Apparatus and method for measuring and monitoring complex permitttivity of materials

A device and a process for measuring and monitoring complex permittivity of materials for quality control in-situ and in the materials measurement laboratory.

Material is kept as an overlay on microstrip, asymmetric stripline, co-planar waveguide, patch or disc resonator (Resonant frequency 0.5 to 20 GHz). This method of measuring relative permittivity () and dissipation factor or loss tangent (tan ) of circuit board substrates, ceramic substrates, ceramic and any insulating or low conductivity bulk materials of any thickness under microstrip overlay conditions

Measurements are made by measuring resonance of a length of a planar transmission line are as follows:

•    Microstrip or Asymmetric stripline open ended direct coupled resonator.
•    Microstrip or asymmetric strip line gap coupled resonator.
•    Microstrip or asymmetric stripline ring resonator.
•    Microstrip or asymmetric strip line patch antenna
•    Microstrip or asymmetric strip line rejection filter.
•    Co-planar waveguide resonators using direct or gap coupling.