Duplexer And Saw Filter; Receiver (Rx) - Nokia 301 Service Manual

RM-839; RM-840; RM-841
System Module
Figure 64 Quark RF block diagram
The RF block uses SMARTi UEmicro that performs the RF back-end functions of receive and transmit function
of the cellular transceiver.

Duplexer and SAW filter

For SAW filters and duplexers, referring to the differential input impedances of transceiver, the GSM SAW
filters with 150 ohm differential impedances and UMTS duplexers with 100 ohm differential impedances were
selected. Taking into account technology, concept study and also cost down trend considerations, smaller
size components were used, 1411 for single SAW filter, 1814 for dual SAW filters and 2016 for UMTS duplexers.
Based on the basic link budget calculations, through the co-banding between GSM and UMTS, simpler
receiving RF blocks (as Figure 1 shown) were achieved with competitive RF performances. Rel5: duplexer
band 1 and band 8, signal SAW filter GSM 850.

Receiver (RX)

The receiver chain consists of the following blocks:
• Antenna external
• FEM (antenna switch) external
• SAW filter external
• LNA internal
• Mixer internal
• VCO PLL (~ 3.6 GHz) internal
• LPF and PGC internal
Page 6 – 32 NOKIA INTERNAL USE ONLY Issue 1
Copyright © 2013 Nokia. All rights reserved.