No description available.

This project explores how to use band-pass filtering with a variety of filters to filter both two and three dimensional surface data. The software developed collects and makes available these filtering methods to support a larger project. It is used to automate the filtering procedure. This paper goes through the work-flow of the program, explaining how each filter was implemented. Then it demonstrates how the filters work by applying them to surface data used to test correlation between friction and roughness [Berglund and Rosen, 2009]. It also provides some explanations of the mathematical development of the filtering procedures as obtained from literature.

The first part of this thesis proposes a method to synthesize the T- and £S-prototype of band-pass filters using the two reflection zeros and the rolloff rate. According to the characteristics of passive components embedded in different substrates, £S-prototype band-pass filter is suitable for implementation on LTCC substrate, while T-prototype band-pass filter is suitable for implementation on organic substrate. The second part of this thesis employs the £S-prototype to design the LTCC band-pass filters. It has been found that mutual coupling and feedback elements can be used to create the multiple transmission zeros. With these synthesized transmission zeros, the stopband attenuation can be enhanced at several specific frequencies. For demonstration, this thesis implements the LTCC band-pass filters in 2.4 GHz ISM band and 3.5 GHz WiMAX band. The measured results show that insertion loss and return loss in the passband for these LTCC filters is less than 2 dB and more than 10 dB, respectively. In addition, these filters have the additional transmission zeros for enhancing the stopband attenuation. Moreover, miniaturization is also a key issue in implementing these LTCC filters. The 2.4 GHz and 3.5 GHz LTCC filter can meet the standard 1608 size and 2520 size, respectively, which are the smallest compared to the other LTCC filters reported for similar applications in the current literature and commercial media.

All-fiber multireflector spectral filters which have potential application in optical communications have been investigated experimentally. These multireflector etalons were produced by aligning equal-length fiber sections with TiO2/SiO2 dielectric mirrors deposited on the end in a silicon v-groove. Fiber sections 1.33mm in length were produced by polishing, with the fibers held in a silicon wafer polishing jig. The fibers were aligned inside the polishing jig using a precision micro positioner. Then four polishing steps with increasingly finer grit were applied to produce high-quality polished end surfaces on each fiber section. Finally, a dielectric mirror was deposited on one end of each fiber section by magnetron sputtering. After characterizing the optical loss, length, and mirror reflectance for each of the fiber sections, sections which were well-matched in length were chosen for assembly of the four-mirror etalon, which had nominal reflectance values of 10%, 50%, 50%, and 10% for the dielectric mirrors. Measured transmittance spectra for a mutireflector spectral filter were compared with calculated spectra. Thermal tuning of the multireflector etalon was also investigated. A 0.34 nm wavelength shift was observed for a 23° C temperature change, in agreement with prediction. increasingly finer grit were applied to produce high-quality polished end surfaces on each fiber section. Finally, a dielectric mirror was deposited on one end of each fiber section by magnetron sputtering. After characterizing the optical loss, length, and mirror reflectance for each of the fiber sections, sections which were well-matched in length were chosen for assembly of the four-mirror etalon, which had nominal reflectance values of 10%, 50%, 50%, and 10% for the dielectric mirrors. Measured transmittance spectra for a mutireflector spectral filter were compared with calculated spectra. Thermal tuning of the multireflector etalon was also investigated. A 0.34 nm wavelength shift was observed for a 23° C temperature change, in agreement with prediction.

No / In this paper, a compact microstrip band-pass filter (BPF) covering the 3.4 to 3.8 GHz spectrum bandwidth for 5G wireless communications is presented. The planar filter uses three resonators, each terminated by a via to hole ground at one end and a capacitor at the other end with 50 Ω transmission line impedances for input and output terminals. The coupling between the lines is adjusted to resonate at the centre frequency with third-order band-pass Butterworth properties. The proposed combline filter is designed on an alumina substrate with a relative dielectric constant of 9.8 and a very small size of 9×5×1.2 mm3. The proposed filter is simulated and optimized using CST microwave studio software. / European Union’s Horizon 2020 research and innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET-722424, UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E022936/1

This thesis realizes miniature bandpass filters using integrated passive device technology. The bandpass filters are designed based on coupled resonator method with single-band and dual-band responses, using a transformer structure with high-density winging pattern. In addition, the designs adopt the electric- and magnetic-field cancellation and the feedback mechanism to produce transmission zeros in the filter responses for enhancing selectivity and stopband rejection. In order to satisfy the specific requirements of commercial bandpass filter products, this thesis designed and implemented a trisection filter with cross coupling on a low-loss RT/Duroid substrate to generate a transmission zero very near the passband.

As the number of wireless devices in the world increases, so does the demand for flexible radio receiver architectures capable of operating over a wide range of frequencies and communication protocols. The resonance-based channel-select filters used in traditional radio architectures have a fixed frequency response, making them poorly suited for such a receiver. The N-path filter is based on 1960s technology that has received renewed interest in recent years for its application as a linear high Q filter at radio frequencies. N-path filters use passive mixers to apply a frequency transformation to a baseband low-pass filter in order to achieve a high-Q band-pass response at high frequencies. The clock frequency determines the center frequency of the band-pass filter, which makes the filter highly tunable over a broad frequency range. Issues with harmonic transfer and poor attenuation limit the feasibility of using N-path filters in practice. The goal of this thesis is to design an integrated active N-path filter that improves upon the passive N-path filter’s poor harmonic rejection and limited outof- band attenuation. The integrated circuit (IC) is implemented using the CMRF8SF 130nm CMOS process. The design uses a multi-phase clock generation circuit to implement a harmonic rejection mixer in order to suppress the 3rd and 5th harmonic. The completed active N-path filter has a tuning range of 200MHz to 1GHz and the out-ofband attenuation exceeds 60dB throughout this range. The frequency response exhibits a 14.7dB gain at the center frequency and a -3dB bandwidth of 6.8MHz.

No description available.

Contemporary wireless systems have advanced toward smart and multifunctional radios such as software-defined or cognitive radios which access a wideband or multiband spectrum dynamically. It is desirable for the wireless systems to have high frequency selectivity early in the receiver chain at RF to relax the dynamic range requirements of subsequent stages. However, integration of high selectivity RF band-pass filters (BPF), or band-stop filters (BSF) is challenging because of limited quality factor (Q) of passive components in integrated circuit (IC) technology [1]. This proposed research achieves the followings: 1. Developing, and demonstrating innovative integrated band-pass filter that relaxes the performance tradeoffs in conventional LC filters to maximally increase filter reconfigurability in frequency tuning range (2-18 GHz), selectivity (Q=5~100) with superior dynamic range (DR>100 dB) at RF to microwave frequency range [2]. 2. Implementing active notch filter system comprised of a Q-enhancement band-pass filter (BPF) and an all-pass amplifier. The notch response is synthesized by subtracting the BPF output from the all-pass output. In the proposed synthetic notch filters, the BPF is responsible for defining selectivity while stop-band attenuation is primarily dependent on the gain matching between the BPF and all-pass amplifier. Therefore, notch attenuation is controllable independently from the bandwidth tuning, providing more operational flexibility. Further, the filter dynamic range is optimized in the all-pass amplifier independently from the selectivity control in the BPF, resolving entrenched tradeoff between selectivity and dynamic range in active filters [3]. 3. Demonstrating the mode reconfigurable LC filter that works in either BPF or BSF for a flexible blocker filtering adaptive to the dynamic blocker environments. 4. Implementing a novel feedback-based interference rejection system to improving the linearity of the BPF for high Q cases, in which the BPF Q is set to a specific value and further increase in Q is achieved using feedback gain. And finally, the second LC tank is added to increase the out of band rejection in band-pass characteristics. / Ph. D.

Orientador: Luiz Carlos Kretly / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-09T03:22:24Z (GMT). No. of bitstreams: 1 Silva_Eduardo_M.pdf: 14948633 bytes, checksum: 63579d1a8844e33a2c577a9aed963b41 (MD5) Previous issue date: 2007 / Resumo: Este trabalho tem como escopo o projeto e implementação de indutores ativos em tecnologia CMOS para operação em sistemas de rádio freqüência. A grande área demandada por indutores passivos integrados, bem como a sua baixa indutância e baixo fator de qualidade associados, apresentam-se como um dos maiores limitantes no projeto de circuitos integrados aplicados às comunicações. Como alternativa, indutores ativos integrados têm sido propostos. O uso de topologias de circuitos que emulam o efeito do indutor passivo convencional torna-se atraente ao passo que o grau de compactação e seletividade podem ser obtidos. Quatro topologias distintas de indutores ativos integrados são abordadas, bem como uma aplicação prática. Resultados de simulação e de experimentos são apresentados / Abstract: This work aims the design and implementation of integrated active inductors in CMOS technology for applications in radio frequency systems. The large area occupied by passive inductors, as well its low quality factor and low inductance, have been detached as one of the major drawbacks in the design of integrated circuits applied to communication systems. Alternately, active inductors have been proposed. Circuits usage which emulates conventional spiral inductors becomes interesting since die area reduction and selectivity can be obtained. Four different topologies of integrated active inductors are discussed, as well a practical application. Simulation results and experimental results are presented. / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica