Carbon nanotubes as base material for fabrication of gap waveguide components

• Ridge gap resonator has been fabricated using bundles of vertically aligned carbon nanotubes as a base material.
• 283 μm high bundles of vertically aligned carbon nanotubes grow in 3 min whereas it takes 92–139 min when the structures of same height are fabricated by etching silicon.
• Resources used to fabricate ridge gap resonator using carbon nanotubes structures are cheaper and the process time is shorter resulting in a much lower process cost.

Microfabrication with Si has its benefits but it is time consuming when etching high ratio structures. Previously a ridge gap resonator has been fabricated in Si, with a pin height of 278 μm. In this paper carbon nanotubes, which can grow hundreds of micrometers within minutes are being used as a base material for a high frequency device. It has been implemented on a ridge gap resonator for 220–325 GHz. Carbon nanotubes based structures offer a rapid and low-cost turnover for prototyping. Measurements comparing two carbon nanotubes-based structures to a previously made Si structure and simulations are presented. From these measurements the unloaded Q-value and the loss/mm have been calculated and shows a loss of 0.079 dB/mm and 0.051 dB/mm for the lower frequency range respectively the higher frequency range, indicating that carbon nanotubes can be used for fast and low-cost prototyping of high-frequency devices.