STW81103 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'STW81103' PDF : 53 Pages View PDF
STW81103
8
Application information
Application information
The STW81103 features three different alternately selectable bands: direct output (2.5 to
3.05 GHz and 4.35 to 5.0 GHz), divided by 2 (1.25 to 1.525 GHz and 2.175 to 2.5 GHz) and
divided by 4 (625 to 762.5 MHz and 1087.5 to 1250 MHz). To achieve a suitable power level,
a good matching network is necessary to adapt the output stage to a 50Ω load. Moreover,
since most commercial RF components have single-ended input and output terminations, a
differential to single-ended conversion may be required.
The different matching configurations shown below for each of the three bands are
suggested as a guideline when designing your own application board.
Inside the evaluation kit is the ADS design for each matching configuration suggested in this
chapter. The name of the corresponding ADS design is given in each figure.
The ADS designs provide only a first indication of the output stage matching, and should be
reworked according to the choices of layout, board substrate, components and so on.
The ADS designs of the evaluation boards are provided with a complete electromagnetic
modelling (board, components, and so on).
8.1
Direct output
If you do not need a differential to single conversion, you can match the output buffer of the
STW81103 in the simple way shown in Figure 28. This illustrates the differential to single-
ended output network in the 2.5 - 5.0 GHz range (MATCH_LC_LUMP_4G_DIFF.dsn).
Figure 28. Differential/single-ended output network
(MATCH_LC_LUMP_4G_DIFF.dsn)
Vcc
100 ohm
RFOUTP
RFOUTN
100 ohm
5.5nH
10pF
10pF
5.5nH
50 ohm
50 ohm
Vcc
Since most discrete components for microwave applications are single-ended, you can
easily use one of the two outputs and terminate the other one to 50Ω with a 3 dB power loss.
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