A Non-Destructive and Simple Setup Method for Dielectric Liquid Characterization in a Wide Frequency Range With Djordjevic-Sarkar Model

This paper introduces a non-destructive and simple setup method for characterizing dielectric liquids over a broad frequency range (up to 30 GHz) using the Djordjevic-Sarkar model. By employing a differential microstrip line and comparing scattering parameters in air-filled and liquid-immersed scenarios, the proposed method achieves precise dielectric constant (DK) and dissipation factor (Df) extraction. 2 Liquid samples (PAO4 and DC-15) were tested using this method. Validation against the cavity resonance method demonstrates a strong agreement for the extracted DK values, with a relative error of less than 1.5 %, indicating high accuracy. However, the method is less sensitive to Df, particularly for low-loss dielectrics, with a relative error of 67 % at the cavity resonance frequency. Despite this limitation, the technique provides a practical approach for wideband dielectric characterization, particularly for applications in immersion cooling and high-frequency electronic systems.