FIELD: physics.
SUBSTANCE: coherent superheterodyne electronic paramagnetic resonance spectrometer contains the voltage adder, the modulation generator, the synchronous detector, the phase shifter of the modulation signal and on-off switch, and the first phase shifter is designed controllable, and one of inputs of the voltage adder is connected to the common contact of the first section of the bipolar switch, the second - to the common contact of on-off switch, and the output - to the controlling frequency of the electrode of UHF signal generator, the output of the modulation generator is connected to one of the switchable contacts of on-off switch and with the modulation signal phase shifter input the output of which is connected to the reference input of the additional synchronous detector the signal input of which is connected to the output of the second synchronous detector, the frequency of the signal of the modulation generator is less than boundary frequency of PLL loop pass-band of the heterodyne generator, but greater than the boundary frequency of PLL loop pass-band of the signal generator.
EFFECT: providing unambiguous, including automatic, configuring of phase ratios leading to exact separation of quadrature signal components.