SCIENTIA SINICA Informationis, Volume 47 , Issue 1 : 73-85(2017) https://doi.org/10.1360/N112015-00301

Nonlinearity correction of low cost UWB X-band LFMCW-SAR source}{Nonlinearity correction of low cost UWB X-band LFMCW-SAR source

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  • ReceivedJan 22, 2016
  • AcceptedFeb 26, 2016
  • PublishedOct 25, 2016


For the application of near range imaging with wideband LFMCW-SAR imaging, this paper presents a scheme to generate X-band signal with 5.1 GHz bandwidth based on a YIG oscillator. This method has a simple structure and low cost. However, it introduces a certain degree of nonlinearity, resulting in range-resolution degradation. Conventional nonlinearity estimation methods do not work well or fail with low SINR. To solve this problem, a two-step high order ambiguity function method, based on wide and narrow band filters, is used to estimate the nonlinear error. The nonlinearity is corrected by resampling. In the end, the nonlinear correction algorithm is validated with simulation data, delay-line data, and rail-SAR data.

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