RH-41
System Module
CCS Technical Documentation
Page 48
Nokia Corporation Confidential
Issue 2 09/2003
Frequency Synthesizers
RH-41 synthesizer consists of three synthesizers: one UHF synthesizer and two VHF syn-
thesizers. UHF synthesizer is based on integrated PLL and external UHF VCO, loop filter,
and VCTCXO. Its main goal is to achieve the channel selection, thus for dual band opera-
tions associated with dual mode. Due to the RX and TX architecture this UHF synthesizer
is used for down-conversion of the received signal and for final up-conversion in trans-
mitter. A common 2 GHz UHFVCO module is used for operation on both low- and high-
band. Frequency divider by two is integrated in Taco.
Two VHF synthesizers consist of: RX VHF Synthesizer, includes integrated PLL and VCO,
and external loop filter and resonator. The output of RX-VHF PLL is used as LO signal for
the second mixer in receiver. TX VHF Synthesizer includes integrated PLL, loop filter, and
resonator. The output of TX-VHF PLL is used as a LO signal for the IQ-modulator of the
transmitter. See depicted block diagrams and synthesizer characteristics from synthesizer
Conversion gain @ RI=1kohm
23.5
24
24.5
dB
IF AGC gain range (5x6 dB)
30
dB
IF AGC gain step (5 steps)
6
dB
IF AGC gain error relative to max
gain
-0.5
+0.5
dB
AMP2 gain
18
dB
-3dB frequency
21
25
29
kHz
LPF: 4th order Chebysev
LPF gain
0
dB
Corner frequency tuning range
14
17
kHz
Corner frequency tuning step
1
kHz
Attentuation @ 30 kHz *
24
dB
Attentuation @ 60 kHz *
55
dB
Attentuation @ 120 kHz *
80
dB
Attentuation @ 240 kHz *
60
dB
Attentuation @ >480 kHz *
40
dB
AGC
AGC gain range
-6
36**
dB
AGC gain range step
7 steps
6
dB
AGC gain error relative to max gain
-0.5
+0.5
dB
Max IF/2nd IF buffer output level
3
V pp (differential)
Parameter
Minimum
Typical/
Nominal
Maximum
Unit/Notes