Microwave Power and Phase Measurements on a Recirculating Planar Magnetron

Abstract

Calibrated microwave power and phase measurements are presented for the first recirculating planar magnetron prototype consisting of two coupled six-cavity 1-GHz planar cavity arrays. The results are presented for a solid cathode and two mode-control cathodes (MCCs) with aluminum or velvet electron emitters. The measurements were conducted using a prototype coaxial microwave power extraction scheme. The experimental operating parameters included: pulsed cathode voltages between −250 and −300 kV, voltage pulselengths of 200-600 µs, axial magnetic fields of 0.1-0.32 T, and entrance currents of 1-10 kA. The results showed improved oscillator frequency locking for the MCCs and increases in power and efficiency using the velvet electron emitter. Index Terms-Cavity magnetron, frequency locking, high-power microwaves (HPMs), recirculating planar magnetron (RPM), vacuum electronics.

Additively Manufactured High Power Microwave Anodes

“…It should be noted that this is the peak anode current, not the current at peak power. line with previous tests of the RPM-12a [10]. The previous work did not use optimized magnetic field timing, leading to spatial variations in the magnetic field profile.…”

“…Fabrication of two different 3-D printed anode structures, each metalized using a different process, is discussed. The RPM performance utilizing each of the printed anodes is compared with the recent performance results obtained using the solid aluminum anode structure as well as with the previous results [10].…”

“…In high-power crossedfield sources, such as relativistic magnetrons [1]- [3], [5], [6] and recirculating planar magnetrons (RPMs) [7]- [10], the SWS, which supports the high electric fields associated with the A-K gap bias as well as the RF wave, also serves as the anode for the electron beam and is directly impacted by a substantial fraction of the electron beam current [1]- [3], [5]- [10].…”

“…We designed the printed anode structures as drop-in replacements (i.e., geometric duplicates) of the previously studied aluminum anode structures described by Franzi et al [10]. Fabrication of two different 3-D printed anode structures, each metalized using a different process, is discussed.…”

Stability of Brillouin flow in planar, conventional, and inverted magnetrons

“…It has a much larger cathode surface area, allowing for higher current and better thermal management. The volume of the device increases linearly with the number of cavities, instead of to the squared power in conventional magnetrons, reducing the magnetic field requirement [11], [14]. Work is also underway at UM to make a CFA based on the RPM design [15], [16].…”