On Band Stitching for Wideband Vector Measurements With Vector Signal Analyzers

—As the bandwidth of radio signals increases signiﬁ- cantly over the evolution of communication systems, the analysis bandwidth of many current instruments becomes insufﬁcient. In this paper, we study analysis bandwidth extension using the so-called band-stitching. Speciﬁcally, we propose a two-step delay estimation method which combines the cross-correlation and an additional reﬁning step to resolve the timing impairment between different sampling branches in post-processing. We verify the method with a sequential measurement setup, using vector signal analyzers (VSAs). The result shows the necessity of conducting the reﬁning step for getting a more accurate delay estimate to successfully recover the original wideband signal. Besides, a good agreement is found between the stitched data and the reference data in terms of the waveforms and error vector magnitude (EVM), which shows the effectiveness and robustness of the proposed calibration method in practice.