Characterization of memory effects in GaN based HPAs for multi function sensors
Typ
Examensarbete för masterexamen
Program
Wireless, photonics and space engineering (MPWPS), MSc
Publicerad
2020
Författare
Divinyi, Andreas
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Truly multi-functional sensor systems are enabled through the recent development
of wideband and multi channel digital back ends to control systems with several
transmitter and receiver modules, in combination with the advancements in the development
of these modules utilizing GaN MMIC based solutions. However, there is
a considerable lack of insight into the problem of long term memory effects in broadband
GaN MMIC power amplifiers required to enable the next generation of small
and lightweight multi functional sensor systems. As such this thesis is focused on
the impact of memory effects when changing between two waveforms representative
of the different operating conditions applicable for a multi function system. Thus a
suitable test bench is designed capable of providing arbitrary waveforms, switching
between them and, record the results. The measurement data is modeled in terms
of exponential time constants in order to quantify the impact on the behavior of
a power amplifier caused by memory effects in terms of amplitude and time. The
results indicate the presence of these memory effects in the amplifier operation after
switching applications and decrease of influence from the previous waveform as time
progress. Furthermore, investigating the effect of timing mismatch between the gate
and RF pulsing showed a significant decrease in device performance.