Antenna Interface; Antenna Installation; Table 11: Return Loss In The Active Band - Siemens TC65 Hardware Interface Description

TC65 Hardware Interface Description
Strictly confidential / Draft
4

Antenna Interface

The RF interface has an impedance of 50Ω. TC65 is capable of sustaining a total mismatch
at the antenna connector or pad without any damage, even when transmitting at maximum
RF power.
The external antenna must be matched properly to achieve best performance regarding
radiated power, DC-power consumption, modulation accuracy and harmonic suppression.
Antenna matching networks are not included on the TC65 PCB and should be placed in the
host application.
Regarding the return loss TC65 provides the following values in the active band:

Table 11: Return loss in the active band

State of module Return loss of module
Receive > 8dB
Transmit not applicable
The connection of the antenna or other equipment must be decoupled from DC voltage. This
is necessary because the antenna connector is DC coupled to ground via an inductor for
ESD protection.
4.1

Antenna Installation

To suit the physical design of individual applications TC65 offers two alternative approaches
to connecting the antenna:
•
Recommended approach: U.FL-R-SMT antenna connector from Hirose assembled on
the component side of the PCB (top view on TC65). See Section 4.3 for details.
•
Antenna pad and grounding plane placed on the bottom side. See Section 4.2.
The U.FL-R-SMT connector has been chosen as antenna reference point (ARP) for the
Siemens reference equipment submitted to type approve TC65. All RF data specified
throughout this manual are related to the ARP. For compliance with the test results of the
Siemens type approval you are advised to give priority to the connector, rather than using the
antenna pad.
IMPORTANT: Both solutions can only be applied alternatively. This means, whenever an
antenna is plugged to the Hirose connector, the pad must not be used. Vice versa, if the
antenna is connected to the pad, then the Hirose connector must be left empty.
TC65_HD_V00.521
Recommended return loss of application
> 12dB
> 12dB
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24.05.2005