  A frequency-diverse computational imaging system synthesized using
three-dimensional (3D) printed frequency-diverse metasurface antennas is
demonstrated. The 3D fabrication of the antennas is achieved using a
combination of PolyLactic Acid (PLA) polymer material and conductive polymer
material (Electrifi), circumventing the requirement for expensive and
time-consuming conventional fabrication techniques, such as machine milling,
photolithography and laser-etching. Using the 3D printed frequency- diverse
metasurface antennas, a composite aperture is designed and simulated for
imaging in the K-band frequency regime (17.5-26.5 GHz). The frequency-diverse
system is capable of imaging by means of a simple frequency-sweep in an-all
electronic manner, avoiding mechanical scanning and active circuit components.
Using the synthesized system, microwave imaging of objects is achieved at the
diffraction limit. It is also demonstrated that the conductivity of the
Electrifi polymer material significantly affects the performance of the 3D
printed antennas and therefore is a critical factor governing the fidelity of
the reconstructed images.
