User's Manual

Table Of Contents
MC55/56 Hardware Interface Description
Confidential / Preliminary
s
MC55/56_hd_v03.00 Page 68 of 104 16.08.2005
4.1.1 Antenna pad
The antenna can be soldered to the pad, or attached via contact springs. To help you ground
the antenna, MC55/56 comes with a grounding plane located close to the antenna pad. The
positions of both pads can be seen from Figure 39.
When you decide to use the antenna pad take into account that the pad has not been
intended as antenna reference point (ARP) for the Siemens MC55/56 type approval. The
antenna pad is provided only as an alternative option which can be used, for example, if the
recommended Hirose connection does not fit into your antenna design.
Also, consider that according to the GSM recommendations TS 45.005 and TS 51.010-01 a
50 connector is mandatory for type approval measurements. This requires GSM devices
with an integral antenna to be temporarily equipped with a suitable connector or a low loss
RF cable with adapter.
To prevent damage to the module and to obtain long-term solder joint properties you are
advised to maintain the standards of good engineering practice for soldering.
MC55/56 material properties:
MC55/56 PCB: FR4
Antenna pad: Gold plated pad
4.1.1.1 Suitable cable types
For direct solder attachment, we suggest to use the following cable types:
RG316/U 50 Ohm coaxial cable
1671A 50 Ohm coaxial cable
Suitable cables are offered, for example, by IMS Connector Systems. For further details and
other cable types please contact http://www.imscs.com
.