Nokia 6150 Manuales De Servicio
PAMS
Technical Documentation
NSM–1
System Module
Original 10/98
Page 3–50
RF Module
Functional Description
This RF module takes care of all RF–functions of the transceiver. RF
block diagram has conventional dual conversion receiver and in transmit-
ter there is a upconversion mixer for the final TX–frequency.
block diagram has conventional dual conversion receiver and in transmit-
ter there is a upconversion mixer for the final TX–frequency.
Architecture contains three ICs. Most of the functions are horizontally and
vertically integrated. UHF functions except power amplifier and VCO are
integrated into CRFU3_e1, which is a BiCMOS–circuit suitable for LNA–
and mixer–function. Most of the functions are in SUMMA, which also is a
BiCMOS–circuit. SUMMA is a IF–circuit including IQ–modulator and PLLs
for VHF– and UHF–synthesizers.
vertically integrated. UHF functions except power amplifier and VCO are
integrated into CRFU3_e1, which is a BiCMOS–circuit suitable for LNA–
and mixer–function. Most of the functions are in SUMMA, which also is a
BiCMOS–circuit. SUMMA is a IF–circuit including IQ–modulator and PLLs
for VHF– and UHF–synthesizers.
Power amplifier is also an ASIC, it is a so called MMIC ( monolithic micro-
wave integrated circuit ). It has three amplifier stages including input and
interstage matchings. Output matching network is external. Also TX gain
control is integrated into this chip.
wave integrated circuit ). It has three amplifier stages including input and
interstage matchings. Output matching network is external. Also TX gain
control is integrated into this chip.
RF block
RF block diagram has conventional dual conversion receiver for GSM and
triple conversion receiver for DCS1800. Both receivers use upper side LO
drive in the first RF mixer, after that lower side LO drive is used. Because
of this there is no need to change I/Q phasing in baseband when receiv-
ing band is changed between DCS and GSM.The two receiver chains are
combined in 73 MHZ IF so they use same rx–chain from that point down
to 13MHz A–D converter. In trans mitter side there are two imagerejection
upconversion mixers,one for GSM and one for DCS 1800, for the final
TX–frequency. Both use upper side LO drive. Because there is only one
external antenna connector used, common for both bands, dualband du-
plexer that has one common antenna input/output is used.
triple conversion receiver for DCS1800. Both receivers use upper side LO
drive in the first RF mixer, after that lower side LO drive is used. Because
of this there is no need to change I/Q phasing in baseband when receiv-
ing band is changed between DCS and GSM.The two receiver chains are
combined in 73 MHZ IF so they use same rx–chain from that point down
to 13MHz A–D converter. In trans mitter side there are two imagerejection
upconversion mixers,one for GSM and one for DCS 1800, for the final
TX–frequency. Both use upper side LO drive. Because there is only one
external antenna connector used, common for both bands, dualband du-
plexer that has one common antenna input/output is used.
Architecture contains three ICs. Most of the functions are horizontally and
vertically integrated. UHF functions except power amplifier and VCO are
integrated
into CRFU3, which is a RF–IC using bipolar process (Ft=25GHz) suitable
for 2GHz LNA– and mixer–functions. CRFU3 also includes divide–by–two
presca– ler for UHF–VCO. Using this divider it is possible to use only one
UHF–VCO running at 2GHz and UHF synthesizer in SUMMA can still use
1GHz LO signal with both systems. The selection between GSM and
DCS1800 operation modes in CRFU3 is done with mode selection signal
derived from MAD IC in baseband. This signal controls the biasing circuit-
ries of the different RF blocks in CRFU3 so that GSM blocks and
DCS1800 blocks are not active at the same time. This way there is no
need for extra voltage regulators and the same CCONT regulator–IC can
be used as in singlebander DCT3 products
Most of the RF–functions are in SUMMA which is a BiCMOS–circuit.
vertically integrated. UHF functions except power amplifier and VCO are
integrated
into CRFU3, which is a RF–IC using bipolar process (Ft=25GHz) suitable
for 2GHz LNA– and mixer–functions. CRFU3 also includes divide–by–two
presca– ler for UHF–VCO. Using this divider it is possible to use only one
UHF–VCO running at 2GHz and UHF synthesizer in SUMMA can still use
1GHz LO signal with both systems. The selection between GSM and
DCS1800 operation modes in CRFU3 is done with mode selection signal
derived from MAD IC in baseband. This signal controls the biasing circuit-
ries of the different RF blocks in CRFU3 so that GSM blocks and
DCS1800 blocks are not active at the same time. This way there is no
need for extra voltage regulators and the same CCONT regulator–IC can
be used as in singlebander DCT3 products
Most of the RF–functions are in SUMMA which is a BiCMOS–circuit.