Microwave properties of dielectric and magnetic materials can be obtained non-destructively in a laboratory setting with a free-space focused beam device or an admittance tunnel lined with absorber. However, these systems are far from portable and may be impractical for use in a manufacturing environment. Instead, a portable and rugged microwave sensor is of interest for characterization of larger structures that don’t easily fit within the geometry of a laboratory system.
This paper describes the use of a new microwave probe design that is optimized to interrogate a small area of a material or component and determine reflection or transmission properties in the 2 to 20+ GHz range. This probe is ruggedized for use in harsh environments and is optimized to have a standoff of 25 to 100 mm from the material under test. Additionally, this paper describes the integration of this probe with industrial robots to spatially map the dielectric properties of flat or curved structures. Example measurements are shown of a multilayer structure of dielectric constituents, where one or two-dimensional maps show spatially dependent properties.
