Asus P552W, Manual

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3.5 General WCDMA debug
3.5.1. WCDMA path and test points
GSM and WCDMA share the same RF circuits from the antenna to
FEM (U1804). The choice of operation band, GSM or WCDMA,
depends on band selection of FEM (U1804).
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WCDMA Tx path
WCDMA transceiver, PMB5701 (U1901), receives analog I/Q
signals coming from analog front-end (U1701), also abbreviated to
AFE, via Pin F4, Pin G3, Pin C3, and Pin B2. After modulation and
mixing, the outgoing differential RF signals from transceiver
PMB5701 (U1901) Pin2 travels to SAW filter (U1904), and PA
AWT6241 (U1906) Pin2 sequentially. The boosted power coming
from AWT6241 (U1906) Pin9 is transmitted to coupler (U1907).
There are two branches of RF signal due to coupler.
One travels to duplexer (U1903) Pin7 and the other is transmitted
to power detector (U1912). The former passes through duplexer
(U1903) Pin2, FEM (U1804) and the connector (CON1801)
sequentially. At last, the RF signal is radiated via the antenna of GM2.
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WCDMA Rx path
Incoming RF signal, from base stations via the WCDMA antenna,
passes through connector (CON1801) and duplexer (U1903) Pin5
sequentially. LNA (U1911) Pin7 receives the signal from duplexer.
Then the amplified signal is transmitted to SAW filter (U1908) and
goes to transceiver PMB5701 (U1901). After down converting the
signal’s frequency and transforming into analog I/Q signals, the
analog I/Q signals from PMB5701 Pin F7, Pin D7, Pin C7, and Pin
C8 travel to AFE (U1701).
Please refer to the figure showed below. This figure demonstrates
corresponding location of WCDMA components. WCDMA RF
signals transmission and receiving paths are showed in it as well.