The L54128 from Mercury Systems is a GPS/GNSS Filter Amplifier with Frequency 1217 to 1237 MHz / 1565 to 1585 MHz, Noise Figure 2.7 to 3.2 dB, Attenuation/Rejection 45 to 55 dB, Current 40 mA, Gain 10 to 14 dB. Tags: Module with Connector. More details for L54128 can be seen below.