Patent Grant
10181634
1. Field of the Invention
The present invention relates to systems and methods for aligning terrestrially based antennas, and in particular to an outdoor unit configured for customer installation and alignment.
2. Description of the Related Art
Satellite transception of communications signals has become commonplace. Satellite distribution of commercial signals for use in television programming currently utilizes multiple feedhorns on a single Outdoor Unit (ODU) which supply signals to one or more receivers (also known as set top boxes or STBs or Integrated Receiver/Decoders or IRDs).
Typically, the ODU comprises an antenna that is aligned so as to direct its sensitive axis to a location that optimizes reception from all relevant satellites. This is accomplished by coarse aligning the antenna so as to receive a signal transmitted by a selected one of the satellites, and then fine-tuning the alignment using a power meter or other alignment tools.
Proper coarse alignment is critical, because the desired satellite may reside in orbital locations close to other nearby satellites and without accurate course alignment, the fine alignment process may mistakenly direct the antenna's sensitive axis at the wrong satellite. Proper fine alignment is likewise critical, as proper alignment assures that the antenna is properly aimed to optimize reception (and transmission, if relevant) of the signals from all transponders of all of the satellites of interest.
Although some consumers may be capable of installing and aligning the antenna to sufficient accuracy, other consumers are not so capable. The result is dissatisfied customers and unnecessary service calls. Hence, currently, such installations are performed either by qualified service technician at the installation location, or in mobile applications, performed using expensive automatic alignment equipment.
What is needed is a method and apparatus that simplifies installation and alignment to the point where it can be accomplished by almost all of consumers, without the need for qualified service technicians. The apparatus and method below satisfies this need.
To address the requirements described above, the present invention discloses a method and apparatus for angularly aligning an antenna disposed at a geographical location. In one embodiment, the apparatus comprises a plurality of reticle members, each reticle member having a reticle, and a plurality of reference members, each adjustably engaged with an associated one of the plurality of reticle members, wherein each of the plurality of reference members comprises an associated template having a reference mark positioned thereon according to the geographical location of the antenna and the antenna is angularly aligned when each reference mark of each template is aligned with the reticle associated with the reference mark. In another embodiment, the method comprises the steps of affixing an associated template having a reference mark positioned thereon according to the geographic location of the antenna to each of the plurality of reference members and angularly aligning each of the plurality of reticle members with each reference mark of each associated template. These features provide significant advantages, including:
Simplified Leveling Scheme: Currently, the procedure for mounting the antenna begins with installing a mounting pole in a vertical (parallel to the gravity vector) position. The improved system includes simplified leveling apparatus which does not require setting the mounting pole in a vertical position. An integrated bubble level may also be provided to aid in leveling the alignment apparatus.
Integrated Compass: Selected embodiments of the alignment apparatus include an integrated magnetic compass. This compass can be used to align the alignment apparatus toward a known heading, such as geomagnetic North with sufficient accuracy to achieve coarse alignment. In this context, coarse alignment occurs when the antenna is sufficiently aligned so as to receive, albeit poorly, a signal from the appropriate satellite transponder. For example, when the antenna is coarsely aligned, at least some Ku-band transponders 107 from the 101 orbital slot can be received and decoded by a receiver so that nonzero signal quality values are reported by the receiver (signal-to-noise values converted to a zero to 100 scale).
Coarse Alignment Enabled by Color-Coded Templates Custom Printed According to the Installation Location: Rather than provide end users with an alignment apparatus with graduated scales and ask that the consumer properly orient the alignment apparatus using those scales (e.g. by adjusting the alignment apparatus to values on those graduated scales, the alignment apparatus uses color-coded templates which have pre-printed marks indicating the desired antenna orientation.
These pre-printed templates are sized and shaped so that they unambiguously fit only one location and orientation on the alignment apparatus. Further, the templates are color coded with other alignment apparatus elements to assure the proper templates are used with the associated elements of the alignment apparatus. Further, the templates may be asymmetric about any axis so that they can only be placed on the appropriate member of the alignment apparatus in the proper location and orientation.
The end-consumer need only mount the templates to the alignment apparatus, and line up the marks on the templates with associated cursors in azimuth, elevation and tilt directions. The resulting pointing is performed with sufficient accuracy to achieve coarse antenna alignment.
Integrated Fine Alignment After Alignment Apparatus is Fully Assembled: The fully assembled alignment apparatus includes fine adjustment mechanisms so that after assembly, signal reception may be optimized.
Referring now to the drawings in which like reference numbers represent corresponding parts throughout:
In the following description, reference is made to the accompanying drawings which form a part hereof, and which is shown, by way of illustration, several embodiments of the present invention. It is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
The uplink center 104 receives program material and program control information from the control center 102, and using an uplink antenna 106 and transmitter 105, transmits the program material and program control information to one or more satellite 108A-108N (hereinafter alternatively referred to as satellite(s) 108). The satellite 108 receives and processes this information, and transmits the video programs and control information to the subscriber receiver station 110 via downlink 118 using one or more transponders 107 or transmitters. The subscriber receiving station 110 receives this information using the outdoor unit (ODU) 112, which includes a subscriber antenna.
The distribution system 100 can comprise a plurality of satellites 108 in order to provide wider terrestrial coverage, to provide additional channels, or to provide additional bandwidth per channel. For example, each satellite may comprise 16 transponders 107 to receive and transmit program material and other control data from the uplink center 104 and provide it to the subscriber receiving stations 110.
While the features disclosed herein will be described with reference to a satellite-based distribution system 100 transmitting media programs, they may also be practiced in any embodiment requiring alignment of a transmitting antenna with a reference position. This may also include terrestrial to terrestrial transmission.
The alignment apparatus 300 also comprises a plurality of reference members 306, 314 and 322. In the illustrated embodiment, the plurality of reference members includes an azimuth reference member 312, an elevation reference member 314, and a tilt reference member 322. Each of the plurality of reference members 306, 314 and 322 comprises an associated template 310, 320 and 326 having a reference mark positioned thereon. The reference mark is located at a position according to the geographical location where the antenna is to be installed. Hence, the azimuth reference member 312 includes an associated azimuth reference template 310 mounted thereon, the elevation reference member 314 includes an associated elevation reference template 320 mounted thereon, and the tilt reference member 322 includes an associated tilt reference template 326 mounted thereon. Also, each reticle member comprises an associated reticle as well. Hence, azimuth reticle member 312 includes azimuth reticle 308, elevation reticle member 316 includes elevation reticle 318 and tilt reticle member 321 includes tilt reticle 324.
The antenna alignment apparatus 300 (and hence, the antenna attached to the antenna alignment apparatus 300) is angularly aligned to direct the antenna in a desired direction (e.g. at a satellite 108 or other element of interest) when each reference mark of each template 310, 320, and 326 is aligned with a cursor of the associated reticle 308, 318, and 324 as is further described below. The alignment apparatus 300 also comprises a base member 302 that can be used to mount the alignment apparatus 300 on a mast or similar structure. The azimuth reference member 306 mounts to the base as described further below.
To assist such leveling, the azimuth reference member 306 comprises a level 406. In one embodiment, the level 406 comprises a bubble level sensitive in two orthogonal directions. The bubble level includes a vessel incompletely filled with a liquid, thus resulting in a bubble, and a circular graduation. The user adjusts the azimuth reference member 306 relative to the base member 302 to orient the bubble so as to be evenly circumscribed by the circular graduation, thus leveling the azimuth reference member 306 (and hence, the rest of the alignment apparatus 300).
As a part of the alignment process, the alignment apparatus 300 must also be oriented in the proper heading. This can be accomplished by rotating the azimuth reference member 306 about the azimuth axis 416 with respect to base member 302 to properly orient the azimuth reference member 306 towards the desired heading (such as magnetic north). To aid in this process, the azimuth reference member 306 may also comprise a compass 408 having needle 414 and a transparent cursor 412 aligned with an indicator 410. In one embodiment, every compass 408 is installed in the same orientation relative to the azimuth reference member 306, and the user is provided an angle value related to the desired offset from magnetic north. The azimuth reference member 306 is oriented to the proper heading by rotating the azimuth reference member 306 about the azimuth axis 414 until the angle value (in the illustrated embodiment, 180 degrees) is achieved. In other embodiments, the indicator 410 or cursor 412 is custom-aligned to the proper direction, and the user rotates the azimuth reference member 306 about the azimuth axis 414 until the needle 414 is aligned with the cursor 414. This has the advantage in relieving the user of the need to understand how to read the compass 408.
Notably, the foregoing concentric sphere geometry of the relevant surfaces can be used to level and point north at the same time, with both a bubble level 406 and compass 408 simultaneously referenceable.
Once leveled and aligned, azimuth reference member 306 can be secured to the base member 302 by tightening locking ring member 404.
In one embodiment the associated reticles, templates, and locations where the templates are to be installed are color coded (e.g. fashioned of the same color) to reduce errors in the process of installing the template on the reference member and the reticle member on the reference member. For example, azimuth template 310 may be green in color, matching the color of the area 506 where the template 310 should be mounted to the associated tab 510, and the reticle 308 of the reticle member 312 may also be of matching green color.
As was the case with the azimuth reference member 306 and azimuth template 310, the elevation reference member 314 includes physical features 902 that permit precise mounting of the elevation template 320, which has matching physical features. For example, the elevation reference member 314 may have a tab 906 analogous to the tab 510 of the azimuth reference member 306, and the elevation reference template 320 may include a slot or aperture through which the tab 906 is inserted.
The elevation reticle member 316 is affixed to the elevation reference member 314 so that it may rotate around the elevation reference member 314 about an elevation axis 908. This can be accomplished via fixing members such as bolts 910 inserted into appropriate apertures in the elevation reference member 314.
This alignment position may be fixed using affixing mechanism such as a screw inserted in aperture 1006.
The foregoing alignment of the device may be performed with most or all of the antenna structure mounted to the alignment apparatus 300 or with the antenna not mounted to the alignment apparatus 300. As the weight of the antenna may skew some of the adjustments (e.g. in elevation and tilt), the antenna structures may be attached to the alignment apparatus 300 (e.g. by attaching dish 202 to the tilt reference member 322 using mounting holes 1302 and the boom 206 to boom mount 1208, the LNB 208 to the boom 206, and routing a cable from the LNB 208 to the receiver 124), and the alignment rechecked using the associated reticles and template reference marks for each axis (azimuth, elevation, and tilt), and set in place with the associated set screws after the antenna structures have been added to the alignment apparatus 300.
This assembly and alignment process completes a coarse alignment of the antenna using the alignment apparatus 300. Notably, the foregoing operations do not require that the antenna actually receive a signal. Instead, the antenna is coarse aligned to a point in space using a ground datum (offered by a level base structure oriented in the proper heading) and the alignment of each template mark with the associated reticle cursor.
The antenna may now be “fine” aligned using fine adjustment mechanisms as further described below. As further described below, this may be accomplished by tuning the receiver 124 to receive a signal from a particular transponder 107 of a particular satellite 108 (and preferably at a particular polarization), and fine adjusting the alignment apparatus 300 in the relevant axes to maximize signal reception. A demodulator in the receiver 124 may be used to peak the signal by maximizing the signal quality meter reading, which may comprise a signal-to-noise ratio of the signal received from the selected transponder normalized to a 0 to 100 scale.
In one embodiment, the transponder used for fine alignment is a Ka-band transponder, and the signal used for fine alignment is transmitted at a particular polarization. This is because the antenna beam pattern is typically tighter (has a smaller half power beamwidth) in the Ka band than the Ku band, and this smaller beamwidth allows for pointing to within a few tenths of a degree of the peak of the beam. Further, the center of the antenna's beam pattern is not constant for different polarizations. Hence, the choice of transponder and polarization is important because the beamwidth of the antenna in the selected frequency band impacts the accuracy of the alignment, and polarization will impact the bias introduced during the pointing process.
The selected polarization used may depend on the Topocentric angle (the angle formed by imaginary straight lines that join two given points in space with a specific point on the surface of the Earth) so that a right-hand circularly polarized transponder may be used at some locations and a left-hand circularly polarized transponder at others. This simplified peaking approach is different from other schemes that use dithering. The simple peaking approach is very simple to use and the alignment apparatus mechanisms are simplified. But it is recognized that the dithering approach (and also other schemes that measure the signal-to-noise ratio for multiple transponders and then use a curve fitting approach to final the optimal position) may provide slightly better positioning and are more tolerant to mispointing errors.
Hence, the alignment apparatus 300 comprises two mechanisms to permit rotation of the antenna about the azimuth axis 416. The first mechanism permits rotation of the azimuth reference member 306 in relation to the azimuth reticle member 312 about the azimuth axis 416, and the second mechanism permits rotation of the elevation reference member 314 in relation to the azimuth reticle member 312 about the azimuth axis 416. These two independent means of adjusting the azimuth angle (fine and coarse) permit the alignment apparatus 300 to be coarsely aligned in azimuth, then fixed in coarse position, then finely aligned with greater resolution in azimuth and fixed in fine position. The azimuth fine adjust geometry rotates in unison with coarse azimuth until coarse lock, and then pivots independently around the same axis with finer resolution. The fine control mechanism uses a fastener through a sliding, pivoting nut 1408 to finely adjust the azimuth geometry relative to the base member 302.
As shown in block 1706, the azimuth reference member 306 is then rotated about the gravity vector to orient the azimuth reference member 306 with respect to magnetic north. A magnetic compass 408 mounted on the azimuth reference member 306 can aid in this process. Preferably, the azimuth reference member 306 and nearby structures (e.g. the base 302 and mast 204 are non-magnetic to permit an accurate determination of magnetic north. In block 1708, the azimuth reference member 306 is affixed to the base member 302, for example, using locking ring member 404.
Next, the azimuth reticle member 312 is mounted to the azimuth reference member 306, as shown in block 1710. The azimuth reticle member 312 is then oriented (e.g. rotated) about the azimuth axis 416 to align the reference mark 702 of the azimuth template 310 with the azimuth reticle cursor 704, as shown in block 1712. Then, the azimuth reticle member 312 is affixed to the azimuth reference member 302 to prevent further motion between these two elements about azimuth axis 416, as shown in block 1714. This can be accomplished via azimuth affixing mechanism 510, which may comprise a screw.
Finally, in block 1910, a signal is received with an antenna coupled to the alignment apparatus 300, and the alignment apparatus 300 is fine aligned in both azimuth and elevation. This can be accomplished by adjusting the antennal assembly 300 alignment in azimuth and elevation (and optionally, tilt) to maximize a signal characteristic of a signal transmitted by a selected transponder 107 and received by the receiver 124.
This signal characteristic may be a measure of signal quality or signal strength measure. The transponder 107 selected for this fine alignment procedure may be a transponder 107 transmitting signals at frequencies for which the antenna has a narrower or narrowest beamwidth than other frequencies. In one embodiment permitting adjustment to within a few tenths of a degree, the fine alignment is performed in azimuth and elevation to peak the signal quality value for one Ka band transponders 107. One approach for fine alignment is to peak the signal received for one Ka-band transponder. The choice of transponder 107 is important because the signals polarization will impact bias introduced during the pointing process. The polarization used may depend on the Topocentric angle so that a right-hand circularly polarized transponder may be preferred for some installation locations and a left-hand circularly polarized transponder may be preferred at other locations.
This simplified peaking approach is different from other schemes that use dithering, but it is recognized that the dithering approach (and also other schemes that measure the signal-to-noise ratio for multiple transponders and then use a curve fitting approach to final the optimal position) may provide slightly better positioning and are more tolerant to mispointing errors.
Another approach is to utilize the three-axis magnetometer, three-axis accelerometer, and three-axis gyroscopes provided in many commercial smartphones to perform the antenna alignment. The accelerometers in such smartphones can be used to make at least some of the angular measurements that are needed for the elevation and tilt processes. This can be accomplished by use of an adapter that is permits the smartphone to be mounted to the several locations on the antenna alignment apparatus 300 and used to align the antenna in the proper direction. For example, the sensors in a smartphone can be used to perform the base leveling, pointing toward north, and setting the elevation and tilt angles (using the smartphone's accelerometers) described above.
Adapters can be used to (1) place the smartphone at the location of the compass 408 in
Finally, alignment of the antenna in azimuth, elevation, tilt may all be accomplished by my mounting the smartphone 2004 to the alignment apparatus 300 as the antenna reflector 202 would be mounted to the tilt reference member 322, using mounting structures 1302. In this case, the alignment apparatus 300 may be placed in different alignment configurations, and the smartphone 2004 used to align the alignment apparatus 300 in about each axis one at a time, or at the same time, using aural or visual feedback.
The smartphone can also be used to aid in the fine adjustment of the alignment apparatus 300. For example, a smartphone can also be used to transmit information from the receiver 124 to the smartphone, thereby providing a portable display of the signal quality. Communications between the receiver 124 and the smartphone may be made via WiFi.
This concludes the description of the preferred embodiments of the present invention. The foregoing description of the preferred embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
| Number | Name | Date | Kind |
|---|---|---|---|
| 7408526 | Pan | Aug 2008 | B2 |
| 7663565 | Son | Feb 2010 | B2 |
| 8350778 | Yeh | Jan 2013 | B2 |
| Number | Date | Country | |
|---|---|---|---|
| 20170187089 A1 | Jun 2017 | US |
