Table of Contents
Advertisement
Why high-power measurements can be
challenging
Two main challenges exist when measuring high-
power devices:
1. The measurements performed on high-power
devices can be different than those required to
characterize lower-power devices. Measurements
of high-power devices also can be performed dif-
ferently than those made at lower power levels.
Pulsed measurements are a good example.
Measurements typically are not pulsed at lower
power levels since device overheating tends not to
be a problem. High power can heat up a device,
affecting its measured characteristics. Many on-
wafer measurements, for example, require pulsed
RF and pulsed DC bias, which reduces the average
power dissipation and keeps the temperature of
the device constant.
4
2. High-power measurements require special
network-analyzer configurations. This can mean
adding attenuation or a coupler between the out-
put of the device under test (DUT) and the input
of the test instrument to protect the receiver. It
can also mean adding amplification to the stimulus
signal if more power is required. Calibration and
accurate measurements become significantly more
complex as additional equipment is added to the
test setup. In some configurations the additional
hardware can make some types of calibration
impossible, or limit the number of measurable
parameters. For example, reverse S-parameters
cannot be measured in some configurations. The
inability to perform certain calibrations can limit
the accuracy of the measurements.
This application note will show configurations
ranging from those that are easy to assemble but
may have limited accuracy or measurement capa-
bility, to more complex configurations that are
very accurate and can make the same measure-
ments as a standard network analyzer.
Advertisement
Table of Contents
