Design And Simulation Of Fourth Order Active Band Stop Filter

ABSTRACT

This seminar is ondesigned and simulation of an active fourth order active band stop filter. The filter isdesigned such that it has butter worth response. The topologies that will be used to implement the filterare the multiple feedback (MFB). The filter is designed for radio frequency identification (RFID) system reader to reject all signalsoutside the band (10-20) kHz and to amplify the low antenna signal. This is because the identificationnumber signals which are transmitted from the tag of RFID are (12.5 kHz) and (15.65 kHz).So the passband of the filter is taken to be (10-20) kHz. The values of the resistors and capacitors of the filtercircuit are calculated and the circuits are then simulated withtheMULTISIMprogramtoreachthefinalconclusionwhichdescribestheresultofsimulationcomparedtothe simulationofthe transferfunctionofthe filterusingMUTLABprogram.

TABLE OF CONTENTS

Cover page/Title page

Certification page

CHAPTER ONE

• Introduction
  • Background of the Study
  • Problem Statement
  • Aims and Objective
  • Significance of the study
  • Applications of fourth order active band stop filter
  • Advantages of fourth order active band stop filter

CHAPTER TWO

• Literature Review
  • Overview of a filter
  • Different types of electronic filter
  • Overview of a band stop filter
  • Types of band stop filters
  • Types of band stop filters
  • Working Principle Of A Band Stop Filter
  • Review Of Related Studies

CHAPTER THREE

• Method
  • Fourth order active band stop filter design
  • Fourth-orderorder active band filterdesignimplementation
  • NImultisimimplementation
  • Matlabimplementation
  • Resultsandanalysis
  • Conclusion

CHAPTER ONE

1.0                                                      INTRODUCTION

1.1                                         BACKGROUND OF THE STUDY

Radio Frequency Identification (RFID) is an enabling technology for remotelyidentifying,monitoring,and tracking various objects of interest using radio wavetransmissions.Theautomaticidentificationofobjectsispossiblebywirelesscommunications between a tag (attached to an object) and its reader (interrogator) atdistantlocation(Gleich et al., 2015).

A typical RFID system is comprised of the following components (Buzug et al., 2012):

• Areader,orinterrogator,withoneormoreantennasthatareconnectedtoahostcomputerthroughvarious kindsofinterfaces.

Ataghasanidentificationnumber(ID)andareaderrecognizes an objectthroughconsecutivecommunicationswiththetagattachedtoit.Thereadersendsouta signal which supplies power and instructions to a tag. The tag transmits its ID to thereader and the reader consults an external data base with received ID to recognize theobject(Buzug et al., 2012).

An active band-pass filter is used for the RFID system reader to reject all signalsoutside the (10-20) kHz signals and to amplify the low antenna signal. These arebecausetheIDsignalsfromthetagare(12.5kHz)and(15.65kHz)andsignalpowerisverylow (Biederer et al., 2019).

In this paper, RFID system is considered with 125 kHz, FSK modulation scheme. Inlow frequency RFID system, analog active filters are used because of the followingadvantages (Biederer et al., 2019):

• The maximum gain or the maximum value of the transfer function may be greaterthanunity.
• The loading effect is minimal, which means that the output response of the activefilter isessentiallyindependentoftheloaddrivenbythefilter.
• Active filters can be smaller, lighter, and more accurate than passive filters whichcan be large and heavy at low frequencies if inductors arerequired.
• Higherorderfilterscaneasilybecascadedsinceeachop-ampcanbesecondorder.

The simplest design of a band-pass filter is the connection of a high-pass filterandalowpassfilterinseries,whichiscommonlydoneinwide-bandfilterapplications. Thus, a first order high-pass and a first-order low-pass provide a second-order band-pass, while a second-order high-pass and a second-order low-pass result ina fourth-order band-pass response. In comparison to wide-band filters, narrow-bandfilters of higher order consist of cascaded second-order band-pass filters(Biederer et al., 2019).

Themostcommon filterresponsesaretheButterworth, Tschebyscheff,andBessel types. Among these responses, Butterworth type is used to get a maximally-flatresponse. Also, itexhibits a nearly flatpass band with noripple. The roll-off issmooth and monotonic, with a low-pass or high pass roll off 20dB/dec for every pole.Thus,afourth orderButterworth band-pass filter would have an attenuation rate of40dB/decand-40dB/dec (Biederer et al., 2019).

This work is on simulation of 4th order active band stop filter. The design will be carried out in order to meet the design specifications and the simulation will be done using MATLABsimulationresultwillbediscussed.

1.2                                                  PROBLEM STATEMENT

Appliances malfunctions when a frequency is transmitted outside the required frequency band. In order to solve this problem a fourth order active band stop filter is used. The filter is designed for radio frequency identification (RFID) system reader to reject all signalsoutside the band (10-20) kHz and to amplify the low antenna signal.

1.3                                     AIM AND OBJECTIVE OF THE STUDY

The aim of this seminar is to carry out a study on design and simulation of fourth order active band stop filter. The objectives of the study are:

1. To carry out a study on the workings of a fourth order active band stop filter
2. Study the operation and application of filters in RFID appliances.

• To carry out a simulation using MATLAB & MULTISIM simulation.

1.4                                           SIGNIFICANCE OF THE STUDY

This study will serve a means of studying the application of filter in electronics and telecommunication.

1.5      APPLICATIONS OF FOURTH ORDER ACTIVE BAND STOP FILTER

The applications include:

• Fourth order active band stop filter is used in various speaker systems to enable and enhance audio quality.
• They are used in Telecommunications (Telephone, Digital Subscriber Line) to reduce the noise while signal transmission.
• It is reduced to clear static in radio devices.
• They are also used in instrument amplifiers, especially for acoustic instruments like Electronic Guitar in reducing the humming sound produced at 60 Hz.
• In the field of medicine, Electrocardiogram (ECG) machine also has Fourth order active band stop filter for hassle-free operations.
• They are a vital part of signal and image processing
• Optical Filters also have Fourth order active band stop filters for use in laser eye protection applications.
• It filters out unwanted noises from the duplexes and switches.

1.6      ADVANTAGES OF FOURTH ORDER ACTIVE BAND STOP FILTER

The advantages include:

• It offers Low Passband insertion loss and group delay.
• Unwanted Signals are effectively suppressed while Transmission.
• These Filters are preferred while transmitting high-power signals.