If you insist on trying this, you would probably want to use a high performance splitter, one that is rated to 2.5 GHz. One way to make up for splitter losses is to include a low noise preamp in line before the splitter. This is something you definitely don't build, you buy it. I'm not familiar with the cable signals from this particular antenna, but I assume they are not downconverted at the antenna, which means that the preamp has to be a very good one with wide bandwidth up to 2.5 GHz also. It should have a noise figure of less than 2 dB, and a modest gain, perhaps about 8 to 10 dB. The gain is enough to make up for the splitter losses which will be around 4.5 dB, and a bit more to help maintain the noise figure of the system, but not so much that you risk overdriving the receiver with too much signal. If you want to learn more about this "noise figure" thing, just ask.
If the signal is downconverted at the antenna, then you can probably relax the bandwidth of the preamp and splitter, but you will probably still want the preamp.