Rf Implementation In Rh-6; Rf Frequency Plan - Nokia RH-6 Series Rf Description & Troubleshooting

RH-6
7 - RF Description & Troubleshooting

RF Implementation in RH-6

The RH-6 RF part is a triple-band direct conversion transceiver. Using direct conversion,
no intermediate frequencies are used for up- or down-conversion.
The VCO is set to either twice or four times the wanted RX or TX frequency, depending on
the band used. The VCO frequency is divided by either 2 or 4 and fed to the mixers
(down-conversion) or modulators (up-conversion). Up- or down-conversion is done in
one step, directly between RF frequency and baseband. All up- and down-conversions
take place in the RF ASIC named Mjoelner (N601).
Mjoelner RF ASIC also contains PLL and LNAs for all used bands. A DC control section is
included in to power and/or control EGSM TX buffer, detector and antenna switch. The
Mjoelner RF ASIC is controlled via a serial bus.
Mjoelner RF ASIC contains an integrated VCXO which uses an external 26 MHz Xtal. No
analogue AFC signal is needed. AFC is done via the serial interface of Mjoelner.
The 26 MHz reference clock is interfaced to the UPP.
The RF supports HSCSD (High Speed Circuit Switched Data) and GPRS (General Packed
Radio Service), meaning multi-slot operation. (This does not require special equipment or
procedures in repair situations.)
The following pictures show the RF frequency plan and the RF block diagram.

RF frequency plan

EG SM : 925-960 MH z
D C S: 1805-1880 M H z
PC S: 1930-1990 M H z
D C S: 1710-1785 M H z
PC S: 1850-1910 M H z
EG SM : 880-915 MH z
Page 8
Company Confidential
M joelner
f/4 f/2
f f
f f
f/4 f/2
PLL
26 M H z
Figure 5: RF frequency plan
Copyright © 2003 Nokia Corporation.
Company Confidential
CCS Technical Documentation
34 20-
39 80
M H z
XT al
1/1
1/2
I-signal
R X
Q -signal
LP R FC LK
R FC LK
I-signal
TX
Q -sign al
Issue 1 10/2003