Abstract: Multiple microwave oscillators can be phase locked such that the power output of multiple oscillators can be coherently combined to achieve a single output which has the total sum power of the multiple oscillators. Multiple oscillators assembled in a power combining array are phase locked using a locking signal provided at each oscillator via strategic placement of a partial obstruction between combined multiple oscillators and a load. This locking signal includes a minimum threshold level and preselected phase. A method for phase locking multiple microwave oscillators includes steps of combining power output of multiple microwave oscillators to achieve a single output to a load and inserting a partial obstruction between said at least two multiple oscillators and said load. The partial obstruction configured to provide a combined microwave oscillator signal including a minimum threshold and preselected phase.

Abstract: A high-power microwave generator employing a plurality of inexpensive commercial magnetron tubes cross-coupled by means of a secondary coupling path between each magnetron output pair, whereby a portion of the output energy from a first magnetron tube is injected into a second magnetron tube and a portion of the output energy from the second magnetron tube is similarly injected into the first magnetron tube. The resulting cross-injection of microwave energies brings the respective magnetron tube pair into a phase-lock sufficiently stable to permit coherent combination of their outputs for many high-power microwave applications, such as directed energy weapon systems. The magnetron phase-locking system requires no external components other than the secondary coupling paths of this invention.