Moving into higher frequencies, in occurrence withmodern applications, poses the issue of higher attenuation ofelectromagnetic waves, which in turn demand more directiveantennas. This paper proposes a directive antenna designoperating at 30GHz based on leaky-wave technology. Themodel consists of two main components. Firstly, a corrugatedparallel plate waveguide serves the purpose of controlling thepropagation of electromagnetic waves, in particular the guidedwavelength. Secondly, an array of continuous transverse stubsare implemented in the parallel plate waveguide, which allowsfor radiation into free space and gives a directive beam due tothe array configuration. Dispersive properties of the waveguideare studied to select appropriate dimensions for the corrugationsand optimization of the transverse stub dimensions is performedby a unit cell parameter analysis. The proposed design producepencil beam radiation in the broadside direction with a gain of24:5 dBi and a 􀀀3dB relative bandwidth of 8:8% and anaperture efficiency of 79%. / Att gå upp i frekvens för att möta krav sattaav moderna tillämpningar för med sig problemet med högreattenuering av elektromagnetiska vågor. Detta sätter i sin turkrav på mer riktade antenner för att kompensera för förlusterna.I rapporten presenteras en riktad läckande-vågsantenn för30GHz. Modellen består av två huvudsakliga komponenter.Först en korrugerad parallellplåts-vågledare, vars syfte är attkontrollera hur vågen propagerar, särskilt med avseende påvåglängd. Sedan en serie med transversella öppningar som tillåterutstrålning, där seriens utformning ger upphov till en direktivstråle. Dimensioner bestäms genom dispersionsanalys av denkorrugerade vågledaren och optimering av den strålande enhetscellensker genom en parameterstudie. Den föreslagna modellenproducerar en riktad stråle med antennvinsten 24:5 dBi, relativabandbredden 8:8% och apertureffektiviteten 79%. / Kandidatexjobb i elektroteknik 2021, KTH, Stockholm

Abstract The focus of this thesis is to study direction of arrival (DoA) estimation algorithms for reconfigurable leaky-wave antennas and advanced antenna arrays. Directional antennas can greatly improve the spectrum reuse, interference avoidance, and object and people localization. DoA estimation algorithms have also been shown to be useful for applications such as positioning for user tracking and location-based services in wireless local area networks (WLANs). The main goal is to develop novel DoA estimation algorithms for both advanced antenna arrays and composite right/left-handed (CRLH) leaky-wave antennas (LWAs). The thesis introduces novel modifications to existing DoA estimation algorithms and shows how these can be modified for real-time DoA estimation using both antenna types. Three modified DoA estimation algorithms for CRLH-LWAs are presented: 1) modified multiple signal classification (MUSIC), 2) power pattern cross-correlation (PPCC), and 3) adjacent power pattern ratio (APPR). Additionally, the APPR algorithm is also applied to advanced antenna arrays. The thesis also presents improvements to the modified MUSIC and APPR algorithms. The complexity of the algorithms is reduced by selecting a smaller number of received signals from different directions. The results show that the selection of the radiation patterns is very important and that the proposed algorithms can successfully estimate the DoA, even in a real-world environment. Based on the results, this thesis provides a good starting point for future research of DoA estimation algorithms to enhance the performance of future-generation wireless networks and the accuracy of localization. / Tiivistelmä Tässä väitöskirjassa tutkitaan suunnanestimointialgoritmeja uudelleen konfiguroituville vuotoaaltoantenneille (LWA, leaky wave antenna) ja kehittyneille antenniryhmille. Suuntaavilla antenneilla voidaan parantaa huomattavasti spektrin uudelleen käyttöä ja esineiden ja ihmisten sijaintipaikannusta sekä pienentää häiriöitä. Suunnanestimointialgoritmit ovat myös osoittautuneet hyödylliseksi esimerkiksi seuranta- ja sijaintipaikannuspalvelusovelluksille langattomissa lähiverkoissa. Työn päätavoite on kehittää uusia suunnanestimointialgoritmeja sekä kehittyneille antenniryhmille että vuotoaaltoantenneille (composite right/left-handed (CRLH) LWA). Työssä osoitetaan, miten olemassa olevia suunnanestimointialgoritmeja voidaan muokata uudella tavalla, jotta ne soveltuisivat molemmille antennityypeille reaaliaikaiseen suunnanestimointiin. Vuotoaaltoantennille on kehitetty kolme erilaista suunnanestimointialgoritmia: 1) muunneltu MUSIC- (multiple signal classification), 2) säteilykyvioiden tehojen ristikorrelaatio- (PPCC, power pattern cross correlation) ja 3) vierekkäisten säteilykuvioiden tehosuhdealgoritmi (APPR, adjacent power pattern ratio). APPR-algoritmia on myös käytetty kehittyneelle antenniryhmälle. Työssä esitetään myös parannuksia muunnelluille MUSIC- ja APPR-algoritmeille. Algoritmien kompleksisuutta voidaan pienentää valitsemalla vähemmän vastaanotettuja signaaleja. Tulokset osoittavat, että signaalien valinta on hyvin tärkeää ja ehdotetut algoritmit estimoivat onnistuneesti saapuvan signaalin suunnan todellisessa mittausympäristössä. Yhteenvetona voidaan sanoa, että tämä väitöstyö on hyvä lähtökohta suunnanestimointialgoritmitutkimukselle, jonka tavoitteena on parantaa tulevien sukupolvien langattomien verkkojen suorituskykyä ja paikannuksen tarkkuutta.

South Africa has among the highest rates of physical and sexual violence against women in the world. Research indicates that understanding the causality of domestic violence is very complex and the measurement of risk factors are deemed challenging. Yet, it is important to understand and identify the risk factors associated with domestic violence to effectively prevent it. This phenomenological research study aimed to investigate the lived experiences of female domestic violence victims and sought to identify risk factors (e.g. alcohol and drug abuse, violence in the family of origin, personality factors, cultural differences, socio-economic factors, and the impact of pregnancy) that may have contributed to the occurrence of domestic violence in their intimate relationships .The participants were selected based on purposive and convenience sampling and also their willingness to participate. The sample consisted of six participants between the ages of 18 – 45 years old, residing in Tshwane, South Africa. The data were obtained through semi-structured interviews. A qualitative methodological design was used to collect and explore information about the participants’ personal experiences with domestic violence. Hycner’s explicitation process was employed to identify the four main themes, namely the participants’ experience of domestic violence; socio economic factors; cultural differences, and domestic violence during pregnancy. Each main theme was comprised of sub-themes. The findings of this study differed slightly in comparison with the existing body of literature that highlight substance abuse as one of the highest risk factors for the occurrence of domestic violence in intimate relationships. In this study, other risk factors such as pregnancy and socio-economic factors played a much bigger role than substance abuse as the key risk factors that contribute to the occurrence of domestic violence. / INingizimu Afrika ingenye yamazwe omhlaba anamazinga aphezulu odlame nokuhlukunyezwa kwabesimame ngokocansi. Ucwaningo lubonisa ukuthi ukuqondisisa izimbangela zodlame lwasekhaya yinto eyisixakaxaka ukuyiqondisisa kanti futhi kuyinselele ukukala izinto ezinobungozi kwabesimame. Kodwa ngisho noma kunjalo, kubalulekile ukuqondisisa kanye nokwazi izinto ezinobungozi ezihambisana nodlame lwasekhaya ukuze lukwazi ukuvinjelwa. Lolu cwaningo oluhlaziya ngaphandle kokuthatha uhlangothi, lunenhloso yokuphenyisisa indlela abantu besimame abangamaxhoba odlame abalubona nolubaphatha ngayo udlame lwasekhaya kanye nokubheka izinto ezinobungozi (ezifana nokusetshenziswa kabi kotshwala nezidakamizwa, udlame emakhaya okuqala abahlukumezi, izinto eziqondene nomuntu siqu, umehluko kwezamasiko, eziphathelene nomnotho nabantu kanye nomphumela ekukhulelweni), okungaba yizinto ezinomthelela kudlame lwasekhaya ebudlelwananeni basekhaya. Abantu ababambe iqhaza kucwaningo bakhethwe ngokulandela isampuli enenhloso yokukhetha abathile abazohlangabezana nenhloso yocwaningo kanye nokuzimisela kwabo ukubamba iqhaza kucwaningo. Isampuli ibinababambi-qhaza abayisithupha abaphakathi kweminyaka engu 18 ukuya kwengu 45 ubudala, okwamanje abahlala eTshwane. I-data itholakala ngokwenza ama-interview ahlelekile kodwa angenamkhawulo kakhulu. Kusetshenziswe idizayini yocwaningo esebenzisa i-qualitative method ukuqoqa nokuthola ulwazi maqondana nezipiliyino zababambi-qhaza kudlame lwasekhaya. Kusetshenziswe inqubo ye-Hycner's explicitation ukuphawula izihloko ezine ezinkulu, ukuyizipiliyoni zababambi-qhaza kudlame lwasekhaya, izinto eziphathelene nabantu nomnotho, umehluko kwezamasiko, udlame lwasekhaya ngesikhathi sokukhulelwa. Isihloko nesihloko esikhulu, besihlukaniswe ngezihlokwana ezincane. Imiphumela yalolu cwaningo yehlukile kancane uma kuqhathaniswa neminye imibhalo ekhona egqamisa ukusetshenziswa kabi kwezidakamizwa njengenye yezinto ezinkulu eziyingozi nembangela yodlame lwasekhaya kanye nakubudlelwane babantu abasondelene kakhulu. Kulolu cwaningo, ezinye izinto eziyizingozi ezifana nokuhlukunyezwa ngesikhathi sokukhulelwa kanye nokuphathelene nabantu nomnotho kunendima enkulu kunokusetshenziswa kabi kwezidakamizwa notshwala njengezinto eziphezulu kakhulu ezinomthelela kudlame lwasekhaya. / Afrika Tshipembe ḽi vhukati ha phimo ya nṱhesa ya khakhathi dza zwa vhudzekani na dza u huvhadza vhafumakadzi kha ḽifhasi. Ṱhoḓisiso i sumbedza uri u pfesesa vhakwameaho nga khakhathi dza mitani zwi a konḓa nga maanḓa na u elwa ha zwiitisi zwa khombo zwi vhonala zwi khaedu vhukuma. Fhedziha, ndi zwa ndeme u pfesesa na u wana zwiitisi zwa khombo zwine zwa tshimbilelana na khakhathi dza miṱani u itela uri dzi kone u thivhelwa. Iyi ndi ngudo ya ṱhoḓisiso nga tshenzhemo yo livhiswaho kha u ṱhoḓisisa tshenzhemo ye vhafumakadzi vho ṱanganaho na khakhathi dza mitani vha tshenzhema na u ṱoda u wanulusa zwithu zwi vhangaho khombo iyi. (zwine zwa nga vha tshumiso ya zwikambi na zwidzidzivhadzi, khakhathi dza murahu muṱani, vhuvha ha muthu, zwiitisi zwa ikonomi ya matshilisano, phambano ya mvelele, u ḓihwala) zwine zwa nga vha zwo livhisa kha u bvelela ha khakhathi dza miṱani kha vhafunani. Vhadzheneli vho tiwa zwo ḓitika nga ndivho nauri vha tsinisa na lutamo lwa u dzhenelela lwa avho vhathu. Sambula yo vhumbwa nga zwipiḓa zwa rathi zwa vhadzheneli vha miṅwaha ya vhukati ha 18 – 45, vhane zwa zwino vha dzula kha ḽa Tshwane. Data yo kuvhanganywa nga kha mbudziso dzi sa langiho kufhindulele. Nḓila ya u tandula ‘qualitative’ yo shumiswa u kuvhanganya na u ṱhaṱhuvha zwidodombedzwa nga ha tshenzhemo dza vhadzheneli nga ha khakhathi dza miṱani. Kuitele kwa Hycner a songo ḓoweleaho kwo shumiswa u wana ṱhoho dza ndeme nṋa; dzine dza vha tshenzhemo ya vhadzheneli nga ha khakhathi dza miṱani, zwiitisi zwa ikonomi ya matshilisano; phambano ya mvelele, na dzikhakhathi dza miṱani nga tshifhinga vho ḓihwala. Ṱhoho khulwane yo vhumbwa nga ṱhoho ṱhukhu. Mawanwa a ngudo iyi a fhambana nyana na mbambedzo na tshivhumbeo tsha maṅwalo ane a vha hone ane a ombedzela tshumiso ya zwidzidzivhadzi sa tshiṅwe tsha tshivhangi tshihulwane tsha khakhathi dza miṱani kha vhushaka ha vhafunani. Kha ngudo iyi, dziṅwe khombo dzi fananho na u ḓihwala na zwiitisi zwa ikonomi ya matshilisano zwi vha zwivhangi zwihulwane u fhira tshumiso ya zwidzidzivhadzi na zwiitisi zwa khombo zwa ndeme zwine zwa vhanga khakhathi dza miṱani. / Psychology / M.A.(Psychology)