Abstract: A circuit arrangement to convert high voltage direct current energy into radio frequency energy that includes photoconductive switch means which is periodically closed by a pulsed light source, such as a laser, to generate the radio frequency energy. A segmented transmission line which includes a plurality of photoconductive switches positioned a half-wavelength apart that are closed simultaneously by the laser may be used to generate the radio frequency energy. The photoconductive switches may also be connected in parallel and closed by time delayed light pulses to generate the radio frequency energy. The pulses generated may also be used to excite a resonator circuit coupled to a load to increase the duration of the high frequency oscillation and to shape (filter) the resultant waveform. Other configurations utilizing photoconductive semiconductor discs and annular metal electrode configurations which may be closed by light pulses are also illustrated.