Design of 71-76 GHz Double-Corrugated Waveguide Traveling-Wave Tube for Satellite Downlink

The growing interest in wireless high-data-rate communications at millimeter waves for both terrestrial networks and satellite communications is stimulating novel solutions to overcome the strong atmospheric attenuation. In particular, the development of high-throughput satellite communication systems for Internet distribution is fundamental to complementing the terrestrial networks and to cover regions not connected to terrestrial backbones, such as at sea or remote areas. Ku-band and Ka-band satellite systems are presently available. Recently, the W-band (71-76 GHz and 81-86 GHz) has been allocated for multigigabit transmissions, providing 5-GHz bandwidth for both uplink and downlink. However, it has been estimated that for enabling high-throughput W-band satellite communication systems, transmission power higher than 50 W is needed. In this paper, a 71-76 GHz double-corrugated waveguide (DCW) traveling-wavetube (TWT) is designed as an amplifier for high-data-rate satellite downlink, with about 70-W output power. The dispersion characteristic of the designed DCW is experimentally validated by a cold test. The proposed TWT is also a test vehicle, scaled in frequency, for a future novel 220-GHz DCW TWT for terrestrial wireless networks.