Measuring Extinction and Monostatic Radar Cross-Sections of Low-Scattering Antennas

This abstract describes methods used to experimentally determine the extinction and monostatic radar crosssections of objects as small as we can measure, as used over a frequency band from 6.6 - 15 GHz. This is motivated by our recent design and fabrication of a dipole antenna which is expected to provide little interference to co-polarized incoming waves at frequencies around 10 GHz. We wished to measure how small this interference is at these frequencies as characterized by the extinction cross-section, σ_ext, which is the sum of the scattering and absorption cross-sections. Because this property is difficult to measure accurately for small cross-sections we also measure the monostatic radar cross-section (RCS), σ_mono, which can be more accurately measured down to very low levels. We were able to measure σ_mono down to -70 dBsm, matching the smallest reference object we had, and σ_ext down to about -45 dBsm. We follow on methods previously used for similar measurements [1], and discuss the effects of different analytical techniques.