Noise reduction in a 2.45GHz strapped magnetron oscillator is experimentally demonstrated by electric priming using anode shape modification. The sideband noise is reduced by approximately 15dB at the nominal operating current and by 28dB at the start-oscillation current; this is due to electron prebunching into the π mode, resulting from the modulation of the drift velocity of the electrons by an azimuthally periodic electric field. In this experiment, a 4.3kV–330mA half-wave rectified input power is employed.

The performance of a 10-vane strapped magnetron oscillator used in microwave ovens was benchmarked using the three-dimensional particle-in-cell (PIC) code MAGIC3D. The formation of the five electron spokes in the oscillation region confirms the -mode oscillation of a 10-vane strapped resonator showing its mode separation with the adjacent mode to be 82%. The measured operating frequency of 2.465 GHz and the saturated output power of 1.04 kW are in good agreement with the simulated values of 2.470 GHz and 1.07 kW, respectively. The magnetron with an efficiency of 75% is operated at the beam voltage of 4.3 kV, the anode current of 0.33 A, and the cathode current of 1.08 A when the external axial magnetic field of 0.19 T is applied. In addition, the measured harmonic components of the radiated output are compared with the simulated one estimated by Fourier transformation of an induced radio-frequency voltage signal, showing good agreement.Index Terms-MAGIC3D, oscillator, PIC code, 10-vane strapped magnetron.

No abstract

No abstract

No abstract