There's no difference between digital and analog tv amplifiers as long as they cover the same frequency range.
Most tv broadcast channels use less power for their digital signals than they used for the analog signal, which means the antenna and amplifier are more critical. You can get amplifiers that increase the signal strength by about 10 dB to 24 dB (10 to over 100 times), but you should start with a good antenna, probably one with at least half a dozen elements.
Finally, you should use a website like
www.tvfool.com to find out where the transmitters are located and how strong their signals are.
Here at home, I get weak signals in the range of 30 to 50 miles that I've only lost during really heavy weather.
Bob