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Enhanced Mode GaAs PHEMT
(E-PHEMT) based MMIC amplifiers
provide users advantages in
both broadband noise figure and
intermodulation performance, setting
them apart from previous generations
of GaAs amplifier designs. Historically
known for their extremely low noise
figure, PHEMTs have also been used
extensively for power applications
in the mobile PA market. Recent
designs possess a combination of
low noise and excellent suppression
of intermodulation distortion, which
improves both ends of the dynamic
range over broad frequency range.
Mini-Circuits lineup of low-noise,
high-dynamic-range, MMIC amplifiers
includes over 30 unique models
in the PSA, PMA and PHA families.
These are broadband, single stage,
Class A, 50Ω MMIC amplifiers. All
offer outstanding noise figure and
intermodulation performance. The
most recent additions to the PMA
family are distinguished through
their low noise performance over
multi-octave bandwidths and high
IP3 performance with low DC power
consumption. Table 1 shows key
performance parameters for selected
models in these amplifier families.
Characterizing Amplifiers
for Complex Waveforms
Radar systems are used in an
increasing variety of applications,
as demand from autonomous
land vehicles and airborne drones
adds to existing usage in shipping,
weather forecasting, air traffic
control (ATC) radar and defence.
The use of commercial off-the-
shelf (COTS) test and measurement
systems has become commonplace
in characterising the radar system
itself but it also offers advantages
in the area that most interests radar
operators - target detection and
tracking.
Field testing is the traditional
approach, but this can prove
extremely time-consuming, complex
and expensive, and may involve
repeatable conditions that are difficult
to configure. The alternative is to set
up real-life radar test simulations
that include many different types of
targets and scenarios. In particular
target generators need to simulate
the range, radial velocity and size of
the target, along with environmental
factors such as for example
precipitation. Radar calculates
the range of a reflection from the
time delay between transmission
and reception. Doppler radars can
also estimate the target radial
velocity from the frequency shift
of transmitted and received signal
carrier frequency. Amplitude of the
echo signal indicates the object’s size
Real-time radar target generation
Dr. Steffen Heuel, Darren McCarthy, Rohde & Schwarz
16 l New-Tech Magazine Europe