By adjusting the transmitting time and the initial phase of distributed radar antennas, the spatial distribution of signal energy transmission can be controlled and then the signal energy can be improved in the spatial region of interest. The fundamentals of distributed coherent transmitting are analyzed, the conditions are presented to form an interference peak, and a spatial interference energy distribution function is defined to represent the gain of the transmitting energy compared to the mean energy, which has a maximum of the number of transmitting antennas. The characteristic of the spatial interference energy distribution function is analyzed in both radar near field and radar far field, indicating that the spatial interference energy distribution function exhibits a stripe shape in radar far field with collocated antennas, and an ellipse shape or a mono-peak shape in radar near field with widely separated antennas. To make a real target contained in a signal interference peak, the distributed coherent transmission works better for lower frequencies and smaller targets in the target tracking mode.
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