ABSTRACT
This chapter focuses on the aspects of metamaterials (MTMs) and develops a conceptual foundation for a unique class of radio-analog signal processing (R-ASP) systems: real-time spectrum analyzers (RTSAs). It introduces R-ASP and its core signal processing component called phaser. The chapter discusses two commonly used spatial phasers: a diffraction grating and leaky-wave antenna (LWA). It also presents 1D/2D RTSAs using LWAs and discusses their typical system features and characteristics. R-ASP might be defined as the manipulation of signals in their pristine analog form and in real time to realize specific operations enabling microwave or mm-wave and terahertz applications. The phasers are fundamentally of two types: temporal phaser and spatial phaser. Typical implementations of an LWA are in slot-waveguides and printed metamaterial transmission line structures. The joint time-frequency representation is a highly informative tool for real-time spectrum analysis. Metasurfaces generally consist of non-uniform spatial arrays of sub wavelength scattering particles.
