Design And Analysis Of High Band Pass Rc Filter

 

ABSTRACT

Active filter plays an important role in today’s world of communication.  A popular application uses an op-amp to build active filter circuits. A filter circuit can be constructed using passive components: resistors and capacitors. An active filter additionally uses an amplifier to provide voltage amplification and buffering. A filter that provides a constant output from dc up to cutoff frequency f_OH. And passes no signal above that frequency is called ideal low pass filter. A filter that provides or passes a signal above the cutoff frequency is called ideal high pass filter. When a filter circuit passes signals that are above one ideal cutoff of frequency and below a second cutoff frequency is called a band pass filter all this filters play a vital role from the day 1 of communication. In this paper, a high band pass RC filters is designed and analyzed using LM741. The output of the filter design by MATLAB & MULTISIM simulation.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

GLOSSARY

CHAPTER ONE

• INTRODUCTION
• BACKGROUND OF THE PROJECT
• PROBLEM STATEMENT
• AIM / OBJECTIVE OF THE STUDY
• SIGNIFICANCE OF THE STUDY
• APPLICATION OF THE STUDY
• RESEARCH OF THE STUDY
• DEFINITION OF TERMS
• ADVANTAGES OF USING AN OP-AMP IN A HIGH PASS FILTER

CHAPTER TWO

LITERATURE REVIEW

• OVERVIEW OF HIGH-PASS FILTER
• BAND PASS FILTER CIRCUIT
• FREQUENCY RESPONSE OF A 2ND ORDER BAND PASS FILTER
• ALGORITHMIC IMPLEMENTATION
• APPLICATIONS HIGH-PASS FILTERS

CHAPTER THREE

3.0     METHODOLOGY

3.1      INTRODUCTION

3.2      HIGH BAND PASS FILTER CIRCUIT

3.2.1  high band pass filter with high voltage gain

3.2.2  voltage gain of an high band pass filter

3.2.3 voltage gain in (db)

3.2.4 Frequency Response of High Band Pass Filter

3.3      ANALYSIS OF HIGH BAND PASS FILTER USING INVERTING OPERATIONAL AMPLIFIER

3.4      HIGH BAND PASS FILTER CALCULATION

3.5     BODE-PLOT

CHAPTER FOUR

• SIMULATION AND RESULT
• SIMULATION OUTPUT
• SIMULATION AND PERFORMANCE OF POWER ELECTRONIC CIRCUITS

CHAPTER FIVE

• CONCLUSION
• REFERENCES

GLOSSARY

FDA = Design and Analysis

FIR = Finite Impulse Response

FPGA = Field-Programmable Gate Array

ASIC = application-specific integrated circuit

CHAPTER ONE

1.0                                                        INTRODUCTION

1.1                                           BACKGROUND OF THE STUDY

There was an era where while making a telephone call over distance places, one had to put his mouth very close to the transmitter, speak very slowly and very loudly so that message can be heard clearly by the person at the other end. Today, we can even make video calls over worldwide with high-quality resolutions. The secret of such a tremendous development of technology lies in Electrical filter theory and Transmission line theory. Electrical filters are circuits that pass only selected band of frequencies while attenuating other unwanted frequencies. One of such filters is High band pass filter [1][2].

In signal processing, the function of a filter is to remove unwanted parts of the signal, such as random noise, or to extract useful parts of the signal, such as the components lying within a certain frequency range [1].

An ideal filter is a network that allows signals of only certain frequencies to pass while blocking all others.

Depending on the region of frequencies that are allowed through or not, filters are characterized as low-pass, high-pass, band-pass, band-reject and all-pass. There are many needs for electric filters, some of the more common being those used in radio and television sets, which allow tuning into a certain channel by passing its band of frequencies while filtering out those of other channels [2].

The FIR filters are widely used in signal processing and can be implemented using programmable digital processors. Due to the high performance requirements and increasing complexity of DSP and multimedia communication applications, filters with a large number of taps are required to increase the performance in terms of high sampling rate. As a result, the filtering operations are computationally intensive and more complex in terms of hardware requirements [3]. The FIR filters perform the weighted summations of input sequences with constant coefficients in most of the signal processing and multimedia applications. The FIR filter is a digital filter widely used in Digital Signal processing applications in various fields like imaging, instrumentation and communications. Programmable digital processor signal (PDPS) can be used in implementing the FIR filter. Nowadays, to make a difference on the market, new industrial control systems have to be highly performing, very flexible and reliable. At the same time, the cost is a key issue.

In order to reduce the cost, time-to-market has to be shortened, the price of a controller device has to be cheap and its energy consumption needs to be reduced [4]. This cost reduction is all the more challenging that new industrial control systems are based on ever increasing sophisticated control algorithms which need a lot of computing resources and need reduced execution time. However, in realizing a large order filter many complex computations are needed which invariably affect the general performance of the common digital signal processors in terms of speed, cost flexibility, stability and so on.

To cope with all these challenges, designers rely more on mature digital electronics technologies that come with friendly software development tools. Following this development, a Field-Programmable Gate Array (FPGA) has become an extremely cost-effective means of realizing computationally intensive digital signal processing algorithms to improve overall system performance.

The FIR filter implementation in FPGA utilizing the dedicated hardware resources can effectively achieve application-specific integrated circuit (ASIC)-like performance while reducing development time cost and risks [4] [5]. Hence, FPGA has become the best choice for the design of signal processing system due to its greater flexibility and higher bandwidth.

In this paper FDA tool from Matlab mathematical computational package with digital signal processing tool-boxes is used to design filter response and generate coefficients tables. In the proposed approach, FIR tool utilizes distributed arithmetic (DA) which actually uses lookup table for storing constant coefficients. So, the use of lookup tables reduces the hardware complexity and hence the new design is more efficient in terms of less area, more speed and low power consumption due to its parallel implementation on FPGA, unlike the traditional DSP that utilizes MAC (unit multiplier and add accumulator) which increases memory resources as filter order increases [6]. System Generator package provided by Xilinx is used for FPGA implementation of each filter specification. The overall filter output waveforms and synthesis reports performances under parallel implementation of FPGA are greatly enhanced with the proposed method.

However, the aim of this study is to design and analyze a high band pass RC filter using op-amp.

1.2                                                  PROBLEM STATEMENT

Damages that occur in our audio output devices such as speaker, ear piece, or tweeters are as a result of direct high frequencies to the devices. The design of high band pass RC filter is to bring solution to this problem. The function of high band pass RC filter is to attenuating bass signals which could interfere with, or damage the device.

1.3                                   AIM AND OBJECTIVE OF THE PROJECT

The aim of this work is to design and analyze a high band pass RC filters is designed using LM741. The output of the filter design by MATLAB & MULTISIM simulation.

1.4                                         SIGNIFICANCE OF THE PROJECT

High-pass filters are used as part of an audio crossover to direct high frequencies to a tweeter while attenuating bass signals which could interfere with, or damage, the speaker. When such a filter is built into a loudspeaker cabinet it is normally a passive filter that also includes a low-pass filter for the woofer and so often employs both a capacitor and inductor. However, the advantages of designing and analyzing high pass RC filter is to show how it is been used to protect sound output devices [11][12].

1.5                                   APPLICATIONS OF HIGH PASS FILTERS

The high pass filter applications mainly include the following [9].

• These filters are used in speakers for amplification.
• High pass filter is used to remove unwanted sounds near to the lower end of the audible range.
• To prevent the amplification of DC current that could harm the amplifier, high pass filters are used for AC-coupling.
• High Pass filter in Image Processing: High pass filters are used in image processing for sharpening the details. By applying these filters over an image we can exaggerate every tiny part of details in an image. But overdoing can damage the image as these filters amplify the noise in the image.

1.6                                                   RESEARCH QUESTION

1. How does a high pass RC filter work?
2. What is difference between low pass and high pass filters?

iii.        What does a band pass filter do?

1. How do you calculate the cutoff frequency of a high pass filter?

1.7                                                  DEFINITION OF TERMS

Frequency response:  is the quantitative measure of the output spectrum of a system or device in response to a stimulus, and is used to characterize the dynamics of the system. It is a measure of magnitude and phase of the output as a function of frequency, in comparison to the input.

Band pass filter: is a device that passes frequencies within a certain range and rejects (attenuates) frequencies outside that range.

1.8             ADVANTAGES OF USING AN OP-AMP IN A HIGH PASS FILTER

Op-amp when used as the active element in a high bypass filter has the following characteristics [9][10]:

1. Higher input impedance.
2. Lower output impedance.

• Wide bandwidth by negative feedback.

1. Easy Gain controlling.
2. Easiness to debug, change components, opamp type.
3. Removal of Input- output impedance mismatch problem.

• Buffers can be added easily to increase power.
• Overall price becomes cheaper.