Electrical engineers have responded to the increasing demand for circuit speed and functionality by reducing transistor feature size and increasing on-chip transistor density. Consequently, interconnect density, both on-chip and the system level is also increasing. Increasing circuit speed translates into shorter clock cycles and signals with faster edge rates, which have multi-GHz bandwidth. Densely packed parallel interconnects will cause signal integrity problems not only due to the increase in crosstalk noise but also due to the intrinsic low pass filter characteristics of the interconnects. The lossy nature of the interconnects is also going to increase due to metal surface roughness at higher frequencies, which will further degrade the signal quality at the receiver input. Embedded Patterned Layer (EPL), which is a patterned floating metal layer between a signal trace and its return path shows promise in reducing far-end crosstalk (FEXT). EPL also allows designers to modify the characteristic impedance of interconnects by varying the different physical parameters of the EPL. This dissertation analyzes the effect of EPL on conductor backed coplanar waveguides (CB-CPW). CB-CPWs excite higher order modes at high frequencies, so work was done to understand the effect of different ground via fence parameters in suppressing the higher modes which helps increase the interconnect bandwidth. A CB-CPW with ground via fence is called a grounded coplanar waveguide (GCPW). A very basic lumped element model transmission line model was developed to account for the effect of floating metals near a transmission line. This model was then used to explain the effect of EPL on a GCPW with large bandwidth. EPL reduces the characteristic impedance of the transmission line. Engineers can then design narrow high impedance transmission lines and use EPL to reduce the impedance to a desired value. This also allows reduction in crosstalk by increasing the spacing between the transmission lines. The EPL also reduced the differential impedance of a grounded conductor backed edge coupled coplanar waveguide, when it was used for differential signaling. Care must be taken to make sure that the EPL is symmetric to both the legs of the differential pair to avoid differential to common mode energy conversion, which can cause electromagnetic interference (EMI) problems. EPL reduced FEXT while increasing near-end crosstalk (NEXT), when the coupled transmission line system was used for single ended signaling. Finally, a statistical method for modeling transmission line metal surface roughness in three dimensional (3D) full wave electromagnetic solvers was developed to account for increased attenuation in transmission lines, at high frequencies, due to metal surface roughness.

Optimisation d’un isolateur coplanaire à déplacement de champ et ondes magnétostatiques opérant en bande X. Résumé en français non fourni / Optimization of an isolator coplanar field displacement and waves magnetostatic operating in X-band. English abstract not supplied

La minimisation des circuits et la montée en fréquence constituent deux enjeux importants des systèmes de communication du futur. Cela nécessite un haut degré d'intégration, des performances plus élevées à coût réduit. Ce travail a pour objectif la conception et la réalisation de nouveaux isolateurs réalisés sur ligne coplanaire asymétrique à base de deux types de matériaux ferrite : hexaferrite de baryum (BaM) et grenat d’yttrium et de fer (YIG). La première étude, présentée sur une structure coplanaire à couche de BaM, a été effectuée pour montrer la faisabilité d’un isolateur à déplacement de champ dans la bande 40-50 GHz. La seconde a utilisé le YIG saturé pour des applications autour de 10 GHz. La nouvelle structure d’isolateur utilise le phénomène physique de déplacement de champ lorsqu’elle est polarisée par un champmagnétique continu. Elle est constituée d’une ligne coplanaire asymétrique gravée sur une couche ou un substrat magnétique et d’un demi-plan de masse arrière. Plusieurs séries de prototypes ont été fabriquées puis caractérisées à partir d’un banc de mesure hyperfréquence composé d’un testeur sous pointes à trois accès et d’un analyseur vectoriel de réseaux. Les résultats expérimentaux sont très encourageants car nous obtenons des pertes d’insertion faibles, dans le meilleur des cas inférieures à 1 dB et une isolation de plus de 16 dB. / The minimization of circuits and the increasing frequency are two important issues of future communication systems. That requires a high degree of integration, higher performance at reduced cost. This work aims to design and implementation of new isolators on coplanar line based on two types of ferrite materials: barium hexaferrite (BaM) and garnet and yttrium iron (YIG). The first study presented on a planar layer of BaM leads to the feasibility of the isolator of field displacement in the 40-50 GHz band. The second one concerns the use of saturated YIG for applications around 10 GHz. The magnetic field displacement phenomenon appears when the magnetic substrate is polarized by a D.C. magnetic field. The new isolator structure is made from an asymmetric coplanar line put on a layer or magnetic substrate with a half ground plane placed under this substrate. Several sets of prototypes are fabricated and characterized from a measurement bench which is composed by a microwave prober and a vector network analyzer. The experimental results are very promising because low insertion loss (less than 1 dB) and isolation (over 16 dB) have been obtained

This diploma thesis solves possibilities of transitions between waveguides and hybrid types of integrated microwave circuits. It describes the basic ways of solutions this transitions in both longitudinal and transverse as well. In thesis is also mentioned the principle of SIW technology, which is in this transitions widely used. The practical part is focused on the modeling and analysis of selected structures in CST MW Studio. Modeled structures are optimized for the lowest possible value insertion loss transition and are adapted to the characteristic impedance on 50. Selected structures are recalculated to a lower frequency band, realized and results of their simulation verified by measurements.

The objective of this thesis is to evaluate a generic process for fabrication and characterization of the Superconductive coplanar waveguide (CPW) resonators. Superconductive CPW resonators with various lengths and shapes are designed to investigate their electrical and magnetic properties as well as resonance properties and sensitivities. In the first part of thesis, two different models are introduced in order to estimate the nonlinear kinetic inductance of a superconducting CPW resonator. The first model is based on Bean critical-state model and the second one is based on current dependence of London penetration depth. The existence of a shift in resonant frequency  of Superconductive CPW resonator caused by a non-linear kinetic inductance is also shown experimentally. Simulations were carried out to estimate the nonlinear kinetic inductance due to the self- induced magnetic field penetration. The rest of the thesis is concerned with development of very smooth Aluminum (Al) thin films with RMS (Root Mean Square) roughness 1~nm and CAD (Computer Aid Design) of superconductive CPW resonators. Experimental investigation of a generic fabrication technique for superconductive CPW resonator is carried out. Many resonators are fabricated with different design parameters, such as centerline or gap width, film thickness and gap capacitors length. The fabrication process is described in detail. Electron Beam Lithography is used to fabricate Nb and Al CPW resonators which are coupled to outer conductors via gap capacitors. We have fabricated GHz frequency CPW resonators with quality factors, Q up 5X10^5.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21619号 / 医博第4425号 / 新制||医||1033(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 増永 慎一郎, 教授 松村 由美, 教授 富樫 かおり / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

No description available.

Yes / A Novel design of a curved single-layered frequency selective surface with an 11 × 11 array of a 13 × 13 mm-sized unit cell has been merged with a miniaturized, CPW-fed ultra-wideband monopole of dimensions (20 × 25 mm2) for gain enhancement. The suggested prototype, crafted on an FR-4 dielectric substrate and demonstrates a very broad bandwidth starting from 2.66 to 17.98 GHz (148%), which covers the entire UWB frequency band. The combined antenna-curved FSS reflector shows a very important gain improvement from 0.2–5.4 dB to 8.8–14.9 dB, having a peak gain increase of 10 dB at 10.6 GHz. Basic design features were studied and discussed through simulations, yielding promising results The proposed structure can be used in UWB and GPR applications. / The full-text of this article will be released for public view at the end of the publisher embargo on 31 Oct 2024.

There has been increased interest in exploring high frequency (mm-wave) spectrum (particularly the 30 and 60 GHz ranges), and utilizing silicon-based technology for reduced-cost monolithic millimeter integrated circuits (MMIC), for applications such as WLAN, inter-vehicle communication (IVC) automotive radar and local multipoint distribution system (LMDS). Although there has been a significant increase in silicon-based implementations recently, this area still has significant need for research and development. For example, one microwave/mm-wave front-end component that has seen little development in silicon is the power amplifier (PA). Two potential technologies exist for providing a solution for low-cost microwave/mm-wave power amplifiers: 1) Silicon-Germanium (SiGe) HBT and 2) Complementary metal-oxide semiconductor (CMOS). SiGe HBT has become a viable candidate for PA development since it exhibits higher gain and higher breakdown voltage limits compared to CMOS, while remaining compatible with BiCMOS technology. Also, SiGe is potentially lower in cost compared to other compound semiconductor technologies that are currently used in power amplifier design. Hence, this research focuses on design of millimeter-wave power amplifiers in SiGe HBT technology. The work presented in this thesis will focus on design of different power amplifiers for millimeter-wave operating frequencies. Amplifiers present the fundamental trade-off between linearity and efficiency. Applications at frequencies highlighted above tend to be point-to-point, and hence high linearity is required at the cost of lowered efficiency for these power amplifiers. The designed power amplifiers are fully differential topologies based on finite ground coplanar waveguide (FGC) transmission line technology, and have on-chip matching networks and bias circuits. The selection and design of FGC lines is supported through full-wave EM simulations. Tuned single stub matching networks are realized using FGC technology and utilized for input and output matching networks. Two 30-GHz range SiGe HBT PA designs were carried out in Atmel SiGe2RF and IBM BiCMOS 8HP IC technologies. The designs were characterized first by simulations. The performance of the Atmel PA design was characterized using microwave/mm-wave on wafer test measurement setup. The IBM 8HP design is awaiting fabrication. The measured results indicated high linearity, targeted output power range, and expected efficiency performance were achieved. This validates the selection of SiGe HBT as the technology of choice of high frequency point-to-point applications. The results show that it is possible to design power amplifiers that can effectively work at millimeter-wave frequencies at lower cost for applications such as mm-wave WLAN and IVC where linearity is important and required transmitted power is much lower than in cellular handset power amplifiers. Moreover, recommendations are made for future research steps to improve upon the presented designs. / Master of Science

In this modern age of information, the demands on data transmission networks for greater capacity, and mobile accessibility are increasing drastically. The increasing demand for mobile access is evidenced by the proliferation of wireless systems such as mobile phone networks and wireless local area networks (WLANs). The frequency range over which an oxygen resonance occurs in the atmosphere (~58-62 GHz) has received recent attention as a possible candidate for secure high-speed wireless data networks with a potentially high degree of frequency reuse. A significant challenge in implementing data networks at 60 GHz is the manufacture of low-cost RF transceivers capable of satisfying the system requirements. In order to produce transceivers that meet the additional demands of high-volume, mobility, and compactness, monolithic millimeter wave integrated circuits (MMICs) offer the most practical solution. In the design of radio tranceivers with a high degree of integration, the receiver front-end is typically the most critical component to overall system performance. High-performance low-noise amplifiers (LNAs) are now realizable at frequencies in excess of 100 GHz, and a wide variety of mixer topologies are available that are capable of downconversion from 60 GHz. However, local oscillators (LOs) capable of providing adequate output power at mm-wave frequencies remain bulky and expensive. There are several techniques that allow the use of a lower frequency microwave LO to achieve the same RF downconversion. One of these is to employ a subharmonic mixer. In this case, a lower frequency LO is applied and the RF mixes with a harmonic multiple of the LO signal to produce the desired intermediate frequency (IF). The work presented in this thesis will focus on the development of a GaAs MMIC 4-X subharmonic mixer in Finite Ground Coplanar (FGC) technology for operation at 60 GHz. The mixer topology is based on an antiparallel Schottky diode pair. A discussion of the mechanisms behind the operation of this circuit and the methods of practical implementation is presented. The FGC transmission lines and passive tuning structures used in mixer implementation are characterized with full-wave electromagnetic simulation software and 2-port vector network analyzer measurements. A characterization of mixer performance is obtained through simulations and measurement. The viability of this circuit as an alternative to other high-frequency downconversion schemes is discussed. The performance of the actual fabricated MMIC is presented and compared to currently available 60 GHz mixers. One particular MMIC design exhibits an 11.3 dB conversion loss at an RF of 58.5 GHz, an LO frequency of 14.0 GHz, and an IF of 2.5 GHz. This represents excellent performance for a 4X Schottky diode mixer at these frequencies. Finally, recommendations toward future research directions in this area are made. / Master of Science