A high frequency electromagnetic radiation generation device is disclosed that includes a high voltage input, a nonlinear transmission line, an antenna, and a pulse recirculating circuit. In some embodiments, the high voltage input may be configured to receive electrical pulses having a first peak voltage that is greater than 5 kV, and/or may be electrically coupled with the nonlinear transmission line. The antenna may be electrically coupled with the nonlinear transmission line and/or may radiate electromagnetic radiation at a frequency greater than 100 MHz about a voltage greater than 5 kV. The pulse recirculating may be electrically coupled with the high voltage input and the antenna. The pulse recirculating circuit may include a diode; a low pass filter; and a delay line. In some embodiments, unradiated energy from the antenna is directed through the pulse recirculating circuit to the nonlinear transmission line with a delay of less than 100 ns.