A widely tunable CMOS Gm-C filter with a negative source degeneration resistor transconductor

Author

Hori, Shinichi ; Maeda, Tadashi ; Yano, Hitoshi ; Matsuno, Noriaki ; Numata, Keiichi ; Hida, Hikaru ; Takahashi, Yuji ; Yamase, Tomoyuki ; Walkington, Robert ; Hikaru, H.

Author_Institution

Photonics & Wireless Device Res. Labs., NEC Corp., Ibaraki, Japan

fYear

2003

fDate

16-18 Sept. 2003

Firstpage

449

Lastpage

452

Abstract

We propose a new negative source degeneration resistor (NSDR) transconductor to achieve a wide continuous-tuning range gm-C filter applicable for IEEE802.11a/b/g wireless-LANs and W-CDMA. The NSDR-transconductor using a source degeneration resistor and positive feedback differential amplifier that acts as a negative resistor. This configuration enables the equivalent source degeneration resistance to be drastically increased without degrading linearity, thus resulting in a wide gm tuning. A 6th -order elliptic low-pass filter using this NSDR-transconductor exhibits a cutoff frequency (f/sub c/) tuning range of 1.5-12MHz, which is two times wider than that of conventional filters. Additionally, we introduce a new figure of merit (FoM) evaluating the basic filter performance. This filter shows 0.35 fj (FoM) in the IEEE802.11a mode, which is, to our best knowledge, the best value in the CMOS channel-select filters.

Keywords

CMOS integrated circuits; IEEE standards; circuit tuning; code division multiple access; digital filters; integrated circuit design; low-power electronics; negative resistance circuits; wireless LAN; CMOS channel-select filters; IEEE802.11a/b/g W-CDMA; IEEE802.11a/b/g wireless-LANs; basic filter performance; cutoff frequency tuning range; elliptic low-pass filter; figure of merit; negative resistor; negative source degeneration resistor transconductor; positive feedback differential amplifier; tunable CMOS Gm-C filter; Cutoff frequency; Degradation; Differential amplifiers; Linearity; Low pass filters; Multiaccess communication; Negative feedback; Resistors; Transconductors; Tuning;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Circuits Conference, 2003. ESSCIRC '03. Proceedings of the 29th European

Conference_Location

Estoril, Portugal

Print_ISBN

0-7803-7995-0

Type

conf

DOI

10.1109/ESSCIRC.2003.1257169

Filename

1257169