3D Simulation of 18-vane 5.8 GHz Magnetron

Propagation Characteristics of a Variant of Disc-Loaded Circular Waveguide

“…One may start validating the analytically obtained dispersion relation (14) with reference to the special cases of the structure: for the case, i) r SH → r W the dispersion relation (14) becomes the same, as that for the disc-loaded circular waveguide of disc-hole radius r BH , disc-thickness T BH , and periodicity L [28,29]; ii) r BH → r W , (14) becomes the same as that for the disc-loaded circular waveguide of disc-hole radius r SH , disc-thickness T SH , and periodicity L [28,29]; iii) r SH = r BH and T SH = T BH , (14) becomes as that for discloaded circular waveguide of disc-hole radius r BH (= r SH ), discthickness T BH (= T SH ), and periodicity L/2 [28,29]; iv) r SH = r BH and T SH + T BH = L, (14) becomes J 0 {γ I n r SH } = J 0 {γ I n r BH } = 0, which is dispersion relation of the smooth-wall circular waveguide of radius r BH (= r SH ); and v) r SH = r BH → r W , (14) becomes J 0 {γ I n r W } = 0, which is dispersion relation of the smooth-wall circular waveguide of radius r W . Also, while considering infinitesimally thin disc, (14) passes to that published for infinitesimally thin discloaded circular waveguide [27,28], and while ignoring the higher order harmonics passes to that published in [36].…”

“…Also, while considering infinitesimally thin disc, (14) passes to that published for infinitesimally thin discloaded circular waveguide [27,28], and while ignoring the higher order harmonics passes to that published in [36]. All these cases are also validated with reference to the dispersion characteristics, obtained using the numerical code developed for solving the dispersion relation (14). In order to validate the dispersion characteristics obtained using the numerical code, a structure model, for typically chosen structure dimensions, is made in workspace of commercially available simulation tool -high frequency structure simulator (HFSS).…”

“…and even in the vacuum electronic devices, such as, linear/particle accelerators [11,12], backward-wave oscillators (BWOs) [13], magnetrons [14], coupledcavity and helix travelling-wave tubes (TWTs) [15][16][17][18][19], cyclotron masers [20,21], gyrotron sources [21][22][23][24] and amplifiers [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39], etc.. In these devices, one may see the periodic beam-wave interaction structures holding either azimuthal or axial periodicity [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]…”

“…In these devices, one may see the periodic beam-wave interaction structures holding either azimuthal or axial periodicity [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39]. The azimuthal periodicity in interaction structure may be seen, for example: in travelling-wave magnetrons [14] for π-mode operation, in gyrotrons [21][22][23][24] for mode rarefaction, in conventional helixTWTs [17] for broadbanding, in gyro-travelling wave tubes (gyroTWTs) [25,26] for higher interaction impedance and, in turn, for higher device-gain. The axial periodicity in interaction structure may be seen, for example, in conventional helix-TWT [17] for higher device-gain, in coupled-cavity TWT [17] for getting fundamentalmode backward-wave characteristics, and in gyro-TWT [27][28][29][30][31][32][33][34][35][36][37][38][39] for broadbanding.…”

DESIGN AND 3-D PARTICLE-IN-CELL SIMULATION OF A 140 GHz SPATIAL-HARMONIC MAGNETRON

“…Although various components have been developed for THz applications [5][6][7][8][9][10][11][12][13][14][15][16][17][18], high power, low cost, and compact THz sources are not readily available [19]. With the rapid advancement of multi-physics based codes, which provide the possibility of simulating the nonlinear beam-wave interaction dynamics [20][21][22][23][24], extending the operating frequency of the existing microwave tube designs [25][26][27][28][29] has become a promising approach for developing compact and powerful THz sources [30][31][32][33][34][35][36]. In accordance with this approach, design and numerical simulations of a 140 GHz spatial-harmonic magnetron (SHM) with a maximum pulse-output power of about 11 kW is presented in this paper.…”