The performance of carbon nanotubes-polymer composites over the millimetre wave frequency band
Recently CNTs have emerged as a very promising way to develop interconnects lines which solve the limitations of transportation capacity and losses associated with the other metal lines in electronic circuits. Signal losses and scattering associated with interconnects are a significant concern for RF and microwave engineers, particularly at high frequency transmission.
CNT-based interconnects are very desirable to be integrated in the electronic components at the giga and terahertz regimes where the high transmission characteristics are desirable. This project will open the door for many potential applications in large area electronics and microwave applications.
Aims and objectives
The project consists of CNT-polymer composites characterisation and testing the performance of these composites in practical RF applications such as antennas.
The samples characterised consisted of CVD grown multiwalled CNTs (average length 1.5 µm, average diameter 9.5 nm) mixed with polymethyl methacrylate (PMMA) to produce composites with 10 wt.% CNT loading. The composites were screen printed unto alumina substrate to fabricate coplanar waveguides (CPW) of several millimeters in length. The scattering or S-parameters of our CPW structures were measured using an HP 8510C vector network analyzer (VNA) connected to a wafer-probing station.
Postgraduate Research Student
Professor Malgorzata Jakubowska, Faculty of Mechatronics, Warsaw University of Technology, Warsaw, Poland.
Ali H. Alshehri, Malgorzata Jakubowska, Marcin Sloma, Michal Horaczek, Diana Rudka, Charles Free and J. David Carey; ‘Performance of Carbon Nanotube-Polymer Composites at Frequencies up to 220 GHz.’ Submitted.
We have characterized the high frequency behaviour of CNT-PMMA composite materials up to 220 GHz. The results have shown decreasing in signal losses with increasing frequency and we interpreted the role played by the capacitive coupling between the nanotubes in determining the high frequency conduction in these CNT composites. The next step in our project is to measure the performance of flexible microstrip patch antennas made from these composites.