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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

A High Linearity and Wide Tuning Range Gm-C Filter

Chang, Yuan-Ming 24 August 2010 (has links)
This thesis has described a wide tuning range transconductor combining source degeneration, cross-coupled, translinear loop to achieve high linearity. The transconductance tuning range from 220£gs to 1050£gs with 1V input range and the total harmonic distortion is -50dB with 0.6Vpp input voltage. And its application to a fifth-order elliptic low-pass Gm-C filter for the front-end RF circuit is presented. In order to transform the passive element circuit into a Gm-C based filter, a GIC flow method has been used. The proposal Gm-C based filter achieve a with performance a low frequency filtering range from 5Mhz to 10Mhz by transconductance tuning.
22

Study and Implementation of Automatic Gain Control, High Voltage Integrated Circuits, and Backplane Transceiver

Yang, Shang-Hsien 26 July 2011 (has links)
Thanks to the advance in CMOS technology, an extensive category of applications has been migrated from traditional BJT-based processes. System-on-a-Chip (SoC) realization of digital, analog, and even high voltage devices is now a reality. To address the challenge imposed by integrating analog and high voltage devices in standard CMOS processes, this thesis aims at the design of three specific topics in particular. With regard to the contents of the thesis, first of all, the theory of linear-in-dB automatic gain control (AGC) is discussed. In succession, a linear-in-dB variable gain amplifier (VGA) is mentioned. The implementation of a Feed-forward Output Swing Prediction AGC featuring a Prediction Parallel-Detect Single-Store Peak Detector (PDSSPD) and a High Input/Output Swing VGA is also described. Furthermore, a digitally programmable gain amplifier for a ZigBee wireless receiver is also mentioned. In response to the advent of CMOS-compatible high voltage tolerant Bipolar-CMOS-DMOS (BCD) process, an operational amplifier for level converting operation is disclosed. A 60-V Li-ion battery charger has also been proposed, along with a novel battery charge mode, namely, the incremental charge (IC) mode. Practical issues regarding the high voltage tolerant BCD process is also briefly discussed. Finally, a backplane transmitter featuring pre-emphasis and a receiver utilizing decisive feedback equalization (DFE) designed for CIC MorPack technology are presented. When packaged in a Leadless Ceramic Carrier (LCC) package, the transmitter can transmit up to 500 Mbps and the receiver can receive up to 125 Mbps, both through DuPont connectors without impedance matching.
23

Mixed Linear/Switching Controller Design of a Voltage Regulator Module

Huang, Chia-Ieh 23 August 2005 (has links)
This thesis presents a Mixed Linear/Switching Control (MLSC) scheme for voltage regulator modules (VRM). The MLSC employs two loops of feedback compensation, inner-loop switching compensation and outer-loop linear regulation. The purpose of the switching compensation is to linearize and stabilize the buck converter under the influence of switching noise and load variation. With switching compensation, the linearized plant of the buck converter can be simplified to a first-order stable transfer function at low frequencies. Accordingly, the outer-loop linear controller can be easily designed to regulate the output voltage using the linear control theory. The advantage of the proposed MLSC scheme is two-fold: easy to design and of low circuit complexity. There is no need of using any current detecting resistor and PWM generator, and also the stability and performance can be easily met by choosing positive controller coefficients. A 12V/1V single-phase VRM with proposed control is designed and simulated, which shows an output regulation with 0.4% steady- state output error and 7% load regulation error in response to the load current steps from 60A/1A to 1A/60A, at a slew rate of 60A/µsec.
24

A Low-Voltage Low-Power Widely Tunable Channel Select Filter

Huang, Ding-jhih 06 July 2006 (has links)
In this thesis, we propose a low voltage low power wide-tuning 4th-order butterworth low-pass OTA-C channel selection filter. It is implemented by using TSMC 0.35£gm 2P4M CMOS technology. The drain voltage of triode-biased input transistors of the OTA is regulated through an active-cascode loop for low power and wide-tuning range. The Gm-C channel selection filter can be programmed from 0.5 to 12MHz. The OTA also employs a circuit to reduce the OTA output current in a high transconductance mode and the total power consumption of filter is suppressed below 3mW.
25

Avaliação de extratos de plantas quanto à atividade antimicrobiana e à detoxificação de micotoxinas / Evaluation of plant extracts on antimicrobial activity and detoxification of mycotoxins

Ponzilacqua Silva, Bárbara 12 December 2018 (has links)
A exposição humana a microrganismos patogênicos e suas toxinas em alimentos constitui um grave problema de saúde pública. O uso indiscriminado de antimicrobianos convencionais promove o aumento da resistência dos microrganismos às principais moléculas existentes no mercado. Além disso, as limitações do uso de substâncias químicas em matérias primas alimentares têm estimulado pesquisas para o desenvolvimento de metodologias eco-amigáveis para evitar a multiplicação de fungos e/ou eliminar suas toxinas. O Staphylococcus aureus é uma das principais bactérias patogênicas que apresenta taxas elevadas de resistência aos antimicrobianos, e por este motivo tem sido objeto de estudo de pesquisas que tentam identificar novos compostos bioativos para o combate de infecções. O Aspergillus parasiticus é um dos principais fungos produtores de aflatoxinas, substâncias carcinogênicas que contaminam diversos tipos de cereais antes e após o processamento. Estudos recentes demonstraram que extratos de plantas possuem atividade antimicrobiana e antifúngica, além de potencial para degradação de micotoxinas. Neste contexto, o presente estudo teve por objetivos avaliar a atividade antimicrobiana in vitro de extratos brutos e liofilizados de folhas de maracujá, araçá, alecrim e orégano sobre células planctônicas de S. aureus e A. parasiticus, bem como verificar a capacidade dos referidos extratos em degradar in vitro a aflatoxina B1 (AFB1), ocratoxina A (OTA) e zearalenona (ZEA). Os efeitos antibacterianos e antifúngicos dos extratos foram avaliados através da determinação da concentração inibitória mínima (CIM) e concentração bactericida / fungicida mínima (CBM/CFM). Os ensaios de degradação da micotoxinas foram realizados em diferentes tempos de incubação (12-48 h) a 37º C, utilizando-se cromatografia líquida de alta eficiência (HPLC) para determinação das concentrações das micotoxinas. O maracujá não demonstrou atividade antimicrobiana tanto para S. aureus quanto para A. parasiticus. Dos quatro extratos estudados, o araçá demonstrou o maior efeito antibacteriano, cujos valores de CIM para extratos bruto e liofilizado foram 0.39 mg/mL e 0.45 mg/mL, respectivamente. Os menores valores de CIM para A. parasiticus foram obtidos com o orégano liofilizado (8.33 mg/mL) e o araçá bruto (3.215 mg/mL). Contudo, não foi possível identificar valores de CFM para o fungo analisado. Não houve efeito de degradação de OTA e ZEA por nenhum dos extratos avaliados. Todos os extratos reduziram a concentração de AFB1 após 48 h de incubação. A maior porcentagem (60.3%) de redução de AFB1 foi obtida com o extrato de alecrim após 48 h de incubação. A atividade antimicrobiana demonstrada pelos extratos das plantas avaliadas indica um potencial para sua aplicação no combate a bactérias patogênicas e fungos toxigênicos. Este é o primeiro estudo realizado com extratos dessas quatro espécies de plantas que evidenciou a capacidade de redução in vitro de AFB1. / Human exposure to pathogenic microorganisms and their toxins in food is a serious public health problem. The indiscriminate use of conventional antimicrobials increases the resistance of microorganisms to the main molecules available in the market. In addition, limitations on the use of chemical substances in food raw materials have stimulated researches for the development of eco-friendly methodologies to avoid the multiplication of fungi and/or eliminate their toxins. Staphylococcus aureus is one of the major pathogenic bacteria with high rates of antimicrobial resistance, and for this reason it has been the subject of research studies aiming to identify new bioactive compounds to combat infections. Aspergillus parasiticus is one of the main aflatoxin-producing fungi, which are carcinogenic substances that contaminate many types of cereals before and after processing. Recent studies have demonstrated that plant extracts have antimicrobial and antifungal activity, as well as potential for degradation of mycotoxins. In this context, the objective of the present study was to evaluate the in vitro antimicrobial effects of crude and lyophilized extracts of leaves from sweet passion fruit, araçá, rosemary and oregano on planktonic cells of S. aureus and A. parasiticus. The in vitro degradation of aflatoxin B1 (AFB1), ochratoxin A (OTA) and zearalenone (ZEN) by the crude extracts was also investigated. The antimicrobial and antifungal effects were evaluated by determining the minimum inhibitory concentration (MIC) and minimum bactericidal / fungicidal concentration (MBC / MFC). Mycotoxin detoxification assays were conducted at different incubation times (12-48h) at 37 °C. The concentrations of mycotoxins were determined by high performance liquid chromatography (HPLC). Sweet passion fruit had no antimicrobial activity on S. aureus or A. parasiticus. Out of the four extracts evaluated, araçá showed the highest antimicrobial effect with MIC of 0.39 mg/mL and 0.45 mg/mL for crude and lyophilized extracts, respectively. The lowest MIC values for A. parasiticus were obtained with lyophilized oregano (8.33 mg/mL) and crude araçá (3.215 mg/mL). However, no MFC values were obtained for the analyzed fungi. Although OTA e ZEN were not degraded by any extract evaluated, all extracts reduced the concentration of AFB1 after 48 h of incubation. The highest percentage of AFB1 reduction (60.3%) was obtained with rosemary extract after 48h of incubation. The antimicrobial activity demonstrated by extracts of the evaluated plants indicates a potential for application against pathogenic bacteria and toxigenic fungi. This is the first study carried out with extracts of these four plants species that demonstrated the in vitro ability for AFB1 reduction.
26

Avaliação de extratos de plantas quanto à atividade antimicrobiana e à detoxificação de micotoxinas / Evaluation of plant extracts on antimicrobial activity and detoxification of mycotoxins

Bárbara Ponzilacqua Silva 12 December 2018 (has links)
A exposição humana a microrganismos patogênicos e suas toxinas em alimentos constitui um grave problema de saúde pública. O uso indiscriminado de antimicrobianos convencionais promove o aumento da resistência dos microrganismos às principais moléculas existentes no mercado. Além disso, as limitações do uso de substâncias químicas em matérias primas alimentares têm estimulado pesquisas para o desenvolvimento de metodologias eco-amigáveis para evitar a multiplicação de fungos e/ou eliminar suas toxinas. O Staphylococcus aureus é uma das principais bactérias patogênicas que apresenta taxas elevadas de resistência aos antimicrobianos, e por este motivo tem sido objeto de estudo de pesquisas que tentam identificar novos compostos bioativos para o combate de infecções. O Aspergillus parasiticus é um dos principais fungos produtores de aflatoxinas, substâncias carcinogênicas que contaminam diversos tipos de cereais antes e após o processamento. Estudos recentes demonstraram que extratos de plantas possuem atividade antimicrobiana e antifúngica, além de potencial para degradação de micotoxinas. Neste contexto, o presente estudo teve por objetivos avaliar a atividade antimicrobiana in vitro de extratos brutos e liofilizados de folhas de maracujá, araçá, alecrim e orégano sobre células planctônicas de S. aureus e A. parasiticus, bem como verificar a capacidade dos referidos extratos em degradar in vitro a aflatoxina B1 (AFB1), ocratoxina A (OTA) e zearalenona (ZEA). Os efeitos antibacterianos e antifúngicos dos extratos foram avaliados através da determinação da concentração inibitória mínima (CIM) e concentração bactericida / fungicida mínima (CBM/CFM). Os ensaios de degradação da micotoxinas foram realizados em diferentes tempos de incubação (12-48 h) a 37º C, utilizando-se cromatografia líquida de alta eficiência (HPLC) para determinação das concentrações das micotoxinas. O maracujá não demonstrou atividade antimicrobiana tanto para S. aureus quanto para A. parasiticus. Dos quatro extratos estudados, o araçá demonstrou o maior efeito antibacteriano, cujos valores de CIM para extratos bruto e liofilizado foram 0.39 mg/mL e 0.45 mg/mL, respectivamente. Os menores valores de CIM para A. parasiticus foram obtidos com o orégano liofilizado (8.33 mg/mL) e o araçá bruto (3.215 mg/mL). Contudo, não foi possível identificar valores de CFM para o fungo analisado. Não houve efeito de degradação de OTA e ZEA por nenhum dos extratos avaliados. Todos os extratos reduziram a concentração de AFB1 após 48 h de incubação. A maior porcentagem (60.3%) de redução de AFB1 foi obtida com o extrato de alecrim após 48 h de incubação. A atividade antimicrobiana demonstrada pelos extratos das plantas avaliadas indica um potencial para sua aplicação no combate a bactérias patogênicas e fungos toxigênicos. Este é o primeiro estudo realizado com extratos dessas quatro espécies de plantas que evidenciou a capacidade de redução in vitro de AFB1. / Human exposure to pathogenic microorganisms and their toxins in food is a serious public health problem. The indiscriminate use of conventional antimicrobials increases the resistance of microorganisms to the main molecules available in the market. In addition, limitations on the use of chemical substances in food raw materials have stimulated researches for the development of eco-friendly methodologies to avoid the multiplication of fungi and/or eliminate their toxins. Staphylococcus aureus is one of the major pathogenic bacteria with high rates of antimicrobial resistance, and for this reason it has been the subject of research studies aiming to identify new bioactive compounds to combat infections. Aspergillus parasiticus is one of the main aflatoxin-producing fungi, which are carcinogenic substances that contaminate many types of cereals before and after processing. Recent studies have demonstrated that plant extracts have antimicrobial and antifungal activity, as well as potential for degradation of mycotoxins. In this context, the objective of the present study was to evaluate the in vitro antimicrobial effects of crude and lyophilized extracts of leaves from sweet passion fruit, araçá, rosemary and oregano on planktonic cells of S. aureus and A. parasiticus. The in vitro degradation of aflatoxin B1 (AFB1), ochratoxin A (OTA) and zearalenone (ZEN) by the crude extracts was also investigated. The antimicrobial and antifungal effects were evaluated by determining the minimum inhibitory concentration (MIC) and minimum bactericidal / fungicidal concentration (MBC / MFC). Mycotoxin detoxification assays were conducted at different incubation times (12-48h) at 37 °C. The concentrations of mycotoxins were determined by high performance liquid chromatography (HPLC). Sweet passion fruit had no antimicrobial activity on S. aureus or A. parasiticus. Out of the four extracts evaluated, araçá showed the highest antimicrobial effect with MIC of 0.39 mg/mL and 0.45 mg/mL for crude and lyophilized extracts, respectively. The lowest MIC values for A. parasiticus were obtained with lyophilized oregano (8.33 mg/mL) and crude araçá (3.215 mg/mL). However, no MFC values were obtained for the analyzed fungi. Although OTA e ZEN were not degraded by any extract evaluated, all extracts reduced the concentration of AFB1 after 48 h of incubation. The highest percentage of AFB1 reduction (60.3%) was obtained with rosemary extract after 48h of incubation. The antimicrobial activity demonstrated by extracts of the evaluated plants indicates a potential for application against pathogenic bacteria and toxigenic fungi. This is the first study carried out with extracts of these four plants species that demonstrated the in vitro ability for AFB1 reduction.
27

Försäljning av flygbiljetter över internet : En studie om hur Scandinavian Airlines skulle kunna öka försäljningen av flygbiljetter via internet / Sales of flight tickets online : A study on how Scandinavian Airlines can increase sales of flight tickets online

CEDERCRANTZ, JAKOB January 2012 (has links)
Under de senare åren har försäljningen av flygbiljetter och hotell på internet ökat. Det har tillkommit många nya företag som etablerats som internetresebyråer. Företagen har tagit marknadsandelar från flygbolagens egna försäljningskanaler vilket har gjort att flygbolagen tappat kontakten med kunderna. Detta medför att flygbolagen får svårare att veta hur deras kunder reser och de kan heller inte få kontakt med dem om det händer något oförutsett. Syftet med denna rapport är att identifiera vilka parametrar som styr kunden att välja var flygbiljetten ska bokas och på det viset kunna ta fram förslag på konkreta förbättringsåtgärder som skulle kunna göra SAS hemsida till en mer konkurrenskraftig försäljningskanal. För att uppfylla målet med denna studie har en marknadsundersökning gjorts bland passagerare på Arlanda flygplats. Undersökningen var i form av en muntligt framförd enkät där samma frågor ställdes till flera utrikesresande under olika dagar och tider i veckan. Resultatet av undersökningen visar att många kunder har låg lojalitet på internet. Valet av vilken aktör som kunderna väljer att boka sin flygbiljett beror oftast på priset. Av de respondenter som bokade sin flygbiljett hos en internetresebyrå gjorde 44 % det på en sida de aldrig bokat på förut. Respondenterna upplever dessutom ofta att det är billigare att boka sin flygbiljett på internetresebyråer och känner inget extra värde i att boka på SAS hemsida. Detta utgör ett visst hot mot SAS men samtidigt skapas möjligheter att utveckla och anpassa sidan efter kundens behov. En sambandsanalys visar att säkerheten att betala, snabbheten och enkelheten att boka en flygbiljett är de parametrar som ökar helhetsintrycket på sidan. SAS har ett lojalitetsprogram som kallas för EuroBonus där resenärer får poäng varje gång de reser med flygbolaget. Det senaste året har den Amerikanska internetresebyrån Expedia lanserat ett lojalitetsprogram. Kunderna som bokar sin SAS‐biljett på Expedia får både SAS Eurobonuspoäng och lojalitetspoäng som de kan utnyttja på Expedias hemsida. Dessa tjänster utgör ett hot mot SAS hemsida och försäljningen där kan minska om inte SAS utvecklar sitt Eurobonusprogram så att de kunder som handlar där får extra Eurobonuspoäng. SAS vill att de resenärer som åker med dem bokar sin flygbiljett på deras hemsida. De vill även att deras hemsida ska ge kunderna ett bra helhetsintryck av att vara en enkel plats att boka flygresor på. För att uppnå detta behöver de få mer information om kundernas bokningsbeteende. Slutsatserna av denna rapport är att SAS bör öka värdet för kunden i att boka sin flygbiljett på deras hemsida. De skulle till exempel kunna utveckla sitt lojalitetsprogram EuroBonus så att de kunder som bokar på hemsidan får extra bonuspoäng. De kan också satsa på att ha korta kampanjer med få destinationer under en begränsad tid. På grund utav tidsbegränsningen skulle det vara svårt för de personer som letar efter de billigaste biljetterna på en internetresebyrå att hitta dessa kampanjer. Det i sin tur skulle innebära att kunderna då måste besöka SAS hemsida. Är priserna tillräckligt attraktiva så kan SAS hemsida uppfattas som den billigaste kanalen i framtiden. / During the last few years, the airplane ticket sales have increased substantially. A lot of new companies have joined the market and established themselves as online travel agencies. The agencies have taken a significant market share from the airline company which has resulted in the airline companies loosing a lot of the consumer contact they used to have. The purpose of this report is to identify what parameters it is that lead the customers to choose where to buy airline tickets and by doing so be able to find ways to make SAS website more competitive. To fulfill the purpose of the report a face‐to‐face market survey has been done among passengers at Arlanda Airport. The survey has been performed all days of the week at several different times of the day. The result of the survey shows that many Internet customers are very disloyal and that the choice of channel mainly depends on the price. Out of the respondents who booked their ticket at an online travel agency 44% did it on a page they never booked at before. The respondents often feel that it is cheaper to book a flight on an online travel agency and do not feel any extra value in booking on the SAS website. This information can be seen as a threat to SAS but also as an opportunity to develop and customize the website to suit customer needs. A correlation analysis shows that the payment security, speed and simplicity of booking an airline ticket are the top parameters that increase the overall impression of the page. SAS has a loyalty program called EuroBonus where travelers get points every time they travel with the airline. This last year the American Internet travel agency Expedia has launched a loyalty program. Customers who book their SAS ticket at Expedia receive both SAS EuroBonus points and loyalty points to use at the Expedia website. These kinds of services can be seen as a threat and might lead to SAS falling behind in sales and even lose customers unless they join the trend and develop their loyalty programs on their own website. SAS would like the travelers flying with them to book the flight at their website. They also want the website to make a good impression being satisfying and easy to use when buying airplane tickets. To make this happen they need more information about the booking habits of their customers. The findings of this report is that SAS should add value for the customer who book their ticket on the SAS website. They could for example develop the Eurobonus loyalty program so that customers who book tickets on the website get extra bonus points. SAS can also try having short campaigns with only a few destinations during a limited period. Because of the time limitation it would be difficult for those who are searching for the cheapest tickets at an online travel agency to find these campaigns. This would mean that costumers will have to visit the SAS website. If the prices are attractive enough the SAS website might be perceived as the least expensive channel in the future.
28

Teoretická východiska tzv. Šikovy reformy / Theoretical basis of the Šik's reform

Syřišťová, Adéla January 2009 (has links)
The main focus of this thesis are the economic-theoretical concepts, which in varying degrees contributed to the creation of an official government program of economic reforms in the sixties of the 20th century in Czechoslovakia. The work will mainly analyze the causes of success Šikova reform movement among economists and the Czechoslovak Communist Party leadership. The first part of the study will address the reorientation of foreign trade and economy of Czechoslovakia to the Soviet Union and its satellite countries, as well as the importance of CSR for the functioning of the Council for Mutual Economic Assistance in the fifties. Briefly mentioned is the first attempt at economic reform led by Kurt Rozsypal issues and other proposals for changes in central planning. The crucial part of this work will be devoted to the theoretical designs and directions, which created the preconditions for the implementation of specific economic reforms in the sixties. The treatment of the topic study should answer the questions: What were the other economic programs and their leaders? These protagonists could significantly affect the program or not?
29

A 65nm, Low Voltage, Fully Differential, SC Programmable Gain Amplifier for Video AFE / En 65 nm, fullt differentiell, programmerbar SC-förstärkare för video-AFE med låg matningspänning

Aamir, Syed Ahmed January 2010 (has links)
<p>Due to rapid growth of home entertainment consumer market, video technology has been continuously pushed to deliver sharper pictures with higher resolution. This has brought about stringent requirements on the video analog front end, which often coupled with the low power and low voltage regulations had to deal with short channel effects of the deep submicron CMOS processes.</p><p>This thesis presents the design of a fully differential programmable gain amplifier, as a subcircuit of a larger video digitizing IC designed at division of Electronic Systems. The switched capacitor architecture of the PGA does not only buffer the signal, but performs compensation for the sync-tip of analog video signal.</p><p>The pseudo differential OTA eliminates tail current source and maintains high signal swing and has efficient common mode feedforward mechanism. When coupled with a similar stage provides inherent common moode feedback without using an additional SC-CMFB block.</p><p>The PGA has been implemented using a 65 nm digital CMOS process. Expected difficulties in a 1.2 V OTA design make themselves evident in 65 nm, which is why cascaded OTA structures were inevitable for attaining gain specification of 60 dB. Nested Miller compensation with a pole shifting source follower, stabilizes the multipole system. The final circuit attains up to 200 MHz bandwidth and maintains high output swing of 0.85 V. High slew rate and good common mode and power supply rejection are observed. Noise requirements require careful design of input differential stage. Although output source follower stabilized the system, it reduces significant bandwidth and adds to second order non-linearity.</p>
30

Automatic tuning of continuous-time filters

Sumesaglam, Taner 15 November 2004 (has links)
Integrated high-Q continuous-time filters require adaptive tuning circuits that will correct the filter parameters such as center frequency and quality factor (Q). Three different automatic tuning techniques are introduced. In all of the proposed methods, frequencyand quality factor tuning loops are controlled digitally, providing stable tuning by activating only one loop at a given time. In addition, a direct relationship between passband gain and quality factor is not required, so the techniques can be applied to active LC filters as well as Gm-C filters. The digital-tuning method based on phase comparison was verified with 1% tuning accuracy at 5.5 MHz for Q of 20. It uses phase information for both Q and center-frequency tuning. The filter output phase is tuned to the known references, which are generated by a frequency synthesizer. The core tuning circuit consists of D flip-flops (DFF) and simple logic gates. DFFs are utilized to perform binary phase comparisons. The second method, high-order digital tuning based on phase comparison, is an extension of the previous technique to high-order analog filters without depending on the master-slave approach. Direct tuning of the overall filter response is achieved without separating individual biquad sections, eliminating switches and their parasitics. The tuning system was verified with a prototype 6th order bandpass filter at 19 MHz with 0.6 MHz bandwidth, which was fabricated in a conventional 0.5 [mu]m CMOS technology. Analysis of different practical limitations is also provided. Finally, the digital-tuning method based on magnitude comparison is proposed for second-order filters for higher frequency operations. It incorporates a frequency synthesizer to generate reference signals, an envelope detector and a switched comparator to compare output magnitudes at three reference frequencies. The theoretical analysis of the technique and the simulation results are provided.

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