I need to deliver 100 mA DC current to my load.
You could try a constant current source from the 5V rail.
Using a constant current instead of the emitter resistor will improve the performance, but it won't reduce the power dissipation. I'd recommend using a video amplifier IC, which will use much less power.
http://www.ti.com.cn/cn/lit/ds/symlink/opa832.pdfEDIT:
How can it deliver 100mA DC to the load? It's AC coupled, so there will be no DC in the load.
I need to deliver 100 mA DC current to my load.
I'm getting a somewhat fed up with your way of providing information bit-by-bit. If it's super secret, don't ask here, but go your own way. If not, don't make us waste our time, we're doing this for free.
Why don't you just what you're trying to do, then we can really help?!
How far away is your load?
What kind of cable?
And so on...