DFM(A)- aspects for a microwave waveguide ring resonator design

In this research manufacturability analysis is made for an E-plane waveguide ring resonator. About the electrical characteristics of the waveguide ring resonator is discussed. Possibilities to utilize concurrent engineering method both for designing and making manufacturability analysis for MW- and RF-components are discussed. For helping to establish the necessary guidelines for easy manufacturing and assembly of the waveguide ring resonator a specialised DFM(A)-questionnaire is generated. The questionnaire gives also new information for collaborative designing approach in MW-/RF- engineering. The advantages and disadvantages of the concurrent engineering design method are evaluated in the research.

Modeling of fractal antennas

In this Master Thesis the characteristics of the chosen fractal microstrip antennas are investigated. For modeling has been used the structure of the square Serpinsky fractal curves. During the elaboration of this Master thesis the following steps were undertaken: 1) calculation and simulation of square microstrip antennа, 2) optimizing for obtaining the required characteristics on the frequency 2.5 GHz, 3) simulation and calculation of the second and third iteration of the Serpinsky fractal curves, 4) radiation patterns and intensity distribution of these antennas. In this Master’s Thesis the search for the optimal position of the port and fractal elements was conducted. These structures can be used in perspective for creation of antennas working at the same time in different frequency range.

Performance Evaluation of Six-Sectored Configuration in Hexagonal WCDMA (UMTS) Cellular Network Layout

The objective of this master's thesis is to evaluate the optimum performance of sixsectored hexagonal layout of WCDMA (UMTS) network and analyze the performance at the optimum point. The maximum coverage and the maximum capacity are the main concern of service providers and it is always a challenging task for them to achieve economically. Because the optimum configuration of a network corresponds to a configuration which minimizes the number of sites required to provide a target service probability in the planning area which in turn reduces the deployment cost. The optimum performance means the maximum cell area and themaximum cell capacity the network can provide at the maximum antenna height satisfying the target service probability. Hexagon layout has been proven as the best layout for the cell deployment. In this thesis work, two different configurations using six-sectored sites have been considered for the performance comparison. In first configuration, each antenna is directed towards each corner of hexagon, whereas in second configurationeach antenna is directed towards each side of hexagon. The net difference in the configurations is the 30 degree rotation of antenna direction. The only indoor users in a flat and smooth semi-urban environment area have been considered for the simulation purpose where the traffic distribution is 100 Erl/km2 with 12.2 kbps speech service having maximum mobile speed of 3 km/hr. The simulation results indicate that a similar performance can be achieved in both the configurations, that is, a maximum of 947 m cellrange at antenna height of 49.5 m can be achieved when the antennas are directed towards the corner of hexagon, whereas 943.3 m cell range atantenna height of 54 m can be achieved when the antennas are directed towards the side of hexagon. However, from the interference point of view the first configuration provides better results. The simulation results also show that the network is coverage limited in both the uplink and downlink direction at the optimum point.

Mikroliuskarakenteisen T-resonaattorin käyttö piirilevyn eristeominaisuuksien määrityksessä

Tässä diplomityössä tutkittiin ja kehitettiin edelleen mikroliuskarakenteisen T-resonaattorin käyttöä laajakaistaisessa piirilevylaminaattien dielektrisyysvakion ja häviökertoimen määrityksessä. Työssä perehdyttiin eristeominaisuuksien määrityksessä tarvittaviin laskentamenetelmiin sekä T-resonaattorin toimintaan. T-resonaattorin suunnittelu ja käyttöä varten valitut laskentamenetelmät on esitelty. Työssä suunniteltiin ja valmistettiin mikroliuskarakenteinen T-resonaattorimittausrakenne, jolla määritettiin erään FR-4 -tyyppisen piirilevylaminaattimateriaalin dielektrisyysvakio sekä häviökerroin mittausten ja laskennan avulla taajuuskaistalla 0,5 - 10 GHz. Tuloksia verrattiin muilla käytössä olevilla menetelmillä määritettyihin tuloksiin. Tulosten perusteella voitiin osoittaa, että mikroliuskarakenteinen T-resonaattori soveltuu hyvin piirilevylaminaattien eristeominaisuuksien määritykseen, ja käytetyt laskenta-menetelmät antavat realistisia tuloksia.

Mikroaaltoresonaattorin mittauselektroniikan kehittäminen

Tässä diplomityössä on kehitetty kapeakaistaisten mikroaaltoresonaattoreiden mittaukseen soveltuvaa elektroniikkaa 400 MHz taajuusalueelle. Työn teoriaosuudessa on tutustuttu RF- ja mikroaaltotaajuuksilla käytettävien resonaattoreiden ominaisuuksiin sekä tarkasteltu erilaisia mahdollisia mittauselektroniikkatoteutuksia. Tarkastelujen perusteella on valittu toteutettavan mittauselektroniikan periaate. Toteutettu mittauselektroniikka hyödyntää suoraa digitaalista taajuussynteesiä hyvän taajuusresoluution saavuttamiseksi. Mittauselektroniikkaa on kehitetty prototyyppien avulla. Työssä on myös vertailtu resonaattoreiden mittaustuloksia käytettäessä kehitettyä mittauselektroniikkaa ja piirianalysaattoria. Kehitetyllä mittauselektroniikalla saadut tulokset vastaavat hyvin piirianalysaattorimittauksen tuloksia.

Antennimittausjärjestelmän toteutus ja ominaisuuksien määrittäminen

Diplomityössä tarkasteltiin antennien säteilykuviomittauksiin käytettävien antennimittaratojen ominaisuuksia. Sovelletun elektroniikan laboratorion antennimittaradasta kehitettiin toimiva säteilykuvion mittausjärjestelmä, johon kuuluvat radiokaiuton kammio, suuntauskoneisto ja antennikannakkeet, HP 8720D -piirianalysaattori ja RF-kaapelointi sekä valmistutetut mitta-antennitorvet. Työssä vertailtiin koaksiaalikaapeleita ja valittiin antennimittaukseen soveltuvat. 1,70–2,60 GHz:n taajuusalueen mittastandardiksi suunniteltiin torviantenni, jonka kaksi prototyyppiä valmistutettiin konetekniikan osastolla. Torviantennien ominaisuudet mitattiin. Antennimittaradan ominaisuudet ja soveltuvuus erilaisiin antennimittauksiin selvitettiin sekä teoreettisesti että mittauksin.

DFM(A)- aspects for a horn antenna design

In this paper aspects of design for manufacturability and assembly (DFMA) are applied to the design of coaxially fed standard gain horn antenna for 1.70 - 2.60 GHz. Possibilities to utilize cross-technological approach method is examined. Methods of DFMA for laser processing are covered and practical design guides and methods are developed. Antenna construction for easy manufacturing and specialized performance is shown. Required dimensions and tolerances are discussed and suitable materials for laser processing are selected.

Microwave Processes in Ferrite-ferroelectric Layered Structure

This work is devoted to investigation of wave processes in new hybrid ferrite/ferroelectric structures. Spin wave devices based on ferrite films have disadvanteges. And their applications are limited. Investigated structures allow to overcome disadvantages. This investigation helps to create new class of devices. Electromagnetic analysis of hybrid spin-electromagnetic waves in ferrite/ferroelectric structures were done. As a result dispersion relation was found. Numerical solution of this dispersion relation gave us follow results. These structures can be effectively tuned by external electric and magnetic field. Methods to increase tuning range were suggested. It was found that such structures have one basic disadvantage which is connected with presence of thick ferroelectric layer. To solve this problem is to use thin ferroelectric films. But this decreases tuning range. It was confirmed by experiment that this structures can be effectively tuned by electric and magnetic fields. Resonance characteristics of ferrite/ferroelectric resonator were succesfully tuned by magnetic and electric field.

Dispersion of Hybrid Electromagnetic-Spin Waves in the Slotline

The presented thesis is devoted to investigation of wave processes in hybrid ferrite / ferroelectric structures. Spin wave devices based on ferrite films have such disadvantages, as huge size of the magnetic systems, low tuning velocity, considerable power inputs for parameters control that limits possible device applications. The considered layered structures allow to overcome the disadvantages mentioned and to promote the development of novel class of tunable microwave devices. The proposed theoretical analysis is intended to construct a model of hybrid electromagnetic-spin waves. Based on the theoretical analysis the experimental investigations were carried out. The experimental resonance characteristics of ferrite / ferroelectric resonator were obtained and their tunability by means of magnetic and electric field was demonstrated.

ZigBee-verkot ja evaluointilaitteen suunnittelu

In this thesis a closer look at ZigBee wireless network protocol was made and a ZigBee evaluation device was designed and built for testing it. ZigBee is a digital wireless network technology published in 2004, which was developed for wireless control and automation systems. It is based on the IEEE 802.15.4-2003 standard, and its aim was to create a reliable wireless networking protocol with secure data transmissions, low power consumption and low manufacturing costs. The low power consumption requirement has also led to a slow data rate and a short range, but in a ZigBee network individual network devices can route messages to each other, so short range is not a problem. In automation and control systems a fast data rate is not usually an important requirement either. ZigBee network can form automatically and one ZigBee network can theoretically include thousands of devices, all of which can communicate with each other. ZigBee network is also self-healing, so an individual device dropping out of the network, like breaking down, does not affect functionality of the network. Evaluation device was designed and implemented in four different versions, which were tested with six different antenna designs. All antennas were tested at a range of 100 meters in an open terrain using two different frequencies and transmission powers. Also a range test was performed for selected antennas using transmission power of 4,5 dBm, which was maximum power of the ZigBee chip used in the evaluation device. Range test resulted in a measured range of several hundred meters, which can be considered as a good result for a short-range technology.

LTE tulevaisuuden mobiiliverkkoratkaisuna

Tässä kandidaatintyössä käytiin läpi kuinka LTE soveltuu tulevaisuuden mobiiliverkkoratkaisuksi. Ensiksi selvitettiin sen kehityshistoriaa ja vaatimuksia. Seuraavaksi käytiin läpi LTE:n teknistä puolta, kuten radiotekniikkaa, taajuusjakoa ja antenneja. Työssä tehtiin katsaus myös uuteen SAE verkkoarkkitehtuuriin. Teknillisen puolen jälkeen työssä käytiin läpi LTE:n kilpailijoita, sekä tutustuttiin tarkemmin sen pahimpaan haastajaan WiMAX:iin. Näiden kahden tekniikan välillä tehtiin myös vertailu. Lopuksi katsottiin tulevaisuuden trendejä ja mobiilin datasiirron kehittymistä sekä tutustuttiin LTE:n seuraavaan versioon LTE-Advanced:iin.

Thermal Stress in a Roll-to-Roll Printed Electronics Substrate

The Roll-to-Roll process makes it possible to print electronic products continuously onto a uniform substrate. Printing components on flexible surfaces can bring down the costs of simple electronic devices such as RFID tags, antennas and transistors. The possibility of quickly printing flexible electronic components opens up a wide array of novel products previously too expensive to produce on a large scale. Several different printing methods can be used in Roll-to-Roll printing, such as gravure, spray, offset, flexographic and others. Most of the methods can also be mixed in one production line. Most of them still require years of research to reach a significant commercial level. The research for this thesis was carried out at the Konkuk University Flexible Display Research Center (KU-FDRC) in Seoul, Korea. A system using Roll-to-Roll printing requires that the motion of the web can be controlled in every direction in order to align different layers of ink properly. Between printers the ink is dried with hot air. The effects of thermal expansion on the tension of the web are studied in this work, and a mathematical model was constructed on Matlab and Simulink. Simulations and experiments lead to the conclusion that the thermal expansion of the web has a great influence on the tension of the web. Also, experimental evidence was gained that the particular printing machine used for these experiments at KU-FDRC may have a problem in controlling the speeds of the cylinders which pull the web.

Radar cross-section measurement using the Doppler effect

In this Master Thesis we discuss issues related to the measurement of the effective scattering surface, based on the Doppler Effect. Modeling of the detected signal was made. Narrowband signal filtering using low-frequency amplifier was observed. Parameters of the proposed horn antennas were studied; radar cross section charts for three different objects were received.

Antenna feed design for omnidirectional broadband antenna

This thesis is about development broadband feed for two-mirror antenna system that match following requirements: beamwidth from 45 to 90 degrees at -3 dB level, circular polarization, absence of radiation to the lower hemisphere area. Literature review was done in the areas of the UWB antennas creation. During the work attempts were made to create a feed in a form of the quad ridged horn and "eleven" antennas. The latter is introduced as the most effective feed among all antennas discussed in thesis. Radiation patterns and other results for "eleven" antenna were obtained. Results were saved as far field sources and placed slightly below focal point into the two-mirror antenna system, because phase center of the “eleven” antenna is predominantly shifted upwards. Directivity patterns for the two-mirror system were obtained and the conclusions about the work results have been made