Frequency- and time-domain characteristics as well as indoor propagation channel impulse response of a compact dual band-notched ultra-wideband (UWB) slot antenna are investigated in this paper. The antenna consists of a narrow rectangular radiation patch and a rectangular wide slot in the modified ground plane. A pair of L-shaped stubs are connected to the radiation patch to obtain band-notched property in WLAN band and a narrow straight stub is placed on the back side of the substrate to create band-notched characteristics in X-band downlink satellite communication system. Moreover, two small parasitic strips are added to the radiation patch to enhance the bandwidth (BW) of the antenna up to 14 GHz. A comprehensive study on time-domain and indoor propagation channel characteristics of the proposed antenna is also presented throughout the paper. A ray-tracing approach based on geometrical optics is applied to analyze the indoor channel characteristics. The designed antenna not only has a wide BW and compact size but also has appropriate radiation and time-domain characteristics over the antenna operating BW. The measured and simulated results are in good agreement. These advantages make the proposed antenna as a desirable option for UWB impulse radio applications.