Sensitivity Analysis of Terahertz Horn Antennas
| dc.contributor.author | George Koj, Andre | |
| dc.contributor.department | Chalmers tekniska högskola / Institutionen för mikroteknologi och nanovetenskap (MC2) | sv |
| dc.contributor.department | Chalmers University of Technology / Department of Microtechnology and Nanoscience (MC2) | en |
| dc.contributor.examiner | Stake, Jan | |
| dc.contributor.supervisor | Stake, Jan | |
| dc.contributor.supervisor | Jayasankar, Divya | |
| dc.date.accessioned | 2023-07-06T14:09:09Z | |
| dc.date.available | 2023-07-06T14:09:09Z | |
| dc.date.issued | 2023 | |
| dc.date.submitted | 2023 | |
| dc.description.abstract | Horn antennas are commonly integrated with waveguide components for terahertz applications. Typically, the antenna structure is milled with the waveguide feed in two metal halves, split along the E-plane, and clamped to form the horn antenna. However, misalignment between two split-blocks due to machining tolerances will degrade the coupling to a free-space fundamental Gaussian mode (Gaussicity). Especially at supra-terahertz frequencies (>3 THz), the tolerances can be a few per cent relative to the wavelength and radically degrade the optical coupling. This master thesis theoretically investigates the split-block misalignment’s effect on a diagonal horn antenna, validated using a scaled experiment at 360 GHz. Moreover, the effect of misalignment is investigated for diagonal-spline and pyramidal horns to find a more robust alternative. The analytical investigation found that an E-plane misalignment leads to a phase and amplitude shift between the TE10 and TE01 modes at the aperture of a diagonal horn, decreasing the Gaussicity. To verify the theoretical investigation, a diagonal horn is machined in split blocks with three different alignment cases and characterised using a WM-570 near-field measurement system. Finally, full-wave electromagnetic simulations of a diagonal, diagonal-spline and pyramidal horn at 360, 415 and 470 GHz are performed and compared for different alignment cases. The measured radiation pattern of a diagonal horn agrees with the analytical and simulated results. A 2-dB decrease in Gaussicity is observed for a misalignment of 6% relative to the wavelength. Furthermore, based on simulated results, a diagonal spline horn has a Gaussicity of 96% and deteriorates less with misalignment than a diagonal horn. In addition, a simple pyramidal horn, with a Gaussicity of 88%, is the least sensitive to misalignment due to the single-mode operation. A diagonal horn is susceptible to alignment errors and, therefore, is concluded to be less suitable as an E-plane split horn for wavelengths where the alignment tolerance is significant. In contrast, the pyramidal or diagonal-spline horns are more robust against E-plane misalignment errors. | |
| dc.identifier.uri | http://hdl.handle.net/20.500.12380/306600 | |
| dc.language.iso | eng | |
| dc.setspec.uppsok | PhysicsChemistryMaths | |
| dc.subject | Far-infrared | |
| dc.subject | Gaussicity | |
| dc.subject | Horn antennas | |
| dc.subject | Terahertz technology | |
| dc.title | Sensitivity Analysis of Terahertz Horn Antennas | |
| dc.type.degree | Examensarbete för masterexamen | sv |
| dc.type.degree | Master's Thesis | en |
| dc.type.uppsok | H | |
| local.programme | Wireless, photonics and space engineering (MPWPS), MSc |