Abstract: A UWB flat antenna apparatus is disclosed. The UWB flat antenna apparatus includes an antenna element pattern, a ground pattern, and a multiple-stage filter including plural filter elements. Therein, the filter elements are electrically connected in series and are stacked, and the multiple-stage filter and the ground pattern are stacked.

Abstract: A communication device is disclosed which is comprised of: a transmitter for transmitting an ultra wide band wireless wave pulse; multiple receivers which are disposed equidistant from the transmitter and receive the ultra wide band wireless wave pulse; and distance-measuring equipment which detects a distance or a direction to an object by measuring time intervals between the first reception times when receivers receive the ultra wide band wireless wave pulse directly from the transmitter and the second reception times when the receivers receive a object-reflected wave of the ultra wide band wireless wave pulse.