Improved Wireless Performance from Mode Scattering in Ventilation Ducts

Ventilation ducts are a convenient infrastructure for distributing wireless signals indoors. Conventional and historical use of single conductor metal waveguides for transmission of communications signals have focused on careful excitation and control of the mode content of the waveguide--something that is possibly infeasible or financially undesirable in a ventilation duct setting. With this in mind we investigate the mode scattering effects present in a ventilation duct T-junction and note with some surprise that improvement in the performance of an IEEE 802.11g communication can result from this scattering.