My research focuses on the
development of dual band power amplifiers for
transmitter applications. Current dual band power amplifiers use DC
switches that are controlled by system signals indicating the current
band
of operation. Instead of such switches I am using dual resonant passive
networks. This novel approach reduces component count and thus saves
space
and increases reliability. The disadvantage is generally a reduction
of
amplifier efficiency due to increased passive losses. The amount of
these
losses is strongly depending on the network topology used, and I am
working towards a topology to minimize these losses.
Besides the traditional concepts described above my approach introduces
the possibility of concurrent operation in both bands.
I am currently developing a high power HF band power amplifier that
operates in the recently introduced Class-E/F mode of operation.