Micropower Microwave HFET Devices and Circuits

This work investigates the use of novel HFET
(Hetero-Junction Field Effect Transistor) devices at
microwave frequencies and at micropower supply
levels. A thorough review of current state-of-the-art
micropower circuit techniques is included and the
Reader is then guided through the intrinsic parameter
extraction methodology employed to analyse these
devices at microwave frequencies. An in-depth RF and
DC analysis based on directly extracted data from
measurements of state-of-the-art buried channel (BC)
Si/SiGe nHMODFET devices is then presented. The
results confirm the RF micropower capability of these
devices by highlighting peaks in mean carrier
mobility and transconductance within an operating
region delimited by the end of sub-threshold
operation and start of linear operation. RF
micropower capability is further confirmed by the
measured characteristics of fabricated circuits
employing these devices. The recently published KAIST
small signal RF model is also successfully fit,for
the first time, to nHMODFET characteristics measured
at micropower levels. Most of the work included in
this book has been published separately by the author
in international, peer-reviewed journals.