If you want to boost the cell signal reaching your hotspot, then something like the Wilson Sleek amplifier should work for you, although I would upgrade the roof antenna to a higher gain than the included antenna. If you want to boost the WiFi signal from the hotspot to your computer, there are other devices for that.
Dutch
2001 GBM Landau 34' Class A
F53 chassis, Triton V10, TST TPMS
Bigfoot Automatic Leveling System
2011 Toyota RAV4 4WD/Remco pump
ReadyBrute Elite tow bar/Blue Ox baseplate