Malhotra, AnkitAnkitMalhotraStagge, PascalPascalStaggeKnopp, TobiasTobiasKnoppBuzug, Thorsten M.Thorsten M.BuzugAhlborg, MandyMandyAhlborg2026-06-102026-06-102026-04-23International Journal on Magnetic Particle Imaging 12 (1): 2604006 (2026)https://hdl.handle.net/11420/63454The magnetic response of superparamagnetic iron oxide nanoparticles (SPIONs) varies significantly during nucle-ation and growth, requiring adaptive signal conditioning to avoid saturation and maintain sensitivity. This work presents the design and experimental characterization of a low-noise variable gain amplifier (VGA) based on the AD603 for this application. The VGA offers a pin-selectable gain range from −10 dB to +30 dB, enabling high gain at early synthesis stages and controlled attenuation at later stages. Performance was evaluated in terms of transient response, gain, phase behavior, and noise characteristics over a frequency range of 1 kHz to 1 MHz. Measurements demonstrate stable gain, limited phase variation, and improved noise performance through parallel amplifier configurations, indicating suitability for low-noise, high-dynamic-range SPIONs measurement systems such as MPS/MPI devices.en2365-903320261Infinite Science Publishinghttps://creativecommons.org/licenses/by/4.0/Technology::610: Medicine, HealthJournal Articlehttps://doi.org/10.15480/882.1729410.18416/IJMPI.2026.260400610.15480/882.17294