Digital Radiometer for Traceable Spectrum Sensing

This paper describes a metrology instrument designed for detecting noise and interference in digital communications. A quadrature detector downconverts in-phase and quadrature channels, which are each digitized at high speed. This architecture makes the upper and lower signal sidebands separable by digital processing, and has spectral resolution that is unprecedented in conventional analog detection. Several considerations for design, system characterization and calibrations are discussed.