Equipment & Components for the Satcom & Microwave/RF Industries

Loop Test and Noise Injection
- Combined System

  • Ku Band, Ka Band and Q Band Models
  • Provides Loop Back Translation Tx to L-Band
  • And Variable L-Band Noise Injection
  • Local & Remote, Ethernet Control
  • Versatile and Comprehensive Test System
  • Tests RF Chain and Receiver/Modem in One

The LTT has a typical 0dB conversion loss at zero input attenuation selected while the base noise level generated is nominally -84dBm/Hz and is injected via a variable attenuator and 20dB 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 effected by either front panel controls or remotely via ethernet with an easy-to-use GUI. Frequency stability of the LO is derived from either the internal OCXO or from a system 10MHz reference

 General Specifications
 Noise Generator Section
 Noise Frequency Range 10-2600MHz
 Total Noise Power +10dBm nom.
 Base Noise Density -84dBm/Hz
 Noise Flatness +/-1.5dB typ.
 Noise Attenuation Range 60dB min.
 Attenuation Steps 0.25dB
 Noise Coupling Factor 20dB nom.
 Noise Level Control
Front Panel Up/Down Buttons & LCD Readout 
Remote via Ethernet with GUI 
 Noise Mute Function - Local & Ethernet
 General Specifications
 Combined System
 Tx Input Connector
Ku – SMA Female
  Ka – 2.92mm Female
  Q – 2.4mm Female
 L-Band Output Connector SMA Female
 Ext. Ref. Input Connector BNC Female
 Noise Output Connector SMA Female
 Ethernet Connector RJ45x2
 Input Power 80-240V, 50/60Hz
 Input Power Connector IEC with Fuse
 Size 19" x 2U x 13.5" (343mm)
incl. connectors & protrusions

The AtlanTecRF LNI series of Noise Injection Loop Test Translator Systems provide the satellite communications engineer with a complete and versatile set up 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 (LTT) function is controllable in terms of input attenuation over a 60dB range in 0.5dB steps and local oscillator (LO) frequency in 25MHz steps while the white noise level is variable by up to 60dB in 0.25dB steps with an additional mute facility

 General Specifications
 LTT Section
 LO Frequency Steps 25MHz
 LO Reference 10MHz Int/Ext
 Internal Ref. Stability +/-0.05ppm over 0+50C
 Internal Ref. Ageing +/-0.1ppm/year
 Maximum Input Level 0dBm
 Conversion Loss 0dB nom.
 Conversion Loss Flatness +/-2dB typ.
 Attenuation Range 60dB min.
 Attenuation Steps 0.5dB
 Impedance 50 ohms
 Input VSWR 1.8:1 typ.
 Output VSWR 1.8:1 typ.
 Signal Related Spurious -25dBc typ.
 LO Related Spurios & Harmonics -30dBm typ.
 Non Signal or LO Related Spurious -60dBc min.
 Attenuation & LO Frequency Control
Front Panel Up/Down Buttons & LCD Readout 
Remote via Ethernet with GUI 
LO Phase Noise (dBc/Hz) typical
Offset Frequency (Hz) LO Frequency (GHz)
12.0 27.0 43.0
100 -65 -60 -50
1K -75 -70 -65
10K -80 -75 -70
100K -80 -80 -70
1M -115 -110 -105

Model No Input
Frequency in Range
Frequency in Range
LNI-1180-1305-Ku 12.75-14.5 0.8-2.6 11.8-13.05
LNI-2500-2700-Ka 27.5-31.5 0.8-2.6 25.0-27.0
LNI-4250-4400-Q 43.5-45.5 0.8-2.6 42.5-44.0

We reserve the right to change standard product specifications without notice but will be pleased to consider control drawings for quotation.

T: +44 (0)1376 550220 F: +44 (0)1376 552145 E: 40A Springwood Drive, Braintree, Essex CM7 2YN, England