A Dielectric Loaded Resonator for the Measurement of the Complex Permittivity of Dielectric Substrates

A new configuration of dielectric-loaded resonator (DR), particularly versatile for the complex permittivity measurement of substrates for microwave circuits, even in the presence of back metal plates, is shown here. To test this technique in a wide interval of the values of the complex permittivity, the versatility of 3-D printing is exploited to print samples with different densities, thus artificially changing the effective permittivity in the interval (1.7-3.1) for the real part and (0.02-0.06) for the imaginary part. The designed resonator, tuned at similar to 12 GHz, is experimentally validated by the comparison of measurements obtained on these samples with a split ring resonator (SRR) and standard transmission/reflection waveguide methods. Then, the versatility of the designed resonator is shown in the characterization of FR4-fiberglass and Kapton polyimide samples.

Automated summary

A new configuration of dielectric-loaded resonator is introduced for the measurement of substrates' complex permittivity in microwave circuits, even in the presence of back metal plates. 3-D printing is utilized to create samples with different densities, allowing for the artificial manipulation of effective permittivity. The performance of the designed resonator is validated experimentally and its versatility is demonstrated in the characterization of FR4-fiberglass and Kapton polyimide samples.