Cascaded switched oscillators

Switched wave oscillators (SWOs) are mesoband sources operating based on a self-initiated switching phenomenon of charged electrodes with high voltages. In high-power applications, they are popular for their simplicity and compactness. However, the radiated power of SWOs is limited due to their physical model restrictions. On the other hand, using multiple sources is not a straightforward solution to increase the power due to the nature of short pulse radiation and synchronization challenges. We recently introduced a MARX-inspired configuration where multiple SWOs are cascaded to enhance power delivery (F. Babaeian, J. S. Tyo, J. E. Fletcher, and H. Zhou, “Cascaded Oscillators for High-Power Microwave Applications,” IEEE Transactions on Plasma Science, 2023). In the proposed configuration, a rectangular waveguide with a short end is coupled with multiple SWOs on one or both sides. Each source is connected to the waveguide through a coax transmission line that is linked to a probe inside the waveguide. The length of the coax transmission line is adjustable as a tuning parameter for synchronization. To excite the waveguide, the first SWO is positioned at a distance equal to a quarter wavelength of the oscillation frequency from the short end of the waveguide. The time delay of the traveling wave from the first source to each subsequent source is estimated to determine the position of the source and its coax length. The design operates by charging each source up to a specific voltage level below its breakdown, with only the first source being externally triggered. Then, the radiated field from the first source excites all subsequent sources. The arrangement of the sources and initial charges can be tuned in different ways to synchronize the wave generated from all sources to receive the maximum possible power output from the waveguide. In this paper, we will elaborate on different arrangements of cascaded oscillators and discuss the associated challenges in synchronizing radiated pulses.