The Ku band (Kurtz-under band) is primarily used for satellite editing and broadcasting satellite television. It is also used by Satellite TV services providers such as DirecTV and Dish Network for their subscriber base. This band is split into multiple segments broken down into geographical regions, as determined by the ITU (International Telecommunication Union).
The Ku band is a portion of the electromagnetic spectrum in the microwave range of frequencies ranging from 11.7 to 12.7GHz. (downlink frequencies) and 14 to 14.5GHz (uplink frequencies).
The most common Ku band digital reception format is DVB (Digital Video Broadcast – the main profile video format). There are other studio profile digital video formats such as the full-blown Digicipher II 4DTV format now extensively used in C-Band communictions.
The ITU Region 2 segments covering the majority of the Americas are between 11.7 and 12.2 GHz, with over 21 FSS North American Ku-band satellites currently orbiting. Each requires a 0.8-m to 1.5-m antenna and carries twelve to twenty four transponders, of which consume 20 to 120 watts (per transponder), for clear reception.
The 12.2 to 12.7 GHz segment of the Ku Band spectrum is allocated to the broadcasting satellite service (BSS). These direct broadcast satellites typically carry 16 to 32 transponders.
Each provides 27 MHz in bandwidth, and consumes 100 to 240 watts each, accommodating downlink receiver antennas as wide as 450 mm (18 inches ).
Ku Band Difficulties:
Unlike C-Band, with the Ku Ban frequencies higher than 10 GHz are transmitted and received used in a heavy rain fall area, a noticeable degradation occurs, due to the problems caused by and proportional to the amount of rain fall (commonly known as known as “rain fade”, a portion of the low power signal is reflected from the rain drops/orbs).
This problem is combatted, however, by deploying an appropriate link budget strategy when designing the satellite network, and allocating a higher power consumption to overcome rain fade loss. In terms of end-viewer TV reception it takes heavy rainfalls in excess of 100 mm per hour to have a noticeable effect.
A similar phenomena, called “snow fade” (when snow accumulation significantly alters the focal point of your dish) can also occur during Winter Season. Also, the Ku band satellites typically require considerably more power to transmit than the C band satellites. However, both Ku and Ka band satellite dishes are smaller (varying in size from 2′ to 5′ in diameter) than C-Band dishes.
Ku Band Satellite Service Downlink Usage Frequency Range
The Ku band downlink uses frequencies between 11.7 and 12.7GHz, which are further subdivided according to their assigned use:
Ku Band Usage Downlink:
- Fixed Satellite Service 11.7 – 12.2GHz
- Broadcast Satellite Service 12.2 – 12.7GHz
Services that can be found on the Ku-band include educational networks, business networks, sports backhauls, private tele-conferences, mobile news truck feeds, international programming, and various SCPC (Single Channel Per Carrier) transmissions of analog audio, as well as FM audio services.
If you already have a operational C-band system in place, you can retrofit it to accept Ku band frequencies. In order to do so, you will need to obtain a Ku-band LNB as well as a C/Ku band feed-horn, plus some coax cable for your Ku-band LNB. As for the coax cable recommended- RG-6 is optimal for low loss in the 950-1450 frequency range- what Ku-band LNB processes.
Ku Band Dish Antenna Compatibility:
If you have a solid dish, you should have no problem converting from C band, to Ku band. However, with a mesh dish, if the “holes” in the mesh are greater than a quarter inch, the chances of computability are not good due to the fact that this type of dish does not reflect Ku-band signals properly. Therefore, we strongly suggestr upgrading to either a solid dish, or a mesh dish in which the hole size under 1/4″, and ideally you’ll want a dish that is 1 piece (or at least very few pieces); as 4 section dish is more optimal than an 8 section dish. The fewer the sections, the more accurate your parabola shape is and thereby the more difficult it is for your dish to become warped (the smaller the number of seams- the better). And insofar as dish mounts go, the H2H (Horizon-to-Horizon) dish mount is more desirable than a polar mount.
This is due to the fact that the Ku-band demands that the dish antenna system is well-targeted and able to closely follow the orbital arc, of which the H2H mount does quite admirably, as compared to a polar mount. Also, bear in mind that you will be adjusting both the azimuth and elevation, which can be a bit tricky occasionally.
Importance of Satellite Antenna Dish Parabola:
The parabolic shape of your dish is of critical importance, as warpage causes signal degradation via mis-reflection, seriously down-grading your overall system performance. Some tape and string is all that is required to do a quick warpage check and some tape.
Anchor a piece of string, stretched as tight as possible, “north” to “south” across your dish face, edge to edge. You’ll want to do the same thing again, with another piece of string, only “east” to “west” across the dish face- at 90 degree angles. Be sure that both strings are tight. If the strings come together anywhere but the direct center, then your dish has sustained warp damage and needs to be bent back into proper parabola shape, for optimal performance. If they connect in the center of your dish, likely that your dish is not warped.
So therefore, you’ll want to use either the tri-supports or quad supports , as they will greatly assist in keeping your C/Ku-band feed-horn highly stable, even in high winds.