Experimental investigation of a Ka band high power millimeter wave generator operated at low guiding magnetic field

Abstract

An overmoded slow wave type Ka band generator is investigated experimentally to produce high power millimeter waves in this paper. The experiments were carried out at the TORCH-01 accelerator. The produced microwave frequency was measured by dispersive line method, and the power was estimated by integrating over the radiation pattern at far field. With relatively low guiding magnetic field of 0.8 T and diode voltage and beam current of 590 kV and 5.2 kA, respectively, a 33.56 GHz millimeter wave with an output power of 320 MW was generated, and the microwave mode was quasi-TM 01 mode.

Suppression of the asymmetric competition mode in the relativistic Ku-band coaxial transit-time oscillator

“…Based on the method of the far-field measurement, 14 two receiving horns placed 5 m away from the window of the radiation antenna were used to measure the microwave power and frequency. The properties of the microwave signal received by the horn were analyzed by the Aglient-92504A oscilloscope, which has the sampling rates as high as 80 Gs/s.…”

Asymmetric modes decomposition in an overmoded relativistic backward wave oscillator

“…In previous reports, two dimensional (2-D) particle-in-cell (PIC) simulation is often utilized to validate this mode selection method. [6][7][8][9][10][11][12] However, in the overmoded SWSs with large value of D=k (here, D and k are the average diameter of SWSs and the wavelength of generated microwave, separately), TM 01 mode is not the only surface wave. 13 Lower order asymmetric modes could become surface waves as well.…”

“…However, by far most designing work of overmoded RBWOs is conducted through 2-D PIC simulations, which cannot reflect the effect of asymmetric surface waves on the beam-wave interaction. [6][7][8][9][10][11][12] In this paper, an X-band overmoded RBWO, whose REB propagates near the surface of SWSs, is illustrated. And then, this device is simulated in 2-D and three dimensional (3-D) PIC codes, separately.…”

“…4,5 However, large transversal dimension of overmoded RBWO brings about the problem of mode competition. Accordingly, previous investigations [6][7][8] have paid much attention on the method of mode selection.…”

Experimental study of a compact P-band coaxial relativistic backward wave oscillator with three periods slow wave structure

“…1-3 Among various HPM generators, the relativistic backward wave oscillator (RBWO) is one of the most promising devices for its advantages of relatively high power, high efficiency, and high repetitive operation rate. 1,4-10 Currently, there are many reports on the RBWOs operating in the frequency regime of S-band, X-band, C-band, and other higher frequency bands, [11][12][13][14][15][16][17][18][19] but researches on the P-band (0.3-1 GHz) RBWOs are rare. However, the P-band HPMs have important potential applications in both military and industrial fields because of their small free-space transmission loss and the strong diffraction property.…”