A conventionally known pulse radar for searching for an object in space by using a pulse wave basically has such a configuration as shown in FIG. 10.
That is, in a pulse radar 10 shown in FIG. 10, a transmitter section 11, when having received a trigger signal G output from a later-described control section 16 in a predetermined period Tg, generates a pulse wave Pt having a predetermined width and a predetermined carrier frequency that are synchronized with the trigger signal G and radiates it into space via a transmission antenna 11a. 
This pulse wave Pt is reflected by an object 1a present in space 1, so that its reflected wave Pr is received by a reception antenna 12a and then detected by a receiver section 12.
A signal processing section 15 analyzes the object 1a present in the space 1 based on a timing at which a detected output D is output from the receiver section 12 with respect to a reference timing, for example, at which the pulse wave is sent from the transmitter section 11 and also based on an output waveform of the pulse wave.
The control section 16 provides various control items on the transmitter section 11 and the receiver section 12 based on results of processing by the signal processing section 15, etc.
It is to be noted that a basic configuration of such a pulse radar 10 is disclosed in the following Patent Documents 1 and 2:    Patent Document 1: Jpn. Pat. Appln. KOKAI Publication No. 7-012921    Patent Document 2: Jpn. Pat. Appln. KOKAI Publication No. 8-313619
The following two types of pulse radar are considered automotive radars being put into practical use recently of those pulse radars that have such a basic configuration.
A first type pulse radar is being developed as something that uses a millimeter waveband frequency (77 GHz) to search a long-distance narrow-angle range with high power for the purpose of assisting in high-speed driving such as prevention of collision of an automobile and driving control.
A second type pulse radar is being developed as something that uses a sub-millimeter waveband frequency (22 to 29 GHz) to search a short-distance wide-angle range with low power for the purpose of assisting in low-speed driving such as recognition of a blind spot of an automobile and parallel parking.
The sub-millimeter waveband for use in the second type pulse radar is generally referred to as an ultra-wide band (UWB) and utilized not only in an automotive radar but also in a medical radar, a walking assist radar for the visually impaired and a short-distance communication system, etc.
Since the UWB is wide, a short pulse having a width of 1 ns or less can be used in a radar system, so that it is expected to realize a short-range radar that has a high distance resolution.
USPTO Backgrounds
USPTO Backgrounds