DESIGN OF AN ANTENNA SYSTEM FOR A KU-BAND MIMO RADAR
There is a large amount of research and development of continuous MIMO radars. The development process of the antenna aperture for MIMO radars is different from the development of traditional antenna arrays. The use of mutually orthogonal signals on the transmitting elements in combination with the digitization of all receiving channels allows to form a virtual antenna array by repeating the receiving antenna array at the locations of the transmitting antenna elements, which significantly improves the angular resolution, and makes it possible to get rid of side lobes. It is necessary to provide a high level of spatial attenuation of the signal between all of the transmitting and all of the receiving elements, to enable continuous mode of operation, so that there is no oversaturation of the receiving paths. In this paper, the process of developing an antenna aperture for a Ku-band MIMO radar is considered, including the following steps: calculating the requirements for spatial attenuation between antenna elements, optimization of antenna elements relative coordinates, electromagnetic simulation of: a single emitter, spatial attenuation of signals, and the resulting characteristics of antenna elements. As a result of the selection and optimization of the receiving and transmitting antenna elements relative coordinates, a structure of 32 transmitting and 16 receiving elements was designed with spatial dimensions of 30 by 19 cm. The formed virtual antenna array consists of 512 elements with effective spatial dimensions of 19 by 38 cm. These results promise the sector of operation of ±60 degrees in both planes and potential resolution of no more than 1.5 by 3 degrees (azimuth and elevation, respectively).Calculation and electromagnetic simulation of spatial signal attenuation between transmitting and receiving antenna elements showed that the designed antenna array configuration allows obtaining an attenuation of 66 dB, which is consistent with the design requirements.