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The goal of the thesis is Ring Laser Integrated Taper-directional Coupler Using Deep Etching to Fabricate Total Internal Reflection Mirrors. In order to total internal reflection, we make deep etching for the total reflection mirror. We use the tapered waveguide coupler, if unidirectional traveling-wave oscillation can be achieved, spatial hole burning effects seen in DFB laser can be avoided. In this paper, two types of ring laser structures are fabricated and discussed, in which (1) 90 degrees total reflection mirrors and (2) circular retro-mirrors. In fabrication process, we get smooth waveguide and highly perpendicularity waveguide by Self-Alignement wet etch method. In order to reduce bending loss and waveguide loss, we make deep etching for the total reflection mirror and circular retro-mirrors.

<p>Ericsson develops a new stripline directional coupler. Its design is described in appendix B and differs from the directional couplers Ericsson uses in current products. The new directional coupler will be used for transmission power measurement in future UMTS 3G base stations.</p><p>The most important parts of directional coupler theory are presented. It is necessary to study this theory to understand how the coupler works and how it should be designed to get good performance.</p><p>Optimal directional coupler termination component values to get high directivity and broad directivity bandwidth have been investigated.</p><p>The trim screws trim ranges have been studied.</p><p>A simple analysis of serial production performance when termination component tolerances are taken into consideration has been done.</p><p>The resistance components reactive (inductive/capacitive) characteristics at 2.14 GHz have been analyzed.</p><p>The directivity performance limitations of the directional coupler, when Ericsson’s band pass filter is connected, are investigated.</p><p>Design changes leading to better performance are proposed. Some important relations between design choices and performance are explained.</p> / <p>Ericsson utvecklar en ny typ av striplineriktkopplare. Dess utformning beskrivs i appendix B och skiljer sig från de riktkopplare Ericsson använder i nuvarande produkter. Den nya riktkopplaren ska användas för uteffektmätning i framtida UMTS 3G basstationer.</p><p>De viktigaste delarna av riktkopplarteori gås igenom. Det är nödvändigt att studera teorin för att förstå riktkopplarens funktion och för att förstå hur den ska designas för att få bra prestanda.</p><p>Optimala värden på riktkopplartermineringskomponenter har laborerats fram för att få så hög direktivitet och stor direktivitets-bandbredd som möjligt.</p><p>Trimskruvarnas trimområde har kartlagts.</p><p>En enkel analys av serieproduktionsprestanda har gjorts med hänsyn till termineringskomponenternas toleranser.</p><p>Resistanskomponenternas reaktiva (induktiva/kapacitiva) karakteristik vid 2.14 GHz har undersökts.</p><p>Riktkopplarens direktivitetsprestandabegränsningar när Ericssons bandpassfilter är inkopplat utreds.</p><p>Förslag till möjliga förbättringar ges. Vissa viktiga samband mellan designval och prestanda klarläggs.</p>

Ericsson develops a new stripline directional coupler. Its design is described in appendix B and differs from the directional couplers Ericsson uses in current products. The new directional coupler will be used for transmission power measurement in future UMTS 3G base stations. The most important parts of directional coupler theory are presented. It is necessary to study this theory to understand how the coupler works and how it should be designed to get good performance. Optimal directional coupler termination component values to get high directivity and broad directivity bandwidth have been investigated. The trim screws trim ranges have been studied. A simple analysis of serial production performance when termination component tolerances are taken into consideration has been done. The resistance components reactive (inductive/capacitive) characteristics at 2.14 GHz have been analyzed. The directivity performance limitations of the directional coupler, when Ericsson’s band pass filter is connected, are investigated. Design changes leading to better performance are proposed. Some important relations between design choices and performance are explained. / Ericsson utvecklar en ny typ av striplineriktkopplare. Dess utformning beskrivs i appendix B och skiljer sig från de riktkopplare Ericsson använder i nuvarande produkter. Den nya riktkopplaren ska användas för uteffektmätning i framtida UMTS 3G basstationer. De viktigaste delarna av riktkopplarteori gås igenom. Det är nödvändigt att studera teorin för att förstå riktkopplarens funktion och för att förstå hur den ska designas för att få bra prestanda. Optimala värden på riktkopplartermineringskomponenter har laborerats fram för att få så hög direktivitet och stor direktivitets-bandbredd som möjligt. Trimskruvarnas trimområde har kartlagts. En enkel analys av serieproduktionsprestanda har gjorts med hänsyn till termineringskomponenternas toleranser. Resistanskomponenternas reaktiva (induktiva/kapacitiva) karakteristik vid 2.14 GHz har undersökts. Riktkopplarens direktivitetsprestandabegränsningar när Ericssons bandpassfilter är inkopplat utreds. Förslag till möjliga förbättringar ges. Vissa viktiga samband mellan designval och prestanda klarläggs.

Polymer-based electro-optical modulators are, generally, applicable to many fields but their applications to analog optical links and silicon photonic integrated circuits are specifically emphasized in this dissertation. This dissertation aims to improve the linearity characteristics of polymer-based electro-optic modulators for their practical application in high speed analog optical links. Domain-inversion technique is employed to linearize a two-section Y-fed directional coupler modulator. The spurious free dynamic range as high as 119dB/Hz2/3 has been demonstrated with 11dB enhancement over the conventional Mach-Zehnder modulator at low frequency. For high speed modulation, a traveling wave electrode with low RF loss and large bandwidth is designed and installed in a linearized Y-fed directional coupler modulator. The spurious free dynamic range has been measured in the range of 110±3dB/Hz2/3 at 2~8GHz frequency. For digital application of polymer-based electro-optic modulators, a hybrid silicon photonic crystal waveguide modulator was investigated with focus on size-reduction and electro-optic efficiency enhancement. The slow group velocity of photonic crystal waveguides promises two orders of magnitude size-reduction in device footprint compared with the conventional strip waveguide. Infiltration of an electro-optic polymer into the slot waveguide can infuse silicon with nonlinear optical properties. To actualize these benefits of a hybrid silicon photonic crystal waveguide modulator, nano-fabrication process was developed and optimized in this work. / text

This thesis presents a method to fabricate a robust optical directional coupler sensor using a solid core fiber (SCF) and a hollow core fiber (HCF). Through evanescent wave coupling mechanism, the optical power is exchanged between SCF and HCF. The hollow core of the HCF can be filled with liquid samples to alter the coupling ratio which imparts change in amount of light propagating through the SCF. Thus, it gives the coupler with ability of sensing refractive index of the sample with good sensitivity of 4.03 ± 0.50 volts per refractive index units (V/RIU) for refractive indices ranging from 1.331 ± 0.003 to 1.403 ± 0.003 with a resolution of 3.5 × 10−3 refractive index units (RIU). The SCF-HCF coupler was also used to sense the temperature based on the concept of temperature dependence on refractive index of the sample inside the hollow core of HCF. Further, the packaging methods are described that protect coupler from ambient environments and improves the life span of sensor. / Graduate

This doctoral thesis is comprised of five parts. The first three parts concern signal processing and electromagnetic modelling of multiport antennas. The last two parts concern signal processing and transmission line theory applied to wave splitting on transmission lines. In Part I, the spherical vector wave expansion of the electromagnetic field is used to completely characterize a multiport antenna. A general framework for modelling an antenna configuration based on measurement data and numerical computation is obtained. The generic electromagnetic model for arbitrary multiport antennas or vector sensors is applied in direction of arrival (DOA) estimation. Next, in Part II using the generic electromagnetic model (from Part I), we obtain the Cramér–Rao bound (CRB) for DOA and polarization estimation using arbitrary multiport antennas. In the Gaussian case, the CRB is given in terms of the transmission matrix, the spherical vector harmonics and its spatial derivatives. Numerical examples using an ideal Tripole antenna array and a non-ideal Tetrahedron antenna array are included. In Part III, the theory of optimal experiments is applied to a cylindrical antenna near-field measurement setup. The D-optimal (determinant) formulation using the Fisher information matrix of the multipole coefficients in the spherical wave expansion of the electrical field result in the optimal measurement positions. The estimation of the multipole coefficients and corresponding electric field using the optimal measurement points is studied using numerical examples and singular value analysis. Further, Part IV describes a Digital Directional Coupler (DDC), a device for wave splitting on a transmission line. The DDC is a frequency domain digital wave splitter based on two independent wide-band measurements of the voltage and the current. A calibration of the digital processor is included to account for the particular transmission line and the sensors that are employed. Properties of the DDC are analyzed using the CRB and an experiment where wave splitting was conducted on a coaxial–cable is accounted for. Finally, in Part V the DDC has been designed and implemented for wave splitting on a medium voltage power cable in a power distribution station using low cost wide–band sensors. Partial discharge measurements are conducted on cross–linked polyethylene insulated power cables. The directional separation capabilities of the DDC are visualized and utilized to separate multiple reflections from partial discharges based on the direction of travel.

The aim of this master’s thesis is to build stand-alone impedance analyzer for mesasuring antennas’ impedance. The vector network analysis is used as measuring method. Analog (with directional coupler and gain and phase detector) and digital (with 8bit AVR microcontrollers) part of analyzer are described and then build.

This work deals with high-frequency power amplifiers. In the theoretical part are briefly summarized the general characteristics and properties of particular working classes of amplifiers focusing on their efficiency. The next section is aimed on design of high-frequency power amplifier for 1296MHz band and its individual components. In this part is desribed design of hybrid combiners - splitters, directional couplers of the coupled lines, amplifiers with RA18H1213G module and power amplifier with transistor BLV958. The work also includes the results of simulations of designed circuit, realization procedure and the measured parameters of manufactured components. In conclusion of this work the theoretical and measured values are compared.

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