Dr Chris Preddy
About
My research project
Multi-functional carbon fibre composites for radio frequency applicationsAn investigation into novel techniques for broadband electromagnetic characterisation of carbon fibre (CF). The eventual objectives of this work are to investigate novel applications of CF in radio frequency (RF) circuit design, such as the integration of novel antennas or transmission lines, and targeted improvement of CF electromagnetic properties by modifying the material system.
An investigation into novel techniques for broadband electromagnetic characterisation of carbon fibre (CF). The eventual objectives of this work are to investigate novel applications of CF in radio frequency (RF) circuit design, such as the integration of novel antennas or transmission lines, and targeted improvement of CF electromagnetic properties by modifying the material system.
Publications
This paper presents the extraction of the complex propagation constant from carbon fiber reinforced plastic (CFRP) transmission lines up to 5 GHz. A test-fixture is designed and fabricated to obtain the propagation constant using a line-line extraction method. Use of this method reduces the required number of fabricated transmission lines compared to calibration algorithms such as TRL. Comparison of the extracted propagation constant with simulation data indicates CFRP conductivity of 1.0 - 1.5 x 10^4 S/m.
A carbon fiber microstrip patch antenna is presented, constructed entirely from fiber-reinforced plastic materials, and fabricated directly into carbon-fiber-reinforced plastic (CFRP) composites as part of the composite manufacturing process. Fabrication of antennas as part of the composite manufacturing process provides numerous benefits, such as conformation to complex curvatures, reduced weight, and reduced aerodynamic impact. Modification of the localized conductivity of the carbon fiber using materials such as copper meshes is shown to improve the gain of the antenna by as much as 5 dB, while also improving the interlaminar shear strength of the composite by 22%.