Siemens MC35 Specifications download pdf (Page 27)

MC35i Terminal Hardware Interface Description

Confidential / Released

MC35i_T_HD_v02.00a Page 27 of 42 16.02.2007

3.5.4 Radio interface

An internal antenna cable adapts the antenna reference point (antenna connector type GSC

from Murata) to the FME (male) connector. The position of the antenna reference point can

be seen in Figure 1.

• Cable loss of the internal cable

<0.4dB @ 900MHz

<0.6dB @ 1800MHz

• The system impedance is 50.

• In every case, for good RF performance the return loss of the customer application

should be better than 10dB (VSWR < 2).

• MC35i Terminal withstands a total mismatch at this connector when transmitting with

power control level for maximum RF power.

Inside the MC35i module a 27nH inductor to ground provides additional ESD protection to

the antenna connector. For details see

Figure 8. To protect the inductor from damage no DC

voltage must be applied to the antenna circuit.

Figure 8: Antenna connector circuit on MC35i module

EMC immunity complies with the vehicular environment requirements according to

EN 301 489-7.

For the application it is recommended to use an antenna with the following FME (female)

connector:

Figure 9: Recommended antenna connector

GSC connector (from Murata)

TRX In / Output

L (27nH)

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Siemens MC35 Specifications Page 27