Efficient Magnetron With a Virtual Cathode

We use particle-in-cell (PIC) computer simulations to demonstrate high-efficiency operation of a magnetron with diffraction output (MDO) that uses a virtual cathode in the interaction space instead of a physical cathode. The cathode generating the electron beam is external to the MDO interaction space and, therefore, is immune from electron bombardment, pulse shortening, decreasing electron efficiency, and frequency shift attributed to expanding cathode plasma. Electronic efficiencies comparable to those achieved with the MDO with a transparent cathode have been achieved in the simulations.