Output Response Analysis of Multiple Feedback Topology for High Gain Realization

International Journal of Research and Scientific Innovation (IJRSI) | Volume V, Issue IV, April 2018 | ISSN 2321–2705

Output Response Analysis of Multiple Feedback Topology for High Gain Realization

Atsuwe, B.A^1*, Kureve, D.²

  ¹Department of Science Education, College of Agricultural and science Education, University of Agriculture, Makurdi, Nigeria
²Department of Electrical/Electronics, College of Engineering, University of Agriculture, Makurdi, Nigeria.
*Correspondence Author: Atsuwe, B.A

Abstract: This paper considers the design of an eighth-order active-R bandpass filter using the multiple feedback (MFB) topology at a centre frequency ( ) of 40 kHz and quality factor (Q) of 25. The filter was simulated using multism work bench version 11.0 software. The simulated response characteristic of gain and bandwidth show that, the gain has an increasing from stage 1 to stage 4 with values of 29.76 dB to 109.89 dB while the bandwidth decreases from stage 1 to 4 with values of 1.71 kHz to 850 Hz signifying a very selective (low bandwidth) filter. Therefore making the filter suitable for high gain realization and highly selective filter. The roll-off however approached that of a single-pole third order filter instead of an eighth-order filter.

I. INTRODUCTION

Filters can be constructed in a multitude of ways. Combinations of capacitors and resistors, as well as operational amplifiers and transistors, have been used effectively for many years to produce reliable and functional filters (John and Jose, 2004). There are numerous elements from which a filter can be made, since there are different configurations those elements can be put together to produce. However, some configurations produce better results in terms of stability, susceptibility to noise, quality factor or mid-band gain, Bandwidth, roll-off rate etc.

Bandpass filter design has nevertheless been a challenge in view of many interrelated dependencies in the circuit parameters. In band pass filter, Quality factor (Q) and mid-band Gain (G) of the filter are generally interrelated and thus do not give the independent control (Attri, 2005). Always there has to be some tradeoff like the narrow bandpass filter tradeoff is circuit stability. Generally, the narrow bandpass filtering action is achieved by increasing the Q value of the normal band pass filter.

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