Artículos

 

Novel Two-Stage Comb Decimator

 

Nuevo decimador comb de dos etapas

 

Gordana Jovanovic Dolecek¹ and Sanjit K. Mitra²

 

¹ National Institute for Astrophysics, Optics and Electronics, Department of Electronics INAOE, Puebla, Puebla Mexico. Correo: gordana@inaoep.mx

² University of California, Department of Electrical and Computer Engineering Santa Barbara, California USA. Correo: mitra@ece.ucsb.edu

 

Article received on 13/06/2011.
Accepted on 29/08/2011.

 

Abstract

A simple method for the design of a multiplier-less comb-based decimation filter is presented. The filter compensates the comb passband droop, and has the desired attenuation in the first folding band. The proposed structure has two decimation stages, both with simpler comb filters. The desired attenuation in the first folding band is achieved by an appropriate number of cascaded combs in the second stage. A simple compensation filter, working at a low output rate, provides the desired compensation in the pass band. The choice of the design parameters is presented along with a comparison of the proposed method to some other existing design methods.

Keyword: Comb filter, decimation, folding bands, compensation.

 

Resumen

Se presenta un método simple para el diseño de un filtro de diezmado basado en filtro comb sin multiplicadores. El filtro compensa la caída en la banda de paso del filtro comb y tiene la atenuación deseada en la primera banda del plegado. La estructura propuesta tiene dos etapas de decimación, ambas con filtros comb simples. La atenuación deseada en la primera banda del plegado se alcanza por un número apropiado de combs en cascada en la segunda etapa. Un filtro simple de compensación trabajando en la baja razón de muestreo de salida provee la compensación deseada en la banda de paso. La elección de los parámetros de diseño es presentada junto con una comparación del método propuesto con algunos otros métodos de diseño existentes.

Palabras Clave: Filtro comb, diezmado, bandas del plegado, compensación.

 

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References

1. Abbas, M., Gustafsson, O., &Wanhammar, L. (2010). Power estimation of recursive and non-recursive CIC filters implemented in deep-submicron technology. 2010 International Conference on GreenCircuists and Systems (ICGCS 2010), Shanghai, China, 221–225.         [ Links ]

2. Aboushadyy, H., Dumonteix, Y., Louerat, M.M., &Mehrez, H. (2001). Efficient polyphase decomposition of Comb decimation filters in ΣΔ analog-to-digital converters. IEEE Transactions on Circuits and Systems II: Analog and Digital Signal processing, 48(10), 898–903.         [ Links ]

3. Gao, Y., Jia, L., Isoaho, J., &Tenhunen, H. (2000). A comparison design of comb decimators for sigma-delta analog-to-digital converters. Analog Integrated Circuits and Signal Processing, 22(1), 51–60.         [ Links ]

4. Hogenauer, E.B. (1981). An economical class of digital filters for decimation and interpolation. IEEE Transactions on Acoustics, Speech, and Signal Processing, 29(2), 155–162.         [ Links ]

5. Jovanovic-Dolecek, G., & Mitra, S.K. (2005). A New Two-stage Sharpened Comb Decimator. IEEE Transactions on Circuits and Systems I: Regular Papers, 52(7), 1414–1420.         [ Links ]

6. Dolecek, G.J., & Mitra, S.K. (2008). A Simple Method for the Compensation of CIC Decimation Filter. Electronics Letters, 44(19), 1162–1163.         [ Links ]

7. Dolecek, G.J. (2009). Simple wideband CIC compensator. Electronics Letters, 45(24),1270–1272.         [ Links ]

8. Dolecek, G.J., & Mitra, S.K. (2010). Two-Stage CIC Based Decimator with Improved Characteristics. IET Signal Processing, 4(1), 22–29.         [ Links ]

9. Dolecek, G.J., & Dolecek, L. (2010). Novel Multiplierless Wide-Band CIC Compensator. InternationalSymposium on Circuits & Systems, (ISCAS 2010), Paris, France, 2119–2122.         [ Links ]

10. Kwentus A. & Willson, Jr. A., (1997). Application of filter sharpening to cascaded integrator-comb decimation filters. IEEE Transactions on Signal Processing, 45(2), 457–467.         [ Links ]

11. Laddomada, M. (2007). Generalized comb decimation filters for Σ∆ A/D converters: Analysis and design. IEEE Transactions Circuits and Systems I: Regular Papers, 54(5), 994–1005.         [ Links ]

12. Mortazavi, S.M., Fakhraie, S.M., &Shoaei, O. (2005). A comparative study and design of decimation filter for high-precision audio data converters. The 17 th International Conference on Microelectronics (ICM 2005), Islamabad, Pakistan, 139–143.         [ Links ]

13. Presti, L. L. (2000). Efficient modified-sinc filters for sigma-delta A/D converters. IEEE Transactions on Circuits and Systems II: Analog and Digital Signal processing, 47(11), 1204–1213.         [ Links ]