Ring-plane traveling-wave amplifier: 40 KW at 9 MM

A 9-mm traveling-wave tube (TWT) amplifier using a ring-plane circuit is described. This tube has produced a peak power of 43 kw at an efficiency of 12 per cent with a solid beam. Several guns producing solid and hollow beams have been used with comparable results at high voltages (15 to 100 kv) and low currents (0.11 to 3.8 a). A waveguide transition (special coupler) incorporating a magic tee is used to couple independently to the two modes that can exist on the slow-wave circuit. The circuits, due to their good heat dissipation capability, can be operated either pulsed or CW. Their large size ( = 1, 2, 3 ...) with useful cross sections comparable with those of ordinary waveguides, makes them attractive for producing kilowatt powers even at much higher frequencies.