A New Method for SIAR Transmitting Waveforms to Reduce the Range-Angle Coupling

Abstract

Synthetic impulse and aperture radar (SIAR) is an orthogonal multiple input multiple output radar. It has several advantages, including the ability to detect multiple targets, Antiradiated Missiles (ARM), and stealth targets. Despite its four-dimensional (4-D) nature, it exhibits a strong coupling between range and angle, which dictates how well SIAR performs in the range-angle domain. Not only does the SIAR use frequency codes to separate the antennas, but also to ensure orthogonality. They can, however, mitigate the strong coupling between range and angle. Pulse-to-pulse frequency code agility is a technique for suppressing the SIAR radar's sidelobes. In this letter, we propose a method for reducing the coupling between range and angle by combining sequential positive, negative and random code with the dot product. The idea of coupling reduction presented in this letter is based on the ratio of each antenna position and frequency codes, which is referred to $\alpha $ k , and multiple $\alpha $ k in an array provides new advantages for target detection. This technique has the potential to significantly reduce the sidelobe levels.