TDA5250D2_07 Datasheet, PDF (47/94 Pages) Infineon Technologies AG – ASK/FSK 868MHz Wireless Transceiver

TDA5250 D2
Version 1.7
Application
Sparam_measured_200M.pcx
Figure 3-9 Sparam_measured_200M
Above you can see the measurement of the evalboard with a span of 200MHz. The evalboard has
been optimized for 3V. The load is about 240+j0 at 868.3MHz.
A tuning-free realization requires a careful design of the components within the matching network.
A simple linear CAE-tool will help to see the influence of tolerances of matching components.
Suppression of spurious harmonics may require some additional filtering within the antenna
matching circuit. Both can be seen in Figure 3-10 and Figure 3-11 The total spectrum of the
evalboard can be summarized as:
Carrier fc
fc-18.1MHz
fc+18.1MHz
2^nd harmonic
3^rd harmonic
+9dBm
-62dBm
-66dBm
-40dBm
-44dBm
Data Sheet
47
2007-02-26