Interwoven-Disk-Loaded Circular Waveguide for a Wideband Gyro-Traveling-Wave Tube

Kesari, Vishal; Keshari, J. P.

doi:10.1109/tps.2013.2241458

Cited by 8 publications

(14 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The same features observed in Fig. 7 are manifested also in this configuration, where electron beam is synchronous to four MTL Bloch modes near the DBE frequency (to be specific, it is synchronous to four Floquet harmonics with wavenumber close to / kd   , according to (16)). The dispersion diagram of Im(k) in Fig.…”

Section: Mixingsupporting

confidence: 69%

“…We plot in Fig. 14 the dispersion diagram of the "hot" structure composed of two segments of MTLs as described by the transfer matrix in (14) interacting with an electron beam, whose electrons have an average velocity 0 0.31 uc  , so satisfying the super synchronism condition (16), and the beam current is 0 15 [mA] I  . The zoomed plots in Fig.…”

Section: Mixingmentioning

confidence: 99%

See 1 more Smart Citation

Theory and New Amplification Regime in Periodic Multimodal Slow Wave Structures With Degeneracy Interacting With an Electron Beam

Othman¹,

Tamma²,

Capolino³

2016

IEEE Trans. Plasma Sci.

View full text Add to dashboard Cite

Section: Mixingsupporting

confidence: 69%

Section: Mixingmentioning

confidence: 99%

Theory and New Amplification Regime in Periodic Multimodal Slow Wave Structures With Degeneracy Interacting With an Electron Beam

Othman¹,

Tamma²,

Capolino³

2016

IEEE Trans. Plasma Sci.

View full text Add to dashboard Cite

“…In this model (model-3) a circular metallic waveguide of inner radius r W is considered in which annular disc of thickness T, inner radius r D and outer radius r W Interwoven disc-loaded circular waveguides [2,9,14,15]. Circular waveguide loaded with metal vanes [16][17][18].…”

Section: Circular Waveguide With Annular Metal Discsmentioning

confidence: 99%

“…This model (model-4) differs from the conventional disc-loaded circular waveguide due to different additional disc included in between two identical consecutive discs of conventional disc-loaded circular waveguide [2,9,14,15]. Thus, this model is considered with a circular metallic waveguide of inner radius r W in which annular disc of thickness T, inner radius r D and outer radius r W are arranged periodically with periodicity L. In addition, another annular disc of thickness T BH , inner radius r BH and outer radius r W are also arranged periodically with periodicity L such that the disc of thickness T BH is placed in middle of two identical consecutive discs of thickness T. The structure is known as the interwoven-discloaded circular waveguide.…”

Section: Interwoven-disc-loaded Circular Waveguidementioning

confidence: 99%

Metal- and Dielectric-Loaded Waveguide: An Artificial Material for Tailoring the Waveguide Propagation Characteristics

Kesari¹

2020

Electromagnetic Materials and Devices

Self Cite

View full text Add to dashboard Cite

In the present chapter a number of loaded structures are studied with circular cross-section to explore the deviation in their dispersion characteristics from their parent circular waveguide. The dielectric and/or metal loading to the waveguide tailors its dispersion characteristics. In general, the dielectric depresses and the metal elevates the dispersion characteristics from the characteristics of their parent circular waveguide. The axial periodicity results in periodic dispersion characteristics with a lower and an upper cutoff frequency (bandpass). However such a characteristic is not reported for the azimuthal periodic structures. The bandpass characteristic arises due to the shaping of the dispersion characteristics. Therefore the dispersion shaping is only possible with axial periodicity and not with the azimuthal periodicity. The sensitivity of the structure (geometry) parameters on the lower and upper cutoff frequencies, the extent of passband and the dispersion shaping are also included. In the axial periodic structures, the periodicity is found to be the most sensitive parameter for tailoring the dispersion characteristics and the disc-hole radius is the most sensitive parameter for shifting the dispersion characteristics over the frequency axis.

show abstract

“…Remarkably, Pierce predicted the small signal gain of a TWT and provided design rules for TWT amplifiers in terms of the SWS and electron beam parameters [2], [9]. In essence, state of the art of the high power TWT technology employs all-metallic slow-wave guiding structures whose dispersion is engineered for (i) matching phase velocity to an electron beam over a wide bandwidth; and (ii) high interaction impedance [10]- [17]. Consequently, dispersion engineering of the SWS eigenmodes would potentially enhance the gain, efficiency and bandwidth of conventional TWTs [18]- [22] and backward wave oscillators (BWOs) [23]- [26].…”

Section: Introductionmentioning

confidence: 99%

A New Amplification Regime for Traveling Wave Tubes With Third-Order Modal Degeneracy

Yazdi

Othman

Veysi

et al. 2018

IEEE Trans. Plasma Sci.

View full text Add to dashboard Cite

Engineering of the eigenmode dispersion of slowwave structures (SWSs) to achieve desired modal characteristics, is an effective approach to enhance the performance of high power traveling wave tube (TWT) amplifiers or oscillators. We investigate here for the first time a new synchronization regime in TWTs based on SWSs operating near a third order degeneracy condition in their dispersion. This special three-eigenmode synchronization is associated with a stationary inflection point (SIP) that is manifested by the coalescence of three Floquet-Bloch eigenmodes in the SWS. We demonstrate the special features of "cold" (without electron beam) periodic SWSs with SIP modeled as coupled transmission lines (CTLs) and investigate resonances of SWSs of finite length. We also show that by tuning parameters of a periodic SWS one can achieve an SIP with nearly ideal flat dispersion relationship with zero group velocity or a slightly slanted one with a very small (positive or negative) group velocity leading to different operating schemes. When the SIP structure is synchronized with the electron beam potential benefits for amplification include (i) gain enhancement, (ii) gain-bandwidth product improvement, and (iii) higher power efficiency, when compared to conventional Pierce-like TWTs. The proposed theory paves the way for a new approach for potential improvements in gain, power efficiency and gain-bandwidth product in high power microwave amplifiers.I.

show abstract

Interwoven-Disk-Loaded Circular Waveguide for a Wideband Gyro-Traveling-Wave Tube

Cited by 8 publications

References 19 publications

Theory and New Amplification Regime in Periodic Multimodal Slow Wave Structures With Degeneracy Interacting With an Electron Beam

Theory and New Amplification Regime in Periodic Multimodal Slow Wave Structures With Degeneracy Interacting With an Electron Beam

Metal- and Dielectric-Loaded Waveguide: An Artificial Material for Tailoring the Waveguide Propagation Characteristics

A New Amplification Regime for Traveling Wave Tubes With Third-Order Modal Degeneracy

Contact Info

Product

Resources

About