ATC Interface Unit

The ATC Interface Unit (AIU) is intended for use in type approval testing of user terminals being developed to operate compliantly on the Inmarsat network in the presence of Ancillary Terrestrial Component (ATC) interference. The AIU can be used with any of the Square Peg physical layer test systems (BPLT, GDU,etc.). When used with the BPLT, it would normally be controlled by the User Terminal Physical Layer Mandatory Test Requirement (UTMTR) scripts. When used with other systems, it would normally be controlled by manually or by a script that is provided with the unit.

The AIU allows the ATC signals to be added at a high level while not exceeding the applicable Out Of Channel Emissions (OOCE) limits.


Test Configuration

The AIU is typically utilized with a commercial signal generator, an SPCI Physical Layer Tester (PLT) platform, and the appropriate application software.

Ordering Info

The AIU is available in two configurations, one which supports passing GPS L1 signals from the Desired Signal In port to the UT or power meter and one which only passes the Inmarsat extended L-band. The variant can be identified by the Part Number (P/N) on the rear of the unit.


RF Frequency Range



1518.0 to 1559.0

Passes Inmarsat extended L-band (XL).


1518.0 to 1578.0

Extends filtering for Inmarsat extended L-band to also pass GPS L1 signals centred at 1575.42 MHz

Square Peg Communications Inc.
4017 Carling Avenue, Suite 200 
Ottawa, ON, Canada K2K 2A3
Tel + 1 613 271 0044
Fax+ 1 613 271 3007
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