A device is provided that creates pulse signals for UWB with a simplified circuit and performs radio transmission/reception in ultrawideband. The signal processor converts transmission data into a transmission baseband and then transmits it to the Manchester converter circuit. The Manchester converter circuit creates Manchester codes, which are converted from an L level to an H level with bit data [1] of transmission data, or from an H level to an L level with bit data [0] of transmission data. The Manchester converter circuit drives the monopulse generator circuit, using the output monopulse. The monopulse generator circuit includes series resonator circuit, produces a monopulse signal of transient response, which converts from positive to negative or from negative to positive, in response to the edge of the pulse. The enable control circuit selects a monopulse signal to be transmitted and then transmits as an UWB transmission signal the monopulse signal modulated based on the bit data [1], [0], from the antenna A.