Starting conditions for backward-wave oscillators with large loss and large space charge

Grow, R. W.; Gunderson, David R.

doi:10.1109/t-ed.1970.17123

Cited by 17 publications

(12 citation statements)

References 4 publications

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“…The Pierce type small-signal analysis of a TWT [1][2][3][4][5][6][7][8], when interpreted for the propagation of energy in the backward direction, usually gives the start-oscillation condition of the device in terms of the Pierce's normalized circuit-gain CN, and the Pierce's normalized space-charge parameter QC [1][2][3][4][5][6]. Under no-loss assumption, the critical circuit-gain follows a co-sinusoidal nature [3,7,20], given as:…”

Section: Discussionmentioning

confidence: 99%

“…The phenomenon of backward-wave oscillation, at or near the upper band-edge of a helix slow-wave structure (SWS) of a traveling-wave tube (TWT) [1][2][3][4][5][6][7][8], is one of the limiting factors for multi-octave operation of the device. Over the past decade, the need for development of compact multi-octave micro-TWTs has rekindled the interest in studying this phenomenon [9][10][11][12][13][14][15][16][17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

“…In the present paper, we develop a method based on an artificial neural network (ANN) algorithm [22] that would yield a closed-form formula for the Pierce's normalized circuit gain CN [1][2][3][4][5][6][7][8] as a condition for the start of backward-wave oscillation in the device. Grow and Gunderson [6] also developed such a closed-form formula for CN, which is valid for relatively higher values of the space-charge parameter QC and the total distributed circuit loss L dB in decibel (QC∼25, L dB ∼200 dB), making the formula applicable to a high power backward-wave oscillator.…”

Section: Introductionmentioning

confidence: 99%

“…Grow and Gunderson [6] also developed such a closed-form formula for CN, which is valid for relatively higher values of the space-charge parameter QC and the total distributed circuit loss L dB in decibel (QC∼25, L dB ∼200 dB), making the formula applicable to a high power backward-wave oscillator. This motivates us to find a similar closed-form formula valid for relatively lower values of QC and circuit loss L dB (0.5≤QC≤1 and 4≤L dB ≤6, typical for mm-wave TWTs [23][24][25][26][27][28]) that can be used to predict the start-oscillation condition for a TWT used as an amplifier, hereby a method based on an ANN algorithm (Section 2).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

A Simple Closed-form Formula for Backward-Wave Start-Oscillation Condition for Millimeter-Wave Helix TWTs

Datta

Kumar

Basu³

2008

Int J Infrared Milli Waves

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An accurate and simple closed-form formula, for backward-wave start-oscillation condition for a millimeter-wave helix traveling-wave tube amplifier was developed, using an artificial neural network (ANN) algorithm. The analysis considers the effects of circuit loss and also the variation of electron beam diameter corresponding to beam filling. The formula is simple and amenable to easy computation, even using a scientific calculator, and without resorting to exhaustive numerical iterative search followed in conventional analyses and, at the same time, without sacrificing the accuracy in results. The formula was validated against published results, and excellent accuracy was observed. The analysis has been further used for inferring some physical interpretations on the effects of beam-filling factor and circuit loss on the start-oscillation condition of a typical millimeter-wave helix traveling-wave tube.Keywords Artificial neural network (ANN) . Backward-wave oscillation (BWO) . Backward-wave interaction impedance . Millimeter-wave traveling-wave tube (TWT) Abbreviations ANN artificial neural network BWO backward-wave oscillation EHF extra high frequency mm-wave millimeter-wave SWS slow wave structure TWT traveling-wave tube Int J Infrared Milli Waves (

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A Simple Closed-form Formula for Backward-Wave Start-Oscillation Condition for Millimeter-Wave Helix TWTs

Datta

Kumar

Basu³

2008

Int J Infrared Milli Waves

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“…The gain parameter of a linear lossy TWT that corresponds to the start-oscillation condition can be expressed by Equation (1) [6]. For gyro-TWT, the gain parameter is described as Equation (2) [7].…”

Section: Conversion Of Linear Twt Parameters To Gyro-twtmentioning

confidence: 99%

Calculation of Start-Oscillation-Current for Lossy Gyrotron Traveling-Wave Tube (Gyro-TWT) Using Linear Traveling-Wave Tube (TWT) Parameter Conversions

Song¹

2013

JEMAA

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The start-oscillation-current of a gyro-TWT (gyrotron traveling-wave tube) determines the stable operating current level of the device. The amplifier is susceptible to oscillations when the operating current level is higher than the start-oscillation current. There are several ways of calculating the start-oscillation current, including using the linear and nonlinear theory of a gyro-TWT. In this paper, a simple way of determining the start-oscillation current of lossy gyro-TWT is introduced. The linear TWT parameters that include the effects of synchronism, loss, and gain, were converted to gyro-TWT parameters to calculate the start-oscillation-current. The dependence on magnetic field, loss, and beam alpha was investigated. Calculations were carried out for a V-band gyro-TWT for both operating and competing modes. The proposed method of calculating the start-oscillation current provides a simple and fast way to estimate the oscillation conditions and can be used for the design process of a gyro-TWT.

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Submillimeter backward wave oscillators

Barnett

Stankiewicz

Heinen

et al. 1987

Int J Infrared Milli Waves

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Starting conditions for backward-wave oscillators with large loss and large space charge

Cited by 17 publications

References 4 publications

A Simple Closed-form Formula for Backward-Wave Start-Oscillation Condition for Millimeter-Wave Helix TWTs

A Simple Closed-form Formula for Backward-Wave Start-Oscillation Condition for Millimeter-Wave Helix TWTs

Calculation of Start-Oscillation-Current for Lossy Gyrotron Traveling-Wave Tube (Gyro-TWT) Using Linear Traveling-Wave Tube (TWT) Parameter Conversions

Submillimeter backward wave oscillators

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