  In the last few years, many advances have been made in the demonstration of
high-average power pulsed THz sources; however, little effort has been made to
study compatible sensitive field-resolved detectors. Here, we investigate
ErAs:InAlGaAs photoconductive receivers optimized for a probe wavelength of
1030 nm and thus suitable for the new class of high-power ultrafast
Ytterbium-based laser sources for THz generation and detection. The performance
of the receiver is tested with a few-cycle THz source with high average power
up to 20 mW and the dynamic range and saturation behavior of the receiver is
thoroughly characterized. Under optimized settings, a dynamic range of more
than 115 dB is reached in a 120 s measurement time with 20 mW of THz average
power, which is among the highest reported values to date. By reviewing the
state-of-the art in TDS measurement and post-processing technology, we identify
current limitations and guidelines for further increasing the dynamic range
towards 150 dB in short measurement times using high average power THz systems.
