We have built similar cavities for some of our customers over the years. For your frequency shift requirement, a suggestion I would make is to use Invar steel with a high surface finish(very low coefficient of thermal expansion) and copper or silver plate. You could likely get away with fairly...
Oops, typo.. meant Throughput. Best of luck on your endeavor!
www.custommicrowave.com
Space Qualified Multifrequency Antenna Feeds - Advanced Microwave & Mechanical Design - Full Catalog of Standard Product
Interesting idea, seems like it would have similar problems that many high efficiency alternative energy systems have. A lack of scalability. It would be very difficult to build a reactor that would have an economically viable throughout & conversion efficiency.
www.custommicrowave.com
Space...
Mician's uWave Wizard is very powerful design software, multiple solver types available, primary focus is on passive devices
http://www.mician.com/evaluationuwavewizard.html
Custom Microwave can offer custom design service or consulting. Our hardware is found on over 200 satellites...