Multibeam Antenna Array Simulation

The work deals with the study of multibeam antenna arrays (MAA) for use in radar systems in order to detect and track a huge number of targets.The principles of construction, features, and applications of multibeam antennas are considered, as well as the calculation and modeling of the MAA. The beamforming circuit (BFC) was built based on the Butler matrix of 3dB square bridges and phase shifters.Such a scheme doesn’t require many of directional couplers (DC) and has a wide bandwidth due to the equality of the geometric paths of wave propagation from the antenna inputs to the emitters. The slotted Vivaldi emitter was chosen as the antenna element, which is capable of operating in a wide frequency band.The broadband emitter allows it to be used in systems that solve various problems: radar, electronic warfare, radio prospecting, and others.The paper considers the calculation and modeling of a multibeam antenna array built according to the Butler scheme.Butler matrices of 4 and 8 elements are considered, as well as a method for obtaining summary and differential diagrams to increase the number of antenna beams by adding hybrid rings to the circuit.Since the summary diagrams have a maximum in the equisignal direction of the beams it is possible to implement the equisignal method of direction-finding (DF) of radiation sources.The equisignal method does not require a narrow beam pattern and increases the DF accuracy. The GNU Octave environment is used to process data and implement the method.The transfer of information between the GNU Octave and electromagnetic analysis environment is carried out using ActiveX framework.