User Guide

RH-21 Company Confidential
System Module Nokia Customer Care
Page 42  2004 Nokia Corporation. Issue 2 07/2004
AMPS/TDMA 800 MHz Front End
TDMA 1900 MHz Front End
The TDMA 1900 LNA is a discrete circuit. It uses an integrated Bias control block, which
is inside the SAFARI. In normal high-gain operation mode, the bias voltage 2.78 V is con-
nected on collector and sink type constant current source is connected on emitter. Bias
current source is adjustable from 0.5 mA to 7.5 mA with 0.5 mA step. Base is biased from
2.78 V voltage via resistor.
When the LNA AGC step is enabled, LNA is in low gain operation mode. Voltage and cur-
rent bias sources and direction of current are switched on the contrary. In this operation
mode, the LNA has good linearity, a low noise figure, and about -3 dB gain.
During the TX-slot, LNA is in power-down mode. This is executed by switching the bias
current source to 0 mA.
Parameter MIN TYP MAX Unit/Notes
Diplexer input loss 0.35 0.4 0.45 dB
Duplexer input loss 2.5 3 4.1 dB
LNA gain: High gain mode
Low gain mode
16
-4.5
16.5
-4
17.3
-3.8
dB
dB
LNA noise figure* 1.4 1.7 2.3 dB
LNA 3rd order intercept (IIP3)* -4 -3 -1.5 dBm
Bandfilter input loss 1.5 2 2.5 dB
Mixer gain* 6 7.5 8 dB
Mixer NF* 8 9 10.5 dB
Mixer IIP3* 4 4.5 5 dBm
Total:
Gain 18.2 18.6 20 dB
Noise Figure 4.6 5.5 7 dB
3rd order intercept (IIP3) -8.9 -7.5 -6.8 dBm
*see Safari spec/measurements
Parameter MIN TYP MAX Unit/Notes
Diplexer input loss 0.45 0.5 0.55 dB
Duplexer input loss 1.3 2.5 3.0 dB