Bovine Calf Serum: Broadband Dielectric Properties and an Emulating Phantom

Bovine calf serum (BCS) is often used as a substitute to emulate synovial fluid, a fluid found in the human joints such as the elbow, knee, shoulder, and hip. To date, the dielectric properties of BCS are unknown, in turn limiting the development of RF/microwave solutions to monitor the joint(s). In this work, we report the first measurements of BCS dielectric properties (permittivity and loss tangent) in the 200 MHz to 20 GHz range. In addition, we present a phantom that accurately emulates the frequency-dependent dielectric properties of BCS. An example demonstration matches the BCS dielectric properties from 0.9 GHz to 1.9 GHz with a deviation of less than ±0.6 in relative permittivity and ±0.031 in loss tangent. Our recipe relies on readily available water, sugar (0.35 M), and salt (0.35 M), making the phantom an easy alternative to BCS for conducting RF/microwave experimental studies. By tweaking the sugar and salt content, our phantom can ultimately match the BCS dielectric properties in any desired frequency band.