User Guide

PAMS Technical Documentation 6 - Troubleshooting
NPE-4
Original ãNokia Corporation. Page 6-35
PCN Signal path
For easy error tracing it is important to know the signal path of the PCN receiver. The
components can be grouped into blocks and drawn as shown below. Note that the pic-
ture shows both EGSM recieiver (bottom) and PCN receiver (top).
Tba
RX/TX Switch
From the antenna-pad (X800) the RF signal is lead to the RX/TX switch (Z802) via a
mechanical switch, the antenna connector (X802).
If no control voltage is present at VC1 or VC2 the RX/TX switch is open to the two RX
outlets GSM_Rx and DCS_Rx. The RX/TX switch will work as a diplexer and EGSM signals
pass to GSM_Rx and PCN signals to DCS_Rx.
From DCS_Rx the PCN signal is feed to the Dual RX SAW filter (Z804) via C806.
Front-end
The PCN front-end consists mainly of two SAW filters (Z804 and Z610) and one LNA
(V810) in-between. The SAW filters provides out-of-band blocking immunity, the LNA
provides front-end gain. The first SAW filter (Z804) is a DUAL package including SAW fil-
ter for both EGSM and PCN. The last SAW filter (Z610) is single ended input and balanced
output providing a balanced signal input for Hagar (N600).
The signal-path is through Z804 (In-band insertion-loss max 4dB), through C811 to the
PCN LNA (V810, RFin).
From the LNA (V810, RF out) the signal is lead through C814, through the 2
nd
EGSM SAW
Z610 (In-band insertion-loss max 4dB), through the balanced matching circuit (C616,
C617, L616) to Hagar (N600).