Low-cost high-resolution handheld VNA using RF interferometry

A low-cost vector network analyzer (VNA) using a novel measurement technique is presented in this paper. The phase measurement is based on RF interferometry. A multiple output direct digital synthesizer (DDS) and low-cost scalar detectors are used for high-resolution phase measurements. A hardware example working up to a frequency of 150MHz and having board dimensions of only 10 cm × 6 cm is introduced. The accuracy is demonstrated by measurements and compared to a commercially available VNA using heterodyne detectors.