Optimization of the Photoconductive Antenna Gap

Terahertz techniques have attracted a lot of attention recently because they not only provide ultra fast data rate for wireless communication systems, but also offer some unique features for a wide range of applications in such as medical imaging, remote sensing and security scanning. The photoconductive antenna is by far the most widely employed device to generate and detect the Terahertz wave. One of the major problems of the antenna is that the generated power (i.e. efficiency) is very low. It was discovered that the output power from antenna is linked the gap of the photoconductive antenna. In this paper, the relationship between the gap and the photoconductive antenna performance is discussed and the optimization gap value can be determined based on the relationship derived in this paper. Simulation results are provided to support and validated the theory.