Experimental harmonic characterization in the Multi-Frequency Recirculating Planar Magnetron

The Multi-Frequency Recirculating Planar Magnetron (MFRPM) is a crossed-field oscillator capable of producing high-power microwaves (HPM). The MFRPM-6+8 is the first prototype MFRPM, which consists of a 6-cavity 1-GHz and 8-cavity 2-GHz set of planar cavity arrays coupled by cylindrical electron beam / RF recirculation bends. Recent experimental work conducted using a -300 kV, 200-300 ns voltage pulse, 0.1-0.3 T axial magnetic field, and Mode-Control Cathode (MCC) showed evidence of potentially significant harmonic 2- and 4-GHz frequency generation from the 1-GHz cavity array. Experiments are currently underway to characterize these harmonics.