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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Design and Implementation of the SAX, a Robotic Measurement System for On-Chip Antennas at 140-325 GHz

Pontusson, Magnus January 2018 (has links)
There is currently a demand of mm‑wave on‑chip antennas to enable all kinds of new applications in several different areas. But the development requires, among other things, special equipment used during the measurement phase due to the small dimensions and the high frequencies. In this project a robotic measurement system, SAX (Single Arm eXtra), was designed and constructed at Micro and Nanosystems (MST) department at KTH Royal Institute of Technology (Sweden). The purpose of the SAX is to enable radiation pattern measurements of on‑chip antennas ( 140 GHz to 325 GHz ), whether the boresight is vertical or horizontal along with other requirements, by moving a converter with the measurement antenna around the antenna in question. Several alternative designs for the basic construction, both from other works and invented by the author, were analyzed based on the requirements for this project and other limitations. The chosen unique design, the SAX, is very compact and uses only one stepper motor. Several parts have been developed in this project to ensure the proper functionality of the SAX. That includes a main operator program, a motor input signal generating program, a motor input signal executing system, a security system, and a system for controlled rotation of the SAX. For the input signal to the motor two different algorithms to generate the time delays were developed and tested. They were adapted to make the motor manage the sweeps of an ever‑changing load with high inertia during acceleration and deceleration. One of them was developed to make the time delay array generation much more efficient albeit with larger approximation error. The SAX worked well and should be rather easy‑to‑use regarding the operation of the system, from the physical maneuvering to utilizing the sub‑systems to the running of the main operator program. It fulfilled the specific requirements by enable a cross pattern measurement from  -60° to +60°  both from above and from the side, adjustment of the radius between 15cm to 45cm , adjustment 10cm in height, to be rotated along the floor in steps of 1°, measurement steps of 1° with an accuracy of less than 0,5° (the largest error was measured to be ≤ 0,461°). However, some calibration work needs to be done before the optimal performance of the system is reached. As a verification of the operation of the system data from measurements of open‑ended waveguides was presented. / Det finns en efterfrågan på chipantenner för millimetervågor eftersom de kan möjliggöra allehanda produkter inom flera olika områden. Forskningen på dessa ställer dock bl.a. speciella krav på utrustning som används under testmätningsfasen p.g.a. de små dimensionerna och den höga frekvensen. I detta projekt har ett robotsystem, SAX (Single Arm eXtra), utformats och konstruerats på avdelningen för Mikro- och nanosystem på KTH. Syftet med SAX är att mäta högfrekventa chipantenner ( 140 GHz till 325 GHz ) genom att förflytta en frekvensomvandlare med tillhörande mätantenn i en cirkulär bana runt antennen ifråga, oavsett om den är riktad vertikalt eller horisontellt och givet andra kravspecifikationer. Flera designalternativ för den grundläggande konstruktionen, både från andras arbeten och framtagna av författaren själv, har analyserats utifrån kravspecifikation för detta projekt och andra begränsningar. Den valda unika designen, SAX, är väldigt kompakt och använder sig bara av en stegmotor. För att möjliggöra funktionen i den slutgiltiga produkten har flera delar tagits fram vilka inkluderar ett operatörsprogram, ett program för genererandet av motorstyrsignaler, ett program för motorstyrning, ett säkerhetssystem och ett rotationssystem för kontrollerad rotation av SAX. För genererandet av motorstyrsignaler i form av tidsfördröjda pulser framtogs två olika algoritmer. De ger anpassade accelerations- och retardationssignaler för att motorn ska klara av att förflytta en föränderlig last med stor tröghet. En av dessa framtogs med syfte att mycket effektivt generera pulstiderna om än med större approximationsfel. SAX fungerade tillfredsställande och torde vara ganska lättanvänd med tanke på vad systemet kräver av operatören, från att fysiskt manövrera systemet till att använda delsystemen till att använda operatörsprogrammet. Systemet uppfyllde de givna specifika kraven genom att möjliggöra mätningar i form av ett kryssmönster från -60° till +60°  både ovanifrån och från sidan, radiejustering från 15cm till 45cm , höjdjustering över 10cm , rotation över golvet i steg om 1° , mätningar i steg om 1° med en noggrannhet på 0,5° (den största avvikelsen uppmättes till ≤ 0,461°). Vidare kalibrering behöver dock utföras för att utnyttja den fulla potentialen hos konstruktionen. För att verifiera funktionsdugligheten för systemet presenterades data från mätningar gjorda på öppna vågledare.
12

Concealment Materials and Techniques for mm-Wave Advanced Antenna Systems

Bharadwaj Sriram, Adhitya January 2018 (has links)
With the advent of the 5G technology standard for communication, it is esti-mated that around 50 billion devices around the world will be interconnectedunder this standard [1]. This has prompted the need to investigate new ma-terials, technologies and methods to conceal antennas for preserving the aes-thetic value of urban centers, and preventing these antenna systems from beingidentified or damaged. The aim of this thesis work was to identify possiblematerials and investigate methods for concealing Ericsson’s 5G mm-Wave Ad-vanced Antenna System(AAS) Radio Base Stations. A study of economicallyviable, commercially available materials for concealment, and methods to deter-mine their dielectric properties was done. A practical investigation of the effectsome available concealment materials on the RF performance of the mm-Wavebase station beams, was also performed. The results from the investigationsand measurements performed led to some useful conclusions and understand-ing about the various concealment material solutions. Overall, the investigatedconcealment materials were found to have two prominent effects:1. Reduction in EIRP (Equivalent Isotropic Radiated Power) of the basestation beams (attenuation).2. Distortion in the shape of the base station beams.The boresight beams for all the investigated cases were found to be attenu-ated(effect 1) by the concealments, but the steered beams were found to beboth attenuated in distorted(effect 2) by the concealments. In particular, con-cealments with a thin dielectric material mesh structure were found to have theleast effect on the base station beams. All other thicker(> λ0/2), compositeconcealments and even those with pure foam structures, were found to have anoticeable effect on the base station beams. In conclusion, thin dielectric mesh,films and paints could hence be of interest as concealment solutions for furtherinvestigations moving forward. / I och med införandet av 5G-tekniken för kommunikation bedöms det att cirka50 miljarder enheter runt om i världen kommer att vara uppkopplade via denna standard [1]. För att bevara det estetiska värdet av stadscentrum och förhindra att 5G-teknikens antenner identifieras eller skadas finns behov att undersöka nya material, tekniker och metoder för att dölja antenner. I detta examensarbete identifieras möjliga material samt undersöks metoder för att dölja Ericssons 5G mm-vågs Advanced Antenna System (AAS) radiobasstationer. Enstudie av ekonomiskt genomförbara, kommersiellt tillgängliga material för döljande och metoder för bestämning av dess dielektriska egenskaper gjordes. En empirisk undersökning av effekten av några tillgängliga maskeringsmaterial på RF-prestanda hos loberna från mm-vågsbasstationer utfördes också. Resultaten från de undersökningar och mätningar som utfördes ledde till några användbara slutsatser och förståelse för egenskaperna hos de olika maskeringsmaterialen. Sammantaget visade sig de undersökta maskeringsmaterialen ha två huvudsakliga effekter:1. Dämpning av EIRP (ekvivalent isotropisk utsrålad effekt) hos basstationsloberna.2. Distorsion av basstationslobernas form.De centrala basstationsloberna för alla undersökta fall visade sig dämpas (ef-fekt 1) av maskeringsmaterialen, men de utstyrda loberna befanns vara både dämpade och förvrängda (effekt 2) av maskeringsmaterialen. Maskeringsmaterial med en tunn dielektrisk nätstruktur visade sig ha den minsta effekten på basstationsloberna. Alla andra tjockare, sammansatta material och ävende med rena skumstrukturer visade sig ha en märkbar effekt på basstation-sloberna. Sammanfattningsvis kan därför tunna dielektriska nät, filmer (plastfolier) och färger vara av intresse som lösningar för vidare undersökningar.
13

W-Band Passive and Active Circuits in 65-nm Bulk CMOS for Passive Imaging Applications

Tomkins, Alexander 07 April 2010 (has links)
The design and implementation of mm-wave switches, variable attenuators, and a passive imaging system in 65-nm CMOS are presented. The design and analysis of shunt switches is presented with a demonstration circuit showing record performance for a single-pole single-throw switch with 1.6dB loss and 30dB isolation at 94GHz. Single-pole double-throw (SPDT) switches are shown, with 4dB insertion loss in the W-band (75-110GHz), and the only reported SPDT switch operating in the D-band (110-170GHz). A novel technique for implementing digitally controlled variable attenuation is presented, resulting in variable attenuation between 4 and 30dB in the W-band. Finally, a W-band radiometer is described integrating a record-high gain CMOS LNA, SPDT switch, and peak detector. This is the highest-frequency imaging system in CMOS with this level of integration, offering a responsivity over 90kV/W, and a noise-equivalent power less than 0.2pW/√Hz.
14

W-Band Passive and Active Circuits in 65-nm Bulk CMOS for Passive Imaging Applications

Tomkins, Alexander 07 April 2010 (has links)
The design and implementation of mm-wave switches, variable attenuators, and a passive imaging system in 65-nm CMOS are presented. The design and analysis of shunt switches is presented with a demonstration circuit showing record performance for a single-pole single-throw switch with 1.6dB loss and 30dB isolation at 94GHz. Single-pole double-throw (SPDT) switches are shown, with 4dB insertion loss in the W-band (75-110GHz), and the only reported SPDT switch operating in the D-band (110-170GHz). A novel technique for implementing digitally controlled variable attenuation is presented, resulting in variable attenuation between 4 and 30dB in the W-band. Finally, a W-band radiometer is described integrating a record-high gain CMOS LNA, SPDT switch, and peak detector. This is the highest-frequency imaging system in CMOS with this level of integration, offering a responsivity over 90kV/W, and a noise-equivalent power less than 0.2pW/√Hz.
15

Gain-Enhanced On-Chip Antenna Utilizing Artificial Magnetic Conductor Reflecting Surface at 94 GHz

Nafe, Mahmoud 04 August 2015 (has links)
Nowadays, there is a growing demand for high frequency-bandwidth mm-wave (30-300 GHz) electronic wireless transceiver systems to support applications such as high data-rate wireless communication and high resolution imaging. Such mm-wave systems are becoming more feasible due to the extreme transistor downscaling in silicon-based integrated circuits, which enabled densely-integrated high-speed elec- tronics operating up to more than 100 GHz with low fabrication cost. To further enhance system integrability, it is required to implement all wireless system compo- nents on the chip. Presently, the last major barrier to true System-on-Chip (SoC) realization is the antenna implementation on the silicon chip. Although at mm-wave frequencies the antenna size becomes small enough to fit on chip, the antenna performance is greatly deteriorated due the high conductivity and high relative permittivity of the silicon substrate. The negative e↵ects of the silicon substrate could be avoided by using a metallic reflecting surface on top of silicon, which e↵ectively isolates the antenna from the silicon. However, this approach has the shortcoming of having to implement the antenna on the usually very thin silicon oxide layer of a typical CMOS fabrication process (10’s of μm). This forces the antenna to be in a very close proximity (less than one hundredth of a wavelength) to the reflecting surface. In this regime, the use of conventional metallic reflecting surface for silicon shielding has severe e↵ects on the antenna performance as it tends to reduce the antenna radiation resistance resulting in most of the energy being absorbed rather than radiated. In this work, the use of specially patterned reflecting surfaces for improving on- chip antenna performance is investigated. By using a periodic metallic surface on top of a grounded substrate, the structure can mimic the behavior of a perfect mag- netic conductor, hence called Artificial Magnetic Conductor (AMC) surface. Unlike conventional ground plane reflecting surfaces, AMC surfaces generally enhance the radiation and impedance characteristics of close-by antennas. Based on this property, a ring-based AMC reflecting surface has been designed in the oxide layer for on-chip antennas operating at 94 GHz. Furthermore, a folded dipole antenna with its associ- ated planar feeding structures has been optimized and integrated with the developed ring-based AMC surface. The proposed design is then fabricated at KAUST clean- room facilities. Prototype characterization showed very promising results with good correlation to simulations, with the antenna exhibiting an impedance bandwidth of 10% (90-100 GHz) and peak gain of -1.4 dBi, which is the highest gain reported for on-chip antennas at this frequency band without the use of any external o↵-chip components or post-fabrication steps.
16

Design and optimization of RF test structures for mm-wave circuit design

Mills, Richard P., III 18 November 2011 (has links)
This work discusses a methodology developed for robust RF test structure design for SiGe HBTs operating at mm-wave frequencies.
17

Radio channel modelling for 5G telecommunication system evaluation and over the air testing

Kyösti, P. (Pekka) 08 May 2018 (has links)
Abstract This thesis discusses radio channel modelling for evolving radio access and of using the models in practice in a setup for radiated testing of radio devices. New telecommunication systems are constantly being developed to address continuously increasing wireless communication needs. The first pieces of intensively developed fifth generation (5G) networks and devices are planned to be available, in some form, approximately by 2020. An interesting feature of 5G concerning propagation and consequently channel modelling, is the expected utilization of frequencies clearly higher than the legacy cellular systems. This work aims to define a channel model for the simulated evaluation of the coming 5G systems. New requirements for the channel model are identified and addressed. Further, over the air (OTA) testing of 5G devices in fading conditions is examined and a new setup is proposed. The test environment aims to reconstruct a time variant electromagnetic (EM) field around a device under test (DUT) considering the spatial, polarimetric, Doppler, and delay dispersion characteristics specified by the target channel model. Components and key design parameters of the setup are designated. It was found that the proposed map-based channel model is capable of fulfilling the identified requirements. Furthermore, the simulations indicate that the state-of-the-art geometry-based stochastic channel model (GSCM) may give over-optimistic multi-user MIMO (MU-MIMO) performance in an urban micro-cellular environment. The sectored OTA concept was shown appropriate for device testing. Key parameters, such as the physical dimensions of the multi-probe anechoic chamber (MPAC) OTA configuration and the number of active probes, were determined by simulations. The 3GPP is the main forum working towards 5G standards. A channel model for 5G evaluations has recently (2016) been specified. The base-line model is a GSCM inherited from the 4G models. However, the author expects that the proposed map-based models will gain popularity in the future, despite the current widespread use of GSCMs. In the 3GPP working group RAN4 (Radio performance and protocol aspects) the test methods for 5G user equipment (UE) are currently (2017) under investigation. The proposed sectored MPAC method has been contributed to and is under consideration in 3GPP. Even if it is not approved for UE testing, the author expects it to be useful for performance testing of base stations (BSs). / Tiivistelmä Tämän väitöskirjan sisältönä on radiokanavamallinnus langattomia tiedonsiirtojärjestelmiä varten ja lisäksi mallien käyttöönottoa tulevien radiolaitteiden säteilevässä testauksessa. Uusia tietoliikennejärjestelmiä kehitetään jatkuvasti, yhtä lailla jatkuvasti kasvavien tiedonsiirtotarpeiden tyydyttämiseksi. Ensimmäisten verkkojen ja päätelaitteiden pitäisi olla saatavilla tulevaan viidennen sukupolven (5G) järjestelmään vuoden 2020 tietämillä. Työn tarkoituksena on määritellä kanavamalli 5G-järjestelmän simulointeja varten ja sitä edeltäen tunnistaa kanavamallin vaatimukset. Lisäksi tutkimuksen aiheena on 5G-laitteiden säteilevä (OTA) testaus häipyvässä radiokanavassa ja uuden testijärjestelmän määrittely tätä tarkoitusta varten. Ehdotetun testijärjestelmän keskeisenä toimintona on halutun sähkömagneettisen (EM) kentän tuottaminen testattavan laitteen ympärille. EM-kentän pitää olla kanavamallin mukainen ja toteuttaa sen häipymä-, tila-, polarisaatio-, doppler- ja viiveominaisuudet. Testijärjestelmän komponentit ja tärkeimmän suunnitteluparametrit pyritään selvittämään tässä työssä. Tutkimuksessa havaittiin, että ehdotettu karttapohjainen kanavamalli toteuttaa 5G-mallille asetetut vaatimukset. Simuloinnit osoittavat myös, että tyypillisessä kaupunkiympäristössä suosittu GSCM-malli yliarvioi kanavan kapasiteetin monen käyttäjän MIMO-tekniikka käytettäessä. Lisäksi osoitettiin sektoroidun OTA-järjestelmän, jossa hyödynnetään useita antenneja, radiokanavaemulaattoria sekä radiokaiutonta huonetta (MPAC), käyttökelpoisuus 5G-laitteiden testaukseen. Kyseisen testausjärjestelmän parametrit määriteltiin. 3GPP on tärkein foorumi, jolla 5G-standardeja luodaan. Siellä on hiljattain (2016) sovittu 5G-simulointeja varten kanavamalli, joka ei ole tässä työssä ehdotetun kaltainen. Standardoitu malli on tyypiltään GSCM ja se on johdettu suoraan edellisen sukupolven (4G) kanavamallista. Kirjoittaja olettaa tästä GSCM:n nykyisestä vahvasta asemasta huolimatta, että ehdotettu karttapohjainen kanavamalli lisää suosiotaan tulevaisuudessa. Parhaillaan (2017) on 3GPP:n RAN4-työryhmässä käynnissä 5G-päätelaitteiden (UE) testimenetelmien määrittelyvaihe. Väitöskirjassa tutkittua sektoroitua MPAC-menetelmää on ehdotettu työryhmälle standardoitavaksi. Vaikka mainittua menetelmää ei siellä standardoitaisikaan UE-testaukseen, niin voidaan olettaa menetelmän olevan hyödyllinen erityisesti tukiasemien säteilevään testaukseen.
18

Optical True Time Delay Device for mm-Wave Antenna Array Beamforming

Almhmadi, Raed Ali M January 2019 (has links)
No description available.
19

High-Frequency Oscillator Design with Independent Gate FinFET

Kelestemur, Yunus January 2019 (has links)
No description available.
20

A New Class of Improved Bandwidth Planar Ultrawideband Modular Antenna (puma) Arrays Scalable to mm-Waves

Logan, John 01 January 2013 (has links) (PDF)
A new class of Planar Ultrawideband Modular Antenna (PUMA) arrays, termed PUMAv3, is introduced to offer improved performance and further meet demand needs for multifunctional systems. PUMAv3 extends the frequency scalability of PUMA arrays to mm-waves (approximately 50 GHz) and improves bandwidth by 50\% without the use of a matching network or external baluns. The major enabling technical innovation is the advent of a new common-mode mitigation mechanism that relies upon capacitively-loaded shorting vias to push broadside catastrophic resonances below the operating band without inhibiting low-end bandwidth performance. Ridged waveguide models are employed to explain the operational principles and accurately predict the location of the common-mode frequency within the new array topology. Additionally, the superstrate loading scheme is split into two exclusive layers to enhance broadside and wide angle impedance levels while maintaining the highest frequency at 97% of the grating lobe frequency and reducing the overall array profile by up to 30%. The PUMAv3 also retains the attractive practical advantages inherent to the PUMA array family: aperture modularity, direct 50-ohm feeding, and low-cost planar multilayer PCB fabrication. Infinite array full-wave simulations of a dual-polarized PUMAv3 satisfying manufacture guidelines suggest 10.6-47.6 GHz (4.5:1) operation with strong VSWR levels out to 45 degrees, high port isolation and low cross-polarization.

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