Microwave (1.7–2.6 GHz) characterization of hydroxylapatite and oxalate using rectangular waveguide

Electromagnetic properties of hydroxylapatite and oxalate powders are characterized over 1.7-2.6 GHz using a WR-430 rectangular waveguide. The effective dielectric constant and loss tangent of both compounds are derived from the measured S parameters. Effective medium theory is then applied to extract the intrinsic property of each compound. The extracted intrinsic dielectric constants are 3.37 and 2.17 for hydroxylapatite and oxalate, respectively. While the loss tangent for the former is from 0.04 to 0.07, and for the latter is from 0.02 to 0.026. The characterization results may be useful for early stage breast cancer diagnosis via microwave related modalities.