Rights statement: ©2021 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.
Accepted author manuscript, 1.1 MB, PDF document
Available under license: CC BY-NC: Creative Commons Attribution-NonCommercial 4.0 International License
Final published version
Licence: CC BY: Creative Commons Attribution 4.0 International License
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Numerical and Experimental Validation of the Passive Performance of a Co-Harmonic Gyro-Multiplier Interaction Region
AU - Constable, DA
AU - Phelps, Alan D. R.
AU - Whyte, Colin G.
AU - He, Wenlong
AU - Cross, Adrian W.
AU - Ronald, Kevin
N1 - ©2021 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.
PY - 2021/10/31
Y1 - 2021/10/31
N2 - The azimuthally rippled cavity for a large orbit, co-harmonic gyro-multiplier, designed to operate at the 2nd and 4th harmonics, at frequencies of 37.5 GHz and 75 GHz, respectively, has been numerically and experimentally confirmed to be insensitive to the polarization of quadrupole, TE2,n-like modes, including the 2nd harmonic operating mode of the multiplier, a cylindrical TE2,2-like waveguide mode. To test the cavity with this mode required the design, construction and measurement of ripple wall mode converters, converting the cylindrical TE2,1 mode to the TE2,2 mode. These were designed to operate at a central frequency of ~37.9 GHz, with predicted mode purity of better than 85%, and 3 dB bandwidth of 161 MHz. The constructed converter had a central operating frequency of 37.7 GHz, with S-parameter measurements used to infer suitable mode purity, and an operational 3 dB bandwidth of 50 MHz. This has allowed farfield phase measurements of the corrugated cavity to be conducted, where the orientation of the geometry to the polarization of both the TE2,1 and TE2,2 modes was shown to have no effect on the dispersion.
AB - The azimuthally rippled cavity for a large orbit, co-harmonic gyro-multiplier, designed to operate at the 2nd and 4th harmonics, at frequencies of 37.5 GHz and 75 GHz, respectively, has been numerically and experimentally confirmed to be insensitive to the polarization of quadrupole, TE2,n-like modes, including the 2nd harmonic operating mode of the multiplier, a cylindrical TE2,2-like waveguide mode. To test the cavity with this mode required the design, construction and measurement of ripple wall mode converters, converting the cylindrical TE2,1 mode to the TE2,2 mode. These were designed to operate at a central frequency of ~37.9 GHz, with predicted mode purity of better than 85%, and 3 dB bandwidth of 161 MHz. The constructed converter had a central operating frequency of 37.7 GHz, with S-parameter measurements used to infer suitable mode purity, and an operational 3 dB bandwidth of 50 MHz. This has allowed farfield phase measurements of the corrugated cavity to be conducted, where the orientation of the geometry to the polarization of both the TE2,1 and TE2,2 modes was shown to have no effect on the dispersion.
KW - Cyclotron resonant masers
KW - electromagnetism
KW - gyrotrons
KW - Microwave measurements
KW - Mode converters
U2 - 10.1109/TMTT.2021.3094219
DO - 10.1109/TMTT.2021.3094219
M3 - Journal article
VL - 69
SP - 4377
EP - 4384
JO - IEEE Transactions on Microwave Theory and Techniques
JF - IEEE Transactions on Microwave Theory and Techniques
SN - 0018-9480
IS - 10
ER -