The LPF2-2R54-SFF from Planar Monolithics Industries is a Microstrip Lowpass Filter with a passband from DC to 2 GHz. It has a high Q with an insertion loss of less than 1.5 dB and a VSWR of under 1.8:1. The low pass filter offers over 50 dBc of rejection from 2.5 to 4 GHz. It is available in a module with SMA (F) connectors.