Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Thesis (MScEng (Electrical and Electronic Engineering))--Stellenbosch University, 2008.
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Stellenbosch : Stellenbosch University
2008
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613893457608704 |
|---|---|
| access_status_str | Open Access |
| author | Vermaak, Elrien |
| author2 | De Swardt, J. B. |
| author_browse | De Swardt, J. B. Vermaak, Elrien |
| author_facet | De Swardt, J. B. Vermaak, Elrien |
| author_sort | Vermaak, Elrien |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MScEng (Electrical and Electronic Engineering))--Stellenbosch University, 2008. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/2073 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:43:23.129Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2008 |
| publishDateRange | 2008 |
| publishDateSort | 2008 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/2073 Development of a low phase noise microwave voltage controlled oscillator Vermaak, Elrien De Swardt, J. B. Van der Walt, P. W. Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. Cavity resonator Microwave Phase noise Theses -- Electronic engineering Dissertations -- Electronic engineering Voltage-controlled oscillators Oscillators, Microwave -- Design and construction Thesis (MScEng (Electrical and Electronic Engineering))--Stellenbosch University, 2008. The topic for this project entailed the development of a ‘Low Phase Noise – Microwave – Voltage Controlled Oscillator’ for use in radar applications. First of all, a low phase noise oscillator was designed. In order to minimise the phase noise of the oscillator, a high-Q, transmission line – cavity resonator was developed. By derivation it was confirmed that an optimal point for minimum phase noise does exist. The latter was done by evaluating the equation for the output power spectral density of the oscillator phase noise (as defined by Leeson’s Phase Noise Model) at its minimum point. Subsequently, the amount of power that needed to be dissipated inside the resonator could be compared to that dissipated in the source and the load. This identified the amount of coupling to the resonator allowed, assuring minimum phase noise. Since a specific amount of coupling to the resonator was sought after, it had to be practically feasible. Therefore several coupling techniques were investigated to ensure the most user-friendly way of tuning the amount of coupling to the resonator, and hence easily reaching the optimum point of minimum phase noise. After successful completion of the low phase noise oscillator design, it was modified for voltage controlled oscillator (VCO) use by means of variable tuning diodes. These varactor diodes were situated inside the cavity of the resonator. Again the most suitable position to place the diodes had to be determined. The latter was done through considerably detailed transmission line theory; where the loaded Q, the tuning bandwidth (amount of change in frequency reached) and the amount of power dissipated inside the resonator were measured against each other. By means of the necessary phase noise measurements, it was confirmed that in order to keep the phase noise to a minimum, the tuning bandwidth had to be kept small and the amount of power dissipated inside the resonator maximised; so as to keep the overall loaded Q-value of the circuit as high as possible. 2008-11-25T06:39:37Z 2010-06-01T08:40:00Z 2008-11-25T06:39:37Z 2010-06-01T08:40:00Z 2008-12 Thesis http://hdl.handle.net/10019.1/2073 en Stellenbosch University application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Cavity resonator Microwave Phase noise Theses -- Electronic engineering Dissertations -- Electronic engineering Voltage-controlled oscillators Oscillators, Microwave -- Design and construction Vermaak, Elrien Development of a low phase noise microwave voltage controlled oscillator |
| title | Development of a low phase noise microwave voltage controlled oscillator |
| title_full | Development of a low phase noise microwave voltage controlled oscillator |
| title_fullStr | Development of a low phase noise microwave voltage controlled oscillator |
| title_full_unstemmed | Development of a low phase noise microwave voltage controlled oscillator |
| title_short | Development of a low phase noise microwave voltage controlled oscillator |
| title_sort | development of a low phase noise microwave voltage controlled oscillator |
| topic | Cavity resonator Microwave Phase noise Theses -- Electronic engineering Dissertations -- Electronic engineering Voltage-controlled oscillators Oscillators, Microwave -- Design and construction |
| url | http://hdl.handle.net/10019.1/2073 |
| work_keys_str_mv | AT vermaakelrien developmentofalowphasenoisemicrowavevoltagecontrolledoscillator |