What the folded dipole resonant frequency should be (CDMA network)?

I am a non technical person and consider building (800 MHz range) yagi antenna from a design by Yagi Calculator. When I printed out the design calculation I found the "confusing detail" which is a driven element resonant frequency. What the folded dipole resonant frequency should be for increasing a modem's signal strength for the broadcasting band 824-849 MHz (communication from a modem to CDMA cell tower) and the broadcasting band 869-894 MHz (communication from cell tower to modem)? I may be mistaken but it seems to me that driven element should be tuned to the 869-894 frequency range if my concern is to download files at high speed.