Russian Physics Journal, Vol. 61, No. 2, June, 2018 (Russian Original No. 2, February, 2018)
AMPLITUDE AND PHASE CHARACTERISTICS OF SIGNALS
AT THE OUTPUT OF SPATIALLY SEPARATED ANTENNAS
FOR PATHS WITH SCATTERING
A. S. Anikin UDC 537.874.4
Conditional statistical characteristics of the phase difference are considered depending on the ratio of
instantaneous output signal amplitudes of spatially separated weakly directional antennas for the normal field
model for paths with radio-wave scattering. The dependences obtained are related to the physical processes on
the radio-wave propagation path. The normal model parameters are established at which the statistical
characteristics of the phase difference depend on the ratio of the instantaneous amplitudes and hence can be
used to measure the phase difference. Using Shannon’s formula, the amount of information on the phase
difference of signals contained in the ratio of their amplitudes is calculated depending on the parameters of the
normal field model. Approaches are suggested to reduce the shift of phase difference measured for paths with
radio-wave scattering. A comparison with results of computer simulation by the Monte Carlo method is
Keywords: phase difference, amplitude ratio, normal field model, radio-wave propagation, amount of
information, signal interference.
One of the directions of modernization of passive radio engineering equipment intended for finding directions
of radio-wave sources is the improvement of the accuracy of phase goniometers [1, 2]. The error in measuring the phase
difference of signals is caused by imperfection of equipment and effect of the radio-wave propagation medium. The
instrumental component of error of measuring instruments is decreased by introduction of the newest element base,
successful circuit solutions, and effective methods of calibration of the receiving channels and antenna systems. The
effect of the radio-wave propagation medium can be reduced by better account of the statistical characteristics of
received signals. To this end, it is necessary to extract completely information on the phase difference from output
signals of goniometer antennas .
The phase difference of signals is conventionally measured disregarding information on their amplitude
difference. Distortions of the signal shape are due to the intrinsic noise of the equipment, typically considered to be
Gaussian, and the difference of the signal amplitudes is not used to refine measurements of the phase difference. In
single-pulse phase goniometers, the amplitudes of the output signals of the antennas are leveled before measuring the
phase difference with a phase detector [4, 5]. When the phase difference is determined from the signal quadratures, their
amplitudes are cancelled by division [4–8].
Experiments demonstrate that under conditions of signal distortions caused by radio-wave scattering on
inhomogeneities of the medium, the amplitude and the phase can be correlated . In addition, experimental data for
hear-ground paths testify to the possible interrelation between the standard deviation (SD) of fluctuations of signal
Tomsk State University of Control Systems and Radioelectronics, Tomsk, Russia, e-mail: firstname.lastname@example.org.
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 142–148, February, 2018. Original article
submitted October 2, 2017; revision submitted January 16, 2018.
1064-8887/18/6102-0364 2018 Springer Science+Business Media, LLC