Analysis of Voltage Ripple in a Floated High Voltage DC Power Supply

The power supply for a Depressed Collector Traveling Wave Tube (TWT) involves two High Voltage DC (HVDC) supplies—one for the cathode and the other for the collector. The cathode supply requires minimal voltage ripple, while the collector supply allows higher ripple levels. Typically, rectification of a step-up transformer s secondary winding, followed by a filter, is employed to reduce voltage ripple. A series resistor limits short circuit energy in the cathode supply. However, upon turning on the collector supply, voltage ripple appears in the cathode terminal. This paper elucidates the origin of this ripple and proposes a solution. Simulation and experimental results are presented to validate the effectiveness of the proposed solution.