User's Manual

LISA-U1/LISA-H1 series - System Integration Manual
3G.G2-HW-10002-2 Advance Information System description
Page 9 of 116
1.2.1 Functional blocks
LISA-U1/LISA-H1 series modules consist of the following internal functional blocks: RF high power front-end, RF
transceiver, Baseband section and Power Management Unit.
RF high-power front-end
A separated shielding box includes the RF high-power signal circuitry, namely:
 Front-End Module (FEM) with integrated quad-band 2G Power Amplifier and antenna switch multiplexer
 Two single-band 3G HSxPA/WCDMA Power Amplifier modules with integrated duplexers
The RF antenna is directly connected to the FEM, 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 to integrated SAW
filters 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 2G power
amplifier module and then directed to the antenna through the FEM. The 3G transmitter and receiver are instead
active at the same time due to frequency-domain duplex operation. The switch integrated in the FEM connects
the antenna port to the passive duplexer 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
fixed gain linear power amplifier.
RF Transceiver
In the same shielding box that includes the RF high-power signal circuitry there are all the low-level analog RF
components, namely:
 Dual-band HSxPA/WCDMA and quad-band EDGE/GPRS/GSM transceiver
 Voltage Controlled Temperature Compensated 26 MHz Crystal Oscillator (VC-TCXO)
 Low Noise Amplifier (LNA) and SAW RF filters for 2G and 3G receivers
While operating in 3G mode, the RF transceiver performs direct up-conversion and down-conversion of the
baseband I/Q signals, with the RF voltage controlled gain amplifier being used to set the uplink TX power. In the
downlink path, the external LNA enhances the RX sensitivity while discrete inter-stage SAW filters additionally
improve the rejection of out-of-band blockers. An internal programmable gain amplifier optimizes the signal
levels before delivering to the analog I/Q to baseband for further digital processing.
For 2G operations, a constant gain direct conversion receiver with integrated LNAs and highly linear RF
quadrature demodulator are used to provide the same I/Q signals to baseband as well. In transmit mode, the
up-conversion is implemented by means of a digital sigma-delta transmitter or polar modulator depending on
the modulation to be transmitted.
In all the modes, a fractional-N sigma-delta RF synthesizer and an on-chip 3.8-4 GHz voltage controlled oscillator
are used to generate the local oscillator signal.
The frequency reference to RF oscillators is provided by the 26 MHz VC-TCXO. The same signal is buffered to the
baseband as a master reference for clock generation circuits while operating in active mode.
Modulation Types Used
GSM  GSMK
GPRS GMSK
EDGE 8PSK
WCDMA  QPSK
HSDPA  16-QAM
HSUPA BPSK
Baseband section and power management unit
Another shielding box includes all the digital circuitry and the power supplies, basically the following functional
blocks: