Development of a tri-polarized dynamic channel sounder for wireless body area network Wireless body area network (WBAN) is expected to be utilized in various fields such as health-care. One of its vital challenges is that dynamic channels suffer severely from fading. Therefore the characterization of WBAN channel is important and many researches have been done in this area. This paper presents a tri-polarized dynamic WBAN channel sounder to realize 3×3 dynamic channel measurement by applying time division multiplexing (TDM), and by using two tri-polarized dielectric resonator antennas (DRAs) and a multi-port oscilloscope. Due to the tri-polarized property of DRA, this present system can contribute to the antenna polarization dependency of WBAN channel as well as the measurement-based antenna de-embedding. In this paper, system configuration, parameter design, DRA antenna, calibration method, and measurement validation are presented.