Airbus Defence and Space


Radar travelling wavetube amplifier (TWTA)

Radar amplifier- flight model- for ERS1-AMI (Active Microwave Instrument) in C-Band This multi - pulse mode operated TWTA is used in space-based Synthetic Aperture RADAR (SAR) and Scatterometer Systems for Remote Sensing. This amplifier has been designed and qualified for the Active Microwave Instrument used in the ESA Remote SensingSatellite program (ERS).

The key technology in this TWTA is the reliable packaging of high voltage / high power-circuitry and transformers for the 15 kV supply voltages of the TWT.

Features / technical details

Frequency: 5,3 GHz

Bandwith: 32 MHz

RF - output power (peak): 4.7 kW

Average microwave output power: 300 W

Pulse duration / pulse repetition frequency: 37,1 µs / 1720 Hz

Phase ripple in SAR mode: < 12° linear / < 1,5° quadratic

Amplitude ripple in SAR mode: < 0.1 dB linear/< 0,05 dB quadratic

Redundancy: redundant system incl. microwave Switches / Filters / Circulators



SAR and Scatterometer instruments for space based Remote Sensing missions Similar Amplifiers are available for X-Band 3.3 kW applications

Reference customers

The first set of amplifiers operated in space on the ESA ERS 1 mission from 1991 to 1999. The second set of amplifiers operates in space on the ESA ERS 2 mission since 1995 The third set of amplifiers operates in space on the Canadian RADARSAT1 mission since 1995.