On the exact realization of log-domain elliptic filters using the signal flow graph approach

Logarithmic (LOG)-domain filters can be designed using the signal flow graph (SFG) synthesis approach and an appropriate set of operators. Following the above procedure, all-pole LOG-domain filters that exactly emulate the operation of the inductor-capacitor LC ladder prototype filter can be implemented. In the case of elliptic LOG-domain filters, the transmission zeros are not precisely realized. This is due to the fact that floating capacitors are used, in order to approximately perform the required differentiations. In this paper an alternative SFG representation of the prototype system is done, in such a way that the corresponding filter configuration can be implemented using only LOG-domain lossless integrators and amplifiers. A third-order LOG-domain elliptic filter was simulated in order to confirm the validity of the proposed technique.

[1]  Christofer Toumazou,et al.  High-order lowpass and bandpass elliptic log-domain ladder filters , 2001, ISCAS 2001. The 2001 IEEE International Symposium on Circuits and Systems (Cat. No.01CH37196).

[2]  Christofer Toumazou,et al.  A unified matrix method for systematic synthesis of log-domain ladder filters , 2001, ISCAS 2001. The 2001 IEEE International Symposium on Circuits and Systems (Cat. No.01CH37196).

[3]  Shousheng He,et al.  Design and implementation of a 1024-point pipeline FFT processor , 1998, Proceedings of the IEEE 1998 Custom Integrated Circuits Conference (Cat. No.98CH36143).

[4]  T. Bially,et al.  Parallelism in fast Fourier transform hardware , 1973 .

[5]  Keshab K. Parhi,et al.  Efficient FFT implementation using digit-serial arithmetic , 1999, 1999 IEEE Workshop on Signal Processing Systems. SiPS 99. Design and Implementation (Cat. No.99TH8461).

[6]  E.E. Swartzlander,et al.  A radix 4 delay commutator for fast Fourier transform processor implementation , 1984, IEEE Journal of Solid-State Circuits.

[7]  Hannu Tenhunen,et al.  A new VLSI-oriented FFT algorithm and implementation , 1998, Proceedings Eleventh Annual IEEE International ASIC Conference (Cat. No.98TH8372).

[8]  D. R. Frey,et al.  Log-domain filtering: An approach to current-mode fil-tering , 1993 .

[9]  D. R. Frey.  Log domain filtering for RF applications , 1996 .

[10]  A.H.M. van Roermund,et al.  The design of low-noise bandgap references , 1996 .

[11]  Gordon W. Roberts,et al.  The design of log-domain filters based on the operational simulation of LC ladders , 1996 .

[12]  D. Frey.  Exponential state space filters: a generic current mode-design strategy , 1996 .

[13]  Barrie Gilbert,et al.  Translinear circuits: An historical overview , 1996 .

[14]  C. Toumazou,et al.  "Log-domain state-space": a systematic transistor-level approach for log-domain filtering , 1999 .

[15]  John V. McCanny,et al.  A 64-point Fourier transform chip for video motion compensation using phase correlation , 1996, IEEE J. Solid State Circuits.

[16]  E. V. Jones,et al.  A pipelined FFT processor for word-sequential data , 1989, IEEE Trans. Acoust. Speech Signal Process..

[17]  Gordon W. Roberts,et al.  Effects of transistor nonidealities on high-order log-domain ladder filter frequency responses , 2000 .

[18]  C. Joanblanq,et al.  A fast single-chip implementation of 8192 complex point FFT , 1995 .