Sundance SMT349 - Manual (Page 8)

Version 2.1 Page 8 of 32 SMT349 User Manual
Figure 1: SMT349 Block Diagram
4 Architecture Description:
The SMT349 is an IF/RF front-end module that completes the transmission and
reception paths of Sundance Digital Radio systems. The design is compatible with
the other Sundance modules such as the SMT370, which operates on SMT8036
hardware platform and complies with the TIM40 specifications.
The digital section of SMT349 is based on the SMT370 digital section design. The
analogue section of SMT349 includes two RF transceiver modules, operating in the
2.4 GHz ISM band. The RF centre frequency of both transceivers is controlled by one
synthesizer which can be set by the FPGA. The FPGA also controls the AGCs
(attenuators) and TX/RX switch for each of the two IF/RF sections. The FPGA can
communicate with other Sundance modules via the SHB, or via the Comports,
through the TIM connectors.
4.1 TX up-converter module
The up conversion from the 70MHz IF to the 2.4 GHz is done in two stages:
- The first stage converts the 1
st
IF to 374 MHz
- The second stage converts to the RF frequency