Comparative study of stripline dipole antenna on semiinfinite and lens substrates at terahertz frequency

The input impedance and radiation characteristics of a stripline dipole antenna on different substrate schemes are presented. Two radiation environments, a semi-infinite galliumarsenide substrate (hereafter called a “semi-infinite substrate”) and a thin gallium-arsenide substrate backed by a silicon lens (hereafter a “lens substrate”), were examined, and the antenna performances were analyzed in a broad frequency range up to 5.0 THz. The semi-infinite substrate approach is useful in the initial investigation of the antenna characteristic itself while saving a significant amount of computational time. The study provides good guidelines for the design of a terahertz photoconductive antenna in that the antenna effect and the lens substrate effect can be individually characterized and optimized for the best possible performance.