  The upcoming 6G mobile communication standard will offer a revolutionary new
feature: Integrated sensing and communication (ISAC) reuses mobile
communication signals to realize multi-static radar for various applications
including localization. Consequently, applied ISAC propagation research
necessitates to evolve from classical monostatic radar cross section (RCS)
measurement of static targets on to bistatic radar reflectivity
characterization of dynamic objects. Here, we introduce our "Bistatic Radar"
(BIRA) and antenna measurement facility for bistatic spherical positioning with
sub-millimeter accuracy on a diameter of up to 7 m and with almost continuous
frequency coverage from 0.7 up to 260 GHz. Currently, BIRA is the only bistatic
measurement facility capable of unrestricted ISAC research: In addition to
vector network analysis, BIRA employs advanced wideband transceiver technology
with an instantaneous bandwidth of up to 4 GHz. These transceivers grant BIRA
the unique ability to characterize dynamic targets in both Doppler and range,
while also significantly accelerating RCS measurements of static objects.
