The BGA123L4 from Infineon Technologies is a RF Amplifier with Frequency 1.55 to 1.615 GHz, Power Gain 16.4 to 19.4 dB, Noise Figure 0.75 to 1.25 dB, Input Return Loss 7 to 9 dB, Supply Voltage 0.4 to 3.6 V. Tags: Surface Mount, Low Noise Amplifier. More details for BGA123L4 can be seen below.