Design of overmoded interaction circuit for 1 kW, 95 GHz, TWT

Kory, C.L.; Read, Michael; Ives, R. Lawrence; Booske, John H.; Borchard, P.

doi:10.1109/ivelec.2008.4556333

Cited by 17 publications

(13 citation statements)

References 17 publications

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“…The performance of the new structure in this paper is better than that of C.L. Kory [6]. Compared with that of Kory, the average output power improves about 250 W, and the electronic efficiency improves about 5.2 percent.…”

Section: Multifrequency Interactionmentioning

confidence: 73%

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Interaction study on overmoded traveling-wave tube at W-band

2012

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The electrical and thermal characteristics have been researched on overmoded traveling-wave tube (TWT) at W-band. A new slow-wave structure (SWS) is presented. The beam-wave interaction is calculated using the 1-D large signal simulation tool TWTSNU. The results show the new structure is working at the fourth mode with the average output power 1.25 kW, electronic efficiency 17.8%, and stable thermal performance.

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Section: Multifrequency Interactionmentioning

confidence: 73%

“…It shows to be very successful. The third mode is adopted by Kory's group, and they designed the W-band TWT, with the average output power 1 kW, gain 40 dB, and electronic efficiency 12.6% [6]. It represents the highest level in the world today.…”

Section: Introductionmentioning

confidence: 99%

Interaction study on overmoded traveling-wave tube at W-band

2012

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“…These investigated structures include a micro-fabricated helical structure with two electron beamlets [40], a suspended ladder structure [41], a wood-pile electromagnetic-bandgap waveguide [15], groove-loaded folded waveguide [26], and selectively metalized micro-fabricated folded waveguide [61]. A cylindrical dielectric omniguide photonic bandgap TWT was in development with a 10 % bandwidth expected [64], but achieved limited success.…”

Section: W-band Twtsmentioning

confidence: 99%

Overmoded W-Band Traveling Wave Tube Amplifier

Temkin¹,

Kowalski²

2014

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Air Force Materiel Command REPORT DOCUMENTATION PAGEForm Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information We report on the design and test of an overmoded W-band TWT. The TWT was designed to operate in the rectangular TM31 cavity mode at 94 GHz. The unwanted lower order modes were suppressed using selectively placed AlN dielectric loading; simulations in 3-D CST Particle Studio confirmed the suppression. The 87-cavity TWT was designed to operate at 30 kV with 320 mA in a 2.5 kG solenoid magnet. The experiment was built in-house at MIT and operated with a 3 microsecond pulsed power supply. An initial beam test was implemented which confirmed operation at 31 kV with 306±6 mA of current detected at the collector and 88 % transmission. The TWT produced 21±2 dB system gain at 94.3 GHz and 27 W of saturated output power in zero-drive stable operation. The TWT had about 6 dB of additional loss due to the input and output coupling; taking that loss into account, the gain on the TWT circuit itself was 27±2 dB circuit gain. CST simulations for the experimental current and voltage predict 28 dB circuit gain, in good agreement with measurements. This experiment demonstrated the first successful operation of an overmoded TWT. The overmoded TWT is a promising approach to high power TWT operation at W-Band and to the extension of the TWT to terahertz frequencies. AbstractWe report on the design and test of an overmoded W-band TWT. The TWT was designed to operate in the rectangular TM31 cavity mode at 94 GHz. The unwanted lower order modes, TM11 and TM21, were suppressed using selectively placed Aluminum Nitride dielectric loading; simulations in 3-D CST Particle Studio confirmed the suppression. The TWT was designed to operate at 30 kV with 320 mA in a 2.5 kG solenoid magnet. Simulations in both 1-D Latte and 3-D CST predicted 31 dB of gain, 200 MHz bandwidth, and 300 W peak output power at 94 GHz. Test structures of 9-and 19-cavities were made via CNC direct machining. Cold test measurements showed suppression of the unwanted modes and transmission of the TM31 mode, which correlated well with HFSS simulations. Two final 87-cavity structures were built and cold tested.The experiment was designed and built in-house at MIT. It was operated with a 3 microsecond pulsed power supply. An initial beam test was implemented which confirmed operation of the TWT at 31 kV with 306±6 mA of current detected at the collector and 88 % transmission of current. Operation of the TWT with the first structure showed 8 dB of system gain and 10 W saturated output power at 95.5 GHz....

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“…By operating in a higher order mode the interaction structure's dimensions can be increased thereby the surface area available for thermal dissipation and reducing the power loss density [1]. However, overmoded operation opens the door to parasitic interactions with both lower and higher order modes.…”

Section: Overmoded Structuresmentioning

confidence: 99%

Design of an overmoded W-band TWT

Comfoltey

Shapiro

Sirigiri

et al. 2009

2009 IEEE International Vacuum Electronics Conference

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We report on the design and cold test validation of an overmoded TWT capable of producing power in excess of 100 Watts in the W-band and above. The TWT operates in the TM 31 mode of a rectangular cavity and has transverse dimensions three times larger than a conventional ladder TWT. Dielectric loading of a resonant cavity was utilized to suppress lower order modes and prevent parasitic oscillations. HFSS and MAGIC3D codes were used to predict performance. An X-Ku band scaled down version of the interaction structure was built and cold tests performed on it showed excellent agreement with HFSS simulations.

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Design of overmoded interaction circuit for 1 kW, 95 GHz, TWT

Cited by 17 publications

References 17 publications

Interaction study on overmoded traveling-wave tube at W-band

Interaction study on overmoded traveling-wave tube at W-band

Overmoded W-Band Traveling Wave Tube Amplifier

Design of an overmoded W-band TWT

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