In this paper, the authors present a six-port network over an Ultra-WideBand (UWB) of 2.8GHz. Its key component is the six-port junction, which consists of a Wilkinson power divider and three 3dB quadrature couplers. This six-port junction is accomplished in a low dielectric constant substrate (Rogers RT/Duroid 5880). Multi-section impedance transformation is applied in the power divider and the quadrature coupler is realized by using two 8.34dB couplers in tandem. An ultra-wideband operation of the six-port junction is verified by full electromagnetic simulations and measurements.