Millimeter vector analyzer for high Q-factor open resonator research

Developing the high-stability vector analyzer of superheterodyne type with coherent heterodyning, having high resolution, allows one to measure the amplitude and phase characteristics of objects with a high degree of accuracy. The radiation source of millimetre electromagnetic waves is the diffraction radiation oscillator (DRO). DROs have high frequency stability (10^-7), small parasitic deviation and low level of phase noise. The small-packaged DRO in frequency a range 30-250 GHz with output power of 0.5-50 Wt as a probing source of radiation allows one to investigate substances and devices with large losses in the millimetre wave range. For achievement of a DRO long-term frequency stability compared with the frequency quartz standards, additional adequate conditions are required. With this purpose the experimental research on increase of frequency stability of 4-mm DRO with PLL was carried out