Installation Instructions

LISA-U2 series - System Integration Manual
UBX-13001118 - R19 Early Production Information System description
Page 9 of 175
1.2 Architecture
Wireless
Base-band
Processor
Memory
Power Management Unit
26 MHz
32.768 kHz
ANT
Swi tch & Multi band & mode PA
DDC (for GNSS)
(U)SIM card
UART
SPI
USB
GPIO(s)
Power on
External reset
V_BCKP (RTC)
Vcc (supply)
V_INT (I/O)
Digital audio (I
2
S)
RF
SWITCH
RF
Transceiver
Duplexers
& Filters
ANT_DIV
RF
SWITCH
Filter
Bank
PA
PMU
Transceiver
PMU
Figure 1: LISA-U2 series block diagram (for available options see Table 2)
1.2.1 Functional blocks
LISA-U2 modules consist of the following internal functional blocks: RF section, Baseband and Power
Management Unit section.
LISA-U2 series RF section
A shielding box contains the RF high-power signal circuitry, including:
 Multimode Single Chain Power Amplifier Module used for 3G HSPA/WCDMA and 2G EDGE/GSM operations
 Power Management Unit with integrated DC/DC converter for the Power Amplifier Module
The RF antenna pad (ANT) is directly connected to the main antenna switch, which dispatches the RF signals
according to the active mode. For time-duplex 2G operation, the incoming signal at the active Receiver (RX) slot
is applied by the main antenna switch to the duplexer SAW filter bank for out-of-band rejection and then sent to
the appropriate receiver port of the RF transceiver. During the allocated Transmitter (TX) slots, the low level
signal coming from the RF transceiver is enhanced by the power amplifier and then directed to the antenna pad
through the main antenna switch. The 3G transmitter and receiver are active at the same time due to frequency-
domain duplex operation. The switch integrated in the main antenna switch connects the antenna port to the
duplexer SAW filter bank which separates the TX and RX signal paths. The duplexer itself provides front-end RF
filtering for RX band selection while combining the amplified TX signal coming from the power amplifier.
A separated shielding box contains all the other analog RF components, including:
 Antenna Switch and duplexer SAW filter bank for main paths
 Antenna Switch and SAW filter bank for diversity receiver
 Up to six-band HSPA/WCDMA and quad-band EDGE/GPRS/GSM transceiver