PUMA T2
Technical Handbook
Technical description
Page 46 OTE Proprietary information
P/N: 779-0306/01
Revision 03
Transmitter section
The base band signal, represented with the two I
TX
, Q
TX
components, enters the
linearizer and is converted into a radiofrequency signal.
This conversion is permitted by the synthesizer, which is also present in the
receiver section, and allows selecting PLL outputs. This is an important feature
because it allows frequency changes in frequency adjacent channels.
The switch block (LO SW), which is located after the synthesizer, generates the
carrier in the frequency range of the transmission band. This carrier is amplified
and then enters the linearizer and permits the radiofrequency conversion.
After the conversion, the signal, enters the driver RF2105L and the power mosfet
amplifier 2SK2974, whose saturated power is 38 dBm in the band of the Hand-held
radio; the output signal (E2) is filtered and after the switch block is sent to the
antenna.
Receiver section
The signal coming from the antenna, enters the switch block then the low noise
amplifier (LNA).
Voltages VR1 and VR2 coming out from the DAC RX are used in order to tune the
LNA gain.
The front end output is mixed by the mixer with the LO1RX RF. The LO1RX is
selected by a synthesizer program.
The output signal enters the mixer and is converted in the Fifh signal that is filtered
by the high-selectivity Fifh filter. Then it is converted in the Fref signal by the
second mixer, located in the AD607 and it is attenuated by the FI amplifier and
filtered by the Fref filter.
At this point it is demodulated by the AD607 and converted into a base band
signal, represented with the I, Q components.
The base band signal components are filtered by the low band filter and sent to the
analogue/digital converter from where they are sent to the base band board.
The reference signal coming out of the VTCXO is used as a reference for the PLL
and also for the integrated time base.
Description of the sections blocks:
IQ AMP
Buffer and levels’ translator (DC) from 1.5 V to 2.5 V to pilot the linearizer.
LINEARIZER
This is a basic device for the transmitter. It includes all the Cartesian loop
components.
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