Validation of Backscatter Link Budget Simulations with Measurements at 915 MHz and 2.4 GHz

The application of backscatter communications is expanding from Radio Frequency Identification (RFID) to ultra-low power connectivity solution for Internet of Things (IoT). Unlike typical short range monostatic (transmitter and receiver are collocated at the reader) RFID applications, the IoT aims for long-range and bistatic (transmitter and receiver are dislocated) applications. This paper validates the bistatic dislocated Backscatter Communication link budget calculation with the measured results at 915 MHz and 2.4 GHz frequencies using RFID and Long Range (LoRAN) technologies in an outdoor and an indoor environment, respectively. It is recommended in this paper that an appropriate Slow Fading Margin (SFM) needs to be included in the backscatter link budget for large TX and RX separation. However, for smaller distances between the RX and backscatter device, only a fast fading margin should be sufficient with reasonable root mean square error. The post analysis of the simulation data revealed a closed match between the simulated and the measured results at both considered frequencies and technologies. It is also acquired that the proposed link budget calculation equation is independent of technology, and is valid for both RFID and LoRAN technology, given that the correct values of the relevant parameters are appropriately included in the link budget calculation.