Study of the <i>π</i>-Mode Operation in the Extended Interaction Circuit

Chang, Zhiwei; Shu, Guoxiang; Tian, Yanyan; He, Wenlong

doi:10.1109/tps.2022.3148111

Cited by 5 publications

(5 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The concept of the converging beam EIA can be further developed at the W band or the THz band. The π mode operation has been used in sheet beam EIAs [ 13 ] and pencil beam EIAs [ 8 , 14 ], and the angular radial beam is also suitable for π mode operations. The angular radial beam EIA is suitable for angular radial integration, which can be used for multi-beam operations.…”

Section: Discussionmentioning

confidence: 99%

“…In W-band or terahertz (THz) klystrons, the extended interaction cavity is widely used, which has the advantages of a large power capacity and a high characteristic impedance. Related research includes W-band pencil beam EIAs [ 7 , 8 , 9 ], W-band multi-beam EIAs [ 10 ], W-band sheet beam EIAs [ 11 ], G-band sheet beam EIAs [ 12 , 13 ], G-band pencil beam EIAs [ 14 , 15 ], and W-band tested EIKs [ 16 , 17 , 18 , 19 ]. In general, the sheet beam has a more uniform beam–wave interaction than the pencil beam, and the current density of the beam can be greatly decreased by the sheet beam.…”

Section: Introductionmentioning

confidence: 99%

“…In reference [ 17 ], the proposed EIK with three extended interaction cavities is driven by a sheet beam of 20 kV and 4 A, which can produce 7.5 kW of peak power with a beam–wave interaction efficiency of 9.38%, and it adopts a single-stage depressed collector and water cooling. In references [ 7 , 8 , 9 ], the operating currents of the pencil beam are less than 1 A, and their beam–wave interaction efficiencies are both less than 10%. To improve the beam–wave interaction capability of W-band EIKs, the AREIAs are implemented and explored.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

An Angular Radial Extended Interaction Amplifier at the W Band

Dong

Wang

Guo

et al. 2023

Sensors

View full text Add to dashboard Cite

In this paper, an angular radial extended interaction amplifier (AREIA) that consists of a pair of angular extended interaction cavities is proposed. Both the convergence angle cavity and the divergence angle cavity, which are designed for the converging beam and diverging beam, respectively, are investigated to present the potential of the proposed AREIA. They are proposed and explored to improve the beam–wave interaction capability of W-band extended interaction klystrons (EIKs). Compared to conventional radial cavities, the angular cavities have greatly decreased the ohmic loss area and increased the characteristic impedance. Compared to the sheet beam (0°) cavity, it has been found that the convergence angle cavity has a higher effective impedance and the diverging beam has a weaker space-charge effect under the same ideal electron beam area; the advantages become more obvious as the propagation distance increases. Particle-in-cell (PIC) results have shown that the diverging beam (8°) EIA performs better at an output power of 94 GHz under the condition of lossless, while the converging beam (−2°) EIA has a higher output power of 6.24 kW under the conditions of ohmic loss, an input power of 0.5 W, and an ideal electron beam of 20.5 kV and 1.5 A. When the loss increases and the beam current decreases, the output power of the −2° EIA can be improved by nearly 30% compared to the 0° EIA, and the −2° EIA has a greatly improved beam–wave interaction capacity than conventional EIAs under those conditions. In addition, an angular radial electron gun is designed.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

An Angular Radial Extended Interaction Amplifier at the W Band

Dong

Wang

Guo

et al. 2023

Sensors

View full text Add to dashboard Cite

show abstract

“…In recent years EID research projects in the high frequency range have tended to move towards higher-order modes both transversely (TM n1 modes) and longitudinally (π modes), based on the more mature, traditional 2π mode. Extensive results show that the TM n1 mode offers a larger longitudinal dimension that facilitates the manufacture of terahertz systems 9 – 11 , while the π mode is increasingly adopted in many EID technologies due to its superior resonator coupling capability 12 – 14 . The measure of power level, as determined by the ratio of power to frequency squared ( Pf 2 (GW·GHz 2 )), indicates that SWS operating in the π mode has achieved reliable physical performance at this stage.…”

Section: Introductionmentioning

confidence: 99%

“…The measure of power level, as determined by the ratio of power to frequency squared ( Pf 2 (GW·GHz 2 )), indicates that SWS operating in the π mode has achieved reliable physical performance at this stage. For instance, a 0.22 THz π-mode bi-periodic EIA, with a cavity M 2 R/Q of 44 Ω, exhibits a Pf 2 value of 0.032, 660 W average power, and 2% efficiency 14 ; a 94 GHz π-mode bi-periodic EIO, operating at an R/Q of 346 Ω, achieves a Pf 2 value of 0.0052 (592 W average power), with an efficiency of 6.6% 12 . However, problems are encountered in practical studies where the π-mode has difficulty extracting power longitudinally in the over-dimensional TM n1 -mode state, thus limiting the saturation output power 15 (primarily due to its excessive external quality factor Q e ).…”

Section: Introductionmentioning

confidence: 99%

High-efficiency terahertz-wave generation based on extended interaction oscillator with strongly-coupled 2π mode operation

Xu,

Lu,

Tang

et al. 2024

Sci Rep

View full text Add to dashboard Cite

A slow-wave structure improvement for enhancing the 2π-mode electronic efficiency is embodied in the validation of an extended interaction oscillator (EIO), which has an electronic efficiency of 6.52% at 0.22 THz from particle-in-cell (PIC) calculations. A 2π-mode bi-periodic slow-wave structure (BPSWS) with staggered long and short slots is utilized for optimizing the circuit performance. The proposed BPSWS has the capability of combining the respective advantages for both π and 2π-mode in terms of coupling performance and output performance, thus supporting a strongly-coupled 2π-mode with higher coupling capability. Compared with the typical mono-periodic SWS (MPSWS), the adopted strongly-coupled 2π-mode effectively improves the characteristic impedance M2R/Q by 103% to 66.79 Ω, the coupling coefficient by 66% to 0.497, and the normalized wave-amplitude by 22%. Accordingly, 503 W of average output power can be derived for the BPSWS-EIO with a 25.7 kV and 0.3 A sheet beam injected. Cold-test experiments were conducted, confirming that the 0.22 THz structure exhibits commendable fabrication precision and consistency and thus demonstrates the expected frequency response.

show abstract