In this master degree work, a digital attenuator and a low noise amplifier (LNA) have been designed and integrated with the RF front-end receiver for IEEE 802.11b Wireless LAN standard. Firstly, the 4-bit digitally controlled attenuator has been designed with theattenuation range of 50 to 80 dB and reflection coefficient less than -25 dB. Next, the single stage wide band low noise amplifier with voltage gain larger than 14 dB and noise figure below 4 dB has been designed to operate at frequency 2.4 GHz. Finally, the integration with a down-conversion mixer has been done and evaluated its performance. The attenuator and low noise amplifier desired in this thesis have been implemented using standard CMOS 0.35µm technology and validated by the simulation tools Cadence Spectre-RF.

The present investigation looks at management consulting engagements through the project management lens, and explores what practitioners do in the initial stages of their projects. In the understanding that the front-end of the project is a very critical and important stage, this text begins by examining the literature on management consulting and on the definitional phase of projects, and demonstrates that the situations encountered in both domains are quite similar. For this reason, this study explores the project management practices that Swedish management consultants employ in the initial phases of the consulting projects. Particularly, it focuses on the practices that reconcile possible gaps in perspectives and expectations that often exist between client and consultant when this relationship is being formed.  The study had an inductive character and is cross-sectional in terms of time-horizon, focusing on the previous experiences of management consultants. In collecting the data, a survey strategy was usedwith semi-structured interviews involving nine Swedish management consultants from eight different consultancies. The process of analysis implied the use of template analysis, which provided researchers with enough flexibility to code, categorize, and interpret necessary findings. The results show that consultants favor practices that revolve around communication and interaction with the client, including interviews, workshops, and meetings, among others. In addition, they stress the importance of the use of documentation in order to reach an agreement on what the project is about. Moreover, these practices were often clearly connected to the issues that they, as project managers, must resolve at the front-end of projects. Interestingly, the results indicate that these challenges, identified by the management consultants, mostly match the ones identified in the project management literature. There is indeed a connection between project management practices and management consulting, from which both fields can benefit.

The Front End of innovation (FEI) or early innovation presents one of the greatest opportunities for improving an entire innovation process in any firm. The purpose of this thesis is to study how customers can be involved in the early phase of innovation in the IT industry. In this study, we did analyze the customer types, their methods of involvement and key elements within the early innovation process or front end of innovation. In accordance with theoretical concepts, this study shows that all fifteen (15) companies working within the I.T industry in Sweden agreed working with innovation/NPD and, equally involve customers in their front end of innovation (FEI). In the I.T industry, innovation comes mainly from the users (customers) and from within the companies (R&D). To a lesser extend, from technological trends, market and suppliers. Amongst the identified phases (elements) of the front end of innovation, Opportunity Identification was found to be the dominant phase for customer involvement. Normal customers, lead, empathic design customers and virtual customers, proved the most dominant customer types integrated within the front end of innovation in the I.T industry.

This dissertation presents a comprehensive design and analysis framework for system-on-a-chip analog-to-digital conversion design. The design encompasses a broad class of systems, which take advantage of system-on-a-chip complexity. This class is exemplified by an interferometric photodetector array based bio-optoelectronic sensor that is built and tested as part of the reported work. While there have been many discussions of the technical details of individual analog-to-digital converter (ADC) schemes in the literature, the importance of the analog front-end as a pre-processor for a data converter and the generalized analysis including converter encoding and decoding functions have not previously been investigated thoroughly, and these are key elements in the choice of converter designs for low-noise systems such as bio-optoelectronic sensors. Frequency domain analog front-end models of ADCs are developed to enable the architectural modeling of ADCs. The proposed models can be used for ADC statistically worst-case performance estimation, with stationary random process assumptions on input signals. These models prove able to reveal the architectural advantages of a specific analog-to-digital converter schemes quantitatively, allowing meaningful comparisons between converter designs. The modeling of analog-to-digital converters as communication channels and the ADC functional analysis as encoders and decoders are developed. This work shows that analog-to-digital converters can be categorized as either a decoder-centered design or an encoder-centered design. This perspective helps to show the advantages of nonlinear decoding schemes for oversampling noise-shaping data converters, and a new nonlinear decoding algorithm is suggested to explore the optimum solution of the decoding problem. A case study of decoder-centered and encoder-centered data converter designs is presented by applying the proposed theoretical framework. The robustness and flexibility of the resulting analog-to-digital converters are demonstrated and compared. The electrical and optical sensitivity measurements of a fabricated oversampling noise shaping analog-to-digital converter circuit are provided, and a sensor system-on-a-chip using these ADCs with integrated interferometric waveguides for bio-optoelectronic sensing is demonstrated.

In this thesis, we studied the narrowband power line communication system. This system mainly utilizes the 60Hz power line as the medium to transmit network signals. In the beginning, we studied the power line channel characteristics and the coupling circuit structure, that was used to couple the signal to the power line. Impedance mismatch and signal attenuation may occur when the loading in the power line network changes. To this end we added a driver to the coupling circuit to reduce the output impedance, and hence enhance signal magnitude. In addition, we add the cross-phase coupling circuit with bandpass filter characteristics at the 220V socket. It was found that our cross-phase coupling circuit was able to improve the performance of the power line communication system when cross-phase transmission took place. Finally, we simulated the indoor power line network environment, measured several kinds of residential appliance noise and analyzed the influence on the power line communication system of the appliance noise.

The human auditory perception system is much more noise-robust than any state-of the art automatic speech recognition (ASR) system. It is expected that the noise-robustness of speech feature can be improved by employing the human auditory based feature extraction procedure. In this thesis, we investigate modifying the commonly-used feature extraction process for automatic speech recognition systems. A novel frequency masking curve, which is based on modeling the basilar membrane as a cascade system of damped simple harmonic oscillators, is used to replace the critical-band masking curve to compute the masking threshold. We mathematically analyze the coupled motion of the oscillator system (basilar membrane) when they are driven by short-time stationary (speech) signals. Based on the analysis, we derive the relation between the amplitudes of neighboring oscillators, and accordingly insert a masking module in the front-end signal processing stage to modify the speech spectrum. We evaluate the proposed method on the Aurora 2.0 noisy-digit speech database. When combined with the commonly-used cepstral mean subtraction post-processing, the proposed auditory front-end module achieves a significant improvement. The method of correlational masking effect curve combine with CMS can achieves relative improvements of 25.9% over the baseline respectively. After applying the methods iteratively, the relative improvement improves from 25.9% to 30.3%.

In this work, a highly linear broadband Low Noise Amplifier (LNA) is presented. The linearity issue in broadband Radio Frequency (RF) front-end is introduced, followed by an analysis of the specifications and requirements of a broadband LNA through consideration of broadband, multi-standard front-end design. Metal-Oxide- Semiconductor Field-Effect Transistor (MOSFET) non-linearity characteristics cause linearity problems in the RF front-end system. To solve this problem, feedback and the Derivative Superposition Method linearized MOSFET. In this work, novel linearization approaches such as the constant current biasing and the Derivative Superposition Method using a triode region transistor improve linearization stability against Process, Supply Voltage, and Temperature (PVT) variations and increase high power input capability. After analyzing and designing a resistive feedback LNA, novel linearization methods were applied. A highly linear broadband LNA is designed and simulated in 65nm CMOS technology. Simulation results including PVT variation and the Monte Carlo simulation are presented. We obtained -10dB S11, 9.77dB S21, and 4.63dB Noise Figure with IIP3 of 19.18dBm for the designed LNA.

The topic of this thesis presents a digital front end (DFE) of the digital video broadcasting over terrestrial (DVB-T). The DVB-T system is similar to most of the prior digital communication system. It is roughly divided into two major parts, one for channel coding/decoding, and the other for modulation/demodulation. The thesis is mainly focused on the DVB-T digital video broadcasting demodulation part of the receiver and the integration of a complete digital front demodulation system. The major operational processor of the DFE is a 2K/8K dual-mode FFT processor, which has been implemented by the TSMC ( Taiwan Semiconductor Manu-facturing Company ) 0.35um 2P4M CMOS process technology to justify the simulation results as well as the correctness of the proposed architecture.

The explosive growth of wireless communication market has led the development of low-cost, highly-integrated wireless communication systems. Even though most blocks in the front-end have successfully been integrated by using the CMOS technology, it is still a formidable challenge to integrate the entire front-end. Thus, the objective of this research is to demonstrate the feasibility of the integrated front-end by using improved circuit techniques as well as the improved process technologies. This dissertation proposes an improved control scheme to enhance the high-power handling capability of an antenna switch. As a part of this research, an antenna switch controller for a GaAs antenna switch was first developed to enhance the performances of the GaAs antenna switch by using the boosted control voltage. To enhance the efficiency of the front-end, efficiency improvement techniques for the antenna switch controller has also been studied. With the suggested efficiency improvement techniques, a fully-integrated antenna switch was implemented using the SOI technology, and exceeding performances over many commercial products for watt-level high-power applications have been successfully demonstrated. As an effort to improve the efficiency of a power amplifier, a linear envelope detector was also implemented, and the results show that the envelope detector is suitable for dynamic biasing of the power amplifier. The research presented in this dissertation, thus, provides a low-cost and high-performance solution for highly-integrated RF front-end used in various wireless communication systems.

<p>In this thesis, design aspects of fully integrated multibandmultistandard front-end receivers are investigated based onthree fundamental aspects: noise, linearity and operatingfrequency. System level studies were carried out to investigatethe effects of different modulation techniques, duplexing andmultiple access methods on the noise, linearity and selectivityperformance of the circuit. Based on these studies and thelow-cost consideration, zero-IF, low-IF and wideband-IFreceiver architectures are promising architectures. These havea common circuit topology in a direct connection between theLNA and the mixer, which has been explored in this work toimprove the overall RF-to-IF linearity. One front-end circuitapproach is used to achieve a low-cost solution, leading to anew multiband multistandard front-end receiver architecture.This architecture needs a circuit whose performance isadaptable due to different requirements specified in differentstandards, works across several RF-bands and uses a minimumamount ofexternal components.</p><p>Five new circuit topologies suitable for a front-endreceiver consisting of an LNA and mixer (low-noise converter orLNC) were developed. A dual-loop wide-band feedback techniquewas applied in all circuits investigated in this thesis. Threeof the circuits were implemented in 0.18 mm RF-CMOS and 25 GHzbipolar technologies. Measurement results of the circuitsconfirmed the correctness of the design approach.</p><p>The circuits were measured in several RF-bands, i.e. in the900 MHz, 1.8 GHz and 2.4 GHz bands, with S11 ranging from–9.2 dB to–17 dB. The circuits have a typicalperformance of 18-20 dB RF-to-IF gain, 3.5-4 dB DSB NF and upto +4.5 dBm IIP3. In addition, the circuit performance can beadjusted by varying the circuit’s first-stage biascurrent. The circuits may work at frequencies higher than 3GHz, as only 1.5 dB of attenuation is found at 3 GHz and nopeaking is noticed. In the CMOS circuit, the extrapolated gainat 5 GHz is about 15 dB which is consistent with the simulationresult. The die-area of each of the circuits is less than 1mm2.</p>