Open AccessPhase Measurements of a 140-GHz Confocal Gyro-Amplifier
Author(s) -
Guy Rosenzweig,
Sudheer Jawla,
Julian Picard,
Michael A. Shapiro,
Richard J. Temkin
Publication year - 2020
Publication title -
journal of infrared, millimeter, and terahertz waves
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.615
H-Index - 59
eISSN - 1866-6906
pISSN - 1866-6892
DOI - 10.1007/s10762-020-00751-w
Subject(s) - amplifier , materials science , voltage , cathode ray , phase (matter) , cathode , optics , adiabatic process , electron gun , optoelectronics , physics , electrical engineering , electron , engineering , cmos , quantum mechanics , thermodynamics
The phase stability of a 140GHz, 1kW pulsed gyro-amplifier system and the phase dependence on the cathode voltage were experimentally measured. To optimize the measurement precision, the amplifier was operated at 47 kV and 1 A, where the output power was ∼ 30W. The phase was determined to be stable both pulse-to-pulse and during each pulse, so far as the cathode voltage and electron beam current are constant. The phase variation with voltage was measured and found to be 130±30°/kV, in excellent agreement with simulations. The electron gun used in this device is non-adiabatic, resulting in a steep slope of the beam pitch factor with respect to cathode voltage. This was discovered to be the dominant factor in the phase dependence on voltage. The use of an adiabatic electron gun is predicted to yield a significantly smaller phase sensitivity to voltage, and thus a more phase-stable performance. To our knowledge, these are the first phase measurements reported for a gyro-amplifier operating at a frequency above W-band.