ALEXANDRIA, Va., July 17 -- Chongguo Yao of Sichuan, China, has developed a phase switch.

According to the U.S. Patent & Trademark Office, the invention relates to a "phase switch (energy switch) comprising a three-cavity system (an end-coupled cavity+side-passed accelerate cavity+an end-coupled cavity) and a separate single couple cavity is disclosed. The phase shift between the adjacent accelerate cavities is .pi. when the three-cavities system is disordered (state `0`); and a microwave pass through the three-cavities system to the adjacent accelerate cavities, the phase between the adjacent accelerate cavities is change to 2.pi. (or 0) when the single couple cavity is disordered ...