METHOD FOR MULTI-SIGNAL DIRECTION-FINDING OF RADIO SOURCES AT SAME FREQUENCY FOR CIRCULAR ANTENNA SYSTEM Russian patent published in 2013 - IPC G01S5/04 

FIELD: radio engineering, communication.

SUBSTANCE: speed of direction-finding is increased using an efficient algorithm for identifying radio signal parameters. In particular, bearings are obtained in a circular antenna system via preliminary input of a system of equations into the computer, said system being derived for a specific pre-measured circular antenna system and at given values of azimuths θk in given ranges: $$y_m(u,\theta ,\beta )={\displaystyle \sum _{i=1}^K{\displaystyle \sum _{l=1}^N(u_i\exp (j{\alpha }_i){\xi }_i^{\cos {\gamma }_m+tg{\theta }_{il}\sin {\gamma }_m})}};$$ m∈[1,M] ξ_i=exp(j(2πR/λ)cosθ_icosβ_i) u_iexp(jα_i) is the complex amplitude of the signal of the i-th radio source; R is the radius of the antenna system; λ is the wavelength of the signal emitted by the radio source; α_i is the initial phase of the i-th signal; γ_m is the angle between a line passing through the centre of the antenna system and the m-th element of the antenna system and the line of origin of the azimuths; M is the number of elements (dipoles) of the circular antenna system; K is the number of radio sources; N is the number of given azimuth samples; at the output of the solution of said system of equations, values of parameters of amplitudes u_iexp(jα_i) and values ξ_i are obtained, which, along with given values θ_i, are transmitted to the input of the unit for calculating elevation bearings β_i through an arccosine function based on the condition: ξ_i=exp(j(2πR/λ)cosθ_icosβ_i).

EFFECT: high rate of direction-finding when receiving radio signals of multiple radio sources operating at the same frequency using circular antenna systems consisting of low-directivity elements.

1 dwg