The BD3438J50200AHF from TTM Technologies is a Balun with Frequency 3.4 to 3.8 GHz, Amplitude Balance ±0.1 to 0.6 dB, Phase Balance 4 to 10 Degree, Insertion Loss 0.7 to 1 dB, Power 1.2 to 2 W. Tags: Surface Mount, Balanced to Balanced. More details for BD3438J50200AHF can be seen below.