A 20 GHz, 75 watt, helix TWT for space communications
Abstract
A space-qualified, helix-type traveling wave tube is being developed for satellite communication systems in the frequency band of 17.7 to 21.2 GHz. The design approach stresses very high efficiency operation, but with very low distortion. The tube provides multi-mode operation, permitting CW saturated power output levels of 75, 40, and 7.5 W. Operation is also anticipated at 5 dB below these saturation levels to achieve the required low distortion levels. Advanced construction features include a five-stage depressed collector, a diamond supported helix slow-wave circuit, and a type M dispenser cathode. High reliability and long life (10 yr) are objectives of the tube design. Preliminary test results on early developmental models of this tube are very encouraging. An output power of 75 to 90 W has been achieved over the full bandwidth with about 40 dB of saturated gain. More importantly, the basic electronic efficiency of the interaction process has been increased from about 7.5-11 percent by the use of the diamond helix support compared to earlier tubes using BeO support rods. This effort is supported by NASA Lewis Research Center and is aimed toward application in the NASA Advanced Communications Satellite Technology Program.
- Publication:
-
EASCON 1983; Proceedings of the Sixteenth Annual Electronics and Aerospace Conference and Exposition
- Pub Date:
- 1983
- Bibcode:
- 1983easc.conf...69H
- Keywords:
-
- Amplifier Design;
- Communication Satellites;
- Helical Windings;
- Microwave Amplifiers;
- Power Conditioning;
- Traveling Wave Tubes;
- Circuit Reliability;
- Frequency Response;
- Nasa Programs;
- Power Efficiency;
- Power Gain;
- Satellite Communication;
- Service Life;
- Signal Distortion;
- Space Communication;
- Traveling Wave Amplifiers;
- Electronics and Electrical Engineering