METHOD OF SINGLE-CHANNEL RADIO DIRECTION FINDING WITH MINIMAL NUMBER OF OMNIDIRECTIONAL ANTENNA ELEMENTS AND FACILITY FOR ITS REALIZATION Russian patent published in 2003 - IPC

FIELD: radio direction finding, radio engineering systems of automatic determination of angular coordinates of direction vector of propagation of electromagnetic energy. SUBSTANCE: proposed method is based on consistent execution of operations of ordering, multiplexing, amplification, frequency selection, demodulation, demultiplexing and computation of arrival angle of quasi-harmonic signal by value of arc tangent of ratio u₂/u₁ where pair of signals arranged in ordered fashion from assemblage of ordered orthogonal signals is used in the capacity of controlling signals f_i(t). Each pair of signals arranged in ordered fashion includes signals presenting sum of two harmonic oscillations with frequencies Ω₁ and Ω₂ computed by mathematical expressions. Signals in pairs simultaneously exhibit in time interval T mutual frequency orthogonality between components with different frequencies and mutual phase orthogonality between components with equal frequencies. Facility for realization of method has antenna system comprising four omnidirectional antenna elements situated on circumference equidistantly one from another, radio receiver of frequency-modulated signals, phase multiplexing and modulation unit, unit forming controlling orthogonal signals incorporating analog signal generating unit, first and second adders and analog inverter, and information processing and display unit incorporating rejection filter for frequency Ω₁, first and second amplifiers, rejection filter for frequency Ω₂, loudspeaker, demultiplexing unit, reference signal former, unit computing and controlling indication, indicator of bearing angle, indicator of amplitude level, initiating pulse former and master generator. In compliance with another variant facility realizing method differs by number of antenna elements ( 5 elements ) and use of amplitude modulation. EFFECT: minimal direction finding time is reduced twice as much, possibility of adjustment of direction finder with lack of a priori information on arrival angle of wave and capability to control operation of direction finder. 3 cl, 4 dwg