Theory and Experiment of Ultra High Gain Gyrotron Traveling-Wave Amplifier

Abstract

In this paper we give a survey of recent methods for the asymptotic and exact enumeration of number fields with given Galois group of the Galois closure. In particular, the case of fields of degree up to 4 is now almost completely solved, both in theory and in practice. The same methods also allow construction of the corresponding complete tables of number fields with discriminant up to a given bound.

Design and Simulation of an Ultra-Broadband Ku-BandGyro-TWT for Radar Applications

“…According to the equation (1) and (4) with the gyro-TWT amplifier boundary conditions of the fields and electrons a set of self-consistent coupled differential equations in slow variables for the fields and electrons could be derived [5,12].…”

“…Use of distributed loss in gyro-TWTs Chu et al [5] marked a major advancement in the suppression of spurious oscillations, thus permitting high gain and power operation. A summary of recent experimental gyro-TWTs employing distributed loss is given in [9] and [10] and a unique distributed loss approach employed in a TE 11 Ka-band gyro-TWT amplifier is described in [11].…”

“…(NTHU), Taiwan, an ultrahigh gain gyro-TWT amplifier produced 93 kW peak power, with 70 dB saturated gain, 26.5 efficiency, and a -3 dB bandwidth of 8.6% at the Ka band [5]. Other gyro-TWT work is being performed at the University of California at 94 GHz [6], at the University of Maryland, College Park, at 32 GHz [7] and a 35 GHz spiral waveguide gyro-TWT has been demonstrated by a collaboration between the University of Strathclyde, Glasgow U.K., and the Institute of Applied Physics, Nizhny Novgorod Russia [8].…”

Analytical Study of the Interaction Structure of Vane-Loaded Gyro-Traveling Wave Tube Amplifier

“…The gyro-TWT uses a non-resonant waveguide interaction structure, operates near the grazing intersection between the beammode line and waveguide-mode dispersion plots for wide device bandwidths [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. In the device, the bunch of electrons formed by relativistic effects twists around the helix system with a pitch substantially greater than the electron pitch.…”

Design and Simulation of a Ka-Band TE11 Mode Gyro-Traveling-Wave Amplifier

“…A Ka band TE 11 mode gyro-TWT has been conducted at the National Tsing Hua University,Taiwan which produced 93 kW saturated peak output power at 26.5% efficiency with a 3dB bandwidth of 8.6%, and an ultrahigh gain of 70dB [5]. In the United States, a TE 01 mode gyro-TWT has been developed at the Naval Research Laboratory (NRL), to provide the required loss for stable operation, the amplifier used a ceramic loaded interaction circuit.…”