Rf Module - Nokia NPL-4 Series Manual

NPL-4/5/RM-104
System Module and User Interface

RF Module

The RF module comprises all RF functions of the NPL-4/5 engine. The US variant NPL-4
includes GSM850/GSM1800/GSM1900 bands and the EU variant NPL-5 and RM-104
EGSM900 / GSM1800 and GSM1900 bands.
All variants support GPRS (MSC10), EGPRS (MSC6) and HSCSD protocols and multislot
classes 1to 6. The aim is to introduce Push to talk Over Cellular (PoC) feature in all vari-
ants.
The core of the RF is the Helgo RF ASIC. Other main components include:
- the power amplifier module which includes two amplifier chains, one for GSM850/
EGSM900 and the other for GSM1800/1900.
- 26 MHz VCTCXO for frequency reference
- 3296-3980 MHz SHF VCO (super high frequency voltage controlled oscillator)
- front end module with a RX/TX switch and four RF bandpass SAW filters
EGSM900 and GSM1800 LNAs (Low Noise Amplifier) for the receiver front-end are inte-
grated in the Helgo while GSM1900 LNA is external.
NPL-4/5 and RM-104 are using lead free components and lead free SMD process.
The RF module includes two metal shields: one for the PA, antenna switch module and
filters and one for Helgo, VCO and VCTCXO.
Internal antenna is based on the PIFA (Planar Inverted F-Antenna) concept.
The RF is controlled by the baseband section of the engine through a serial bus, referred
later on as RFBus. This serial bus is used to pass the information about the frequency
band, mode of operation, and synthesizer channel for the RF. In addition, exact timing
information and receiver gain settings are transferred through the RFBus.
Physically, the bus is located between the baseband ASIC called UPP and the Helgo.
Using the information obtained from UPP the Helgo controls itself to the required mode
of operation and further sends control signals to the front end and power amplifier mod-
ules. In addition to the RFBus there are other interface signals for the power control loop
and VCTCXO control and for the modulated waveforms.
Copyright © 2005 Nokia Corporation. All rights reserved.
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