Wireless Equivalent Circuit Modeling of UHF RFID ICs Using the Common Acceptance Region Method
Heydarzadeh Azar, Ramin (2026)
2026
Master's Programme in Computing Sciences and Electrical Engineering
Informaatioteknologian ja viestinnän tiedekunta - Faculty of Information Technology and Communication Sciences
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Hyväksymispäivämäärä
2026-02-25
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202602242768
https://urn.fi/URN:NBN:fi:tuni-202602242768
Tiivistelmä
Many different industries are using Radio Frequency Identification (RFID) technology widely for tracking and identification purposes. Regarding systems that use passive UHF RFID, the performance of the tag relies heavily on the power transfer efficiency between the antenna and the IC inside the tag. Achieving maximum power transfer requires a perfect matching between the antenna and the complex, non-linear impedance of the IC. However, relying on manufacturer datasheet values for impedance matching is often inaccurate because these values do not account for the parasitic effects introduced during the tag assembly process.
This thesis addresses this problem by developing accurate equivalent circuit models for two specific UHF RFID ICs: the NXP UCODE G2iL, and Impinj Monza R6. A wireless measurement approach combined with electromagnetic simulation was employed to characterize the chips in their fully assembled state. Multiple tag designs were fabricated using chemical etching and milling techniques. We used the Voyantic Tagformance system to take measurements of their performance inside an anechoic chamber, while corresponding simulations were conducted using Ansys HFSS.
A Common Acceptance Region methodology was utilized to determine the optimal resistance and capacitance values that minimized the error between simulated and measured realized gains across all tag designs. The analysis yielded unified equivalent circuit models for each IC: R = 2026 Ω, C = 0.94 pF for G2iL; and R = 1547 Ω, C = 1.17 pF for Monza R6. These models were validated using a separate set of tag designs, showing a strong agreement between the difference between the theoretical read range and the actual measured read range with a relative error of less than 13%.
This thesis addresses this problem by developing accurate equivalent circuit models for two specific UHF RFID ICs: the NXP UCODE G2iL, and Impinj Monza R6. A wireless measurement approach combined with electromagnetic simulation was employed to characterize the chips in their fully assembled state. Multiple tag designs were fabricated using chemical etching and milling techniques. We used the Voyantic Tagformance system to take measurements of their performance inside an anechoic chamber, while corresponding simulations were conducted using Ansys HFSS.
A Common Acceptance Region methodology was utilized to determine the optimal resistance and capacitance values that minimized the error between simulated and measured realized gains across all tag designs. The analysis yielded unified equivalent circuit models for each IC: R = 2026 Ω, C = 0.94 pF for G2iL; and R = 1547 Ω, C = 1.17 pF for Monza R6. These models were validated using a separate set of tag designs, showing a strong agreement between the difference between the theoretical read range and the actual measured read range with a relative error of less than 13%.