Suhash Chandra Dutta Roy

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Following a brief review of previous work on bandstop filters, the inadequacy of a recent work to obtain a perfect notch or perfect absorption at the notch frequency ω0 is demonstrated. A simple and elegant alternative solution, based on purely analytical arguments, is then presented. The resulting network is shown to achieve perfect matching as well as perfect absorption at the notch frequency and has several other advantages. A comparison has also been made with the conventional bridged-T band-stop filter.



bandstop filter, bridged-T network, circuit design

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S. C. Dutta Roy, “Analyzing the parallel-T RC network – yet another method”, IETE J. Educ., vol. 44, pp. 111-116,

S. C. Dutta. Roy, “A quick method of analyzing parallel ladder networks”, Int. J. Elect. Eng. Educ., vol. 13, pp. 70-75, Jan. 1976.

S. C. Dutta Roy, “Miller’s theorem revisited”, Circuits, Syst. Signal Proces., vol. 19, pp. 487-499, Dec. 2000.

S. C. Dutta Roy, “On second order digital bandpass and bandstop filters", IETE J. Educ., vol. 49, pp. 59-63, May-Aug. 2008.

S. C. Dutta Roy, “Interference rejection in a UWB syetem: an example of LC driving point synthesis”, IETE J. Educ., vol. 50, pp. 55-58, May-Aug. 2009.

S. C. Dutta Roy, “On some three terminal lumped and distributed RC null networks”, IEEE Trans. Circuit Theory, vol. CT-11, pp. 98-103, Mar. 1964.

S. C. Dutta Roy and B. A. Shenoi, “Notch networks using distributed RC elements". Proc. IEEE, vol. 54, pp. 1220-1221, Sept. 1966.

S. C. Dutta Roy. "On the design of parallel-T resistance capacitance networks for maximum selectivity”, J.ITE, vol. 8, pp. 218-223, Sept. 1962.

S. C. Dutta Roy, “Parallel—T RC network : limitations of design equations and shaping the transmission characteristic”, lndian J. Pure Appl. Phys., vol. 1, pp.175-181, May 1963.

S. C. Dutta Roy, "Dual input null networks”, Proc. IEEE, vol. 55, pp. 221-222, Feb. 1967.

S. C. Dutta Roy and N. Choudhury, “An application of dual input networks", Proc. IEEE, vol. 56, pp. 647-646. May 1970.

S. C. Dutta Roy and R. P. Sah. "Dual input distributed RC notch filter”, lnd. J. Pure Appl. Phys., vol. 9, pp. 762-763, Sept. 1971.

S. C. Dutta Roy, S. B. Jain and B. Kumar, "Design of digital notch filters”, IEE Proc. – Vision, Image Signal Process., vol. 141, pp. 334-338, Oct. 1994.

B. Kumar, S. B. Jain and S C. Dutta Roy, "On the design of FIR notch filters", IETE J. Res., vol. 43, pp. 65-68, Jan.- Feb. 1997.

S. B. Jain, B. Kumar and S. C. Dutta Roy, "Design of FIR notch filters by using Bernstein polynomials”, Int. J. Circuit Theory Applic., vol. 25, pp. 135-139, Mar.-Apr. 1997.

S. C. Dutta Roy, S. B. Jain and B. Kumar, ”Design of digital FIR notch filters from second order llR prototype", IETE J. Res., vol. 43, pp. 275-279, Jul.-Aug. 1997.

S. B. Jain, B. Kumar and S. C. Dutta Roy, ”Semi-analytic method for the design of digital FIR filters with specified notch frequency", Signal Process., vol. 59, pp. 235-241, 1997.

Y. V. Joshi and S. C. Dutta Roy, ”Design of llR digital notch filters”, Circuits, Syst. Signal Process., vol. 16, pp. 415-427, 1997.

Y. V. Joshi and S. C. Dutta Roy. "Design of lift notch filters with different passband gains”,IEE Proceedings — Vision, Image Signal Process., vol. 147, pp. 11-19, Feb. 1998.

Y. V. Joshi and S. C. Dutta Roy. "Design of IIR multiple notch filters based on all-pass filters”, IEEE Trans.Circuits Syst.-II: Trans. Briefs, vol, 46, pp. 134-138, Feb. 1999.

S. C. Dutta Roy, B. Kumar and S. B. Jain, “FIR notch filter design – a review” (invited paper), Facta Universitatis (NIS) – Series : Electron. Energ., vol. 14, pp. 295-327, Dec. 2001.

A. S. Alkanhal, “Compact bandstop filters with extended upper passbands”, Active and Passive Components, vol. 2008, DOI: http://dx.doi. Org/10.11552008/356049.

O. P. Gupta and R. J. Wenzel, “Design tables for a class of optimum new bandstop filters”, IEEE Trans. Microw. Theo. Tech., vol. 18, pp. 402-404, July

K. S. K. Yeo and P. Vijaykumar, “Quasi-elliptic microstrip bandstop filters using tap coupled open loop resonators”, Prog. Electromag. Res., vol. 35, pp. 1-11, 2013.

Y. S. Mezaal, H. T. Eyyuboglu and J. K. Ali, “Wide bandpass and narrow bandstop microstrip filters based on Hilbert fractal geometry: design and simulation results”, PLOS One, vol. 9, e115412, 2014.

M. M. Bait-Sawailam, “Miniaturized bandstop filters using slotted complementary networks”, Int. J. Dig. Inform. and Wireless Commun.,vol. 4, pp. 401-407, Mar. 2014.

D. R. Jachowski, “Narrowband absorption bandstop filtres with multiple signal paths”, US Patent no. 7323955B2, Pub: Jan. 29 2008.

W. M. Pathelbab and M. B. Steer, “Design of bandstop filters utilising circuit prototypes”, IEE Microw, Ant. Propag., vol. 1, pp. 523-526, March 2007.

D. R. Jachowski, “Tunable lumped element notch filter with constant bandwidth”, Proc. IEEE Int. Wireless Inf. Technol. Syst. Conf.,, pp. 1-4, 2010.

T. C. Lee, J. Lee, E. J. Naglich and D. Peroulis, “Octave tunable lumped element notch filter with resonator Q-independent zero reflection coefficient”, Proc. IEEE MTT-S Int. Digest, pp. 1-4, 2014.

J. Lee, T. Leeand W. J. Chappel, “Lumped element realization of absorptive bandstop filter with anomalously high spectral isolation”, IEEE Trans. Microw. Theo. Tech., vol. 60, pp. 2424-2430, Aug. 2012.

J. S. Chieh and J. Rowland, “Quasi-lumped element bridged-T absorptive bandstop filter”, IEEE Microw. Wireless Compon. Lett., vol. 26, pp. 264-266, Apr. 2016.


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