Room temperature S-parameter imaging is a radio frequency measurement technique used to determine the material properties of a sample. In this technique, a device called a vector network analyzer (VNA) is used to measure the reflection and transmission coefficients (S-parameters) of the sample over a range of frequencies.

To perform S-parameter imaging, the sample is placed in the near-field of a probing antenna that is connected to the VNA. The VNA then measures the S-parameters of the sample at each frequency in the desired frequency range. This process is repeated at multiple locations on the sample surface to create an image of the material properties across the surface.

The resulting S-parameter image can be used to extract various material properties of the sample, such as its dielectric constant and conductivity. These properties are important in many applications, such as antenna design, electromagnetic compatibility, and microwave circuit design.

One advantage of room temperature S-parameter imaging is that it can be performed without altering the sample or requiring any special preparation, as opposed to other techniques such as scanning electron microscopy. Additionally, the technique is non-destructive, allowing for repeated measurements on the same sample.