Chelton offer a wide range of L1, L2 and combined L1 & L2 band GPS FRPA (Fixed Reception Pattern Antenna) and GPS amplifier products.
These can be used in conjunction with amplified splitters with up to 7 ports.
Also available is Chelton's Anti-Jam GPS Systems which offer up to 100 times more immunity to jammers than a conventional GPS antenna.
https://www.chelton.com/our-capabilities/antennas/navigation-antennas/gps/