The computational requirements of scientific research are constantly growing. In the field of radio astronomy, observations have evolved from using single telescopes, to interferometer arrays of many telescopes, and there are currently arrays of massive scale under development. These interferometers use signal and image processing to produce data that is useful to radio astronomy, and the amount of processing required scales quadratically with the scale of the array. Traditional computational approaches are unable to meet this demand in the near future. This thesis explores the use of heterogeneous parallel processing to meet the computational demands of radio astronomy. In heterogeneous computing, multiple hardware architectures are used for processing. In this work, the Graphics Processing Unit (GPU) is used as a co-processor along with the Central Processing Unit (CPU) for the computation of signal processing algorithms. Specifically, the suitability of the GPU to accelerate the correlator algorithms used in radio astronomy is investigated. This work first implemented a FX correlator on the GPU, with a performance increase of one to two orders of magnitude over a serial CPU approach. The FX correlator algorithm combines pairs of telescope signals in the Fourier domain. Given N telescope signals from the interferometer array, N2 conjugate multiplications must be calculated in the algorithm. For extremely large arrays (N >> 30), this is a huge computational requirement. Testing will show that the GPU correlator produces results equivalent to that of a software correlator implemented on the CPU. However, the algorithm itself is adapted in order to take advantage of the processing power of the GPU. Research examined how correlator parameters, in particular the number of telescope signals and the Fast Fourier Transform (FFT) length, affected the results.

This Master’s thesis deals with digital decimation filter design for undersampling and filtering of sigma-delta ADC signal. Filter cascade is designed in Matlab according to given requirements and is then described in VHDL language aiming for minimum area. Implemented filter functionality is compared to Matlab-generated reference filters in created verification environment. Finally the design is synthesized in specified technology and verified on gate level.

Software-defined radio is a continuously developing technology applied in fields of mobile communications and among others. It is a radio communication system where software is used to implement parts of its functionality in an embedded system or computer. Devices which can transmit and receive different radio protocols based on software has major advantages. The ability to be able to reconfigure and change functionality on the fly to adapt to different environments is suited for multiple different applications, one of such is the environment in space. Distortions such as phase, frequency and timing offset all occur in such environment. The effects of these distortions can be reduced using different synchronization techniques in the receiver. A polyphase symbol timing synchronizer with two different timing error detectors, is designed in Simulink consisting of an 8-tap polyphase filter bank, a zero-crossing or Gardner timing error detector, a second order Phase-locked loop and a numerically controlled oscillator. The initial design uses floating-point precision. A fixed-point model is implemented using Xilinx System Generator and is used to generate a custom IP. Simulation is done by implementing a transceiver model with Simulink for the transmitter and parts of the receiver. The polyphase symbol timing synchronizer locks after about 4000 symbols for lower signal-to-noise and the Gardner timing error detector performs better than the zero-crossing error detector at higher signal-to-noise ratios.

No description available.

In-phase and quadrature (I/Q) signal generation is often required in modern transceiver architectures, such as direct conversion or low-IF, either for vector modulation and demodulation, negative frequency recovery in direct conversion receivers, or image rejection. If imbalance between the I and Q channels exists, the bit-error-rate (BER) of the transceiver and/or the image rejection ratio (IRR) will quickly deteriorate. Methods for correcting I/Q imbalance are desirable and necessary to improve the performance of quadrature transceiver architectures and modulation schemes. This thesis presents the design and characterization of a monolithic 5-6 GHz Silicon Germanium (SiGe) inductor-capacitor (LC) tank voltage controlled oscillator (VCO) with tunable polyphase outputs. Circuits were designed and fabricated using the Motorola 0.4 ìm CDR1 SiGe BiCMOS process, which has four interconnect metal layers and a thick copper uppermost bump layer for high-quality radio frequency (RF) passives. The VCO design includes full-wave electromagnetic characterization of an electrically symmetric differential inductor and a traditional dual inductor. Differential effective inductance and Q factor are extracted and compared for simulated and measured inductors. At 5.25 GHz, the measured Q factors of the electrically symmetric and dual inductors are 15.4 and 10.4, respectively. The electrically symmetric inductor provides a measured 48% percent improvement in Q factor over the traditional dual inductor. Two VCOs were designed and fabricated; one uses the electrically symmetric inductor in the LC tank circuit while the other uses the dual inductor. Both VCOs are based on an identical cross-coupled, differential pair negative transconductance -GM oscillator topology. Analysis and design considerations of this topology are presented with a particular emphasis on designing for low phase noise and low-power consumption. The fabricated VCO with an electrically symmetric inductor in the tank circuit tunes from 4.19 to 5.45 GHz (26% tuning range) for control voltages from 1.7 to 4.0 V. This circuit consumes 3.81 mA from a 3.3 V supply for the VCO core and 14.1 mA from a 2.5 V supply for the output buffer. The measured phase noise is -115.5 dBc/Hz at a 1 MHz offset and a tank varactor control voltage of 1.0 V. The VCO figure-of-merit (FOM) for the symmetric inductor VCO is -179.2 dBc/Hz, which is within 4 dBc/Hz of the best reported VCO in the 5 GHz frequency regime. The die area including pads for the symmetric inductor VCO is 1 mm x 0.76 mm. In comparison, the dual inductor VCO tunes from 3.50 to 4.58 GHz (27% tuning range) for control voltages from 1.7 to 4.0 V. DC power consumption of this circuit consists of 3.75 mA from a 3.3 V supply for the VCO and 13.3 mA from a 2.5 V supply for the buffer. At 1 MHz from the carrier and a control voltage of 0 V, the dual inductor VCO has a phase noise of -104 dBc/Hz. The advantage of the higher Q symmetric inductor is apparent by comparing the FOM of the two VCO designs at the same varactor control voltage of 0 V. At this tuning voltage, the dual inductor VCO FOM is -166.3 dBc/Hz compared to -175.7 dBc/Hz for the symmetric inductor VCO -- an improvement of about 10 dBc/Hz. The die area including pads for the dual inductor VCO is 1.2 mm x 0.76 mm. In addition to these VCOs, a tunable polyphase filter with integrated input and output buffers was designed and fabricated for a bandwidth of 5.15 to 5.825 GHz. Series tunable capacitors (varactors) provide phase tunability for the quadrature outputs of the polyphase filter. The die area of the tunable polyphase with pads is 920 ìm x 755 ìm. The stand-alone polyphase filter consumes 13.74 mA in the input buffer and 6.29 mA in the two output buffers from a 2.5 V supply. Based on measurements, approximately 15° of I/Q phase imbalance can be tuned out using the fabricated polyphase filter, proving the concept of tunable phase. The output varactor control voltages can be used to achieve a potential ±5° phase flatness bandwidth of 700 MHz. To the author's knowledge, this is the first reported I/Q balance tunable polyphase network. The tunable polyphase filter can be integrated with the VCO designs described above to yield a quadrature VCO with phase tunable outputs. Based on the above designs I/Q tunability can be added to VCO at the expense of about 6 mA. Future work includes testing of a fabricated version of this combined polyphase VCO circuit. / Master of Science

Modern radio astronomy’s demand for high sensitivity and wide fields of view is met through innovations that reduce receiver system noise temperatures and integrate technology supporting parallel processing and larger instantaneous bandwidths. The advanced L-band phased array camera for astronomy (ALPACA) is a fully cryogenic 69 dual-polarized dipole PAF and digital beamformer back end for the Green Bank Telescope. This instrument will form 40 dual-polarized beams yielding a 0.35 sq. deg field of view on the sky with a 305.2 MHz processing bandwidth. The target system noise temperature is 27 K. A structured technique to map critically sampled and oversampled polyphase filter banks (PFBs) onto a systolic array for implementation on a field programmable gate array (FPGA) is shown. This method provides unique insights into the operation of these algorithms. A case study for an oversampled PFB operating at 666.67 Msps shows that these designs effectively utilize FPGA resources, maintain high-throughput, and are flexible solutions for varied application requirements. A new class of FPGA, the Radio Frequency System-on-Chip (RFSoC), is integrated as a full-functioning software-defined hardware platform in an open-source signal processing toolchain. This provides astronomers with essential hardware for contemporary scientific research. The demonstration for an experimental technique for measuring antenna radiation efficiency using the antenna Y factor method is presented. The noise contribution of the ALPACA dipole when operating at cryogenic temperatures is estimated. Our findings show that the antenna is expected to contribute less than 1 K to the instrument’s overall system noise temperature. Research contributions of this work are: the integration of new high-performance digital hardware in radio astronomical PAF digital back ends, an open-source RFSoC signal processing development toolchain, an oversampled PFB using an FPAG-based systolic array design, and estimating the cryogenic noise temperature of an ALPACA dipole from its radiation efficiency.

To develop more competitive solutions, one of the trends in the development of drive systems for electric and hybrid electric vehicles (EVs/HEVs) is to integrate the power electronic converter and the electric motor. This thesis aims to investigate the performance and the operation of modular converters in integrated motor drive systems for EVs/HEVs. In the first part, the concept of integrated modular motor drive systems for EVs/HEVs is introduced. Three suitable modular converter topologies, namely, the stacked polyphase bridges (SPB) converter, the parallel-connected polyphase bridges (PPB) converter and the modular high frequency (MHF) converter, are evaluated and compared with conventional electric drives in terms of power losses, energy storage requirements, and semiconductor costs. In the second part of the thesis, the harmonic content of the dc-link current of the SPB converter is analyzed. By adopting an interleaving modulation the size of the dc-link capacitor can be reduced without increasing the switching frequency, which is beneficial for achieving a compact integrated system. This method allows for around 80% reduction of the dc-link capacitance for vehicle drives, resulting in a significant size reduction of the power converter and improved integration. Finally, a communication-based distributed control system for the SPB converter is presented. The communication delay arising from the serial communication is inevitable, thus a timing analysis is also presented. It has been found that stability is maintained even when the baud rate of the SPI communication is lower than 1 Mbps, indicating that other communication protocols with lower bandwidths can also be adopted for this topology. The analytical investigations provided in this thesis are validated by experiments on a four-submodule laboratory prototype. Experimental results verify the correctness of the theoretical analysis, as well as the dynamic performance of the distributed control system. / <p>QC 20161121</p>

Il est débattue sur le temps closural finale de l'océan paléo-asiatique et la position. Certains géologues ont préconisé la suture "Solonker" marque la zone closural finale du Permien , tandis que d'autres insistent sur le fait Paléozoïque milieu. Nos trois domaines d'étude, le Hongqi , le Ondor Somme et le Mandula ont essentiel et important de résoudre ces controverses. Les unités litho-tectonique reconnus dans le domaine Hongqi-Ondor Sum sont le mélange Belt de Hongqi-Ondor Sum, la Belt de l'arc Bainaimiao, craton du Nord de Chine et les roches sédimentaires post-orogéniques. Le mélange Belt de Hongqi-Ondor Sum connu déformation ductile en deux phases et une phase de la déformation ductile-fragile. D1 est responsable de la S1 foliation, linéation minérale L1, et intrafolial pli F1. Les critères cinématiques indiquent un sens cisaillement de top-to-the-NW. D2 est caractérisée par divers taille de plis asymétriques avec axe presque NE correspondant à la poussée NW cisaillement. D3 formé le cadre régional dans le Hongqi et les zones Ondor Sum. La zone Mandula contient les sédiments olistostrome, les sédiments turbiditiques et roches volcanosédimentaires. Grains de zircons détritiques dans des échantillons sédimentaires indiquent la zone d'étude Mandula reçu des matériaux d'arc Bainaimiao et matières contemporaines de l'éruption volcanique du Permien. Les sédiments et les roches volcaniques dans la région Mandula soumettent un NW-SE ou près de N-S du raccourcissement. Les données géologiques indiquent qu'une subduction et collsion dans Paléozoïque inférieur, et rifting et fermeture rift dans Palezoic supérieur. Les fragments ophiolitiques "Solonker" sont en effet olistostrome. Composants ophiolitiques typiques ne sont pas observés dans la région Mandula. / It is hotly debated about the final closural time and position of the Paleo-Asian Ocean. Some geologists advocated the “Solonker” suture marks the final closural zone in Permian, whereas others insist in middle Paleozoic. Our three study areas, the Hongqi, the Ondor Sum and the Mandula is essential and important to solve those controversies. The litho-tectonic units recognized in the Hongqi-Ondor Sum area include the Hongqi-Ondor Sum mélange belt, the Bainaimiao arc belt, North China Craton and post-orogenic unconformably sedimentary rocks. The Hongqi-Ondor Sum mélange belt experienced two phase ductile deformation and one phase ductile-brittle deformation. D1 is responsible for the regional greenschist foliation S1, elongated mineral lineation L1, and intrafolial fold F1. The kinematic criteria indicates a top-to-the-NW shearing sense. D2 is characterized by various sized of unsymmetrical folds with nearly NE axis corresponding to the NW thrust shearing. D3 formed the regional framework in the Hongqi and the Ondor Sum areas. The Mandula area contains olistostrome sediments, turbiditic sediments and volcano-sedimentary rocks. Detrital zircon grains in sedimentary samples argue the Mandula study area received the southern Bainaimiao arc materials and coeval Permian volcanic erupting materials nearby. The sediments and volcanic rocks in Mandula area subject a nearly NW-SE or N-S compressional shortening. The geological data support that an Early Paleozoic subduction and collsioan, Late Palezoic rifting and rift closure model. The so called “Solonker” ophiolitic fragments indeed are olistostrome. Typical ophiolite components are not observed in the Mandula area.

Emerging technologies such as Bluetooth and 802.11b (Wi-Fi) have fuelled the growth of the short-range communication industry. Bluetooth, the leading WPAN (wireless personal area network) technology, was designed primarily for cable replacement applications. The first generation Bluetooth products are focused on providing low-cost radio connections among personal electronic devices. In the WLAN (wireless local area network) arena, Wi-Fi appears to be the superior product. Wi-Fi is designed for high speed internet access, with higher radio power and longer distances. Both technologies use the same 2.4GHz ISM band. The differences between Bluetooth and Wi-Fi standard features lead to a natural partitioning of applications. Nowadays, many electronics devices such as laptops and PDAs, support both Bluetooth and Wi-Fi standards to cover a wider range of applications. The cost of supporting both standards, however, is a major concern. Therefore, a dual-mode transceiver is essential to keep the size and cost of such system transceivers at a minimum. A fully integrated low-IF Bluetooth receiver is designed and implemented in a low cost, main stream 0.35um CMOS technology. The system includes the RF front end, frequency synthesizer and baseband blocks. It has -82dBm sensitivity and draws 65mA current. This project involved 6 Ph.D. students and I was in charge of the design of the channel selection complex filter is designed. In the Bluetooth transmitter, a frequency modulator with fine frequency steps is needed to generate the GFSK signal that has +/-160kHz frequency deviation. A low power ROM-less direct digital frequency synthesizer (DDFS) is designed to implement the frequency modulation. The DDFS can be used for any frequency or phase modulation communication systems that require fast frequency switching with fine frequency steps. Another contribution is the implementation of a dual-mode 802.11b/Bluetooth receiver in IBM 0.25um BiCMOS process. Direct-conversion architecture was used for both standards to achieve maximum level of integration and block sharing. I was honored to lead the efforts of 7 Ph.D. students in this project. I was responsible for system level design as well as the design of the variable gain amplifier. The receiver chip consumes 45.6/41.3mA and the sensitivity is -86/-91dBm.

It is hotly debated about the final closural time and position of the Paleo-Asian Ocean. Some geologists advocated the "Solonker" suture marks the final closural zone in Permian, whereas others insist in middle Paleozoic. Our three study areas, the Hongqi, the Ondor Sum and the Mandula is essential and important to solve those controversies. The litho-tectonic units recognized in the Hongqi-Ondor Sum area include the Hongqi-Ondor Sum mélange belt, the Bainaimiao arc belt, North China Craton and post-orogenic unconformably sedimentary rocks. The Hongqi-Ondor Sum mélange belt experienced two phase ductile deformation and one phase ductile-brittle deformation. D1 is responsible for the regional greenschist foliation S1, elongated mineral lineation L1, and intrafolial fold F1. The kinematic criteria indicates a top-to-the-NW shearing sense. D2 is characterized by various sized of unsymmetrical folds with nearly NE axis corresponding to the NW thrust shearing. D3 formed the regional framework in the Hongqi and the Ondor Sum areas. The Mandula area contains olistostrome sediments, turbiditic sediments and volcano-sedimentary rocks. Detrital zircon grains in sedimentary samples argue the Mandula study area received the southern Bainaimiao arc materials and coeval Permian volcanic erupting materials nearby. The sediments and volcanic rocks in Mandula area subject a nearly NW-SE or N-S compressional shortening. The geological data support that an Early Paleozoic subduction and collsioan, Late Palezoic rifting and rift closure model. The so called "Solonker" ophiolitic fragments indeed are olistostrome. Typical ophiolite components are not observed in the Mandula area.