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Tuneable VHF and UHF notch filters for protection against jamming
Thesis (MEng)--Stellenbosch University, 2021.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : Stellenbosch University
2021
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| _version_ | 1867613984041992192 |
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| access_status_str | Open Access |
| author | Fourie, Jack |
| author2 | Meyer, Petrie |
| author_browse | Fourie, Jack Meyer, Petrie |
| author_facet | Meyer, Petrie Fourie, Jack |
| author_sort | Fourie, Jack |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MEng)--Stellenbosch University, 2021. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/123833 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:44:49.127Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2021 |
| publishDateRange | 2021 |
| publishDateSort | 2021 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/123833 Tuneable VHF and UHF notch filters for protection against jamming Fourie, Jack Meyer, Petrie Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering Frequency stability UCTD UHF radio VHF radio Tuning -- Electronic equipment Radio frequency interference -- Protection Thesis (MEng)--Stellenbosch University, 2021. ENGLISH ABSTRACT: A novel narrow-band helical resonator stop-band filter, with PIN-diode based switched frequency states, is presented for the first time. The use of PIN- diodes offers a very low-loss discrete tuning solution, as the ’on’-resistance of typical PIN-diodes can be orders of magnitude lower than that of varactor diodes. Furthermore, PIN-didoes are very well suited to high-power applications. The filter makes use of PIN-diodes to effectively change the length of the helical resonator, and in addition to the favourable characteristics of the PIN- diodes, thereby also implements inductive tuning, which naturally results in a very constant stop-band width. The development of the filter is performed in two stages - one a fixed frequency notch filter, and the next a5-state switched- frequency filter. To compare, a varactor-tuned LC notch filter is also designed, manufactured, and tested. A first p roof-of-concept prototype of the switched helical resonator filter yielded excellent results, with a centre frequency range of 180-450 MHz, notch depths of better than 30 dB over 10 MHz notch band- width, -3 dB notch bandwidths of 35 MHz, very low pass-band insertion loss of better than 1 dB, and much better power handling than the LC counterpart. AFRIKAANSE OPSOMMING: ’n Nuwe nouband heliese resoneerder stopbandfilter, met PIN-diode geskakelde frewkensie toestande, word vir die eerste keer voorgestel. Die gebruik van PIN- diodes maak ’n baie lae-verlies, diskrete frekwensieverstelling moontlik, as ge- volg van die lae ’aan’-weerstand van PIN-diodes, wat tipies grootte-ordes laer kan wees as die van varaktor-diodes. PIN-diodes is ook baie geskik vir hoö- drywing toepassings. Die filter maak gebruik van PIN-diodes om effektief die lengte van ’n heliese resoneerder te verstel, en skep sodoende ’n induktiewe fre- kwensieverstelling. Hierdie aspek, bykomend tot die voordele van PIN-diodes, is baie voordelig vir die skep van amper konstante bandwydte stopbande. Die ontwikkeling van die filter is in twee stappe -een ’ n vaste frekwensie heliese resoneerder stopbandfilter, en d ie volgende ’ n 5 -toestand g eskakelde frekwen- sie filter. Asvergelyking, word ’ n varaktor-verstelbare L C-filter ook ontwerp en getoets. ’n Eerste prototipe van die geskakelde heliese resoneerder filter toon uitstekende werkverrigting, met ’n senterfrekwensieverstelling van 180- 450 MHz, stopband verswakking van groter as 30 dB oor 10 MHz stopband- wydtes, -3 dB stopbandwydtes van 35 MHz, baie lae deurlaatband insetverlies van 1 dB, en beduidend beter drywingshantering as die LC-filter. Masters 2021-11-22T06:38:33Z 2021-12-22T14:24:03Z 2021-11-22T06:38:33Z 2021-12-22T14:24:03Z 2021-12 Thesis http://hdl.handle.net/10019.1/123833 en_ZA Stellenbosch University 143 pages application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Frequency stability UCTD UHF radio VHF radio Tuning -- Electronic equipment Radio frequency interference -- Protection Fourie, Jack Tuneable VHF and UHF notch filters for protection against jamming |
| title | Tuneable VHF and UHF notch filters for protection against jamming |
| title_full | Tuneable VHF and UHF notch filters for protection against jamming |
| title_fullStr | Tuneable VHF and UHF notch filters for protection against jamming |
| title_full_unstemmed | Tuneable VHF and UHF notch filters for protection against jamming |
| title_short | Tuneable VHF and UHF notch filters for protection against jamming |
| title_sort | tuneable vhf and uhf notch filters for protection against jamming |
| topic | Frequency stability UCTD UHF radio VHF radio Tuning -- Electronic equipment Radio frequency interference -- Protection |
| url | http://hdl.handle.net/10019.1/123833 |
| work_keys_str_mv | AT fouriejack tuneablevhfanduhfnotchfiltersforprotectionagainstjamming |