Highly-linear CMOS cross-coupled compensator transconductor with enhanced tunability
Proposed is the design of a CMOS highly-linear differential cross-coupled compensator transconductor that combines both cross-quad and cascomp linearisation techniques with enhanced tunability. The proposed cross-coupled compensator linearises the total drain current while maintaining a high input voltage swing range. It achieves a wide tunable gm" nulling over 500mV differential input signal and a tunable 50 increase in gm flatness. The proposed linearised transconductor achieves a measured 20dB IM3 distortion reduction after linearisation. The linearised transconductor enhanced tunability technique achieves IM3 better than -78dBc at 1GHz at an optimum bias condition with ease and precision without reducing the linear signal handling capability, thus improving the overall transconductor dynamic range performance.
El-Khatib, Z., MacEachern, L, & Mahmoud, S.A. (2010). Highly-linear CMOS cross-coupled compensator transconductor with enhanced tunability. Electronics Letters, 46(24), 1597–1598. doi:10.1049/el.2010.2332