Characterization of high impedance of multilayer coplanar waveguide transmission line design for integration with nanodevices

Abstract

Terahertz technology has recently attracted the attention of the researchers due to its wide range of applications such as security and military, biomedicine and health care, astronomy and biology. There are many scrutinized research papers among the terahertz applications with nanodevices such as self-switching devices. They need monolithic microwave integrated circuits for integration. It is evident that the system impedance of transmission lines is 50 Ω. However, the main limitation of self-switching diodes is high level of impedance in megaohms which is a huge value and is not so easy to implement. Paper focuses on the design and simulation of the coplanar waveguide transmission line structures with higher impedance by applying multilayer technology for the integration with self-switching diodes. Using multilayer technology in design allows wide range of impedances. Two approaches have been targeted such that meets all the requirements of integration with nanodevice. First approach is a widening the gap of the polyimide dielectric layers used in the fabrication of these components. Several design structures have been considered such as positioning the location of signal and grounds contacts with respect to the position of the dielectric layers. As the result the highest characteristic impedance of about 90 Ω was achieved at operating frequency of 110 GHz. Secondly, novel coplanar waveguide transmission line structure was investigated where the V – shape structure was joined with the signal elevated structure. The terahertz application research may effect on high data transmission rate of no less than 10 GBit/s and thereby in increase of traffic volume.