An Adaptable Time Domain Gating Implementation with Enhanced Edge Treatment for Facilitating Vector Frequency Domain Data Analyses

The utilization of time domain gating through Fourier analysis, a technique commonly employed in commercial Vector Network Analyzers (VNAs), has become an established practice for data post-processing. Despite its effectiveness, the specific implementation often remains enigmatic, leading to challenges in comprehending measurement uncertainties. Furthermore, once the data has been downloaded to a computer, it is difficult to further process or adjust gating parameters. To address these issues, we have developed a comprehensive library. The library incorporates a range of functions including inverse chirp-Z transform to convert from frequency to time domain, gating operation, and post-gate edge treatment. These functions can be used in a standalone application, or seamlessly integrate into users’ programs, such as Matlab, Python, C#, or others. Our other objective is to offer transparency in the implementation, thereby enabling users to gain a clear understanding of the underlying algorithms and aiding in uncertainty evaluation. In addition to incorporating the conventional “edge renormalization” approach found in commercial VNAs, we introduce a novel method termed Spectrum Extension Edgeless Gating (SEEG). This method involves extending frequency domain data beyond the edges in a physically meaningful manner before applying time domain gating. Numerous applications of measurement attest to the efficacy of the SEEG approach, notably in significantly mitigating edge-related errors while improving measurement accuracy.