d to prevent previously contact with these separation patterns 39, 40. In addition, the first stage amplifier transistor 41 is connected to a second stage amplifier transistor p or middle of the separation pattern 43 while, likewise, the first stage amplifying transistor 42 is connected to the second stage amplifying transistor 45 by means of the separation transistor 44. Either of the first stage transistors 41, 42 operates depending on which of the two linearly polarized waves is received. That is, when the first linearly polarized wave is received, the first stage amplifying transistor 41 operates, and when the second linearly polarized wave is received, the first stage amplifying transistor 42 operates. Any of the linearly polarized waves is input to the second stage transistor 45. The portion of the circuit board 31 which is located within the waveguide 30 is formed in a substantially T-shaped configuration providing a notch 31 b, in FIG. where the short circuit pattern 35 and the second probe 36 are formed. That is, the provision of the notch 31 b is allowed, so that the electrical wave (the second linearly polarized wave) detected by the second probe 36 is not attenuated . On the other hand, in the portions of the front and rear surfaces of the circuit board 31 that are opposite the periphery of the end 30a of the rear opening of the waveguide 30, a ground electrode 37 comprising a welded layer is provided. . These ground electrodes 37, 37 are each connected to each other by means of a plurality of through holes 31a for electrical conduction of the front and rear surfaces that are provided through the circuit board 31, while the short circuit pattern 35 is connected to the ground electrode 37. Furthermore, since the jaw portion 32a of the metal cover 32 is fixed to the periphery of the opening end 30a of the waveguide 30 by means of the circuit board 31 by means of a front 38, the waveguide 30 and the metal cover are each adapted under pressure to the ground electrode 37 on both surfaces of the circuit board 31. Incidentally, the circuit board 31 and the metal cover 32 that are fixed to the portion of the waveguide 30, are located inside a box 46 that houses the circuit to cover it by a cover 47. As shown in Figure 9, a connector is provided. Alida 48 projecting outwardly from this case 46 to emit the received signal. Incidentally, since the waveguide 30 is formed in a cylindrical shape, the distribution of the electromagnetic field of the electrical wave propagating therein mainly takes the TE11 mode. However, in reality, due to the presence of discontinuous points caused by the physical variation in size of the waveguide or circuit board 2, the TM01 mode also occurs, which allows an isolation of only a short time to be inadequately obtained. approximately 25dB between the first and second linearly polarized waves. That is, in the first probe 33 which detects the first linearly polarized wave, a second linearly polarized wave is detected and, in the second probe 36 which detects the second linearly polarized wave, the first linearly polarized wave is detected. Further, since the transmission loss of the received electrical wave propagating through the waveguide 30 increases at the frequency (eg, 9GHz) less than the frequency bandwidth (10.7 GHz - 12.75 GHz) of the electric wave that is introduced into the waveguide 30 (the waveguide exhibits the performance of a bypass filter), the insulation is further reduced, and if the frequency becomes smaller, then the amplification of the first transistors stage amplifiers 41, 42 becomes larger, which causes the first probe 33, the separation pattern 39, the first stage amplifying transistor 41, the separation patterns 43, 44, the first stage amplifying transistor 42, the separation pattern 40 and the second probe 36 form a closed circuit which results in an extraordinary oscillation. Therefore, the converter receiving satellite transmissions in accordance with the present invention can eliminate the electromagnetic field from unnecessary mode TM01 to cause the insulation between the first and second linearly polarized waves to be greater to thus prevent the occurrence of the extraordinary oscillation.

BRIEF DESCRIPTION OF THE INVENTION To solve the above problem, the converter receiving satellite transmissions in accordance with the present invention is provided with a waveguide in which the transmission electric wave traveling thereon travels in the form of a first wave of TE11 mode linearly polarized, and a second linearly polarized TE mode wave intersecting at a right angle to each other, a first probe located at a predetermined position within the waveguide to detect the first linearly polarized wave, a first reflective conductor disposed about 1 / 4 wavelength of the transmission wave separated from the first probe in the direction of travel of the electric wave, a second probe disposed in the vicinity of the first reflective conductor to detect the second linearly polarized wave, and a second reflecting conductor arranged approximately 1/4 wavelength of the transmission wave separated from the A probe in the direction of travel of the electric wave, in which an electrically conductive columnar portion is raised thereon to be located in the vicinity of the inner peripheral surface of the waveguide parallel to the axial line thereof. In the converter receiving satellite transmissions according to the present invention, the above waveguide has an opening end at a position about 1/4 wavelength of the previous transmission electric wave separated from the first probe in the In the direction in which the transmission electrical wave travels, a circuit board is disposed at the front opening end, the previous reflective conductor is provided on the front and rear surfaces of the circuit board, one on the side of the first probe, while that the second probe is provided on the other surface, a metal bottom cover is provided to approximate with the cover in the approximately% wavelength position of the transmission electrical wave separated from the second probe in which the electrical wave travels , the inner lower surface of the metal cover is made in the second reflective conductor, and the The former electrically conductive columnar is formed integrally with the metal cover on the inner bottom surface. In addition, in the converter receiving satellite transmissions in accordance with the present invention, the height of the electrically conductive columnar portion is adjusted to 1/4 wavelength of a predetermined frequency that is less than the lowest frequency of the wave electric transmission. Further, in the converter receiving satellite transmissions according to the present invention, the above predetermined frequency is set at 1 to 2 GHz less than the lowest frequency of the transmission electric wave.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional side view of an outdoor converter that receives satellite transmissions in accordance with the present invention; Figure 2 is a front view of the outdoor converter that receives satellite transmissions in accordance with the present invention; Figure 3 is a rear view of the outdoor converter that receives satellite transmissions in accordance with the present invention, which illustrates the internal construction thereof; Figure 4 is an external view of the external converter of satellite transmissions according to the present invention; Fig. 5 is a characteristic view explaining how the isolation feature of the outdoor converter receiving satellite transmissions in accordance with the present invention is improved; Figure 6 is a cross-sectional side view of a conventional outdoor converter that receives satellite transmissions; Figure 7 is a front view of the conventional outdoor converter that receives satellite transmissions; Figure 8 is a rear view of the conventional converter receiving satellite transmissions, illustrating the internal construction thereof; and Figure 9 is an external view of the conventional outdoor converter that receives satellite transmissions.

DESCRIPTION OF THE PREFERRED MODALITY A converter that receives satellite transmissions in accordance with the present invention is described below in relation to figures 1 to 5. There, figure 1 is a side view in cross section thereof, figure 2 is a front view thereof Figure 3 is a rear view thereof illustrating its internal construction, Figure 4 is an external view thereof, and Figure 5 is a characteristic view explaining how the insulation feature is improved. Referring to Figures 1 to 4, a waveguide is formed into a cylindrical shape whose both ends are open, through which mainly the electric wave of mode TE11 propagates. Further, at its rear opening end 1a, a circuit board 2 formed with a microtire line for extension is provided and, furthermore, a cylindrical metal cover having a lower jaw portion 3a is disposed in a position approximating the opening end 1a by means of the circuit board 2. Further, within the waveguide 1, a first probe 4 is disposed at a position about 1/4 wavelength of the received electrical wave (its bandwidth of frequency varies from 10.7 GHz to 12.75 GHz) in front of the rear circuit board 2 to detect the first wave of linearly polarized TE11 mode (eg, a horizontally polarized wave). This probe cousin 4 is substantially L-shaped, whose proximal terminal portion is connected to the circuit board 2, and the portion extending linearly from the proximal terminal portion is covered with an insulating member made of, for example, Teflon, for it is incorporated into a depression 1b of the waveguide 1, so that its tip terminal side can protrude in the waveguide 1 by a predetermined size. From the front and rear surfaces of the circuit board intersecting at a right angle with the axial line of the waveguide 1, a short circuit pattern 6 constituting a first reflective conductor is provided on the surface of the side of the first probe 4 to reflect the first linearly polarized wave to be detected by the first probe 4 while, on the other surface, a second probe 6 is molded to detect the second linearly polarized TE11 wave (e.g., the perpendicularly polarized wave) intersecting a right angle with the first linearly polarized wave. Here, since the circuit board 2 is negligibly thin comparatively with the wavelength of the received electrical wave, after all, the short circuit pattern 6 and the second probe 7 are each located approximately 1/4 of the length of wave separated from the first probe in the direction in which the electric wave travels (the direction of A). Further, in this example, the inner bottom surface of the metal cover 3 is formed on a short circuit surface 3b, which constitutes a second reflective conductor, to reflect the second linearly polarized wave for detection by the second probe 7. Here, a substantially circular columnar portion 3d protruding parallel to the axial line of the waveguide 1 is provided from the short circuit surface, constituting the inner inner surface of the metal cover 3, in proximity with the inner wall 3c. This columnar portion 3d is integrally formed with the metal cover 3 by a cast metal casting method, and its height is adjusted to A of wavelength of the predetermined frequency (eg, 9 GHz) which is less than the frequency lower (10.7 GHz) of the frequency bandwidth of the received signal that is input to the waveguide 1. Incidentally, on the circuit board 2, a processing circuit is provided for approximately processing (amplifying or converting the frequency of) the signal detected by means of the first probe 4 and the second probe 7, which are each connected to first stage amplifying transistors 10, 11 by means of separation patterns 8, 9 on the circuit board 2, as shown in FIG. 3. In addition, exhaust depressions 3e, 3f are provided. on the metal cover 3 to prevent previously contacting these separation patterns 8, 9. In addition, the first stage amplifier transistor 10 is connected to the second stage amplification transistor 13 by means of the separation pattern 12 while, at the same time , the first stage amplifying transistor 11 is connected to the second stage amplifying transistor 13 by means of the separation pattern 14. Either of the first stage amplifying transistors 10, 11 operates depending on which of the linearly polarized waves it receives. That is, when the first linearly polarized wave is received, the first stage amplifier transistor 10 operates, and when the second linearly polarized wave is received, the first stage amplifier transistor 11 operates. Any of the linearly polarized wave signals is input to the second stage 13 transistor.

The portion of the circuit breaker 2 which is located within the waveguide 1 is formed in a substantially T-shaped manner by the provision of a notch 2b, as shown in Figures 2, 3, and a short circuit pattern 6 and a second probe 7 is formed in this portion substantially in T. That is, the provision of the notch 2b is allowed, so that the electrical wave detected by the second probe 6 (the second linearly polarized wave) is not attenuated. On the other hand, provided on the portions of the front and rear surfaces of the circuit board 2 that are opposite the peripheral edge of the rear opening end 1a of the waveguide 1, there is a ground electrode 15 comprising a welded layer, and are connected to each other by means of a plurality of through holes 2a for electrical conduction of the front and rear surfaces that are provided on the circuit board along the peripheral edge portion of the opening end 1a, while the pattern short circuit 6 is connected to the ground electrode 15. Furthermore, since the jaw portion 3a of the metal cover 3 is fixed to the peripheral edge portion of the opening end 1a of the waveguide 1 by means of the board circuit 2 by means of a front 16, the waveguide 1 and the metal cover 3 are each adapted with pressure with the electrode to ground 15 on both surfaces s of the circuit board 2. By the way, the circuit board 2 and the metal board 3 fixed to the rear portion of the waveguide 1 are located inside the box 17 housing the circuit, to be covered with a cover 18 As shown in Figure 4, an output connector 19 is provided to project outwardly from this cover 17 to emit the received signal. As described above in the present invention, since the columnar portion 3b is made to protrude from the short circuit surface 3b of the metal cover 3, and the protruding position is in proximity with the internal wall 3c separated from the central position of the short circuit surface 3b, the electric wave of mode TE01 whose electric field is focused on the inner wall 3c, rotated in the circumferential direction, is attenuated. Since the height of the columnar portion 3d conforms to A of the wavelength of the frequency which is less than the lowest frequency of the received frequency bandwidth, the electric wave of mode TE01 at that frequency is attenuated. Therefore, this columnar portion 3d corresponds to a trap circuit referred to in the field of electrical circuits. As a result, a curve B of Figure 5 exhibits isolations between the first linearly polarized wave and the second linearly polarized wave when the height of the columnar portion 3d is set to V * wavelength of 9 GHz, and at 9 GHz, a great isolation is obtained, so that it becomes difficult for an extraordinary oscillation to occur, which is achieved with the feedback caused by the first probe 4, the separation pattern 8, the first stage 10 amplifier transistor, the separation 12, 14, the first stage 11 amplifier transistor, the separation pattern 9 and the second probe 7. In addition, as the insulation at 9 GHz becomes greater, the insulation of 30dB over the entire received frequency bandwidth (10.7 GHz to 12.75 GHz) can be assured, with the result that the insulation can be improved by more than 5dB than conventional insulation (curve C) when the 3d columnar portion is not provided. By the way, if there is no fear of the extraordinary starting oscillation of the frequency bandwidth of the received electric wave and only the insulation is improved, then the height of the columnar portion 3d can be preset to VA of the wavelength of an appropriate frequency (eg, 11.7 GHz, which is substantially the center frequency) within the frequency bandwidth of the received electric wave. further, it is easy for extraordinary oscillation to occur at frequencies where the insulation is accompanied by the deteriorating characteristic of the waveguide 1 as the bypass filter is reduced, while the amplification of the first stage 10, 11 transistors does not be thus reduced. These frequencies are approximately 1 to 2 GHz less than the lowest frequency of the received electric wave. Therefore, if the height of the electrically conductive columnar portion 3d is also adjusted to this frequency in accordance with this frequency, then extraordinary oscillation can be effectively prevented. As described above, since the external converter receiving satellite transmissions in accordance with the present invention comprises a waveguide through which the electric wave of transmission traveling thereon travels as the first wave of TE11 mode linearly polarized, and as the second wave of linearly polarized TE mode intersecting each at a right angle to each other, a first probe disposed at the predetermined position within this waveguide to detect the first linearly polarized wave, a first reflective conductor arranged in the approximately wavelength position separated from the first probe in the direction in which the electrical wave travels, a second probe disposed in the vicinity of the first reflective conductor to detect the second linearly polarized wave, and a second, reflective conductor arranged approximately of wavelength separated from the second probe in the dir ection in which the electric wave travels to reflect the second linearly polarized wave, over which the electrically conductive columnar portion rises, so that it lies in the vicinity of the inner peripheral surface of the waveguide parallel to the axial line from it, it can be made to attenuate the electric wave so that TM01 exists mixed within the waveguide. Therefore, it becomes possible to improve the insulation between the first linearly polarized wave that is detected by the first probe, and the second linearly polarized wave that is detected by the second probe. Further, in the converter receiving satellite transmissions in accordance with the present invention, since the height of the electrically conductive columnar portion is adjusted to the wavelength of the predetermined frequency which is less than the lowest frequency of the wave electric transmission, you can avoid the extraordinary oscillation that tends to occur at low frequencies to also improve the insulation within the frequency bandwidth of the transmission electric wave. Likewise, in the converter receiving satellite transmissions in accordance with the present invention, the waveguide has the wavelength-opening end separated from the first probe in the direction in which the transmission electrical wave travels , where the circuit board is arranged, the first reflective conductor is provided on one surface of the circuit board on the side of the first probe while, on the other surface, the second probe is provided, the metal bottom cover is provided. to approximate with the lid to the position approximately% of the wavelength of the electric wave separated from the second probe in the direction in which the electric wave travels, and the inner bottom surface of this metal cover is made to constitute the second reflective conductor while, on this inner bottom surface, the electrically conductive columnar portion It is formed integrally with the metal cover. As a result, it becomes possible to minimize the distance from the first probe to the second reflective conductor in order to miniaturize the entire waveguide in this way, while the electric wave is easily eliminated in an unnecessary way.

Claims (4)

NOVELTY OF THE INVENTION CLAIMS

1. - An external converter that receives satellite transmissions, characterized in that it comprises: a waveguide in which the electric wave of transmission traveling in it travels as a first wave of linearly polarized TE11 mode and as a second wave of TE linearly polarized intersecting at a right angle to each other; a first probe for detecting said first linearly polarized wave, arranged at a predetermined position within said waveguide; a first reflecting conductor for reflecting said first polarized wave, disposed approximately VA of the wavelength of said electrical transmission wave separated from said first probe in the direction in which the electrical wave travels; a second probe for detecting said second linearly polarized wave, arranged in the vicinity of said first reflective conductor; and a second reflective conductor for reflecting said second polarized wave, disposed approximately VA of the wavelength of said electrical transmission wave separated from said second probe in the direction in which the electric wave travels; an electrically conductive columnar portion being raised on said second reflective conductor, so that it lies in the vicinity of the inner peripheral surface of said waveguide parallel to the axial line thereof.

2. - The outdoor converter that receives satellite transmissions according to claim 1, further characterized in that said waveguide has an opening end at a position approximately% of the wavelength of said electrical transmission wave separated from said first probe in the direction in which the electric transmission wave travels, a circuit board is disposed at said opening end, said first reflecting conductor is provided on the surface of said circuit board facing said first probe, said second probe is provided on the surface of said circuit board opposite the surface on which said first reflective conductor is provided, a metal bottom cover is provided to approximate with a cover a position approximately VA of the wavelength of said separate transmission electric wave of said second probe in the direction in which the The electric wave travels, and the inner bottom surface of said metal cover is made in said second reflective conductor, while said electrically conductive columnar portion is formed integrally with said metal cover on said inner bottom surface.

3. The outdoor converter that receives satellite transmissions according to claim 1, further characterized in that the height of said columnar electrically conductive portion is adjusted to% of the wavelength of a predetermined frequency that is less than the lowest frequency of said electric transmission wave.

4. - The external converter that receives satellite transmissions according to claim 3, further characterized in that said predetermined frequency is adjusted 1 to 2 GHz less than said lower frequency of said electric transmission wave.