Electronic Engineering

This work presents a multichannel IC architecture which is able to process and digitize simultaneous current pulses in every input channel with no deadtime. The analog to digital conversion is performed in two steps: 6 MSBs are quantized by the Charge Pulse System (CPS) and 8 LSBs are obtained from a later ADC for a total of 14 ENOB at the output. An IC designed for sensors with fast pulse current responses is currently under development. The CPS extended input range can take advantage of high gain sensors thus improving overall SNR of the detector. Energy resolution dependent applications such as PET might benefit from this novel DAQ architecture.

Multipliers are the key components of ALU units used in many functions like signal processing applications, Fourier transformation and digital filters. Vedic mathematics which provide simple mathematical approaches is found to attain increased speed and reduced power consumption as in comparison to conventional multiplier designs. Leakage power has become a serious issue in the microelectronic circuit design as the technology scales down to deep submicron process. Sleep transistor technique is a simple concept to mitigate the effect of leakage power which uses extra transistors to turn off power supplies in the logic circuit during standby mode. In this paper, 8 bit Vedic multiplier is designed using power gating and drain gating technique along with its different variations.

Power system network will never operate under ideal conditions but contains power quality problems. FACTS based controllers like DVR, DSTATCOM and APF (active power filter) are some of the compensating devices used to improve power quality. UPQC (unified power quality conditioner) is a back-to-back converter topology with common DC-link voltage employed to improve power quality. This paper presents multi-level (three-level) UPQC as power quality conditioner in distribution system. The pulses from hysteresis control trigger UPQC where reference currents are generated using IRP (instantaneous reactive power) control theory for shunt controller and SRF theory for series controller. Analysis is presented with the conditions like UPQC as series compensator conditioning source voltage, UPQC as shunt compensator compensating harmonics in source current and UPQC as (series and shunt) compensator conditioning source voltage and harmonics. System proposed is build and analysis is presented us...

This paper describes a fully integrated Low Noise Amplifier (LNA) + mixer + first filtering stage, suitable for direct conversion receivers. Its key feature is a current driven passive mixer loaded by a low impedance. Measurements performed on a 0.18 pm CMOS prototype, confirm that this architecture, when compared to a classic one, gives a much smaller flicker noise (70 kHz llf comer), together with an excellent noise figure (4.4 dB integrated from 10 kHz to 1.92 MHz), while requiring only 15 mW of power. Moreover, a very good linearity is simultaneously achieved (I1P3 = -I dBm). The main limitation of the present implementation is the bandwidth of the opamp that implements the mixer load. Due to this, IIP3 degrades at higher frequency (IIP3 about -12 dBm at 10 MHz). This is however not a fundamental limitation.

This paper introduces a design of an ASAR (Asynchronous Successive Approximation Register) ADC (analog-to-digital converter) using a Charge Scaling DAC (digital-to-analog converter). As the name itemizes the word asynchronous, the ASAR ADC is independent of the clock signal. The proposed ASAR ADC consists of a comparator, Charge Scaling DAC and digital control logic block. The proposed ADC was simulated using 180nm CMOS technology which dissipates 32.419μW power when operated on a single 1 V power supply which is lesser compared to other architectures such as current scaling DAC and voltage scaling DAC.

Abstracf-A novel internal quadhand antenna for radiotelephone handset applications is presented. The design uses a hybrid of ceramic and conventional antenna technologies and shows good effciency characteristics. With a volume of 3.5cc, the antenna is smaller than current in-sewice tri and quad band designs. A method of extending the design for diversity or MIMO applications at the higher frequencies is discussed. Index terms-dielectric antenna, handset antenna, high dielectric ceramics, MIMO antennas.

Code division multiple access (CDMA) suffers from intersymbol interference (ISI) and multi-user interference (MUI) in a frequency-selective multipath fading channel, but when properly designed, it enjoys multipath diversity. Orthogonal frequency division multiple access ...

Resonant converters can operate at high switching frequencies with low switching losses. However, in order to reduce switching losses resonant frequency has an important role in the design. In this study, a DSP based closed loop phase locked loop (PLL) control algorithm for parallel resonant inverter is designed and simulated with MATLAB/Simulink. The validity of the Simulink model of current source inverter is tested for different loads and gain values obtained from Jury's stability. The developed DSP controlled parallel resonant inverter tracks the resonant frequency and achieves soft switching.

Single Carrier Frequency Division Multiple Access (SCFDMA) system performs better than multicarrier transmission systems due to its inherent single carrier structure. It is a strong candidate for uplink communication due to its lower peak to average power ratio (PAPR) but it is high sensitive to carrier frequency offset. However the problem of intercarrier interference (ICI) in SCFDMA system is not addressed. In this paper conjugate cancellation method is used to reduce the effect of frequency offset in SCFDMA system. Bit error rate of OFDMA and SCFDMA system is compared in different multipath channels using zero forcing equalizer (ZFE) and Minimum mean square error (MMSE) equalizers. Simulation results shows that ZFE performs better for additive white gaussian noise (AWGN) and pedestrian channels but its performance gets degraded in vehicular channels. MMSE equalizer performs better than zero forcing equalizer up to 0.2 normalized frequency offset in vehicular channels.

Signal transduction from a cell's surface to cytoplasmic and nuclear targets takes place through a complex network of interconnected pathways. Phosphorylation cycles are common components of many pathways and may take the form of a multi-layered cascade of cycles or incorporate species with multiple phosphorylation sites that effectively create a sequence of cycles with increasing states of phosphorylation. This work focuses on the frequency response and sensitivity of such systems, two properties that have not been thoroughly examined. Starting with a singularly phosphorylated single-cycle system, we compare the sensitivity to perturbation at steady-state across a range of input signal strengths. This is followed by a frequency response analysis focusing on the gain and associated bandwidth. Next, we consider a two-layer cascade of single phosphorylation cycles and focus on how the two cycles interact to produce various effects on the bandwidth and damping properties. Then we consider the (ultra)sensitivity of a doubly phosphorylated system, where we describe in detail first-order ultrasensitivity, a unique property of these systems, which can be blended with zero-order ultrasensitivity to create systems with relatively constant gain over a range of signal input. Finally, we give an in-depth analysis of the sensitivity of an n-phosphorylated system.

Power dissipation is becoming a limiting factor in the realization of VLSI systems. The principal reasons for this are maximum operating temperature and, for portable applications, battery life. Because of the relatively greater complexity, the power dissipation in digital signal processing (DSP) applications is of special significance, and low power design technique,'; are now emerging. This paper provides an overview of the techniques and methodologies that have emerged in the past few years for DSP system design. These include techniques for minimizing power at architectural ~.nd algorithmic levels including DSP programming issues. In addition, the paper indicates some potential design directions.

Selection of dynamic dividers in CMOS PLLs for GHzs applications allows remarkable reduction in power loss without affecting phase noise and power supply sensitivity. Frequency dividers are combination of classic TSPC logic (true-single-phase-clock) and E_TSPC logic (extended TSPC). The designed PLL with % 8/9 prescaler is used for wireless LAN applications and synthetic of frequencies between 5.14 to 5.70 GHz. In this paper a % 8/9 prescaler has designed at 0.25 micrometers process for 2.5_3 GHz band width. This prescaler has been designed with 2.5v power supply with using E_TSPC logic. In this circuit in addition to decrement of power consumption, divider can work in a nearly high speed. Subsequently the dimensions of transistors have been improved and power consumption has been reduced from 3.8mw to 2.9mw. Then, the layout of circuit has been designed with L-Edit software. The simulation results of are identical to that we expect according to earlier Spice simulations.

Location of faults on aging cables is of great interest to maintainers of aircraft, cars, power distribution systems, communication systems, etc. One class of methods for locating faults is frequency domain reflectometry (FDR), using sine waves as the forcing function. A new frequency domain method called mixedsignal reflectometry (MSR) is described in this paper and compared to data from phase detection FDR (PDFDR) methods. The MSR is less expensive and smaller than the PDFDR and has very similar performance. A prototype system using the 100-200-MHz bandwith with 256 40-kHz steps is shown to have a resolution of about 10 cm, very similar to a PDFDR in the same frequency band.

Quantum measurements are a fundamental component of quantum computing. However, on modern-day quantum computers, measurements can be more error prone than quantum gates, and are susceptible to nonunital errors as well as non-local correlations due to measurement crosstalk. While readout errors can be mitigated in post-processing, it is inefficient in the number of qubits due to a combinatorially-large number of possible states that need to be characterized. In this work, we show that measurement errors can be tailored into a simple stochastic error model using randomized compiling, enabling the efficient mitigation of readout errors via quasi-probability distributions reconstructed from the measurement of a single preparation state in an exponentially large confusion matrix. We demonstrate the scalability and power of this approach by correcting readout errors without matrix inversion on a large number of different preparation states applied to a register of eight superconducting transmon qubits. Moreover, we show that this method can be extended to mid-circuit measurements used for active feedback via quasi-probabilistic error cancellation, and demonstrate the correction of measurement errors on an ancilla qubit used to detect and actively correct bit-flip errors on an entangled memory qubit. Our approach enables the correction of readout errors on large numbers of qubits, and offers a strategy for correcting readout errors in adaptive circuits in which the results of mid-circuit measurements are used to perform conditional operations on non-local qubits in real time.

Wireless local-area networks (WLANs) have been deployed as office and home communications infrastructures worldwide. The diversification of the standards, such as IEEE 802.11 series demands the design of RF front-ends. Low power consumption is one of the most important design concerns in the application of those technologies. To maintain competitive hardware costs, CMOS has been used since it is the best solution for low cost and high integration processing, allowing analog circuits to be mixed with digital ones. In the receiver chain, the low noise amplifier (LNA) is one of the most critical blocks in a transceiver design. The sensitivity is mainly determined by the LNA noise figure and gain. It interfaces with the pre-select filter and the mixer. Furthermore, since it is the first gain stage, care must be taken to provide accurate input match, low-noise figure, good linearity and a sufficient gain over a wide band of operation. Several CMOS LNAs have been reported during the last decade, showing that the most research has been done at 802.11/b and GSM standards (900-2400MHz spectrum) and more recently at 802.11/a (5GHz band). One of the more significant disadvantages of 802.11/b is that the frequency band is crowded and subject to interference from other technologies, as is 2.4GHz cordless phones and Bluetooth. As the demand for radiofrequency integrated circuits, operating at higher frequency bands, increases, the IEEE 802.11/a standard becomes a very attractive option to wireless communication system developers. This paper presents the design and implementation of a low power, low noise amplifier aimed at IEEE 802.11a for WLAN applications. It was designed to be integrated with an active balun and mixer, representing the first step toward a fully integrated monolithic WLAN receiver. All the required circuits are integrated at the same die and are powered by 1.8V supply source. Preliminary experimental results (S-parameters) are shown and promise excellent results. The LNA circuit design details are illustrated in Section 2. Spectre simulation results focused at gain, noise figure (NF) and input/output matching are presented in Section 3. Finally, conclusions and comparison with other recently reported LNAs are made in Section 4, followed by future work.

This work presents the effects of radio-frequency Local Oscillator non-idealities on OFDM inter-carrier interference. The synthesizer has the main role on modulation and demodulation process of base band IQ signals to radio frequency channels which need to fulfill several requirements imposed by standards specifications. Phase and frequency stability are crucial, since the synchronization of the entire system depends on the accuracy of this circuit. The discussed OFDM system is based on a simulation scenario including radio-frequency channel conversion considering Local Oscillator with configurable phase noise power and bandwidth. This feature allows the study of global system based on Local Oscillator output spectrum. Sub-channel spacing, cyclic redundancy and pulse shaping are configurable. The obtained results indicate that free run oscillator phase noise characterization is not appropriate when the Local Oscillator in the radio-frequency front end is based on synthesizer architecture. System evaluation is based on error vector magnitude. The relation of this metric with the Local Oscillator phase noise allows the performance estimation of the global system.

Abstract1— This paper presents the design and simulation of a 5GHz monolithic low-noise amplifier integrated with an active Balun. Intended to WLAN applications, the fully integrated circuit was implemented in a 0.18μm CMOS technology. The simulations, optimized to noise ...

We propose a unified model for large signal and small signal non-quasi-static analysis of long channel symmetric double gate MOSFET. The model is physics based and relies only on the very basic approximation needed for a charge-based model. It is based on the EKV formalism [Enz C, Vittoz EA. Charge based MOS transistor modeling. Wiley; 2006] and is valid in all regions of operation and thus suitable for RF circuit design. Proposed model is verified with professional numerical device simulator and excellent agreement is found.

Modular structured multilevel inverter is very useful for electrical application especially in high voltage and high power applications. The main function of this multilevel inverter is to produce multilevel AC output voltage from several separate DC sources. This project is to derive a newmathematical formulation of multilevel voltage source inverter switching instants. The proposed method for this project is based on the sinusoidal natural sampling PWM (SPWM) by comparing several modified modulation signal with a triangular carrier signal. This resulting intersection points between this modulation and carrier signal become the switching instants of the PWM pulses. Derivation also based on Alternative Phase opposition disposition (APOD). A cascaded multilevel inverter is selected as a topology for this project due to major advantages compare with other topology. The derived formula is analyzed by using MATLAB simulation software. It is found that the results that use the derived formula are almost identical to simulation result.

Nowadays power inverters serve as an important emergency power supply system in events of main power supply failure. The AC output voltage of a power electronic inverter is usually non-sinusoidal and hence has a high harmonic content. Sinusoidal Pulse Width ...

Logic compatible gain cell (GC)-embedded DRAM (eDRAM) arrays are considered an alternative to SRAM because of their small size, non rationed operation, low static leakage, and two-port functionality. But traditional GC-eDRAM implementations require boosted control signals in order to write full voltage levels to the cell to reduce the refresh rate and shorten access times. The boosted levels require an extra power supply or on-chip charge pumps, as well as nontrivial level shifting and toleration of high voltage levels. In this paper, we present a novel, logic compatible, 3T GC-eDRAM bit cell that operates with a single-supply voltage and provides superior write capability to the conventional GC structures. The proposed circuit is demonstrated in 0.25μm CMOS process targeted at low power, energy efficient application

The following article analyses some results of investigation "Present state and trends of using computers in Slovenian primary and secondary schools". This research the author performs biannual for Ministry of education and sport and national project "Informatization of Slovenian education system". Research project has covered the following topics: analysis of ICT, design and defi nition of didactical aspects of ICT in Slovenian learning system, design and defi nition of didactical forms, methods, approaches, models of ICT in education and training, their practical value, and compatibility with contemporary educational systems goals. The article presents some problems on educational hardware, software, pedagogic staff and some didactic criteria of learning Informatics and Computer sciences and computer applications in the Slovenian educational process. Članak analizira neke od rezultata istraživanja »Sadašnje stanje i trendovi korištenja računala u slovenskim osnovnim i srednjim školama. Istraživanje autor izvodi u dvogodišnjim ciklusima za Ministarstvo obrazovanja i sporta i nacionalnog projekta "Informatizacija slovenskog školstva". Istraživački projekt pokriva slijedeće teme: analiza ICT-a, dizajna i određivanje didaktičkih aspekata ICT-a u slovenskom sustavu za učenje, oblikovanje i određivanje didaktičkih formi, metoda, pristupa, modela informacijske i komunikacijske tehnologije u obrazovanju i osposobljavanju, njihove praktične vrijednosti te kompatibilnost sa suvremenim ciljevima obrazovnih sustava. U članku se navode neki od problema obrazovnog hardvera, softvera, pedagoškog osoblja i neke didaktičke kriterije učenja informatike i računalne znanosti i računalne aplikacije u slovenskom obrazovnom procesu.

The reliable and efficient operation of three-phase transmission lines is crucial for ensuring the stability and integrity of electrical power distribution networks. Fault detection and location represent critical aspects of maintaining grid reliability. This research paper introduces a novel approach for fault detection and location in three-phase transmission lines, specifically targeting positive sequence faults. The proposed method leverages Support Vector Machines (SVM) as a robust machine learning technique to analyze the electrical signals from the transmission lines. Positive sequence fault signals are extracted and processed to develop a fault detection and location model. Unlike traditional methods that rely on complex mathematical algorithms or time-consuming simulations, this approach offers a data-driven solution for fault detection and location. The research focuses on the identification of positive sequence faults, which are common and often indicative of early-stage problems in the power grid. By utilizing SVM, the model demonstrates high accuracy and efficiency in identifying these faults, minimizing false alarms, and enhancing the reliability of fault detection systems. Furthermore, the model's ability to pinpoint the location of the fault within the transmission line is a valuable asset for power grid operators. Rapid fault localization aids in reducing downtime, improving response times, and ultimately ensuring the continuous supply of electricity to consumers.

A fully scalable and SPICE compatible wide band model up to 80 GHz of on-chip interconnects is presented in this paper. The series branch of the proposed model consists of an RL ladder network to characterize the skin and proximity effects as well as substrate skin effect. Their values are obtained from a technique based on a modified effective loop inductance model and complex image method. A CG network is used as the shunt branch of the model, which accounts for capacitive coupling through the oxide and substrate loss due to the electrical field. The values of these elements are determined by analytical formulas. The model is validated by both full-wave simulation and measurements. The simulated S-parameters of the model agree well with the measured S-parameters of on-chip interconnects with different widths and lengths over a wide frequency band from DC up to 80 GHz.

This paper describes the current conveyors used as a basic building block in a variety of electronic circuit in instrumentation and communication systems. Today these systems are replacing the conventional Op-amp in so many applications such as active filters, analog signal processing, and converters. A detailed study is presented here for its applications.

This chapter proposes the combination of temporal processing through Rake combining based on direct sequence-spread spectrum (DS-SS), and multiple antenna beamforming or antenna spatial diversity as a possible physical layer access technique for fifth generation (5G) small cell base stations (SBS) operating in the millimetre wave (mmWave) frequencies. Unlike earlier works in the literature aimed at previous generation wireless, the use of the beamforming is presented as operating in the radio frequency (RF) domain, rather than the baseband domain, to minimise power expenditure as a more suitable method for 5G small cells. Some potential limitations associated with massive multiple input-multiple output (MIMO) for small cells are discussed relating to the likely limitation on available antennas and resultant beamwidth. Rather than relying, solely, on expensive and potentially power hungry massive MIMO (which in the case of a SBS for indoor use will be limited by a physically small form factor) the use of a limited number of antennas, complimented with Rake combining, or antenna diversity is given consideration for short distance indoor communications for both the SBS) and user equipment (UE). The proposal's aim is twofold: to solve eroded path loss due to the effective antenna aperture reduction and to satisfy sensitivity to blockages and multipath dispersion in indoor, small coverage area base stations. Two candidate architectures are proposed. With higher data rates, more rigorous analysis of circuit power and its effect on energy efficiency (EE) is provided. A detailed investigation is provided into the likely design and signal processing requirements. Finally, the proposed architectures are compared to current fourth generation long term evolution (LTE) MIMO technologies for their anticipated power consumption and EE.

Supercapacitors, one of the most promising energy storage technologies for high power density industrial applications, exchange the energy mostly through power electronic converters, operating under high frequency components due to the commutation. The high frequency produces important effects on the performance of the supercapacitors in relation to their capacitance, inductance and internal resistance (ESR). These parameters are fundamental to evaluate the efficiency of this energy storage system. The aim of the paper is to obtain an accurate model of two supercapacitors connected in series (functional and extrapolated unit) to represent the frequency effects for a wide range of frequencies. The methodology is based on the definition of an appropriate equivalent electric circuit with voltage dependance, obtaining their parameters from experimental tests, carried out by means of electrochemical impedance spectroscopy (EIS) and the use of specific software tools such as EC-Lab® and S...

Today, the advent of radar sensing in applications requiring ever higher precision, such as automotive and industrial monitoring, needs the development of systems with superior resolution, stability and accuracy on 2D/3D spaces. Multiple-input multiple-output (MIMO) radar systems have been studied for more than twenty years, proving to achieve excellent resolutions by merging simultaneous observations from sparse multiple radars. In addition, long-term frequency/phase coherence among distributed signals to and from remote and widely distributed radar frontends, enables a centralized architecture where, in a common base station (BS) site, all the received signals can be coherently processed in synergy, allowing to further improve detection, localization and imaging capabilities. Radio-over-fiber (RoF) solutions represent an enabling technology for guaranteeing coherence among all radar signals coherently generated in the BS and distributed/collected to/from the radar heads by means of optical fiber links. Despite the unprecedented frequency-agility provided by photonics-based radiofrequency (RF) up-/downconversion in the optical domain, for applications requiring massive low-cost production and power efficiency, such as advanced driver-assistance systems, it might be convenient to transmit and receive conventionally generated RF signals, and to limit the use of photonics, as in RoF, to RF signal distribution through cheap high-capacity optical links, in order to avoid EM interference, minimize loss, signal distortion and link encumbrance, still keeping the coherence among distributed signals. In this work, we present a MIMO radar-over-fiber (RaoF) network, where a common BS transmits and receives RF signals through optical standard single-mode fiber (SSMF), to and from two remote radar transmitters (TXs) and four receivers (RXs), all remote with respect to the BS and distributed on a 3m-long baseline, and employing cheap patch antennas. Electro-optic conversion is achieved through direct modulation (DM) of lowcost, power-effective and high-speed vertical-cavity surfaceemitting lasers (VCSELs) working in the 1.3 µm-wavelength regime. Such a wavelength ensures propagation over SSMF with negligible distortions up to the km-range. The system is tested in a down-scaled indoor scenario and an RF carrier of 8.5 GHz is used, due to the limited frequency response of the employed VCSELs. System performance is evaluated with 1.4 GHz-bandwidth signals, comparing non-coherent and coherent signal elaboration. In addition, dual-band operation in the same RF region is tested, This paragraph of the first footnote will contain the date on which you submitted your paper for review. It will also contain support information, including sponsor and financial support acknowledgment. For example, "This work was supported in part by the U.S. Department of Commerce under Grant BS123456." The next few paragraphs should contain the authors' current affiliations, including current address and e-mail. For example, F. A. Author is with the confirming that VCSEL-based optical links are a viable way to guarantee phase coherence among the distributed signals and among multiple frequency bands. Coherent MIMO processing also confirm the potential to achieve superior range and crossrange resolution than non-coherent data fusion.

In this paper, the concept of information diversity in both the space and frequency domains is investigated for multiple-input multiple-output (MIMO) radars with widely separated antennas. Compared to phased-antenna arrays and multistatic radars, they can exploit more degrees of freedom, allowing them to maximize the information content upon centralized data fusion, thus granting unprecedented target detection and localization capabilities. This analysis proceeds in parallel with the running progresses of microwave photonics (MWP), which could represent, in the near future, a new paradigm for the development of centralized MIMO radar architectures. Thus, understanding the implications of information diversity becomes essential to foretell the system effectiveness in detecting and resolving closely spaced targets, as well as in suppressing sidelobes which may lead to false alarms. Performance metrics are proposed and evaluated to characterize the effects that information diversity has on centralized MIMO radars with widely separated antennas. On the other hand, the proposed methodology could reveal precious for designing the optimum system configuration.

Multi-static SARs from LEO orbits allow the single-pass high-resolution imaging and detection of moving targets. A coherent MIMO approach requires the generation of multi-band, thus orthogonal, signals, the fusion of which increases the system resolution. Up to now the synchronization capability of SAR signals of different satellites is critical. Here, we propose the use of photonics to generate, receive and distribute the radar signals in a coherent multi-static SAR constellation. Photonics overcomes issues in the implementation of MIMO SAR, allowing for the flexible generation of multi-band signals and centralized generation in a primary satellite with coherent distribution to all the secondary satellites of the SAR signals over FSO links. The numerical analysis shows the proposed system has a NESZ < −29.6 dB, satisfying the SAR system requirements. An experimental proof of concept based on COTS, for both signal up- and down-conversion, is implemented to demonstrate the system ...

Today, the advent of radar sensing in applications requiring ever higher precision, such as automotive and industrial monitoring, needs the development of systems with superior resolution, stability and accuracy on 2D/3D spaces. Multiple-input multiple-output (MIMO) radar systems have been studied for more than twenty years, proving to achieve excellent resolutions by merging simultaneous observations from sparse multiple radars. In addition, long-term frequency/phase coherence among distributed signals to and from remote and widely distributed radar frontends, enables a centralized architecture where, in a common base station (BS) site, all the received signals can be coherently processed in synergy, allowing to further improve detection, localization and imaging capabilities. Radio-over-fiber (RoF) solutions represent an enabling technology for guaranteeing coherence among all radar signals coherently generated in the BS and distributed/collected to/from the radar heads by means of optical fiber links. Despite the unprecedented frequency-agility provided by photonics-based radiofrequency (RF) up-/downconversion in the optical domain, for applications requiring massive low-cost production and power efficiency, such as advanced driver-assistance systems, it might be convenient to transmit and receive conventionally generated RF signals, and to limit the use of photonics, as in RoF, to RF signal distribution through cheap high-capacity optical links, in order to avoid EM interference, minimize loss, signal distortion and link encumbrance, still keeping the coherence among distributed signals. In this work, we present a MIMO radar-over-fiber (RaoF) network, where a common BS transmits and receives RF signals through optical standard single-mode fiber (SSMF), to and from two remote radar transmitters (TXs) and four receivers (RXs), all remote with respect to the BS and distributed on a 3m-long baseline, and employing cheap patch antennas. Electro-optic conversion is achieved through direct modulation (DM) of lowcost, power-effective and high-speed vertical-cavity surfaceemitting lasers (VCSELs) working in the 1.3 µm-wavelength regime. Such a wavelength ensures propagation over SSMF with negligible distortions up to the km-range. The system is tested in a down-scaled indoor scenario and an RF carrier of 8.5 GHz is used, due to the limited frequency response of the employed VCSELs. System performance is evaluated with 1.4 GHz-bandwidth signals, comparing non-coherent and coherent signal elaboration. In addition, dual-band operation in the same RF region is tested, This paragraph of the first footnote will contain the date on which you submitted your paper for review. It will also contain support information, including sponsor and financial support acknowledgment. For example, "This work was supported in part by the U.S. Department of Commerce under Grant BS123456." The next few paragraphs should contain the authors' current affiliations, including current address and e-mail. For example, F. A. Author is with the confirming that VCSEL-based optical links are a viable way to guarantee phase coherence among the distributed signals and among multiple frequency bands. Coherent MIMO processing also confirm the potential to achieve superior range and crossrange resolution than non-coherent data fusion.

This study is to maintain and extend the power standards at National Physical Laboratory (NPL) in the United Kingdom. The calibration service of microwave power sensors at high frequencies is endangered because a limited number of traceable waveguide power sensors is available at 50 GHz and above. In this thesis, the technologies of sensing microwave power in waveguides are reviewed, and the bolometric power sensor is investigated further, as its principle is suitable for the traceability requirement at NPL. The conventional design technique of bolometric sensor based on transmission line theory is generalised and two power sensor designs are introduced. The X-band sensor was fabricated, measured at the University of Birmingham and calibrated at NPL. Excellent linearity and high effective efficiency of the design was obtained. The high frequency power sensor designs based on the proposed technique can be scalable to 300 GHz and above, and a W-band sensor is introduced as an example. In order to add more flexibility in selecting frequency and bandwidth, a novel design of microwave power sensor with integrated filter function is described. An analytical power sensor synthesis technique using coupling matrix is presented for the first time. An X-band power sensor with integrated third order Chebyshev filter function was designed and manufactured. Experiential measurements in Birmingham and NPL are in good agreement with simulation and theoretical expectation. This work is the outcome of a three years PhD programme in a collaboration between the

This paper presents a four-channel beamforming TX implemented in 65 nm CMOS. Each beamforming TX is comprised of a C-2C split-array multiphase switched-capacitor power amplifier (SAMP-SCPA). This is the first use of multiphase interpolation (MPI) for beam steering. This technique is ideal for low-frequency beamforming and MIMO, as it does not require passive or LO-based phase shifters. The SCPA is ideal for use as the core element since it can perform frequency translation and data conversion, and drive an output at high power and efficiency in a compact die area. A prototype four-element beamforming TX, occupying 2mm×2.5mm, can achieve a peak output power of 24.4 dBm with a peak system efficiency (SE) of 24%, while achieving <1∘ phase resolution and <1 dB gain error. When transmitting a 15 MHz, 64-QAM long-term evolution (LTE) signal it outputs 18.4 dBm at 14% SE with a measured adjacent channel leakage ratio (ACLR) of <−30 dBc and an error vector magnitude (EVM) of 3.27% ...

This paper presents study of a 6.78 MHz RF source with impedance matching network based inductively coupled plasma generator ignition system for an H-ion source. Two types of 10 turn RF antenna (solenoid coil) were developed, to couple the RF power to the ignition plasma chamber. The antenna's electric parameters were measured using Vector Network Analyzer (VNA). A copper conductor of 3 x 4 mm size with 10 turn solenoid coil was selected for simulation and experimental prototype antenna. Two L-types of (CCL and LCL C-capacitor and Linductor) matching network were selected for impedance matching network for RF antenna. Initial simulations are carried out using ELSIE and LT-spice for frequency range from 5 to 8MHz. The matching network along with RF antenna was matched to ~ 50 Ωimpedance at 6.78 MHz with capacitive nature. An experimental prototype RF power source, 10 turn antenna (coil) and a matching network was developed to validate the simulation results. The prototype ignition system along with impedance matching network L-type with CCL was tested for inductively coupled hydrogen plasma generation and experimental results presented. Hydrogen plasma generation starts at minimum antenna coupled RF power of 150 watts, once initiated hydrogen plasma maintains to a minimum RF power of 10 watts.

With increasing switching frequency and higher power density of converter systems, electromagnetic interference (EMI) problems introduce additional design constraints that should be considered in the earliest system design stages. To comply with EMC standards, the conducted and radiated emission levels generated by power electronic systems have to be controlled, necessitating the use of EMI filter circuits. Thus, EMI filter components have to be examined in detail, including their high-frequency behaviour in combination with PCB placement and parasitic couplings. An optimised arrangement of filter components is required to fulfil EMI specifications with minimum constructional effort. In order to speed up EMI filter design, nowadays mostly based on a trial-and-error process, virtual prototyping and accurate electromagnetic simulators are required.

To meet the needs of future wireless optical networks, this paper introduces a high-speed, hybrid multiplexed, coherent free-space optical (FSO) communication system that integrates an orbital angular momentum (OAM) multiplexed signal with an orthogonal frequency division multiplexing (OFDM) technique. Two independent QAM polarized beams, each carrying in-phase and quadrature (I/Q) phase 16-QAM-OFDM modulated data, are combined using mode division multiplexing (MDM) to increase the capacity of the proposed system. The reason of choosing OFDM is its capability to support higher data rate, and mitigating intersymbol interference (ISI). The signal is detected using a coherent detection-based digital signal processing (DSP) algorithm at the receiver end. The proposed hybrid FSO system is evaluated in low and heavy dust environments using bit error rate (BER), link distance, optical signal-to-noise ratio (OSNR), and received optical power performance matrices. The simulation results demonstrate the successful transmission of a 120 Gb/s single carrier over the longest link ranges of 1.5 and 0.40 km, respectively, under low and heavy dust weather environments below the signal degradation threshold value (forward error correction (FEC) limit) of BER 2.2 × 10 -3 in strong turbulent conditions.

This paper describes a new design approach for a power amplifier (PA) of the highly efficient hybrid envelope elimination and restoration (H-EER) transmitter. Since the PA operates mostly at the average power region of the modulation signal, power-added efficiency (PAE) of the PA at the average drain voltage is very important for the overall transmitter PAE. Accordingly, the PA is designed to have a maximum PAE in that region. The performances of the proposed PA and a conventional PA under H-EER operation are evaluated via ADS and MATLAB simulations using a behavioral large-signal model of a silicon LDMOSFET, which verifies that the proposed PA has significant advantages for the H-EER transmitter in both PAE and output power. A saturated amplifier, inverse class F, has been implemented using a 5-W peak envelope power LDMOSFET for 3GPP forward-link single-carrier wideband code-division multiple-access at 1 GHz with a peak-to-average power ratio of 9.8 dB. An envelope amplifier is built that has an efficiency of above 68% and peak output voltage of 31 V for an interlock experiment. The overall PAE of the transmitter with a conventional PA is 35.5% at an output power of 29.2 dBm. On the other hand, the transmitter with the proposed PA delivers significantly improved performances: PAE increased by 4% and output power by 2.5 dB. The H-EER transmitter has been linearized by the digital feedback predistortion technique. The measured error vector magnitude is reduced to 1.47% from 6.4%. These results clearly show that the proposed architecture is a good candidate for efficient linear transmitters. Index Terms-Adjacent channel leakage ratio (ACLR), digital feedback predistortion (DFBPD), efficiency, error vector magnitude (EVM), hybrid envelope elimination and restoration (H-EER), linearity, peak-to-average power ratio (PAPR), poweradded efficiency (PAE), power amplifier (PA), RF transmitter, wideband code-division multiple-access (WCDMA).

In this work, we characterise the performance of a Sharp optical aerosol sensor model GP2Y1010AU0F. The sensor was exposed to different environments: to a clean room, to a controlled atmosphere with known aerosol size distribution and to the ambient atmosphere on a busy city street. During the exposure, the output waveforms of the sensor pulses were digitised, saved and a following offline analysis enabled us to study the behaviour of the sensor pulse-by-pulse. A linear response of the sensor on number concentration of the monosized dispersed PSL particles was shown together with an almost linear dependence on particle diameters in the 0.4 to 4 micrometer range. The gathered data about the sensor were used to predict its response to an ambient atmosphere, which was observed simultaneously with a calibrated optical particle counter.

In a Phase I Small Business Innovative Research (SBIR) project for NASA Langley, we developed and evaluated three formats of conceptual prototype cockpit wake vortex displays, a 2D plan view display, a 2D co-planar display, and a 3D synthetic vision system display. In each, the wake was presented along with conventional information on the 2D nav display, the vertical situation display, and the forward-looking SVS display. In the first stage of evaluation, three pilots carried out a two rounds of usability analyses on the displays in dynamic flight scenarios. The co-planar display was revealed to have the fewest problems. In the second stage, we evaluated the three displays, and some variants using a dynamic computational model of attention-situation awareness (A-SA), to reveal that the SVS display with wake information redundantly presented on a coplanar display yielded highest situation awareness and shortest noticing time for the appearance of the wake. The 2D nav display was poorest.

Computational models of aircraft pilot performance will gain importance over the next decades, as major evolutions in the national airspace continue to emerge with the NextGen program. Evaluating new technology, or procedures such as self-separation, requires time and resourceconsuming pilot-in-the-loop (PITL) simulations. Models can augment PITL findings and they can help to constrain the scope of PITL simulations. If they are validated, such computational models may actually answer some design questions in place of PITL simulations. This paper summarizes a review of modeling efforts to address pilot performance, and elaborates on pilot-automation interaction models. In the transition to NextGen operations, a major concern is identifying and evaluating potential concepts well before they are put into operation. One approach is through the use of computational modeling to predict operator performance, or human performance modeling. Computational modeling provides a means of predicting performance and evaluating numerous "what if" situations, and is thus particularly useful for evaluating to-be-built systems. In addition, models need to make valid predictions of operator performance. This requires comparing model predictions with actual human performance in real or (for to-be-built systems) simulated conditions.

This paper presents an overview of DelSi, a MATLAB toolbox developed for the design and simulation of delta-sigma modulators. The DelSi toolbox can synthesize a stable noise-transfer function for complex network structures. The modelling tool consists of two crc qq programs, sdMod.c, a single stage delta-sigma modulator and firfilt.c, a decimating FIR filter. Cascaded modulators can be constructed using the programs as building blocks. The simulation tools support the inclusion of nonideal effects caused by circuit imperfections, such as amplifier finite open-loop gain, incomplete settling and saturation as well as capacitor ratio mismatches. Two design examples are presented: one for a 1-1-1 cascade and the other for a single-stage fifth modulator.

A new Auxiliary Converter Topology with SiC Components for Railway Applications WANG, LUYU 2016 Document Version: Publisher's PDF, also known as Version of record Link to publication Citation for published version (APA): WANG, LUYU. (2016). A new Auxiliary Converter Topology with SiC Components for Railway Applications. (1 ed.).

WDM-PON has been considered a promising solution for future fronthaul links concerning new mobile networks applications. However, in order to avoid inventory problems and reduce operation costs, there is a need for colorless sources, where the same basic optical source can be used regardless of the desired wavelength. Also, the digital RoF scheme, which has been employed so far, might require a bandwidth that is prohibitive even for optical fiber links. In this paper, we propose and numerically investigate a bidirectional colorless WDM-PON fronthaul transporting analog RoF signals as an alternative to meet these demands. All simulations were performed using a framework calibrated with experimental data. For the downstream, we employ a double-cavity self-seeding technique, while the upstream is performed by a cascaded-RSOAs carrier-reuse approach. BER and EVM simulation analysis are presented for various data rates, modulations formats and RF bands ranging from 1 to 5 GHz, demonstrating the feasibility of our proposed topology as a novel fronthaul approach.

Differential amplifiers can be an appropriate solution in the implementation of radio astronomy receivers, due to their efficient interference and harmonic isolation. In this paper, two different topologies are presented. The first one consists of two single ended amplifiers in a balanced topology. The second one is formed by cascading two simple differential stages. Both circuits operate in the 300MHz to 1GHz bandwidth. Firstly, gain and noise characterizations of each amplifier have been done. Lastly, noise analysis of the whole reception system, formed by the antenna and the differential amplifiers, is presented.