Since gravitational waves are disturbances in the curvature of spacetime, I would certainly put this in the ‘odd patent’ category. This was granted to the mysterious Dr. Pais, who has more than a few notorious patents. In future posts I will detail some of the strange circumstances associated with his work.
Google patent link for US10322827B2.
Abstract: A high frequency gravitational wave generator including a gas filled shell with an outer shell surface, microwave emitters, sound generators, and acoustic vibration resonant gas-filled cavities. The outer shell surface is electrically charged and vibrated by the microwave emitters to generate a first electromagnetic field. The acoustic vibration resonant gas-filled cavities each have a cavity surface that can be electrically charged and vibrated by acoustic energy from the sound generators such that a second electromagnetic field is generated. The two acoustic vibration resonant gas-filled cavities are able to counter spin relative to each other to provide stability, and propagating gravitational field fluctuations are generated when the second electromagnetic field propagates through the first electromagnetic field.