Circuits for processing radio frequency ("RF") and microwave signals are
fabricated using field effect transistors ("FETs") that have one or more
strained channel layers disposed on one or more planarized substrate
layers. FETs having such a configuration exhibit improved values for, for
example, transconductance and noise figure. RF circuits such as, for
example, voltage controlled oscillators ("VCOs"), low noise amplifiers
("LNAs"), and phase locked loops ("PLLs") built using these FETs also
exhibit enhanced performance.