Analysis of the power capacity characteristics of coaxial slow-wave structures

Bai, Zhen; Zhang, Jun; Zhong, Huihuang; Zhang, Dian; Meng, Dong Dong

doi:10.1088/0022-3727/49/22/225104

Cited by 11 publications

(4 citation statements)

References 16 publications

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“…Due to the large transversal dimension (D/λ = 6.6), dozens of asymmetric modes could exist in coaxial SWS, although the distance between the inner and outer conductors only allows two symmetric modes, quasi-TEM and TM 01 , to exist. The dispersion curves are shown in figure 2, calculated by a method described in [24], which is derived from [23]. Figure 2(a) shows the dispersion curves of the modes whose lower limit frequencies are within the frequency passband of the fundamental mode.…”

Section: Asymmetric Modes Output Problem In a Ka-band Super Overmoded...mentioning

confidence: 99%

Elimination of the asymmetric modes in a Ka-band super overmoded coaxial Cerenkov oscillator

Bai¹,

Zhang²,

Zhong³

et al. 2017

J. Phys. D: Appl. Phys.

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The issue of asymmetric modes output of a Ka-band super overmoded coaxial Cerenkov oscillator is analyzed in this paper. Due to serious passband overlapping in a super overmoded coaxial slow wave structure (SWS), the asymmetric competition mode EH11 can hardly be suppressed thoroughly by the methods adopted in moderately overmoded devices, especially in the startup of oscillation. If the output structures reflect the asymmetric modes, the asymmetric mode competition in SWS will be aggravated and the normal operation state will be destroyed. In order to solve this problem, a taper waveguide is inserted at a specific position to achieve the destructive interference of the reflected TM11, and a special support structure is designed to avoid reflection of TE11. With these methods, asymmetric mode competition can be successfully eliminated, and the oscillator is capable of achieving a steady fundamental mode operation performance.

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Section: Asymmetric Modes Output Problem In a Ka-band Super Overmoded...mentioning

confidence: 99%

Elimination of the asymmetric modes in a Ka-band super overmoded coaxial Cerenkov oscillator

Bai¹,

Zhang²,

Zhong³

et al. 2017

J. Phys. D: Appl. Phys.

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“…The relativistic backward wave oscillator (RBWO) is one of the most promising high power microwave (HPM) generators, because of its high operating stability, high output power, and excellent repetitive operation performance [1][2][3][4][5][6][7][8][9][10]. In the HPM community, researchers commonly concentrate on obtaining output with a higher power, higher efficiency, and longer pulse duration [5,[11][12][13][14][15][16][17][18][19][20]. Recently, great progress has been made in obtaining high conversion efficiency of RBWOs at gigawatts level [7-10, 16, 20, 21].…”

Section: Introductionmentioning

confidence: 99%

A novel self-injection relativistic backward wave oscillator

Fan¹,

Sun²,

Chen³

et al. 2021

J. Phys. D: Appl. Phys.

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A novel self-injection relativistic backward wave oscillator (RBWO) has been proposed. By introducing a self-injection path into the RBWO, a small portion of the energy in the reflector can be coupled to the upstream of the reflector, and then the formed electric field in the self-injection path region can pre-modulate the passing electron beam, to promote a frequency-locking oscillation of the electron beam. The pre-modulated electron beam can be expected to enhance the beam-wave interaction and suppress parasitic mode oscillation, which is beneficial for maintaining the dominant role of the operating mode. The proposed self-injection RBWO shows great potential for improving the conversion efficiency and pulse duration time. Through particle-in-cell simulation, a microwave with a power of 10.6 GW is obtained, when the beam voltage is 1.08 MeV, and the beam current is 18.6 kA. The conversion efficiency is 53%.

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“…First, as the output power increases higher and higher, the problem of power handling capacity becomes more and more serious for the operation of RBWO [17], [18], especially…”

Section: Introductionmentioning

confidence: 99%

Theoretical Research on Properties of Spatial Harmonics in Corrugated Waveguide

Teng

Wang

et al. 2019

IEEE Access

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This paper investigates the dependence of the properties of the spatial harmonics on the overmoded ratio of the corrugated waveguide operating in TM 01 at 30 GHz with the consideration of the effects of the ripple shape. It is found that as the overmoded ratio grows, the electric fields concentrate towards the ripple surface, which weakens the enhancement of the power handling capacity caused by augmentation of the overmoded ratio. As the overmoded ratio grows, the ratio between the field amplitudes of the −1st spatial harmonic and the fundamental harmonic increases monotonically. Therefore, the total electric fields composed of the spatial harmonics become the spatial beating-wave with the single frequency, whose amplitudes vary along z-axis with the spatial period determined mainly by the −1st spatial harmonic and the fundamental harmonic. Researches on coupling impedances show that with the same overmoded ratio, the corrugated waveguide consisting of the improved rectangular ripples provides better synchronous coupling for the wave-beam interaction than that of the sinusoidal ripples does. Moreover, it is better to choose the fundamental harmonic close to the light line as the synchronous wave for the wave-beam interaction in the low magnetic field. In that case, even if the electron beam keeps far away from the ripple surface, the synchronous wave still provides strong enough coupling for the electron beam. INDEX TERMS Corrugated waveguide, coupling impedance, field distribution, high power microwave generation, overmoded ratio.

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Analysis of the power capacity characteristics of coaxial slow-wave structures

Cited by 11 publications

References 16 publications

Elimination of the asymmetric modes in a Ka-band super overmoded coaxial Cerenkov oscillator

Elimination of the asymmetric modes in a Ka-band super overmoded coaxial Cerenkov oscillator

A novel self-injection relativistic backward wave oscillator

Theoretical Research on Properties of Spatial Harmonics in Corrugated Waveguide

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