A previous investigation of a modified circle-like slot antenna with dual-band-notched properties is extended. Frequency-domain characteristics have proved that the proposed antenna has very wide impedance bandwidth and shows good radiation characteristics. In this Letter, time-domain properties in terms of the antenna pulse response and power spectral density are investigated. Moreover, a study of indoor propagation channel characteristics when the proposed antenna is applied as transmitter and the receiver antenna is presented. A frequency-domain measurement setup and a sub-band divided ray tracing method are applied to measure and simulate the ultra-wideband indoor channel characteristics. The results show that the proposed antenna has also good time-domain characteristics and it is suitable for indoor and short range applications.