Effects of mutual influence of elements of a phased antenna array with wide bandwidth when operating for reception and transmission

When a phased antenna array operate with a wide bandwidth (bandwidth – octave), there are undesirable effects of interaction between radiators, radiators and feeder line, as well as there is an effect of radio signal scattering when passing the interface between the medium of the transmitter and air. These effects significantly deteriorate the antenna performance, weakening the power and, respectively, the transmission range, as well as deteriorating the quality of signal reception. The most well known phenomena arising from the operation of array elements are: 1) redistribution of currents in the radiators, which leads to distortion of the radio signal waveform; 2) changing the input impedance of each element leads to an increase in the SWR and reflection coefficient, which leads to reflection of energy in the feeder line back to the source; 3) occurrence of incidental main maxima in case of improper placement of emitters in the phased array; 4) a drop in the output power of amplifiers in the output stage of the radar transmitter; 5) increase in the level of side lobes of the directional pattern of the phased antenna array. The objective of the article is to evaluate the dependence of matching on active and reactive loads and to carry out modeling of optimal conditions for antenna operation, providing the correct matching of feeder line and radiators and ensuring the passage of the interface with the least losses. The conducted modeling allows to find optimal electrical characteristics (current, voltage, etc.) for proper operation of the phased antenna array at the stage of phased antenna array design.