Walker, George William
(2016)
Design and Analysis of the Onsala 4mm Receiver and
other Antenna Configurations for Millimetre Wave
Astronomy.
Masters thesis, National University of Ireland Maynooth.
Abstract
This thesis outlines several different topics associated with the design and analysis
of millimetre and submillimetre systems. A major topic is the design, analysis and
verification of a 4 mm receiver for the 20 m telescope at Onsala Space Observatory,
Onsala, Sweden. The 4mmreceiverwas designed to be installed parallel to the existing
3 mm channel to target new science at that longer wavelength. Gaussian beam
mode analysis was used to produce the fundamental optical design. This is computationally
efficient, and provides all critical beam characterization through the optical
train within the paraxial limit. The design was analysed more accurately with
physical optics, using GRASP, a commercial software package developed by TICRA.
Following the manufacture of the system, experimental verification was performed
at Onsala Space Observatory. Measurements of the beam were compared with simulations
to verify the operation at 69 GHz.
In addition to this, an investigation was carried out into the development of lens
antennae fed by planar antennae with good beam characteristics, as an alternative
to horn antennae in the W band. A variety of patch designs were considered, with
the effect of a lens placed in front of them. This adds the required directionality to
the beam to launch or receive signals efficiently. CST Microwave studio was used
for this investigation.
Finally, the behaviour of absorbing bolometer detectors housed in waveguide cavities
was examined, in particular the effects of varying the absorber and input waveguide
position for a number of different cavity geometries. The goal was to analyse
the effect of these parameters on the optical coupling: how much incident radiation
was absorbed in a thin absorbing layer of tantulum associated with a TES detector.
This work was directed towards the SAFARI instrument for proposed SPICA missions.
The analysis tool was CSTMicrowave Studio.
| Item Type: |
Thesis
(Masters)
|
| Keywords: |
Design; Analysis; Onsala 4mm Receiver; Antenna; Configurations; Millimetre Wave Astronomy; |
| Academic Unit: |
Faculty of Science and Engineering > Experimental Physics |
| Item ID: |
8768 |
| Depositing User: |
IR eTheses
|
| Date Deposited: |
07 Sep 2017 11:12 |
| URI: |
|
| Use Licence: |
This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available
here |
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