Title :
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
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;
Conference_Titel :
Solid-State Circuits Conference, 2003. ESSCIRC '03. Proceedings of the 29th European
Conference_Location :
Estoril, Portugal
Print_ISBN :
0-7803-7995-0
DOI :
10.1109/ESSCIRC.2003.1257169
