(A) Field of the Invention
The present invention is related to a dish antenna, and more specifically, to an adjustment method for a dish antenna.
(B) Description of Related Art
A satellite television system employs a dish antenna to collect satellite signals, and the signals are then reflected to low noise block down converters (LNB) equipped at the focus of the dish antenna for amplifying the signals and reducing their frequencies down to around 1 GHz, i.e., the radio signals are transformed to an intermediate frequency. The adjusted signals are transmitted via a cable to an indoor television channel selector for selecting the signals of a desired channel, and the selected signals are then amplified, modulated and converted into video and audio signals for television viewing.
A dish antenna is a highly directional receiving device, which has to be precisely directed toward satellites in orbit at 36,000 kilometers altitude. For example, if a dish antenna with a 180 cm diameter shifts 2 cm horizontally, or 3 cm vertically, the signals will become weak or even disappear. In addition, if a dish antenna uses the Ka band, i.e., 26-40 GHz, an adjustment accuracy of 0.1 degrees is needed, and the tolerance has to be within 0.02 degrees for aiming at satellites precisely.
Normally, a dish antenna using the Ka band is adjusted by using a programmable logic controller (PLC) in control of servo motors; however, the high cost significantly limits its popularity.
Moreover, the dish antenna 10 is fixed after being adjusted, and there is no need for further adjustment. Accordingly, the adjusting mechanism is used only one time and is not cost-effective.
The present invention provides an adjustment method for a dish antenna, in which the related rotating angle adjustment mechanism can be reused, so as to effectively reduce the assembly cost for the dish antenna.
In accordance with an embodiment of the present invention, an adjustment method for a dish antenna includes the steps of (1) providing an angle adjustment apparatus for the dish antenna, the angle adjustment apparatus including a base member, a first rotation member and a second rotation member, wherein the first rotation member is secured to the second rotation member and can rotate by a first rotation angle relative to the second rotation member, the second rotation member is secured to the base member and can rotate by a second rotation angle relative to the base member; (2) connecting a first rotating angle adjustment mechanism and/or a second rotating angle adjustment mechanism to the angle adjustment apparatus, wherein the first rotating angle adjustment mechanism connects the first rotation member and the second rotation member, and the second rotating angle adjustment mechanism connects the second rotation member and the base member; (3) adjusting a first rotation angle between the first rotation member and the second rotation member by using the first rotating angle adjustment mechanism, and/or adjusting a second rotation angle between the second rotation member and the base member by using the second rotating angle adjustment mechanism; and (4) detaching the first rotating angle adjustment mechanism and/or the second rotating angle adjustment mechanism from the angle adjustment apparatus for use with another dish antenna.
As shown in
When the end 2145 of the first screw 2141 and the second rotation member 212 are fixed, the relative angle between the second rotation member 212 and the first rotation member 213 can be fine-tuned by rotating the screw nut 2142. Because the threads are of different thread directions, the first screw 2141 and the second screw 2143 approach or depart from the screw nut 2142 as the screw nut 2142 is rotated. Accordingly, the second rotation member 212 and the first rotation member 213 move in relative motion around a pivot 216 (see
Likewise, the screws 2151, 2153 and the screw nut 2152 of the second rotating angle adjustment mechanism 215 have equivalent or similar structures. Accordingly, the second rotation member 212 can rotate clockwise or counterclockwise relative to the base member 211. When the second rotating angle adjustment mechanism 215 extends, the second rotation member 212 rotates counterclockwise relative to the base member 211. In contrast, when the second rotating angle adjustment mechanism 215 extracts, the second rotation member 212 rotates clockwise relative to the base member 211.
Because the dish antenna usually needs not to be further adjusted after the adjustment is completed, the first rotating angle adjustment mechanism 214 and the second rotating angle adjustment mechanism 215 no longer provide any function after adjustment. In this embodiment, the two ends of the first rotating angle adjustment mechanism 214 and the second rotating angle adjustment mechanism 215 are detachable. After the first rotating angle adjustment mechanism 214 and the second rotating angle adjustment mechanism 215 adjust the angles of the dish antenna, the first rotating angle adjustment mechanism 214 and the second rotating angle adjustment mechanism 215 can be detached from the angle adjustment apparatus 21 of the dish antenna 20, i.e., the first rotating angle adjustment mechanism 214, the second rotating angle adjustment mechanism 215 and the angle adjustment apparatus 21 are disassembled, as shown in
Because the elevation angle of a dish antenna of a directional satellite is more important than the horizontal angle thereof, some dish antennas only have the first rotating angle adjustment mechanism. In an embodiment, a rotating angle adjustment mechanism that can adjust both the first rotation angle and the second rotation angle is employed. For example, the lengths of the rotating angle adjustment mechanism connecting to the angle adjustment apparatus at different places are designed to be the same. After the first rotation angle is adjusted, the rotating angle adjustment mechanism is disassembled and reassembled to another corresponding place for adjusting the second rotation angle.
In view of the above, the adjustment method of a dish antenna is shown in
The above-described embodiments of the present invention are intended to be illustrative only. Numerous alternative embodiments may be devised by those skilled in the art without departing from the scope of the following claims.
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98104425 A | Feb 2009 | TW | national |
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Number | Date | Country | |
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20100201599 A1 | Aug 2010 | US |