Adjacent-channel power
ratio (ACPR): The ratio of the
integrated signal interference
power in an adjacent channel
to the integrated power in the
desired channel
Error vector magnitude
(EVM): A measure of the distortion
in the I-Q constellation
diagram of a signal due to phase
or amplitude differences; it’s the
length of the error vector drawn
from the ends of the vector to the
desired constellation plot to the
vector drawn to the actual constellation
plot expressed as a percentage
of the peak signal level
Harmonics: The level of the
harmonics compared to the main
signal carrier expressed in dBc
Third-order intercept (IP3):
This measure of intermodulation
distortion (IMD) involves a virtual
point where extended plots
from power input versus power
output of the fundamental signal
and the third-order product
power intersect; it’s a theoretical
point where the third-order intermodulation
level is equal to the
fundamental signal level; IP3 is
expressed in dB
One-dB compression point
(P1dB): A general measure of
the maximum output power
available from a linear amplifier;
it’s the point where the amplifier
gain drops at high signal levels to
a point 1 dB below the theoretical
linear power level
Power-added efficiency
(PAE): A measure of the efficiency
of a power amplifier that
considers the RF drive power as
well as normal dc power input
and power output expressed as a
percentage.
Peak to average power ratio
(PAPR): Also known as crest
factor, it’s the ratio of the peak
power of a waveform to its
average value expressed as a
percentage
Power output: Given in watts
but also given in dBm