A general radio frequency pulse generation device used in, for example, a radar generates a pulse signal having a certain pulse width through a pulse generator, inputs the pulse signal to a low pass filter having a certain frequency characteristic to generate a monopulse, inputs the monopulse to a mixer, and multiplies a carrier wave input from a radio frequency oscillator of a certain frequency by the monopulse to generate a radio frequency pulse. The generated radio frequency pulse is radiated from a transmitting antenna and used, for example, for measurement of a distance to an object.
For a radio frequency pulse radiated from an antenna to the outside, in order to prevent interference with other radio devices or the like, for example, a frequency band permitted by a legal regulation is specified. In the past, a technique of adjusting a pulse pattern of a radio frequency pulse so that the radio frequency pulse complies with a legal regulation has been known. For example, in the general radio frequency pulse generation device, a waveform of the pulse signal output from the pulse generator is adjusted using the low pass filter.
Further, Patent Document 1 discloses a technique of preventing interference, for example, by changing a band by changing a pulse shape or a center frequency when interference from other radio devices or the like is detected. As a result, when an interference wave is detected, it is possible to shift a transmission wave to a band other than a band having an interference wave within a range of complying with a legal regulation. In the technique disclosed in Patent Document 1, a pulse shaping unit changes a pulse shape and shifts a band of a transmission wave.
In a technique disclosed in Patent Document 2, a method of cutting a radio frequency signal of a local oscillator in a pulse form by performing on/off control by a clock signal having an arbitrary delay using two GaAs switches as a pulse shaping circuit is used. In this method, a pulse shape is decided according to rising and falling response characteristics of the GaAs switch.