CS  Vol.5 No.10 , October 2014
A Comparison of Higher-Order Active Band-Pass R-Filter Response with Equivalent Band-Pass RC-Filter Response at Varying Q-Factors
Abstract: In this paper a comparison of a sixth-order active band pass R-filter output response with the output response of a sixth-order band pass RC-filter at different quality factors (Q = 2, 5, 7, 8 and 10) was carried out at a fixed frequency of 10 KHz. The architecture used in the design is the multiple feedbacks for both filter networks. The simulated response characteristics show that both filters (R- and RC-filters) have their mid-band gains increasing with Q, while their bandwidths monotonically decreased with Q-values. The bandwidths are in the range of 22.23 dB to 62.97 dB and –55.49 dB to –50.81 dB (Q = 2 to 10) for R- and RC-filters respectively. At higher Q-values, R-filter showed better selectivity with a smaller bandwidth (400 Hz) at the edge of the pass band, when compared to 450 Hz for the RC-filter. The roll-off rate around –58.9 dB/decade for the R-filter appears to be that of a third-order filter response, while the RC-filter has its response in the range –106 to –132 dB/decade which is in the neighbourhood of an ideal sixth-order response (roll-off of 120 db/decade). A shift in the center frequency with Q was observed for the RC-filter only.
Cite this paper: Amah, A. , Ahemen, I. and Atsuwe, B. (2014) A Comparison of Higher-Order Active Band-Pass R-Filter Response with Equivalent Band-Pass RC-Filter Response at Varying Q-Factors. Circuits and Systems, 5, 229-237. doi: 10.4236/cs.2014.510025.

[1]   Hong, J. and Lancaster, M.J. (2001) Microstrip Filters for RF/Microwave Applications. John Willey & Sons Inc., New York, 1-8.

[2]   Attri, R.K. (2005) Practical Design Evaluation of Extremely Narrow Bandpass Filter Topologies. Instrumental Design Series (Electronics). www.slideshare-net/rkattri/practical-design-extremely-narrow-bandpass-filter-topologies

[3]   Sonderstrand, M.A. (1976) Design of Active-R Filter Using Only Resistance and Operational Amplifier. International Journal of Electronics, 8, 417-437.

[4]   Mohan, N. and Patil, R.L. (1992) Ripple Pass Function and Their Active-R Realization. Indian Journal of Pure Applied Physics, 30, 749-750.

[5]   Shinde, G.N. and Patil, P.B. (2002) Study of Active-R Second-Order Filter Using Feedback at Non-Inverting Terminals. Bulletin of Pure and Applied Science, D21, 23-31.

[6]   Srinivasan, S. (1992) Synthesis of Transfer Function Using the Operation Amplifier Pole. International Journal of Electronics, 73, 1279-1283.

[7]   Kadam, A.B. and Mahajan, A.M. (1995) Effect of Positive Feedback on the Response of Active-R Filter. Journal of the Instrument Society of India, 25, 48-55.

[8]   Shinde, G.N., Patil, P.B. and Mirkute, P.R. (2003) A Third Order Active-R Filter with Feed forward Input Signal. Sadhana, 28, 1019-1026.

[9]   Kim, H.K. and Ra, J.B. (1977) An Active Biquadratic Building Block without External Capacitors. IEEE Transactions on Circuit and Systems, CAS-24, 12, 690-694.

[10]   Toumazou, C., Payne, A. and Pookaiyaudom, S. (1995) The Active-R Filter Technique Applied to Current-Feedback Op-Amps. Circuit & Systems, 2, 1203-1206.

[11]   Chavan, U.N. and Shinde, G.N. (2013) Synthesis of Third Order Active-R Multifunction Filter Using Feed Forward Input Signal. International Journal of Modern Engineering Research, 3, 3560-3563.

[12]   Qasem, A.A. and Shinde, G.N. (2013) Widerpassband Third-Order Active-R Filter with Multifeedback Signal for Different Center Frequencies (f0). International Journal of Communication & Computer Engineering, 4, 2278-4209.

[13]   Qasem, A.A. and Shinde, G.N. (2014) Comparison of Third-Order Active-R Filter with and without Using Multiple Feedforward Signal. International Journal of Physics & Mathematical Sciences, 4, 193-201.

[14]   Franco, G. (1988) Design with Operational Amplifiers and Analog Integrated Circuit. McGraw-Hill, New York.

[15]   Clayton, G.B. (1983) Operational Amplifier Experimental Manual. Butterworth & Co. Ltd., Belfast.

[16]   Shinde, G.N. and Mulajkar, D.D. (2010) Electronically Tunable Current Mode Second Order High Pass Filter with Varible Central Frequency f0. Progress in Electromagnetic Research Symposium Proceedings, Xi’an, 22-26 March 2010, 1661-1664.

[17]   Jacob, J.M. (2003) Advanced AC Circuits and Electronics Principles and Applications. Cengage Learning, 150-152.

[18]   Floyd, T.L. (1997) Electronic Devices International Edition. 5th Edition, Prentice-Hall, Inc., Upper Saddle River.

[19]   Blauchi, G. and Sorrentino, R. (2007) Filter Simulation and Design. McGraw-Hill Professional, New York, 129-130.