Diamond is an astonishing material. Used mainly for jewelry, it is today studied for electronic devices to be operated in harsh environment or as the base material for high power, high frequency applications due to the unique electrical, physical, chemical and mechanical properties. Diamond can be classified as a wide band gap semiconductor and suitability for performance in the microwave range is today demonstrated through an affordable deposition technology and rather simple device structures. Difficulties related to availability of large crystalline substrates and effective doping can be overcome with polycrystalline substrates in some cases demonstrating performances better than epitaxial ones.
Conte, G., Rossi, M.C. (2011). Diamond: a technology on the frontier. In Advanced Techniques for Microwave Systems (pp. 297-311). Kerala : Giuseppe Schettini.