Open Access460 μW 32 dB image rejection ratio second‐order active‐RC complex filter with improved power efficient opamp
Author(s) -
Wang J.,
Ye L.,
Chen L.,
Liu J.,
Liao H.
Publication year - 2013
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2012.3690
Subject(s) - operational amplifier , chebyshev filter , phase margin , bandwidth (computing) , electronic engineering , image response , frequency compensation , cmos , feed forward , active filter , electrical engineering , amplifier , engineering , intermediate frequency , telecommunications , voltage , radio frequency , control engineering
An ultra‐low‐power second‐order Chebyshev active‐RC complex filter for a low‐IF ultra‐low‐power receiver is presented. By utilising a pole‐cancellation push‐pull buffer with feedforward phase compensation technology, the operational amplifier (opamp) realises superior stability while maintaining high gain bandwidth and ultra‐low power consumption. A second‐order complex filter with four proposed opamps and an adaptive bias fabricated in standard 180 nm CMOS process consumes only 460 μW at 1.8 V power supply. The measured centre frequency is 3 MHz and bandwidth is 2 MHz, while it achieves 32 dB image rejection ratio at the centre frequency.