The number of vehicles has increased significantly in recent years, which causeshigh density in traffic and further problems like accidents and road congestions.A solution regarding to this problem is vehicle-to-vehicle communication, wherevehicles are able to communicate with their neighboring vehicles even in the absenceof a central base station, to provide safer and more efficient roads and toincrease passenger safety.The goal of this thesis is to investigate basic physical layer parameters of ainter-vehicle communication system, like emission power, spectral emission, errorvector magnitude, guard interval, ramp-up/down time, and third order interceptpoint. I also studied the intelligent transportation system’s channel layout inEurope, how the interference of other systems are working in co-channel and adjacentchannels, and some proposals to use the allocated frequency bands. On theother hand, the fundamentals of OFDM transmission and definitions of OFDMkey parameters in IEEE 802.11p are investigated.The focus of this work is on the measurement of transmitter frontend parametersof a new testbed designed and fabricated in order to be used at inter-vehiclecommunication based on IEEE 802.11p.

In many applications of image processing there is a need to extract the solid background which it is usually sky for outdoor images. In our application we present this solution. We developed an automatic algorithm for detection and extraction of sky regions in the color image based on color classification. In which the input image should be in the RGB color space and the blue color is detected and classified. Then the color image is transformed to the binary form and the connected regions are extracted separately. The connected regions are then sorted in a descending order according to the biggest area and the biggest region is identified. Then we merged all objects that have similar sky properties. Experimental results showed that our proposed algorithm can produce good results compared to other existing algorithms.

A technique for wall compensation in the ultra-wideband (UWB) through-wall imaging radar is presented. The UWB system can be utilize in high precision measurements, but due to phase distortion and amplitude attenuation caused by the wall the precision is limited, the target is displaced, and the image is defocused. 

In order to mitigate the wall effects, two methods are applied in this project. First, the unknown wall transfer function is estimated using real data measurements to design the inverse filter. Secondly, FIR Wiener filter is designed to improve the received m-sequence. After all, each method is tested using three parameters, the signal to noise ratio (SNR), the signal to clutter ratio (SCR), and the relative position error (RPE). 

The inverse filter can eliminate the wall effects very well; it could correct not only the position of the target but also the image defocus. The new method can give improve the image quality and that can extend the use of UWB radar in many applications. 

The idea is to improve or help the treatments that exist in the market in the medical field. Treatments such as mammography or radiotherapy make use of X-rays. X-rays are electromagnetic radiation in a high frequency band, this type of electromagnetic is dangerous to health because ionizing radiation is used, ionized atoms interact with matter. For this reason, in our work we give alternative solution to these treatments without any risk to health. This project consists in the use of non-harmful frequencies such as microwave. In this way, we will make an antenna with medical applications whose frequency range will be between 300 MHz and 30 GHz, specifically between 950MHz and 2.45GHz (medical range). The first step will be the detection of the tumour and classification of this, but our work is about another technique called hyperthermia. This technique consists in increase the temperature with a value of 40-43 degrees in the tumour area. Tumour resistance decreases when heat is applied to this. When combining a treatment with oncologic hyperthermia, the effect of radiotherapy is most effective (between 1.5-5 times). The most important part is study antenna in body tissues characteristics as SAR, depth penetration and antenna size; this theory part is essential to know the best parameters and what case use this. In work development we will choose and design antennas for the different parts of the body in some specific frequencies and choose circular antennas in frequencies of 915 MHz and 1.8 GHz. Finally, we will take measurements about temperature increase with meat and say some conclusions.

This report shows a robust and efficient implementation of a speed-optimized algorithm for object recognition, 3D real world location and tracking in real time. It details a design that was focused on detecting and following objects in flight as applied to a football in motion. An overall goal of the design was to develop a system capable of recognizing an object and its present and near future location while also actuating a robotic arm in response to the motion of the ball in flight.

The implementation made use of image processing functions in C++, NVIDIA Jetson TX1, Sterolabs’ ZED stereoscopic camera setup in connection to an embedded system controller for the robot arm. The image processing was done with a textured background and the 3D location coordinates were applied to the correction of a Kalman filter model that was used for estimating and predicting the ball location.

A capture and processing speed of 59.4 frames per second was obtained with good accuracy in depth detection while the ball was well tracked in the tests carried out.

Planen var att konstruera en PCI-Express-till-PCI brygga för fyra MoCA radiokort. Problem uppstod då det visade sig att PLC8112 inte kunde hantera fyra PCI samtidigt som var utlovat från tillverkaren av bryggan. För att lösa problemet fick PCI6152 läggas till i designen. Det är en PCI-till-PCI brygga som också ska klara att hantera upp till fyra PCI enligt tillverkaren. Fyra MoCA radiokort förbrukar mycket ström. Två spänningsregulatorer lades till i designen för att kunna leverera de strömmar som krävs. För att säkerställa att radiokorten som ansluts till Linkfire inte blir för varma så placeras en temperatursensor under ett radiokort. Temperatursensorn har endast av/på lägen och till den ansluts två fläktar, därmed så betraktas dem som en fläkt då de inte är individuellt styrda.

This report intends to impart a good understanding of routing modules used in modern transceiver systems. The radar system at RadarBolaget AB needed to have a good routing module for its newly designed transceiver antenna. In this report, studies have been done related to two majorly used routing modules in modern electronics industry; Microwave Circulator and RF/Microwave Switch. First off, different characteristics of routing modules are discussed. After having discussed important design parameters, practical design considerations for two routing modules are presented in a profound way. Theoretical knowledge for both of these two devices is presented in the beginning, followed by their practical designs using standard simulation software like HFSS and ADS. The report concludes its findings in a way that at the end of this report, reader becomes acquainted with ample information to be able to choose the best option available among all of the discussed designs. An FET RF Switch is chosen at the end of this project to be used for transceiver system which should be able to satisfy specifications specified by RadarBolaget AB. This project was carried out by two students of Master Program in Electronics/Telecommunications at Högskolan i Gävle in collaboration with RadarBolaget AB, Gävle, Sweden.    

Focusing techniques and detection of targets is usually associated to defense and military use. However in recent past things have moved ahead. Now target detection using UWB radars is being done in many industries and corporations. Radarbolaget AB is one of them; one of their projects uses UWB radars to detect steel strips inside a furnace. This research solves a potential problem of detecting middle steel strip out of total three strip edges which can be seen by radar placed on the front. For better understanding of the reader, existing system and introductory UWB radar principles are discussed. As there can be many solutions to focusing of targets here (steel strip edge detection). Available focusing techniques have been discussed in detail along with the possible physical and simulation setups. Later in the document, detection methods have been proposed. UWB time reversed signal detection is a fairly new method and a very limited research has been done so far. PRBS sequence has been focused on in detection mechanism. Results section show that the pulse of the PRBS works better and produces more promising results rather than a repetitive signal. Time reversal methods for locating the target have been used to find the approximate location of the target. Manual distance calculations from target to the transmitter and receiver have been done. Comparison of actual distance from target to the transmitter is compared with simulation results. Different model simulation setups and their results have proved that using UWB Time reversed signals; a still or moving target can be detected with centimeter window precision.

The detection of cracks in sand moulds has long been a challenge for both safety and maintenance purposes. Traditional image processing techniques have been employed to identify and quantify these defects but have often proven to be inefficient, labour-intensive, and time-consuming. To address this issue, we sought to develop a more effective approach using deep learning techniques, specifically semantic segmentation. We initially examined three different architectures—U-Net, SegNet, and DeepCrack—to evaluate their performance in crack detection. Through testing and comparison, U-Net emerged as the most suitable choice for our project. To further enhance the model's accuracy, we combined U-Net with VGG-19, VGG-16, and ResNet architectures. However, these combinations did not yield the expected improvements in performance. Consequently, we introduced a new layer to the U-Net architecture, which significantly increased its accuracy and F1 score, making it more efficient for crack detection. Throughout the project, we conducted extensive comparisons between models to better understand the effects of various techniques such as batch normalization and dropout. To evaluate and compare the performance of the different models, we employed the loss function, accuracy, Adam optimizer, and F1 score as evaluation metrics. Some tables and figures explain the differences between models by using image comparison and evaluation metrics comparison; to show which model is better than the other. The conducted evaluations revealed that the U-Net architecture, when enhanced with an extra layer, proved superior to other models, demonstrating the highest scores and accuracy. This architecture has shown itself to be the most effective model for crack detection, thereby laying the foundation for a more cost-efficient and trustworthy approach to detecting and monitoring structural deficiencies.

As the concerns about global energy consumption increased the matter of energy consumption in Radio Access Networks (RANs) became an important issue especially with the exponential growth in demanded traffic. This interest of developing innovative technologies to reduce the expected energy consumption by the mobile communication sector was driven by environmental concerns and cost reduction.

The aim of this thesis is to introduce a new methodology to make the Radio Access Network (RAN) more energy efficient based on jointly the demanded throughput and a realistic traffic profile. Furthermore, to find a metric that quantifies the relation between the Energy Efficiency (EE), Spectrum Efficiency (SE) and demanded throughput.

The proposed methodology for reducing the energy consumption in the RAN characterizes the offered throughput in order to determine the sufficient energy needed. The manner for reducing the energy consumed by the RAN is simply by switching (OFF/ON) Base Stations (BSs) based on the demanded throughput which introduces an energy efficient RAN.

The results show a significant reduction in the energy consumption with regard to the demanded traffic. Moreover, it gives a measure of the EE with consideration to the SE which enhances the performance evaluation from an EE point of view during the RAN planning phase.

In the radar systems, the crosstalk or antenna-to-antenna interference between the radar antennas is useful in some cases. However in some application the received signal is too weak such as wall crack detection and it might affect the accuracy of the radar system. The aim of this thesis is to design, fabricate and test a single layer metamaterial absorber operates from 1 GHz to 4 GHz. The metamaterial absorber can be used as a barrier between the antennas or even in the antenna housing in order to reduce or prevent the antenna-to-antenna interference.

The method used to fulfill the goal is to shift the frequency response of a known structure by changing the dimension to the wanted band. The software HFSS used to design and simulate the proposed structure which made of L-shaped copper placed diagonally over a substrate separating it from a continuous copper plane. The simulation results exhibit a wideband absorption response of 2.42 GHz ranging from 1.9 GHz to 4.32 GHz. The structure has been simulated over the dimension variation to investigate the flexibility and sensitivity of the designed single layer structure.

The fabricated metamaterial absorber measured over the direct incident waves. The structure reveals a wideband absorption response of 1.69 GHz ranging from 2.23 GHz up to 3.92 GHz with more than 90% absorptivity. The structure also exposed that the response of the structure starts to create two bands within the wanted band by increasing the angle of the incident waves. 10° polarization angle gives more than 80% absorptivity response. 

This work focuses on applying and evaluating various noise reduction methods to

extract desired sounds from a noisy industrial environment. Noise reduction is a

technique used to minimize or eliminate unwanted noise in a signal, improving its

quality and making it more useful for analysis and interpretation. In today’s

industrial environments, noise reduction is crucial to ensure high accuracy in sound

measurements. The introduction provides a background on why this work is

necessary and presents the goals and research questions related to effective noise

reduction.

The work explains the key concepts of noise reduction, with a specific focus on

methods such as FIR (finite impulse response) band-pass filters, adaptive filters,

spectral subtraction, and Wiener filters. These techniques are evaluated based on

their ability to improve signal quality by reducing ambient noise. A literature review

was conducted to examine previous research and identify the most effective

techniques for this study.

The results showed that the combination of noise reduction methods and FIR band-

pass filters was particularly effective in handling both stationary and non-stationary

noise. (Stationary noise is constant and predictable over time, while non-stationary

noise varies and is more difficult to filter out.) Adaptive filters and spectral

subtraction performed best in reducing non-stationary noise, while the Wiener filter

was most effective in environments with stable, stationary noise. However, the

Kalman filter performed worse under the tested conditions. The study confirmed

that the correct sequencing and combination of different noise reduction methods

are essential to optimize signal quality and effectively reduce noise.

The study concludes that the strategic use of noise reduction methods, in

combination with FIR band-pass filters, is crucial for achieving optimal signal

preservation and noise reduction. This contributes to improved performance in

noisy industrial environments and supports higher accuracy in sound analysis.

A 3-link robotic arm was designed, constructed, and tested as part of the thesis work. This prototype will assist students in applying their robotics and control system theory knowledge to real results. The kinematic equations are created to help with trajectory planning. Evaluation of different parameters was determined like (angles at which the servo motor operated, link length at which the servo can carry, spatial velocity, DH parameter, and Homogeneous transformation matrix). An Arduino-based closed-loop control system is built. Four Servo motors were used which are being controlled by Arduino UNO and Leonardo. The Arduino IDE is used to write proper codes. The main aim of the study was to apply the knowledge of robotics and control systems to develop a functional mini robot from scratch. Specifically, the thesis presents how to build a robotic arm that can move and lift objects. And, this task is done by using different controlling techniques where potentiometer, Bluetooth Module, and IR senor were used and compared which technique gives better results. The structural components had several issues. The project's linkages foundation and gripper are all 3-D printed pieces that are being designed using Autodesk Inventor Professional 2021 software. Although they did not cause any problems with strength, there were some difficulties with properly tightening the gears onto the shaft. To overcome these difficulties glue is being used so that all servo motors hold with the link properly. In a broad sense, the robot can position and orient the end-effector to pick and place the object accurately from a distance.

Digitization has been given a greater role in the monitoring and control of a processing plant. This trend will grow globally to achieve a smarter production chain that generates ecenomic profits.

The purpose of this thesis was to develop an existing process that respresents an automated drilling station. THis i scontrolled by integrating Java-netbeans software into the PLC hardware with a user interface that can read the data flow of PLC.The drilling station is controlled by PLC.

This work describes the possible methods for achieving integration between Java-netbeans and PLC.

 The essential part of the work was literature study, programming of source code and programming of PLC. This work achieved all the objectives.

Wireless communication provides low-cost, high-speed and flexible communication in present days. Hence antenna plays a vital role in the wireless communication sector. The main concern of this paper is therefore to design a 3.4 GHz rectangular Microstrip patch antenna. Moreover, the feed probe based rectangular patch antenna will be designed. The performance of the designed rectangular patch antenna will be evaluated by analysing the major parameters of the simulation results. Hence the radiation pattern, gain, impedance matching and reflection coefficient or return loss calculation will be executed by the HFSS software to evaluate the performance of the antenna. 

This work focuses on different kinds of Switch Mode Power Amplifiers (SMPAs) using LDMOS technologies. It involves a literature study of different SMPA concepts. Choosing the suitable class that achieves the high efficiency was the base stone of this

work. A push-pull class J power amplifier (PA) was designed with an integrated LC resonator inside the package using the bondwires and die capacitances. Analysis and motivation of the chosen class is included. Designing the suitable Input/Output printed circuit board (PCB) external circuits (i.e.; BALUN circuit, Matching network and DC

bias network) was part of the work. This work is done by ADS simulation and showed a simulated result of about 70% drain efficiency for 34 W output power and 16 dB gain at 2.14 GHz. Study of the losses in each part of the design elements is also included.

Another design at lower frequency (i.e.; at 0.94 GHz) was also simulated and compared to the previous design. The drain efficiency was 83% for 32 W output power and 15.4 dB Gain.

To find devices mimicking the human nose have under some time been an area of interest for researchers. These devices can potentially be a useful tool to achieve UN: s global goals for sustainable development, Agenda 2030.

This project is an experimental quantitative study with the aim to investigate the possibility to create a stand-alone measuring system for detecting and identifying spoiled milk and rotten meat in a fridge.

A wireless measuring system with an array of gas sensors was developed together with interface for remote control. Measurements was made from known measuring objects for two weeks. Thereafter measurements of unknown measuring objects were also done for two weeks.

The result of the study showed that the developed measuring system can be remotely controlled to detect and identify spoiled milk and rotten meat without external software. The measuring system has an accuracy of 89% when it comes to classify unknown measurement objects.

This study shows that the measuring system can detect and identify spoiled milk and rotten meat via remote control.

We show that the combined use of radio frequency absorbers and directive antennas can produce significant changes of the radio propagation channel properties along the positions of a virtual array inside a reverberation chamber. A multidimensional characterization of the channel was performed at 40 antenna positions with spacing of 0:233λ at 1 GHz. The average power, the Ricean K-factor, the coherence bandwidth, the r.m.s. delay spread, the mean delay, the beamforming power angle spectrum and array antenna correlation have been studied for different arrangements in the reverberation chamber. The analysis shows that the joint average over time and frequency channel behavior is, as expected, rather homogeneous along the very large array. However, individual realizations of the channel present a pronounced selective behavior in space, time and frequency with parameters varying along the positions of the virtual array suggesting that a heterogeneous behavior of the radio channels can be emulated in reverberation chambers. An important application of the presented study comprises testing of antenna array designs and algorithms in multipath environments. Further development may lead to Over The Air testing of Multiple Input Multiple Output antenna systems of various sizes, i.e., from small to very large arrays.

Channel coding has been largely used for the purpose of improving error performance on a communications system. Typical methods based on added redundancy allow for error detection and correction, this improvement however comes at a cost of bandwidth. This thesis focuses on channel coding for the bandwidth-limited channel where no bandwidth expansion is allowed.

We first discuss the idea of coding for the bandwidth-limited channel as seen from the signal space point of view where the purpose of coding is to maximize the Euclidian distance between constellation points without increasing the total signal power and under the condition that no extra bits can be added. We then see the problem from another angle and identify the tradeoffs related to bandwidth and error performance.

This thesis intends to find a simple way of achieving an improvement in error performance for the bandwidth-limited channel without the use of lattice codes or trellis-coded modulation.

The proposed system is based on convolutional coding followed by multilevel transmission. It achieved a coding gain of 2 dB on Eb/No or equivalently, a coding gain of approximately 2.7 dB on SNR_norm without increase in bandwidth. This coding gain is better than that obtained by a more sophisticated lattice code Gosset E₈ at the same error rate.

The rapid expansion of photovoltaic (PV) systems has raised voltage concerns. This paper investigates voltage variations measured at four hundred on-line PV installations in Sweden. Small (<10 kW inverter size) three phase residential PV systems had the least impact whereas single phase systems had the most impact for the same amount of power injected per phase. PV systems were grouped based on post code location into urban and rural areas. Urban areas were found to be more resilient to PV induced  voltage fluctuations with a narrower back-ground voltage band in comparison to rural areas, indicating that PV inverter measurements can be an efficient method to empirically determine grid strength.

Software-Defined Networking (SDN) offers a centralized network management approach that can effectively address the complex and varied traffic demands characteristic of Industrial Internet of Things (IIoT) environments by decoupling the control plane from the data plane. The centralized control architecture of SDN necessitates the performance optimization of controllers to manage diverse traffic efficiently within IIoT applications. This paper explores the criteria for selecting controllers in SDN-enabled IIoT (SD-IIoT) environments, utilizing the Less Complex Analytic Network Process (LC-ANP) to establish their prioritization. A ranking system for SD-IIoT controllers is formulated using LC-ANP, and experimental validation of this method underscores its effectiveness in optimizing controller performance. The proposed approach enhances the overall efficiency of SDN-enabled IIoT networks, as evidenced by experimental evaluations measuring delay, throughput, packet loss ratio, and jitter across five different topologies with varying nodes and edges. The experiments indicate an overall increase in the average throughput, and a decrease in delay, jitter, and packet loss ratio. The results also show that the suggested strategy and proposed controller surpass the benchmark controller in complex network topologies. These results confirm the method’s capacity to significantly improve network performance in SD-IIoT applications.

Wireless systems have become an inevitable part of modern technologies serving humankind. The rapid growth towards large dimensional systems, e.g. 5th generation (5G) technologies, incurs needs for improving the performance of the systems and considering aspects to make them as far as possible environmentally friendly in terms of power efficiency, cost, and so on. One of the key parts of every wireless communication system is the radio frequency (RF) power amplifier (PA), which consumes the largest percentage of the total energy. Hence, accurate models of RF PAs can be used to optimize their design and to compensate for signal distortions. This thesis starts with two methods for frequency-domain characterisation to analyse the dynamic behaviour of PAs in 3rd-order non-linear systems. Firstly, two-tone signals superimposed on large-signals are used to analyse the frequency-domain symmetry properties of inter-modulation (IM) distortions and Volterra kernels in different dynamic regions of RF PAs in a single-input single-output (SISO) system. Secondly, three-tone signals are used to characterise the 3rd-order self- and cross-Volterra kernels of RF PAs in a 3 × 3 multiple-input multiple-output (MIMO) system. The main block structures of the models are determined by analysing the frequency-domain symmetry properties of the Volterra kernels in different three-dimensional (3D) frequency spaces. This approach significantly simplifies the structure of the 3rd-order non-linear MIMO model.

The following parts of the thesis investigate techniques for behavioural modelling and linearising RF PAs. A piece-wise modelling technique is proposed to characterise the dynamic behaviour and to mitigate the impairments of non-linear RF PAs at different operating points (regions). A set of thresholds decompose the input signal into several sub-signals that drive the RF PAs at different operating points. At each operating point, the PAs are modelled by one sub-model, and hence, the complete model consists of several sub-models. The proposed technique reduces the model errors compared to conventional piece-wise modelling techniques.

A block structure modelling technique is proposed for RF PAs in a MIMO system based on the results of the three-tone characterisation technique. The main structures of the 3rd- and higher-order systems are formulated based on the frequency dependence of each block. Hence, the model can describe more relevant interconnections between the inputs and outputs than conventional polynomial-type models.

This thesis studies the behavioural modelling and compensation techniques in both the time and the frequency domains for RF PAs in a 3 × 3MIMO system. The 3D time-domain technique is an extension of conventional 2D generalised memory polynomial (GMP) techniques. To reduce the computational complexity, a frequency-domain technique is proposed that is efficient and feasible for systems with long memory effects. In this technique, the parameters of the model are estimated within narrow sub-bands. Each sub-band requires only a few parameters, and hence the size of the model for each sub-band is reduced.

Multiple-input multiple-output (MIMO) frequency-domain Volterra kernels of nonlinear order 3 are experimentally determined in bandwidth-limited frequency regions. How the effect of higher nonlinear orders can be reduced and how this affects the estimated errors are discussed. The magnitude and phase of the kernels areKramers-Kronig consistent. The self- and cross-kernels have different symmetries and the kernels are therefore determined and analyzed in different regions in the 3D frequency space. By analyzing the properties along certain paths in the 3D frequency space, the block structures for the respective kernels are determined. These block structures contain the significant blocks of the general block structures for third-order kernels. The device under test is a MIMO transmitter for radio frequency signals.

In this paper, a new approach is proposed to decompose the basis functions in a piece-wise modeling technique for nonlinear radio frequency (RF) power amplifiers. The proposed technique treats the discontinuity problem of the model output at the joint points between different operating points, whereas preserves the linear and nonlinear properties of the original model within each region. Experimental results show that the proposed technique outperforms the conventional piece-wise model in terms of model errors.

Modern telecommunications are moving towards (massive) multi-input multi-output systems in 5th generation (5G) technology, increasing the dimensionality of the system dramatically. In this paper, the impairments of radio frequency (RF)power amplifiers (PAs) in a 3x3 MIMO system are compensated in both time and frequency domains. A three-dimensional(3D) time-domain memory polynomial-type model is proposed as an extension of conventional 2D models. Furthermore, a 3D frequency-domain technique is formulated based on the proposed time-domain model to reduce the dimensionality of the model, while preserving the performance in terms of model errors. In the 3D frequency-domain technique, the bandwidth of a system is split into several narrow sub-bands, and the parameters of the system are estimated for each subband. This approach requires less computational complexity, and also the procedure of the parameters estimation for each sub-band can be implemented independently. The device-under-test (DUT) consists of three RF PAs including input and output cross-talk channels. The proposed techniques are evaluated in both behavioural modelling and digital pre-distortion(DPD) perspectives. The results show that the proposed DPD technique can compensate the errors of non-linearity and memory effects by about 23.5 dB and 7 dB in terms of the normalized mean square error and adjacent channel leakage ratio, respectively.

A new two-tone test method for radio frequency power amplifiers is presented. The test signal is a two-tone probing-signal superimposed on large-signals of different amplitude. The amplifier is, thus, excited in different amplitude regions. The amplitude and phase of the 3rd order intermodulation (IM) products are measured vs. frequency spacing and probing-signal amplitude in each region. The IM magnitude is a measure of the nonlinearity, while the frequency dependence and asymmetry are measures of the memory effects in the different regions. A Doherty and a class-AB amplifier were tested. For both amplifiers the IM magnitude increased by ∼15 dB from the lowest to the highest amplitude region. For the Doherty amplifier the behavior of the IM products vs. frequency spacing was similar in all regions, indicating similar memory effects. For the class-AB amplifier the IM vs. frequency spacing was significantly different in the different regions, which indicates different memory effects.

The 3rd-order Volterra kernels of a radio frequency (RF) power amplifier (PA) are characterized using a large-signal and a two-tone probing-signal. In this technique, the magnitude and phase asymmetries of the kernels of the PA excited by the probing-signal are analyzed in different amplitude regions of the large-signal. The device under test is a class-AB PA operating at 2.14 GHz. The maximum sweeping frequency space of the probing-signal is 20 MHz. The results indicate that the Volterra kernels of the PA show different behaviors (frequency dependency and asymmetry) in different regions.

A new block-structure behavioral model is proposed for radio frequency power amplifiers in a 2x2 multiple-input multiple-output system including input cross-talk. The proposed model forms kernels of blocks of different nonlinear order that correspond to the significant frequency response of measured frequency domain Volterra kernels. The model can therefore well describe the input-output relationships of the nonlinear dynamic behavior of PAs. The proposed model outperforms conventional models in terms of model errors.

The purpose of this master thesis was to study if the drain efficiency of power amplifiers can be maintained at power back off using a technique called load modulation.

The amplifier classes studied are E, F and D-1. The target figure was to obtain a 10 to 12 dB dynamic range of amplitude with reasonable efficiency. Studies of power amplifiers have been made to understand how power is generated. Several different load modulation networks have been evaluated. Attempts to derive design equations for the modulation networks have also been done.

The thesis work was carried out with simulations in ADS 2006. As active devices commercially available bare-die transistor models have been used. The power rating of the dies are 15 W.

A dynamic range of amplitude of over 15 dB has been achieved with drain efficiency greater than 60 percent. The peak output power is in the 40 – 45 dBm range.

The following Master Thesis will talk about a C-PV prototype using bifacial PV technology, based on the Solarus Collector. The Solarus Collector consists in two PV cells built on a metallic receiver, where there are some water channels flowing through it, allowing to cool down the PV cells, thus increasing their efficiency. The collector also presents a reflector to provide irradiance to the back part of the receiver, where the other PV cells are located. The new prototype will present bifacial PV cells but not a metallic receiver. This construction aims to reduce the price of the receiver, but will not have a system to cool down the solar cells. This Master Thesis will be developed in the Solarus facilities, in collaboration with the Solarus members.

In order to grasp an idea of this prototype, two main procedures will be done. Regarding the bifacial technology, a bifacial PV module will be measured under different conditions, depending on which sides can be illuminated or shaded. On the other hand, a thermodynamic simulation will be carried out on different geometries of the reflector and receiver, in order to figure out the evolution of the temperatures on the new prototype. This simulation will be done with a finite element method, widely known in this applications.

The results will show several problems concerning this prototype. Although the measurements of the bifacial PV module will result beneficial and informative, the problem with the temperature will tend to back down this prototype. The lack of some system to cool down the bifacial cells will imply that the receiver could reach unacceptable temperatures. This hypothesis will be drawn under some specific conditions, so they will not be completely devastating to the idea of using bifacial cells, but perhaps a different approach should be used in case it is desired to continue this work. 

Abstract

In this thesis, a measurement system was set to perform comprehensive measurements on RF power amplifiers. Data obtained from the measurements is then processed mathematically to obtain three dimensional graphs of the basic parameters affected or generated by nonlinearities of the amplifier i.e. gain, efficiency and distortion. Using a class AB amplifier as the DUT, two sets of signals – both swept in power level and frequency - were generated to validate the method, a two-tone signal and a WCDMA signal. The three dimensional plot gives a thorough representation of the behavior of the amplifier in any arbitrary range of spectrum and input level. Sweet spots are consequently easy to detect and analyze. The measurement setup can also yield other three dimensional plots of variations of gain, efficiency or distortion versus frequencies and input levels. Moreover, the measurement tool can be used to plot traditional two dimensional plots such as, input versus gain, frequency versus efficiency etc, making the setup a practical tool for RF amplifiers designers.

The test signals were generated by computer then sent to a vector signal generator that generates the actual signals fed to the amplifier. The output of the amplifier is fed to a vector signal analyzer then collected by computer to be handled. MATLAB® was used throughout the entire process.

The distortion considered in the case of the two-tone signals is the third order intermodulation distortion (IM3) whereas Adjacent Channel Power Ratio (ACPR) was considered in the case of WCDMA.

This thesis is aimed at people who are interested in using the new environmentally friendlymethods of electricity generation or people who already use small wind turbines and solarpanels with the need for an additional energy source in small cabins or remote locations whereaccess to electricity networks is impossible. Aims of this work is first to build a system forgenerating electricity using a bicycle. Second is determining the amount of electrical energy aperson can generate with the system. Finally answer if this system could be used as a supportsystem for electricity generation in small scale.

The first objective is to design a system using power control where the power generatedsupplied the loads. The mechanical part will be constructed as part of the energy source, thenwill be designed a control for controlling the power via electronic components, electrical loadssupplied by the system, will be simulated. To know the generated power to the control circuitwill install a meter and a serial communication device for communicating with a computer.

It carries out a research on other systems and products in the Swedish market, to answer whetherthis system can be a backup system for electricity generation in small scale.

The construction of a pedaling power system is achieved using a twelve volt direct currentmotor with permanent magnet as an energy source. System has the ability to show in an LCDdisplay and transmit through the serial ports, the value of the generated power. System canguide the power to the loads by using a microcontroller. Power generated by the system showedthat it is significant to be considered as an additional energy source, stand-alone or integratedwith other systems.

Multi-carrier modulation (MCM) is today’s method of choice for communication systems. This is also true for SI-POF. The basics of MCM and special characteristics for the optical transmission using SI-POF are explained within this paper. Current approaches for MCM over SI-POF are described: Teleconnect’s G.hn based solution for home networking and Innodul’s DMT-based Gigabit solution.

For higher data rate and attractive price level internet service Very High Data rate Subscriber Line 2 (VDSL2) is a perfect option. VDSL2 is a great achievement in Digital Subscriber Line (DSL) technology. It has a good impact in modern triple play (Voice, Data and Video) Internet service but for modern world applications required more data rate than the VDSL2 system can provide but it should be inexpensive and easy to install. So the desired goal of this thesis work is to achieve higher bitrates for VDSL2 system, by transmitting multiple VDSL2 signal using Plastic Optical Fiber (POF) channel instead of copper channel. POF channel is a suitable solution for high data rate application. Moreover POF is very rugged and suitable for high data rate application because of optical based transmission and it’s also very easy to implement into the interior networking. Moreover POF doesn’t have any impact of Electro Magnetic Interference because of optical transmission. So several VDSL2 signals are amplitude modulated to allocate specific frequency band and combined together which can be called as frequency division multiplexing and POF is used as channel to carry the combined signal which provide much higher bit rate than single signal and efficiently utilize the bandwidth of the channel. Then at the receiver end the combined signals are split and amplitude demodulate at the respective receiver to recover the expected frequency band for the receiver.       

The World today is deeply transformed by the advancement in wireless technology. The envision of a smart society where interactions between physical and virtual dimensions of life are intertwined and where human interaction is mediated by machines, e.g., smart phones, demands increasingly more data traffic. This continual increase in data traffic requires re-designing of the wireless technologies for increased system capacity and flexibility. In this thesis, aspects related to behavioral modeling, characterization, and linearization of multi-channel/band power amplifiers (PAs) are discussed.

When building a model of any system, it is advantageous to take into account the knowledge of the physics of the system and include into the model. This approach could help to improve the model performance. In this context, three novel behavioral models and DPD schemes for nonlinear MIMO transmitters are proposed.

To model and compensate distortions in GaN based RF PAs in presence of long-term memory effects, novel models for SISO and concurrent dual-band PAs are proposed. These models are based on a fixed pole expansion technique and have infinite impulse response. They show substantial performance improvement. A behavioral model based on the physical knowledge of the concurrent dual-band PA is derived, and its performance is investigated both for behavioral modeling and compensation of nonlinear distortions.

Two-tone characterization is a fingerprint method for the characterization of memory effects in dynamic nonlinear systems. In this context, two novel techniques are proposed. The first technique is a dual two-tone characterization technique to characterize the memory effects of self- and cross-modulation products in concurrent dual-band transmitter. The second technique is for the characterization and analysis of self- and cross-Volterra kernels of nonlinear 3x3 MIMO systems using three-tone signals.

The demands for high data rates and broadband wireless access requirethe development of wireless systems that can support wide and multi-bandsignals. To deploy these signals, new radio frequency (RF) front-ends are requiredwhich impose new challenges in terms of power consumption efficiencyand sources of distortion e.g., nonlinearity. These challenges are more pronouncedin power amplifiers (PAs) that degrade the overall performance ofthe RF transmitter.Since it is difficult to optimize the linearity and efficiency characteristicsof a PA simultaneously, a trade-off is needed. At high input power, a PAexhibits high efficiency at the expense of linearity. On the other hand, atlow input power, a PA is linear at the expense of the efficiency. To achievelinearity and efficiency at the same time, digital pre-distortion (DPD) is oftenused to compensate for the PA nonlinearity at high input power. In case ofmulti-channel PAs, input and output signals of different channels interactwith each other due to cross-talk. Therefore, these PAs exhibit differentnonlinear behavior than the single-input single-output (SISO) PAs. The DPDtechniques developed for SISO PAs do not result in adequate performancewhen used for multi-channel PAs. Hence, an accurate behavioral modeling isessential for the development of DPD for multi-channel RF PAs.In this thesis, we propose three novel behavioral models and DPD schemesfor nonlinear multiple-input multiple-output (MIMO) transmitters in presenceof cross-talk. A study of the source of cross-talk in MIMO transmittershave been investigated to derive simple and powerful modeling schemes.These models are extensions of a SISO generalized memory polynomial model.A comparative study with a previously published MIMO model is also presented.The effect of coherent and partially non-coherent signal generationon DPD performance is also highlighted. It is shown experimentally thatwith partially non-coherent signal generation, the performance of the DPDdegrades compared to coherent signal generation.In context of multi-channel RF transmitters, PA behavioral models andDPD schemes suffer from a large number of model parameters with the increasein nonlinear order and memory depth. This growth leads to highcomplexity model identification and implementation. We have designed aDPD scheme for MIMO PAs using a sparse estimation technique for reducingmodel complexity. This technique also increases the numerical stability whenlinear least square estimation model identification is used.A method to characterize the memory effects in a nonlinear concurrentdual-band PAs is also presented. Compared to the SISO PAs, concurrentdual-band PAs are not only affected by intermodulation distortions but alsoby cross-modulation distortions. The characterization of memory effects inconcurrent dual-band transmitter is performed by injecting a two-tone testsignal in each input channel of the transmitter. Asymmetric energy surfacesare introduced for the intermodulation and cross-modulation products, whichcan be used to identify the power and frequency regions where the memory effects are dominant.

A characterization technique for RF PAs excited with multiple signals is presented. The technique can be used for characterization of memory effects in IM/CM products. The extracted information can in return be of use for modifying behavioral models to better capture memory in IM/CM products.

Electrical anomalies due to trapping effects in Gallium Nitride (GaN) power amplifiers (PAs)give rise to long-term or strong memory effects. We propose novel models based on infinite impulse response (IIR) fixed pole expansion techniques for the behavioural modeling and digital pre-distortion of single-input-single-output (SISO) and concurrent dual-bandGaN PAs. Experimental results show that the proposed models outperform the corresponding finite impulse response (FIR) models by up to 17 dB for the same number of model parameters. For the linearization of a SISO GaN PA the proposed models give adjacent channel power ratios (ACPRs) that are 7 to 17 dBlower than the FIR models. For the concurrent dual-band case, the proposed models give ACPRs that are 9to 14 dB lower than the FIR models.

A dual two-tone technique for the characterization of memory effects in concurrent dual-band transmitters is revisited to modify a 2D-DPD model for the linearization of concurrent dual-band transmitters. By taking into account the individual nonlinear memory effects of the self- and cross-kernels, a new 2D modified digital pre-distortion (2D-MDPD) model is proposed, which not only supersedes the linearization performance but also reduces the computational complexity compared to the 2D-DP Dmodel in terms of a number of floating point operations (FLOPs). Experimental results show an improvement of 1.7 dBin normalized mean square error (NMSE) and a 58% reduction in the number of FLOPs.

This paper proposes three novel models for behavioral modeling and digital pre-distortion (DPD) of nonlinear 2$,times,$ 2 multiple-input multiple-output (MIMO) transmitters in the presence of crosstalk. The proposed models are extensions of the single-input single-output generalized memory polynomial model. Three types of crosstalk effects were studied and characterized as linear, nonlinear, and nonlinear & linear crosstalk. A comparative study was performed with previously published models for the linearization of crosstalk in a nonlinear 2 $,times,$2 MIMO transmitter. The experiments indicate that, depending on the type of crosstalk, the selection of the correct model in the transmitter is necessary for behavioral modeling and sufficient DPD performance. The effects of coherent and partially noncoherent signal generation on the performance of DPD were also studied. For crosstalk levels of ${-}{hbox{30}}$ dB, the difference in the normalized mean square error and adjacent channel power ratio was found to be 3–4 dB between coherent and partially noncoherent signal generation.

The paper presents a 2D extended envelope memory polynomial (2D-EEMP) model for concurrent dual-band radio frequency (RF) power amplifiers (PAs). The model is derived based on the physical knowledge of a dual-band RF PA. The derived model contains cross-modulation terms not included in previously published models; these terms are found to be of importance for both behavioral modeling and digital pre-distortion (DPD). The performance of the derived model is evaluated both as the behavioral model and DPD, and the performance is compared with state-of-the-art2D-DPD and dual-band generalized memory polynomial (DB-GMP) models. Experimental result shows that the proposed model resulted in normalized mean square error (NMSE) of -51.7/-51.6dB and adjacent channel error power ratio (ACEPR) of -63.1/-63.4 dB, for channel 1/2, whereas the 2D-DPD resulted in the largest model error and DB-GMP resulted in model parameters that are 3 times more than those resulted with the proposed model with the same performance. As pre-distorter, the proposed model resulted in adjacent channel power ratio (ACPR) of -55.8/ -54.6 dB for channel 1/2 and is 7-10 dB lower than those resulted with the 2D-DPD model and2-4 dB lower compared to the DB-GMP model.

A method to characterize the memory effects in a nonlinear concurrent dual-band transmitter is presented. It is an extension of the conventional two tone test for power amplifiers to concurrent dual band transmitters. The output signal of a concurrent dual-band transmitter is affected not only by intermodulation products but also by cross-modulation products. In one frequency band, the transmitter is excited by a two tone signal which frequency separation is swept. In the second band the transmitter is concurrently excited by an other two tone signal with slightly wider frequency separation. The frequency difference of the two signals is fixed during the frequency sweep. The two tone test is made at different power levels. The upper and lower third-order inter- and cross-modulation products are measured. The asymmetry between the upper and lower third-order inter- and cross-modulation products are measures of the transmitter's memory effects. The measurement results show that the memory effects are more dominant in the third-order intermodulation products than in the cross modulation products. An error analysis and system calibration was performed and measurement results for two different devices are presented.

This rebuttal is to "€œOn dual-band amplifications using dual two-tone: Clarifications and discussion". In the following, we provide our reply.

The indirect learning architecture (ILA) is the mostused methodology for the identification of Digital Pre-distorter (DPD) functions for nonlinear systems, particularly for high power amplifiers. The ILA principle works in black box modeling relying on the inversion of input and output signals of the nonlinear system, such that the inverse is estimated. This paper presents the impact of disturbances, such as noise in the DPD identification. Experiments were performed with a state-of-art Doherty power amplifier intended for base station operation in current telecommunication wireless networks. As expected, a degradation in the performance of the DPD (measured innormalized mean square error (NMSE)) is found in our experiments. However, adjacent channel power ratio (ACPR) can be a misleading figure of merit showing improvement in the performance for wrongly estimated DPD functions.

The spectrum analyzer is a standard tool used to measure signals in the frequency domain. Traditional spectrum analyzers are based on sweeping a local oscillator and using this to mix signals down to an intermediate frequency (IF) and, subsequently filter them with a filter of settable characteristics, called the Resolution Bandwidth (RBW). This is still the preferred method when the requirement on dynamic range of the signals being measured is large. However, this approach has the drawbacks of being relatively slow, not adaptive and flexible for some specific need and certain special measurement functionalities cannot be done due to the sweeping. Due to this, Ericsson production test development would like to perform software-based spectrum analysis on sampled In-phase and Quadrature (IQ) signals.

In this thesis, the introduction of IQ-signals and synthetic spectrum analysis (SSA) are presented. The statistical properties of root mean-square (RMS) and sample detectors for standard spectrum analyzer are investigated. The effect of swept time on statistical properties of the RMS and sample detectors were investigated and the results are presented in this work. The results of swept time effect for sample detector show the change in the variance of the statistical properties when continuous wave (CW) and two-tone test signals were used, however, for bandlimited Gaussian test signal, the variance of the statistical properties is not changed. For RMS detector, the swept time using two-tone and Gaussian test signals show the change in the variance of the statistical properties. Whereas, for CW test signal the statistical properties result in shift from higher power distribution level to lower power distribution level with increase in sweep-time.

The emulation of spectrum analysis functionalities (RBW, envelope detector and 0detectors) for IQ-signal has been implemented in MATLAB. The verification of the implemented functionalities has been done by investigating the statistical properties of RMS and sample detectors for SSA for various test signals. These were found to agree with standard spectrum analyzer results.

Moreover, the comparison of spectral traces and statistical properties between implemented functionality and standard spectrum analyzer have done. The results are showing agreement with industrial standard spectrum analyzer results.

Characterizing power amplifiers require test set-ups with performance superior to the power amplifiers. A commonly used method is to use an IQ-demodulator. However, problem arises due to imperfections in the demodulator such as IQ-imbalance; an alternative method is to use a direct down converter to intermediate frequency. The drawback then is the limited bandwidth. However, the required bandwidth of the ADC does not need to be exceptional. According to Zhu’s general sampling theorem is it enough to sample the output signal at the Nyquist rate of the input. However, even though the required sampling rate is reduced the demands on the analog bandwidth remains. Unfortunately, commercially available instruments such as vector signal analyzers can not be used for this purpose since their analog bandwidth is too small. In this paper a test-bed is designed to utilize the Zhu’s general sampling theorem. The RF front-end has frequency range of 500 MHz – 2.7 GHz and a bandwidth of 1 GHz. All performance data are verified with measurements.

A decrease in life cycle cost is a key issue for testing of mobile communication systems. The rapid development and edge technology requires high performance instruments and state of the art measurement technology. It is desired to use virtual/synthetic instruments and put the measurement technology in software independent of hardware, i.e. software driven measurements. Increased flexibility and modularization, both in hardware and software, are requirements to support the cost decrease. The hardware basis is signal generation and signal analysis.

In this paper state of the art signal generation and signal analysis capabilities are demonstrated in a modular and flexible architecture. A direct IF synthesis is used to generate 1 WideBand Code-Division Multiple Access (WCDMA) carrier with more than 72 dB Adjacent Carrier Leakage Ratio (ACLR) 2 carrier with more than 68 dBc ACLR over a total bandwidth of 100 MHz. The signal analysis capabilities, ACLR performance, for a WCDMA carrier is better than -70 dBc and for a continuous wave better than -85 dBc over a bandwidth of 42.5 MHz. The critical down converter in the set up doesn’t degrade the performance.