At the Satellite 2017 conference, AtlanTecRF launched its LNI series of noise injection loop test translator (LTT) systems, designed to cut the testing time of satellite communications systems and modems. This unique product provides the satellite communications engineer with a complete and versatile setup for off-satellite loop back testing of the transmit (Tx) signal to L-band, combined with the ability to inject white symmetrical Gaussian noise for simultaneous receiver and modem testing.
The loop test function can be controlled via the input attenuation, over a 60 dB range in 0.5 dB steps, the local oscillator (LO) frequency in 25 MHz steps and the white noise level, up to 60 dB in 0.25 dB steps with an additional mute capability.
The LTT has a typical 0 dB conversion loss with no input attenuation, while the base noise level generated is nominally −84 dBm/Hz and is injected via a variable attenuator and 20 dB directional coupler into the LTT’s L-Band output. The noise level can be muted completely for LTT-only operation and is also switchable to an external output for noise-only operation. Filtering is included to prevent noise appearing at the Tx input port or mixing with the synthesised LO output.
Control of both LTT and noise injection is by either front panel controls or remotely via Ethernet, with an easy-to-use graphical interface. Frequency stability of the LO is derived from either the internal OCXO or from a system 10 MHz reference.
Speaking at the product launch at Satellite 2017 in Washington, D.C., Geoff Burling, AtlanTecRF CEO said, “This new, exciting and revolutionary test system will cut testing time by combining the normal loop back signal test with noise injection at modem level, all in one compact 2U rack unit. Whether in factory system testing, or at a satcom ground terminal, this unique product will greatly enhance the capability for satellite communications engineers.“
In addition to the 2U x 19” configuration, the AtlanTecRF LNI noise injection LTT systems are available in portable bench mount instruments for transportation to multiple test sites and laboratory locations.