| A TE11 Ka-Band Gyro-TWT Amplifier with High-Average Power Compatible Distributed Loss |
JUN 2004 |
10 pages |
| Authors:
Dean E. Pershing; Khanh T. Nguyen; Jeffrey P. Calame; Bruce G. Danly; Baruch Levush; NAVAL RESEARCH LAB WASHINGTON DC VACUUM ELECTRONICS BRANCH
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 | Current amplifier research at the Naval Research Laboratory Vacuum Electronics Branch emphasizes techniques to extend the bandwidth and average power capability of gyro devices for millimeter wave radar applications. This paper will discuss the implementation of a wideband high-gain gyro-traveling wave tube amplifier design, with a measured peak output power of 78 kW, gain ^60 dB, and a 3-dB bandwidth of 4.2 GHz (12%) at 52 kW in Ka-band. The ... |
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| A Gyrotron-Traveling-Wave Tube Amplifier Experiment with a Ceramic Loaded Interaction Region |
JUN 2002 |
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| Authors:
Morag Garven; Jeffrey P. Calame; Bruce G. Danly; Khanh T. Nguyen; Baruch Levush; NAVAL RESEARCH LAB WASHINGTON DC VACUUM ELECTRONICS BRANCH
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 | The design and experimental study of a 35-GHz gyrotron-traveling-wave tube (gyro-TWT) amplifier operating in the circular TE01 mode at the fundamental cyclotron harmonic are presented. The interaction circuit in this experiment consisted of a new type of ceramic loading that provided the required loss for stable operation. A saturated peak power of 137 kW was measured at 34.1 GHz, corresponding to a saturated gain of 47.0 dB and an efficiency ... |
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| Higher Order Mode Excitations in Gyro-Amplifiers |
MAY 2001 |
7 pages |
| Authors:
Khanh T. Nguyen; Jeffrey P. Calame; Bruce G. Danly; Baruch Levush; Morag Garven; NAVAL RESEARCH LAB WASHINGTON DC VACUUM ELECTRONICS BRANCH
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| In gyro-devices, a nonlinear output taper is often employed as the transition from the near cutoff radius of the interaction circuit to a much larger output waveguide. The tapers are usually designed to avoid passive mode conversion, and thus do not consider the effect of a bunched beam. However, recent simulations with the self-consistent MAGY code Botton et aL, IEEE Trans. Plasma Sci. 26, 882 (1998) indicate that higher order ... |
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| Design of a Ka-Band Gyro-TWT for Radar Applications |
JAN 2001 |
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| Authors:
Khanh T. Nguyen; Jeffrey P. Calame; Dean E. Pershing; Bruce G. Danly; Morag Garven; NAVAL RESEARCH LAB WASHINGTON DC VACUUM ELECTRONICS BRANCH
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| The design of a Ka-band gyrotron traveling wave tube (TWT) amplifier capable of operating over a wide range of peak powers and bandwidths is presented. The amplifier operates in the TE11 mode at the fundamental cyclotron harmonic. Instantaneous bandwidths in the range of 2.5 to 3.9 GHz (at 1 dB below saturation) with corresponding peak powers between 92.2 and 57.9 kW can be achieved by simply adjusting the mod-anode voltage ... |
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| Modeling of Gyroklystrons with MAGY |
JUN 2000 |
20 pages |
| Authors:
Khanh T. Nguyen; Baruch Levush; Thomas M. Antonsen Jr.; Moti Botton; Monica Blank; NAVAL RESEARCH LAB WASHINGTON DC VACUUM ELECTRONICS BRANCH
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| The self-consistent time-dependent code MAGY is presently being used for designing and modeling gyrodevices. In this paper, the code's self- consistent capability is used to investigate three different issues relating to the operation of gyroklystron amplifiers. These are the effect of window reflection on the properties of the output waves, higher order mode excitation in nonlinear output tapers, and excitation in cutoff drift sections. The first two effects can potentially ... |
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| Modeling and Design of Millimeter Wave Gyroklystrons |
MAY 1999 |
8 pages |
| Authors:
Baruch Levush; M. Blank; Jeffrey P. Calame; Bruce G. Danly; Khanh T. Nguyen; NAVAL RESEARCH LAB WASHINGTON DC VACUUM ELECTRONICS BRANCH
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| A series of high power, high efficiency Ka-band and W-band gyroklystron experiments has been conducted recently at the Naval Research Laboratory (NRL). Stagger tuning of the cavities for bandwidth enhancement is commonly used in the conventional multicavity klystrons. The desired stagger tuning is usually achieved via mechanical tuning of the individual cavities. However, in the millimeter wave regime, particularly, in the case of the high average power operation, it is ... |
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