This paper describes a L-Band Transmit/Receive (T/R) module developed by Thales Alenia Space as front-end element of the Main Mission Antenna for Iridium Next satellites constellation. The T/R module peculiar design features, linked to its telecommunication application, are discussed. Those include adjustable operating conditions, high linearity on both Tx and Rx, single and multi-carrier operations, very high out of band rejection, amplitude and phase alignment without the need of external controls and calibrations.