The Concept of Substrate Integrated E-plane Waveguide and Circuits

In this thesis, a new type of substrate integrated waveguide is proposed for implementing E-plane type of waveguide circuits on printed circuit boards. obviously, these E-plane type of circuits cannot be realized by the conventional substrate integrated waveguide. The so-called substrate integrated E-plane waveguide consists of two circuit boards attached to each other. Two copper strips are inserted in between two circuit boards, where plated through holes are penetrated through them along the transmission direction. The plated through holes and copper strips altogether played as side walls of a conventional waveguide to support longitudinal and vertical currents. Simulation is carried out and the result shows that the proposed waveguide is able to guide horizontally polarized electromagnetive wave. An E-plane inductive septa filter, two one-dimensional E-plane offset waveguide filters, and an air-filled evanescent-mode band-pass filter are proposed as examples to prove that E-plane type of circuits are able to be built based on this new synthesized waveguide structure

Design and Implementation of Wave Digital Filters

One of possibilities of the Wave Digital Filters (WDF) design is using the classical LC-filters theory. The aim of this paper is to demonstrate the design of WDF from the LC filter and the implementation of WDF on the fixed-point digital signal processor. The theory of wave digital filter has been developed by using the classical scattering parameter theory. The theory of ladder filters is well-known, and so our present problem can thus be reduced to a problem how to replace the L and C elements of the filters by adaptors and delay elements, adders and multipliers

AstroGrid-D: Grid Technology for Astronomical Science

We present status and results of AstroGrid-D, a joint effort of astrophysicists and computer scientists to employ grid technology for scientific applications. AstroGrid-D provides access to a network of distributed machines with a set of commands as well as software interfaces. It allows simple use of computer and storage facilities and to schedule or monitor compute tasks and data management. It is based on the Globus Toolkit middleware (GT4). Chapter 1 describes the context which led to the demand for advanced software solutions in Astrophysics, and we state the goals of the project. We then present characteristic astrophysical applications that have been implemented on AstroGrid-D in chapter 2. We describe simulations of different complexity, compute-intensive calculations running on multiple sites, and advanced applications for specific scientific purposes, such as a connection to robotic telescopes. We can show from these examples how grid execution improves e.g. the scientific workflow. Chapter 3 explains the software tools and services that we adapted or newly developed. Section 3.1 is focused on the administrative aspects of the infrastructure, to manage users and monitor activity. Section 3.2 characterises the central components of our architecture: The AstroGrid-D information service to collect and store metadata, a file management system, the data management system, and a job manager for automatic submission of compute tasks. We summarise the successfully established infrastructure in chapter 4, concluding with our future plans to establish AstroGrid-D as a platform of modern e-Astronomy.Comment: 14 pages, 12 figures Subjects: data analysis, image processing, robotic telescopes, simulations, grid. Accepted for publication in New Astronom

Design and modeling of a CMOS VCO using wave digital filters / by WeiBo Li.

Wave digital filters (WDFs) transform an analog network into a topologically equivalent digital structure. A natural application of WDF is the simulation of electric circuits since measurements of any desired node voltages and branch currents are available during all time-steps in WDF structures. WDF structures tend to preserve most of the good properties of their analog counterpart. In this work, WDF techniques applied to transient simulation are studied. After a review o f the basic theory of WDFs and the treatment of nonlinear elements in WDFs, WDF simulations for different circuits, including a simple RC circuit, an anharmonic oscillator and a CMOS LC voltage controlled oscillator (VCO), are presented. Special detail is put on the design and modeling of the LC VCO. The LC VCO was designed and fabricated using the TSMC (Taiwan Semiconductor Manufacturing Co., LTD) CMOS 0.1 Sum technology. The linear frequency tuning range of the LC VCO is from 2.526 GHz to 3.015 GHz for control voltages from 0 to 1 V with a 1.712 mA tail current. WDF simulation results are compared with the exact solution if possible or otherwise with the results obtained with other simulation methods. The comparison shows that WDF techniques are efficient for the simulations of linear circuits and circuits with one nonlinear element. The potential of WDF for the simulation of large networks with many nonlinear elements is also discussed in this thesis

Studies on Implementation of . . . High Throughput and Low Power Consumption

In this thesis we discuss design and implementation of frequency selective digital filters with high throughput and low power consumption. The thesis includes proposed arithmetic transformations of lattice wave digital filters that aim at increasing the throughput and reduce the power consumption of the filter implementation. The thesis also includes two case studies where digital filters with high throughput and low power consumption are required. A method for obtaining high throughput as well as reduced power consumption of digital filters is arithmetic transformation of the filter structure. In this thesis arithmetic transformations of first- and second-order Richards’ allpass sections composed by symmetric two-port adaptors and implemented using carry-save arithmetic are proposed. Such filter sections can be used for implementation of lattice wave digital filters and bireciprocal lattice wave digital filters. The latter structures are efficient for implementation of interpolators and decimators by factors of two. Th

Combined MASS-DIMM instrument for atmospheric turbulence studies

Several site-testing programs and observatories currently use combined MASS-DIMM instruments for monitoring parameters of optical turbulence. The instrument is described here. After a short recall of the measured quantities and operational principles, the optics and electronics of MASS-DIMM, interfacing to telescopes and detectors, and operation are covered in some detail. Particular attention is given to the correct measurement and control of instrumental parameters to ensure valid and well-calibrated data, to the data quality and filtering. Examples of MASS-DIMM data are given, followed by the list of present and future applications.Comment: Accepted by MNRAS, 11 pages, 8 figure

A MINIMAL PASSIVE MODEL OF THE OPERATIONAL AMPLIFIER : APPLICATION TO SALLEN-KEY ANALOG FILTERS

International audienceThis papers stems from the fact that, whereas there are passive models of transistors and tubes, a minimal passive model of the operational amplifier does not seem to exist. A new behavioural model is presented that is memoryless, fully described by its interaction ports, with a minimal number of equations, for which a passive power balance can be defined. The proposed model handles saturation, asymmetric power supply, and can be used with non-ideal voltage references. To illustrate the model in audio applications , the non-inverting voltage amplifier and a saturating Sallen-Key lowpass filter are considered

Analysis and Design of Low-Cost Waveguide Filters for Wireless Communications

The area of research of this thesis is built around advanced waveguide filter structures. Waveguide filters and the waveguide technology in general are renowned for high power capacity, low losses and excellent electromagnetic shielding. Waveguide filters are important components in fixed wireless communications as well as in satellite and radar systems. Furthermore, their advantages and utilization become even greater with increase in frequency, which is a trend in modern communication systems because upper frequency bands offer larger channel capacities. However, waveguide filters are relatively bulky and expensive. To comply with more and more demanding miniaturization and cost-cutting requirements, compactness and economical design represent some of the main contemporary focuses of interest. Approaches that are used to achieve this include use of planar inserts to build waveguide discontinuities, additive manufacturing and substrate integration. At the same time, waveguide filters still need to satisfy opposed stringent requirements like small insertion loss, high selectivity and multiband operation. Another difficulty that metal waveguide components face is integration with other circuitry, especially important when solid-state active devices are included. Thus, improvements of interconnections between waveguide and other transmission interfaces are addressed too. The thesis elaborates the following aspects of work: Further analysis and improved explanations regarding advanced waveguide filters with E-plane inserts developed by the Wireless Communications Research Group, using both cross coupled resonators and extracted pole sections (Experiments with higher filter orders, use of tuning screws, degrees of freedom in design, etc. Thorough performance comparison with competing filter technologies) - Proposing novel E-plane filter sections with I-shaped insets - Extension of the E-plane filtering structures with metal fins to new compact dual band filters with high frequency selectivity and miniaturized diplexers. - Introduction of easy-to-build waveguide filters with polymer insert frames and high-performance low-profile cavity filters, taking advantage of enhanced fabrication capabilities when using additive manufacturing - Developing new substrate integrated filters, as well as circuits used to transfer signals between different interfaces Namely, these are substrate integrated waveguide to metal waveguide planar transitions that do not require any modifications of the metal waveguides. Such novel transitions have been designed both for single and orthogonal signal polarizations