TY - GEN A1 - Okocha, Jonathan A1 - Andrei, Cristina A1 - Rudolph, Matthias T1 - On the repeatability of low cost varactor—based RF impedance tuners T2 - 2025 55th European Microwave Conference (EuMC) N2 - This paper introduces a concise methodology for assessing the repeatability of low-cost, varactor-based RF impedance tuners by employing a dB-based metric that quantifies how accurately each tuner reproduces a target impedance over repeated cycles. Both blocked and cyclical measurement strategies are used to highlight large impedance transitions near high-reflection states that exacerbate non-idealities. In addition, the method rigorously characterizes issues such as systematic offsets, drift, and hysteresis, common challenges that can impair tuner performance, allowing targeted improvements. Demonstrations with a BST varactor prototype underscore the importance of identifying and quantifying these effects to ensure consistent tuner performance in real-world RF testing environments. KW - RF impedance tuning KW - Tuner repeatability KW - Mechanical tuner KW - Electronic tuners KW - Load-pull KW - Measurement methodology KW - Smith chart tuners KW - dB-based metric KW - Tuner accuracy Y1 - 2025 SN - 978-2-87487-081-1 U6 - https://doi.org/10.23919/EuMC65286.2025.11234977 SP - 683 EP - 686 PB - IEEE CY - Piscataway, NJ ER -