Power Control; Antenna Circuit; Rf Performance - Nokia RH-41 Series Technical Documentation Manual

RH-41
System Module
is +31 to +36dB and linear output power is +30dBm (typical condition) with –28dB ACP.
The nominal efficiency is 40%.

Power Control

For power monitoring, there is a power detector module (PDM) build up from a (dual)
coupler, a biased diode detector, and an NTC resistor. RF signals from both bands are
routed via this PDM. The RF isolation between couplers is sufficient not to lose filtering
performance given by duplex filters.
The diode output voltage and NTC voltage are routed to BB A/D converters for power
control purposes. The TX AGC SW takes samples from diode output voltage and compares
that value to target value, and adjust BB I-and Q-signal amplitude and/or Taco PGA set-
tings to keep power control in balance.
NTC voltage is used for diode temperature compensation and for thermal shutdown
when radio board's temperature exceeds +85°C.
False TX indication is based on detected power measurement when carrier is not on.
The insertion loss of coupler is –0.42dB (max) at cellular band and –0.48dB (max) at PCS
band. Typical values for insertion losses are about –0.2dB. The filtering performance of
diplexer is taken in account in system calculations.

Antenna Circuit

Here the antenna circuit stands for duplex filters and the diplexer. The cellular band
duplex filter is band pass type SAW filter with typical insertion loss about –2.0dB. The
PCS band duplex filter is band stop (for receiver band) type ceramic filter and its typical
insertion loss is about –1.7dB. Insertion losses of diplexer are –0.45dB and –0.55dB (at
maximum) for cellular and PCS band, typical values being about –0.30dB and -0.35dB.

RF Performance

The output power tuning target for power level 2 after diplexer (or after switch for exter-
nal RF) is +27.3dBm for digital modes and +24.8 dBm for analog mode. See the following
table. Modulation accuracy and ACP will be within limits specified in IS-136/137.
Page 50
Nokia Corporation
CCS Technical Documentation
Confidential Issue 2 09/2003