iDirect infinity : Max throughput with smallest dish ?

iDirect infinity: What is the Maximum throughput with smallest dish possible???

Who out there is pushing 6meg down and 6 meg up with iDirect?  Or even something close to that?

We are looking to run 6 up and 6 down.  We need the smallest footprint possable...    Anyone got any suggestions?  
1.2M dish with 16w BUC????

The downlink to your small dish is not a problem. There are many satellites with high power downlinks intended for antennas under 1m diameter. Remember that all satellite TV receivers are receiving mutiple carriers with bit rates in excess of 30 Mbit/s.

For your uplink, the problem is that you may cause interference into the adjacent satellites. To keep your uplink power down you need to try to find a satellite that has a reasonably small size uplink beam, so it has a high G/T receive at the satellite. Being near the centre of an uplink beam will help. Then do link budget calculations.  Having a really large receive teleport dish at the other end will help. Contact the satellite operator for more exact link budgets, and rules about your off-axis emission limits towards the adjacent satellites.  Use advanced turbo coding and lower the FEC rate so that you need minimum Eb/No overall.

If you use a high power BUC with a small dish make special arrangements to support the weight of the BUC. A heavy BUC may distort the dish and severely degrade the gain and increase adjacent satellite interference. The RF radiation hazard to people is also severe so make certain no one can get into the vicinity of the dish when it is transmitting. 16W will cook your eye lens in a moment.

Best regards, Eric.

Do you have any experience with lower bit rates and a 1.2m dish ? If you can make 256k work with say 1 watt, then 6 MHz will need 24 watt. If you can make 256k work with say 2 watt, then 6 MHz will need 48 watt.

Note your test location in the uplink beam contours. If you are moving about to other places further from the beam centre, more eirp power will be need. -3 dB down on the uplink G/T contours means twice the watts or 1.4 times antenna diameter (=+3dB gain) is needed.

The sidelobe interference problem really comes with smaller dishes which have a wider main beam and less discrimination between the main beam gain and the sidelobe gain. If you are happy with 1.2m then stick with that and widen out the carrier proportional to the power. As long as you widen the carrier bandwidth proportional to the watts then the interference/40kHz into adjacent satellites will remain unchanged.

Best regards, Eric.