부산대학교 도서관

In this work, we explore efficient ultra-wideband radar waveforms and signal processing techniques for achieving high performance radar systems in low-cost hardware. This paper describes the generation of nonlinear constant-amplitude frequency modulated (FM) waveforms with autocorrelation functions that resemble linear FM waveforms that are amplitude-apodized by an arbitrary window function. The principle of stationary phase is used to solve for a time-frequency curve that produces a waveform with a power spectral density (PSD) that is similar to a desired PSD but dependent only on waveform phase. This method is extended to nonlinear (NL) synthetic wideband waveforms (SWWs), wherein an ultra-wideband nonlinear waveform having arbitrary spectral weighting is synthesized from non-uniform stepped-frequency nonlinear frequency modulated (NLFM) sub-pulses. A novel reconstruction algorithm, Non-Uniform Frequency Stitching (NUFS) is presented for obtaining high range resolution performance from such non-uniform nonlinear SWW (NUNL-SWW) waveforms with minimal grating lobe contamination.