Terahertz photonic transmitters with a high-gain open-ended rampart slot array antenna

We propose to integrate a high-gain open-ended rampart slot array antenna in our edge-coupled terahertz (THz) photonic transmitters. By locating the open circuits at the end of each quarter-wavelength slot antenna, the reflected terahertz wave can constructively interference with the input wave and hence produce higher gain. In addition, the folded feeding networks turn more propagating waves into the effective radiating segments rather than the dispersive surface waves. A THz resonant cavity is also designed under our monolithic THz-wave circuits. A 300-nm gold layer is coated below the substrate to serve as a reflecting mirror to reflect back the THz waves to the antenna. The resonant cavity design not only provides a robust base for post device process but also greatly enhances the gain of antenna. With the design of openended rampart slot array antenna and THz resonant cavity, we demonstrate that the gain of antenna can reach 8-9 dBi.