Specifications

TC35 / TC37 Hardware Interface Description
TC35_37_HD_02_V03.10 - Released Page 57 of 92 21.12.2001
4.3 Antenna interface (antenna reference point – ARP)
There are no special antenna systems specified for TC35 and TC37. All RF interfaces
(connectors or pad) have an impedance of 50" with an SWR ≤2. TC35 and TC37 are
capable of sustaining a total mismatch at the antenna connector or pad when transmitting
with power control level for maximum RF Power.
Table 19: Return loss
State of module Return loss of module Recommended return loss of application
Receive 8dB min higher than 12dB min
Transmit not applicable higher than 12dB min
Idle 5dB max not applicable
4.3.1 Options of connecting the antenna
In order to suit the physical design of individual applications SIEMENS cellular engines
provide various RF interfaces to connect an external or internal antenna:
• On TC35, a GSC connector is assembled on the PCB. The GSC connector is made by
Murata. Though present on the board, the antenna pad is not connected.
Figure 22: Antenna connector circuit on TC35
• TC37 comes with a gold plated antenna pad and a switching coax connector. Both
options can be applied alternatively: Whenever an antenna is plugged into the coax
connector the switch opens, thus disconnecting the pad. Vice versa, removing the
antenna from the switch connector closes the switch and thus, activates the pad.
Figure 23: Antenna connector circuit on TC37
GSC connector (from Murata)
TRX Output
L (27nH)
Matching circuit
A
ntenna pad
Coaxicon connector (from AMP)
TRX output