Drift step recovery devices utilization for electromagnetic pulse radiation

Utilization of drift step recovery devices for high power electromagnetic short pulse radiation is discussed here. Possibility of powerful impulse radiation is connected with decision of two problems: how to reach stable extremely powerful impulse of nanosecond and subnanosecond duration with repetition rate of dozens and hundreds of kHz; and how to bring to antenna and radiate such energy? Among solid-state devices for short pulse generation the drift step-recovery devices look the most suitable ones. Drift step-recovery diodes (DSRD) and transistors (DSRT) are capable to form nanosecond impulses with up to MW peak power and hundreds of kHz repetition rate. High efficiency, compactness, lightweight and reliability of these switches make its very promising devices for UWB radars and communications. Taking into account nature of drift-step recovery devices the appropriate antenna structure should be found. To combine the drift-step recovery technology with energy accumulation into antenna is proposed and discussed. The DSRD/DSRT switches, interrupting antenna current, are able to hold very high over voltage, taking place at the breaking of antenna current. Therefore a level of electromagnetic pulse radiation is basically determined by antenna current driver capabilities. Prototype of antenna-generator was developed, manufactured and successfully used in transmitter module of the VLY-2 ground penetrating radar. As high peak voltage as 250 ... 300 Volts with pulse repetition frequency 100 kHz can be achieved with 12 Volts powering. Power consumption of this module didn¿t exceed 5 Watts. Description of the transmitting module operation principles and schematics are presented here. It is shown that proposed schematics could be utilized to achieve such impulse peak power as 100 kW and more.