Circuits and methods for generating a pulse are provided. The generating can comprise receiving at least one trigger input signal with a pulse generating circuit; generating a voltage pulse having a duration less than the avalanche time of a transistor in response to at least a portion of the at least one trigger input signal with the pulse generating circuit; transmitting the voltage pulse from the pulse generating circuit to a terminal of the transistor, the transistor constructed and arranged to be operable in an avalanche mode; and outputting an avalanche pulse from at least one terminal of the transistor in response to the voltage pulse. In some embodiments, the pulse can be transmitted with an antenna in a radar system, and a return pulse can be received and processed.