Towards the design of an imaging setup using photoconductive antennas

Abstract

Photoconductive antennas (PCAs) are an interesting candidate for imaging systems due to their relatively low cost and ability to provide a bandwidth of hundreds of GHz. The large bandwidth of PCAs allows for sub-millimeter depth resolution. However, the often-used single-element PCAs are intrinsically limited in the amount of power they can radiate due to several saturation effects. To increase the radiated power, array-based PCAs have been introduced by the scientific community. In the first part of this work, the impact of adding a leaky wave cavity to a lens-coupled Photoconductive Connected Array (PCCA) is studied. The fields radiated by the lens are found using a Physical Optics method, and the effect of the lens on the energy spectra of the radiated fields is quantified. Measurements of two fabricated PCCA geometries are compared with simulations. In the second part of this work, an imaging setup is designed to benchmark several state-of-the-art PCAs. Subsequently, the coupling between two PCAs in an imaging setup is studied via a field-matching formalism.