650 W pulse generator for ultra-wideband (UWB) radar application

A 650 W pulse generator for ultra-wideband (UWB) radar application is presented. Key device is a npn silicon power transistor operating in the avalanche mode. After optimizing the circuit parameters and the bias conditions of the pulse generator, ultra-short electrical pulses with a peak value of 650 W, terminated into an optimum load of 5 ohms, and a pulse width of 1.38 ns have been obtained. For direct feed of a TEM horn antenna the circuit parameters were also optimized to a load impedance of 50 ohms, still delivering 302 W. A balun transformer exhibiting a power loss of 6 percent was used to provide symmetrical pulses for the stimulation of a TEM horn. Due to the simple circuit structure, flexibility in circuit design, reliable performance and low cost, the presented pulse generator seems to be very suitable for ultra-wideband radar sensor applications.