The Microwave Spectrometer at the Institute of Radio Astronomy of NASU: Recent Upgrades

We report the results of the recent considerable improvements of the microwave spectrometer at the Institute of Radio Astronomy of NASU. In order to extend frequency range we have designed and constructed new generator blocks and provided a possibility of frequency tripler application. Now the spectrometer covers the frequency range from 34 GHz to 420 GHz with a gap from 183 GHz to 200 GHz. Improvement of measurement accuracy was achieved by applying a modified function for approximation of experimental records which takes into account distortions of lineshape caused by reflections in absorbing cell. The spectral resolution was improved by means of construction of a new absorbing cell with enlarged diameter.