The underside of the logic board is teeming with components.

Skyworks 77352-15 GSM/GPRS/EDGE power amplifier module

SWUA 147 228 is an RF antenna switch module

Triquint 666083-1229 WCDMA / HSUPA power amplifier / duplexer module for the UMTS band

Avago AFEM-7813 dual-band LTE B1/B3 PA+FBAR duplexer module

Skyworks 77491-158 CDMA power amplifier module

Avago A5613 ACPM-5613 LTE band 13 power amplifier