Low-cost SDR-based Reader for Chipless Sensor Tag

Vector Network Analyzers (VNA) is known as a common tool for reading radio frequency (RF) responses from chipless sensor tags. However, it is not practical to use a VNA for mobile inspection due to its bulkiness and high cost. In this study, we demonstrate using a low-cost software-defined radio (SDR) platform, the Adalm Pluto, to capture RF responses from a chipless sensor tag. We developed an algorithm for SDR to acquire RF responses from a chipless moisture sensor tag in frequency range of 2 GHz to 3 GHz. The spectral responses obtained by both SDR and VNA are compared through experiments involving varying moisture levels in material. Our findings show that, as an alternative to VNAs, the Adalm Pluto proves to be an effective tool for acquiring chipless tag responses with satisfactory accuracy.