Optimization of 0.34 THz log-periodic antenna for superconducting terahertz emitter

A log-periodic antenna for intrinsic Josephson junction (IJJ) terahertz (THz) emitter is investigated. The IJJs are designed as a microbridge fabricated with misaligned superconducting thin film deposited on the MgO substrate. By adjusting the dimension of the substrate in the electromagnetic simulation, an optimized structure is obtained for the IJJ THz emitter at 0.34 THz. Moreover, a hemispherical silicon lens is added for improving the log-periodic antenna gain and beam directivity.