Radio propagation modeling and measurement of uneven terrain model

Conventionally, when propagation modeling is conducted for a specific environment, the ground surface is oftentimes treated as a flat one even if the surface profile undulates moderately. This is especially common across various commercial propagation prediction tools, which treat the ground to be a flat surface whenever possible, because doing so will simplify the whole propagation modeling process. However, in cases when the ground surface is not flat in the upfront, special efforts should be made to model the ground surface as it is so that the model can retain the precision results of propagation prediction. In this work, we present a physical representation of terrain irregularities constructed using common materials, acknowledging the electromagnetic limitations of these materials compared to actual ground and building materials. Propagation measurements were conducted at 900 MHz, 2.4 GHz, 5.8 GHz and 24 GHz, and the results are compared against our in-house ray-tracing simulation that has incorporated an integrated scattering factor. The results for 900 MHz are useful for understanding the UHF RFID propagation. Additionally, for all four frequencies, we have further engaged the CST Studio Suite for generating ray-tracing results. The outcome of this work is applicable to places with an uneven terrain, such as a cave. This work also establishes a foundation for future properly scaled models that maintain the relationship between model dimensions and measurement frequencies.