A new design technique of CMOS continuous-time VHF current-mode bandpass ladder filters using VHF bandpass biquads

Author

Wu, Chung-Yu ; Hsu, Heng-Shou

Author_Institution

Dept. of Electron. Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan

Volume

1

fYear

1996

fDate

13-16 Oct 1996

Firstpage

219

Abstract

In this paper, a new design technique to implement VHF current-mode bandpass ladder filters directly by using the VHF current-mode bandpass biquads is proposed and analyzed. The VHF current-mode bandpass biquads are implemented by the transresistance (Rm) amplifier-capacitor structure. Moreover, the special Q-enhancement technique is applied to the biquad to obtain the tunable and high-quality factor Q. Starting from the prototype of LC ladder bandpass filter and assigning the proper state variables, the state equations of the LC ladder bandpass filter are rewritten in terms of the current-mode state variables and current-mode high-Q bandpass biquadratic functions. Thus, the current-mode ladder filter can be constructed by directly using the current-mode high-Q bandpass biquads as basic cells. A 6th order current-mode bandpass ladder filter with the center frequency up to 50 MHz has been successfully designed by using the current-mode high-Q biquadratic bandpass filters. It has the advantageous features of low component sensitivity and simple structure. It is also free from DC instability problems

Keywords

CMOS analogue integrated circuits; Q-factor; VHF filters; band-pass filters; biquadratic filters; continuous time filters; integrated circuit design; ladder filters; linear network synthesis; 0.8 micron; 50 MHz; CMOS continuous-time filters; Q-enhancement technique; VHF bandpass biquads; active filters; bandpass biquadratic functions; current-mode bandpass ladder filters; current-mode state variables; design technique; high-quality factor; low component sensitivity; state equations; transresistance amplifier-capacitor structure; Band pass filters; CMOS technology; Equations; Frequency; Magnetic separation; RF signals; Radiofrequency amplifiers; Transfer functions; Tunable circuits and devices; VHF circuits;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronics, Circuits, and Systems, 1996. ICECS '96., Proceedings of the Third IEEE International Conference on

Conference_Location

Rodos

Print_ISBN

0-7803-3650-X

Type

conf

DOI

10.1109/ICECS.1996.582782

Filename

582782