  In this paper, we present millimeter-wave (mmWave) penetration loss
measurements and analysis at E-bands-73 GHz and 81 GHz. Penetration loss was
measured for common building materials such as clear glass, metal, tinted
glass, wood, and drywall on the campus of Boise State University in the city of
Boise. A horn antenna with a gain of 24 dBi was used at the transmitter and
receiver at both bands, and both antennas were boresight-aligned with respect
to the test material. A total of twelve locations were selected to test five
materials. We tested two indoor materials (clear glass and wood) in at least
two locations to determine the effect of penetration loss of materials in
similar compositions. The average penetration loss and standard deviation were
estimated for these indoor materials. We measured an average penetration loss
of 2 to 9 dB for wood and glass, respectively. Furthermore, we measured the
penetration loss of common indoor and outdoor building materials. We studied
that outdoor materials had larger penetration losses, e.g., we obtained a
penetration loss of 22.69 dB for outdoor metal, where this value dropped to
16.04 dB for indoor metal at 73 GHz. Similar results were also obtained for the
81 GHz channel, where the largest penetration loss was measured to be 26.5 dB
through a tinted glass door in an outdoor setting.
