3-D Printed microwave and tetrahertz passive components

This thesis presents the design of microwave and terahertz filters, fabricated using different types of 3-D printing technology. The work demonstrates the potential of using 3-D printing in the fabrication of microwave and terahertz passive components. The first project introduces a compact coaxial cavity resonator filter which was fabricated using stereolithography 3 D printing process. The size and volume of this filter reduced by almost half, by fitting one resonator inside another resonator. This filter is ideal for fabrication by 3 D printing, as such a complex structure cannot be made easily by other methods. This project demonstrates the advantage of using 3-D printing in fabrication of components with complex structures. The second project introduces three waveguide bandpass filters operating at centre frequency of 90 GHz, which were fabricated using the micro laser sintering process. The filters were the highest frequency metal 3-D printed filters reported at the time of publication. The third project introduces two waveguide filters operating at centre frequency of 180 GHz, which were also fabricated using the micro laser sintering process. These are the world highest frequency waveguide filters fabricated by a metal 3-D printing process. The capability of reproducibility of the micro laser sintering process is also discussed in this thesis. The fourth project introduces a hybrid coaxial bandpass filter with two symmetrical transmission zeros, which was fabricated using stereolithography 3-D printing process. In this project the main-line couplings and input/ output coupling were realized using PCB lines, the idea of using PCB lines instead of coupling irises or probes is to allow different topologies to be designed easily by altering the PCB layout. Finally, the fifth project introduces a terahertz waveguide bandpass filter with embedded H plane waveguide bends. This filter is being fabricated using 3-D screen printing

Research data supporting the publication “High-Q 100 GHz Photonic Crystal Resonator Fabricated from a Cyclic Olefin Copolymer”

Measured and simulated data supporting the publication “High-Q 100 GHz Photonic Crystal Resonator Fabricated from a Cyclic Olefin Copolymer” is provided. The S-parameter measurements were performed using a Keysight PNA-X N5247B vector network analyzer with Keysight N5295AX03 frequency extension modules and coaxial to waveguide adaptors. Full-wave electromagnetic simulations were performed using the finite-element method (FEM) solver in CST Microwave Studio

Zero-bias Schottky Diode Power Detector for D-band

The D-band (110 - 170 GHz) waveguide-based zero-bias Schottky diode (ZBD) power detector is reported. The design aims to get high responsivity across the band. The circuit is fabricated on a 50 μm thick quartz substrate. A 3D model and spice model of a commercially available zero-bias Schottky diode are used in the design. The detector achieves the average responsivities of nearly 5000 V/W and a minimum of 1900 V/W at higher frequencies. The detector circuit is housed in a gold-plated metallic block for measurements.</p