Many wireless coMMunications systems must be able to measure
received signal strength. To provide sufficient bandwidth to
cover the Ultra Wideband (UWB) spectrum, a pair of researchers
has expanded on the capabilities of a previously introduced
system comprising an integrated CMOS broadband detector that
uses the nonlinear behavior of a CMOS transistor in deep triode
mode. The detector is now incorporated into a feedback loop for
gain and filter control of an impulse-UWB receiver by Kenneth A.
Townsend and James W. Haslett from the University of Calgary and
TRLabs (Calgary, Canada). The wideband RF power-detection system
uses NMOS devices operating in the triode regime to generate an
average current that is proportional to RF input power. Using a
piecewise linear logarithmic approximation, the current is
converted to voltage and then amplified. The power detector
occupies an active area of 0.36 mm2 in a 0.18-m process. It
consumes 10.8 mW from the power supply. When measured at
discrete frequencies, error bet