Nonlinear Frequency Offset Beam Design for FDA-MIMO Radar

Abstract

The beam pattern of frequency diversity array (FDA) radar has a range–angle two-dimensional degree of freedom, which makes it possible to distinguish different targets from the same angle and brings a new approach to anti-jamming of radars. However, the beam pattern of conventional linearly frequency-biased FDA radar is range–angle-coupled and time-varying. The method of adding nonlinear frequency bias among the array elements of the FDA array has been shown to eliminate this coupling property while still allowing for better beam performance of the emitted beam. In this paper, we obtain a decoupled and time-invariant beam direction map using the FDA-multi-input–multi-output (FDA-MIMO) radar scheme and then obtain a sharp pencil-shaped main sphere beam pattern with range–angle dependence using a linear frequency offset scheme weighted by a Chebyshev window. Finally, the anti-interference performance of the proposed method is verified in an anti-interference experiment.

Improving the accuracy of a digital spectral correlation-interferometric method of direction finding with analytical signal reconstruction for processing an incomplete spectrum of the signal

“…In Fig. 4, the following is indicated: "P5grad" is the error in estimating the bearing for the case of selection (5) (discarding) one spectral sample, which is the overlap of the signal and interference, and "P6grad" is the error in estimating the bearing for the case of restoring (15) one spectral sample masked by the interference.…”

“…In Fig. 6, the following is indicated: "P9grad" is the standard deviation of the bearing estimate for processing with selection (discarding) of one masked extreme upper spectral sample, and "P10grad" is the standard deviation of the bearing estimate for the proposed direction-finding method with restoration (15) of the spectral sample of the signal masked by interference.…”

“…In [15], masking interference is combated using an active emitting radar, which has both direction and range selection. In [16], a direction-finding method with protection against multipath propagation of radio waves is proposed.…”