The Algorithm of the Phased Antenna Array Beam Forming with Spatially-Selective Radiation of the Orthogonal Signals

The possibility of forming narrow beams when using a small number of transmit-receive channels determines the popularity of using multiple-input multiple-output (MIMO) technology in modern antennas of systems for various purposes. However, the requirement to separate orthogonal signals emitted by multiple transmitting elements determines the main disadvantage of MIMO structures. Time and frequency separation of signals leads to energy losses and narrowing of the operating frequency band, which is unacceptable in systems where detection range and time delay resolution are critical characteristics. The widespread of code division is due to the simultaneous emission of orthogonal signals and the preservation of a given frequency band. In this case, the use of the Walsh and Fourier sequences leads to the formation in the two-dimensional spectrum of the signal reflected from the target, side maximums, the level of which is comparable to the main one, in terms of the Doppler frequency. As a result, there is an ambiguity in determining the speed of targets. As a solution to this problem, this paper considers a method consisting in the simultaneous emission of orthogonal signals in given directions and spatial selection of the transmitting beam by DP of the receiving antenna. A description of the proposed method is given, on the basis of which mathematical modeling is carried out, and the obtained results, also noted in the presented work, are analyzed.