Extension of the range of resonator scanning spectrometer into submillimeter band and some perspectives of its further developments

Abstract

Extension of the working frequency of modern resonator spectrometers into submillimeter wave range is described. Experimental record of atmospheric absorption spectrum covering 45–370 GHz range is demonstrated for the first time, and measured water vapor J′ ka′, kc′ – J ka, kc = 5 1,5–4 2,2 at 325 GHz line parameters are presented. For the first time pressure lineshift for the 325-GHz water vapor line is measured. Further extension of working range is discussed. New estimations of physical limits of time needed for measurements of absorption in the whole Backward Wave Oscillator (BWO) range are given for phase continuous synthesizer regime. Basic schemes of fast broadband continuous phase synthesized sources are discussed. Verification of the previous measurements of water vapor 3 1,3–2 2,0 at 183 GHz line parameters is presented. Comparisons with ringdown resonator spectrometers are given.