The design and fabrication of miniature microwave bandpass filters using multilayer liquid crystal polymer technology

This thesis presents the design and fabrication techniques for miniature microwave bandpass filters using multilayer liquid crystal polymer (LCP) technology. As a multilayer technology for microwave devices, LCP is of low cost and light weight. It also has excellent electrical properties across a wide frequency range. These characteristics make it promising for the development of next generation microwave devices for applications across commercial, defence and civil sectors. However, very limited work has been found in the open literature to apply this technology to the design of miniature bandpass filters, especially at low microwave frequencies. In addition, the reported work shows lack of fabrication techniques, which limits the size reduction of multilayer LCP devices. To address these problems, this thesis develops advanced fabrication techniques for sophisticated LCP structures, such as multilayer capacitors, via connections and cavities. These techniques are then used to support the design of novel miniature bandpass filters for wideband and narrowband applications. For the design of miniature wideband bandpass filters, a cascaded approach, which combines highpass and lowpass filters, is presented first to provide a flexible design solution. This is followed by another novel ultra-wideband bandpass filter which produces extra transmission zeroes with minimum number of elements. It does not only have high performance but also a compact structure for high yield fabrication. For narrowband applications, two types of advanced coupled-resonator filters are developed. One type produces a very good selectivity at the upper passband edge, and its spurious-free stopband is extremely wide and of high interference attenuation. The other type, based on novel mixed-couplings approaches developed in this thesis, provides a solution to produce almost the same response as the coupling matrix prototype. This type is used to generate arbitrarily-located transmission zeroes. All designs presented in this thesis are simulated using CAD design tools and then validated by measurements of fabricated samples. Good agreements between simulations and measurements are shown in the thesis

Emulated reactance and resistance by a SSSC incorporating energy storage device

Static Synchronous series compensator without energy storage device can exchange only reactive power with the network and can operate in limited operating range in two quadrants only. When energy storage device is connected at the DC bus of SSSC (SSSC – ES), it can also exchange real power with the network. Operating range of SSSC will be much broader and it covers all the four quadrants. However, emulated reactance and resistance by SSSC – ES is likely to affect the performance of a distance protection system. This paper presents a detailed model of an SMIB system with SSSC – ES. Injected voltage by SSSC – ES in all the four quadrants of operation is presented. Impact of operation of SSSC _ ES in different quadrants and various control strategies for SSSC – ES on impedance emulated by SSSC – ES during steady state condition and transient system disturbance is discussed.

MATLAB Simulation Model to Improve Voltage Sag Due to Starting of Induction Motor Using STATCOM

In industrial sector or process continuity plant the continuity of the industrial processes becomes a more important factor for the organisation profit and economical balance. But sometime its get interrupted due to electrical faults, low voltage supply, voltage sag some mechanical faults or man made mistakes. Out of it voltage sag is one of the most persisting factors to be taken in to account, starting high power loads like induction motors or heavy loads draws a very large amount of current then the system rated specified voltages. So these sags gets detected by the under voltage relays or over current relays and consequently act in opening up of the breaker and hence brings distortion in the process continuity of the plants working processes. And further the cost of restarting the process again and delay in the order supply acts more to the damage done. So, it’s really necessary to compensate for the reactive power or the voltage sag occurred during this time. So one of the available alternative is the modern generation FACT controller like STATCOM which is a shunt operated reactive power compensating device or reactive power exchanging device for improving the voltage system profile of the system, so here in this thesis report we will try to investigate the operation of the STATCOM. Its device characteristics, its constructional details and take a special model in the MATLAB simulation to how the compensating ability of the STATCOM and its benefits and con will be figured out. Here we will also find out some of the other ways to improve the voltage sag improvement and theirs features. Little focus will be also on the reactive power analysis, how it affects the system and its necessity will be discussed in brief. Little light will also be given to the FACTS class of the device its modern trends and its benefits to the electrical engineering sector. Here in the STATCOM circuit which comes across the FACT device class will be using a voltage source PWM operated inverter circuits for its operation. The facts technology is mainly based upon implementing power electronics technology in the field of power system dynamics for its stability and improvement of the various important contributing part of the ower system like reactive power compensation, improvement of the stability of the system

Investigation of Thermal Effects in Different Lightweight Constructions for Vehicular Wireless Power Transfer Modules

This paper presents a thermal investigation of lightweight on-board receiver modules of wireless power transfer systems for electric vehicles. The studied modules are capable of receiving up to 11 kW at a resonance frequency of 85 kHz over a distance of 110–160 mm. The receiver modules were built as sandwich and space–frame concept to design stiff and lightweight structures. The high transmission power of automotive wireless power transfer systems combined with the multi-part assembly of receiver modules led to challenges in heat management. To address this, the physical behaviour of the proposed lightweight concepts were studied on component and system level using a hardware-in-the-loop testing facility for wireless power transfer systems. Special emphasis was laid on the validation of a thermal simulation model, which uses analytical calculated power losses taking into account their temperature dependency. The proposed simulation model is consistent with the experimental validation of the critical active components. The performed systematic studies build the basis for a more sophisticated thermal dimensioning of various constructions for wireless power transfer modules. Document type: Articl

Optimized Weight Point ADF using SOS Algorithm

Active dc filter (ADF) has become the most viable alternatives for the compensation of the harmonics in the power system analysis. These filters are capable enough to minimize the total harmonic distortion (THD) and provide compensation towards the power quality issues appearing in the transmission system. A simulated model of a HVDC system is designed in MATLAB and the disturbance is injected in the form of load change and the controller efficacy is checked. This paper basically deals with the operational characteristics of the active filter for specific voltage rating irrespective of load and used to reduce harmonics present in the output voltage of the HVDC converter when cascaded with the inverter. The gains of the ADF are optimized with Symbiotic Organism Search Optimization (SOS) with THD as a constraint

Numerical Modeling Analysis of Wafer Warpage and Carrier Mobility Change due to Tapered Through-Silicon-Via Geometry

Three-dimensional integration is a solution that vertically stacks multiple layers of silicon chips by Through-Silicon-Vias (TSVs) to enhance the performance of microelectronic devices. The tapered TSV profile can help to overcome the technical difficulties. However, an easily overlooked issue is that tapered TSV can cause wafer warpage during the fabrication processes. Wafer warpage can cause chip misalignment and impose additional deformation. In an effort to investigate the TSV geometric effect, a large number of finite element analysis (FEA) simulations were performed to quantify the thermal stress distribution and the thermally induced curvature. It was found that the tapered geometry alone can induce significant wafer bending, which has not been reported by other researchers. The effect of taper angle, TSV radius, TSV pitch, and wafer thickness were quantitatively studied. In addition, the incorporations of anisotropic silicon property and intermediate layers between the copper TSV and silicon into the numerical models were assessed. Thermally induced stress concentration around copper TSV near the wafer surface can lead to degradation of the device performance by affecting the carrier mobility in transistors. This piezoresistivity effect can cause serious reliability concerns. The size of keep-out zone (KOZ), which is identified as a threshold of 5% carrier mobility change, was also quantified for various transistor types in different channel directions

Methodology and applications of electrostatic discharge current reconstruction by near-field scanning technique

Electrostatic discharge (ESD) can cause interference in or damage to circuits or systems in many ways e.g., by E- field or H- field coupling or via conduction paths. Although one can roughly estimate the voltage and current at the injection location during an ESD event, the real offending parameter is mostly the ESD current spreading throughout the system. Those currents can be simulated if great simplifications of the system are acceptable. However, even in moderately complex systems, the ability to simulate is limited by a lack of models and computational resources. Independent of the complexity, but obviously not free of its own limitations, is a measurement technique that captures the current as a function of time and location through the system. This article describes an ESD current measurement technique that permits reconstruction the injected current spreading as a movie from the magnetic near-field scanning results. It describes the validation of the technique using a simplified case study. The study examined the simulation and measurement of a simplified PCB ESD structure; the design, characterization, modeling, and optimization of current scanning probes; the implementation and analysis of time domain and frequency domain scanning methods; the scanning raw data frequency and directional response compensation algorithms; the current spreading visualization methods and implementation; the modeling of simplified PCB current injection structure and verification of ESD current reconstruction results; two directions of system-level analysis with current reconstruction scanning method --Abstract, page iii

Dynamic Wireless Power Transfer System For The Unmanned Aerial Vehicles

UAVs have limitless applications to help our daily lives for the autonomous operations. UAVs have a limited power capacity due to weight constraints and are therefore not able to travel long distances. Ground stations for recharging UAVs throughout different points can increase the flight time of the UAVs with the current UAV battery capacity. This study investigates how the wireless charging system for the ground station can be made more robust when there are misalignments. The wireless charging system is monitored by an Arduino, micro controller, to assess the current condition of charging. The Arduino is able to change the capacitance of the wireless charging system to optimize the resonant frequency when misalignment occurs. The weight to fly of the UAV is limited and battery source power is the huge drawback. In order to increase the flight time, increasing battery run time, or position ground stations to recharge the UAV rapidly are possible methods. In this study method of improving the ground station\u27s wireless recharging ability by using microprocessor to provide more dynamic recharging is explained. The ground station is equipped with an inductive charging system and successfully recharges the UAV. The ground station has been further improved to use magnetic resonant coupling to create better efficiency and wider controlling range. The resonant frequency is tunable by the Arduino, a micro processor, to change capacitance of varactors. By changing capacitance of the varactor, the magnetic resonant coupling wireless power transfer system can work in wider range from the ground station