Passive microwave imaging of incoherent sources is often approached in a lensless configuration through array-based interferometric processing. We present an alternative route in the form of a coded aperture realized using a dynamic metasurface. We demonstrate that this device can achieve an estimate of the spectral source distribution from a series of single-port spectral magnitude measurements and complex characterization of the modulation patterns. The image estimation problem is formulated in this case as compressive inversion of a set of standard linear matrix equations. In addition, we demonstrate that a dispersive metasurface design can achieve spectral encoding directly, offering the potential for spectral imaging from frequency-integrated, multiplexed measurements. The microwave dynamic metasurface aperture as an encoding structure is shown to comprise a substantially simplified hardware architecture than that employed in common passive microwave imaging systems. Our proposed technique can facilitate large scale microwave imaging applications that exploit pervasive ambient sources, while similar principles can readily be applied at terahertz, infrared, and optical frequencies.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics