  This paper presents millimeter wave (mmWave) penetration loss measurements
and analysis at 73 GHz using a wideband sliding correlator channel sounder in
an indoor office environment. Penetration loss was measured using a carefully
controlled measurement setup for many common indoor building materials such as
glass doors, glass windows, closet doors, steel doors, and whiteboard writing
walls. Measurements were conducted using narrowbeam transmitter (TX) and
receiver (RX) horn antennas that were boresight-aligned with a test material
between the antennas. Overall, 21 different locations were measured for 6
different materials such that the same type of material was tested in at least
two locations in order to characterize the effect of penetration loss for
materials with similar composition. As shown here, attenuation through common
materials ranged between 0.8 dB/cm and 9.9 dB/cm for co-polarized antennas,
while cross-polarized antennas exhibited similar attenuation for most
materials, but up to 23.4 dB/cm of attenuation for others. The penetration loss
results presented here are useful for site-specific planning tools that will
model indoor mmWave networks, without the need for expensive measurement
campaigns.
