A 70 kHz-70 GHz VNA automatic calibration approach with improved performance

A novel VNA automatic calibration structure has been created that improves the performance of the transfer calibration to 70 GHz and down to kHz-scale frequencies. While over-determined methods have been used for years, the presented structure uses a newer switching arrangement to minimize losses and parasitics thus reducing standards proximity issues. Additionally, the use of semi-transmissive reflection standards further helps reduce accuracy loss through the automatic calibration process. Operation of the structure will be presented as will quantification of the standards behavior and analysis of a transfer calibration showing a residual directivity and source match of better than about 45 dB to 70 GHz.