– 5–5 –
RX path is a direction down conversion architecture that eliminates the need for Intermediate Frequency (IF) components.
The device includes three bands integrated LNAS, a quadrate demodulator, baseband amplifier circuit with I/Q outputs
and three stages of DC-offset correction.
The DCOC correction loop ensures DC-offsets, generated in CX74063, do not overload baseband chain.
The receiver can be calibrated to optimize IP2 performance, which ensures limited baseband interfering signal amplitude.
The CX74063 also features an integrated, fully programmable, sigma-delta fraction-N synthesizer suitable for GPRS
multi-slot operation.
■
Transceiver - - Receiver
RX LO
source from chip
Figure 5.4. Receiver block diagram
Antenna
RF SAW
FILTER
RXIN
RXIP
RXQN
RXQP
900
1800
1900
T/R
Switch
&
Display
DCOC
LNA
VGA