A matrix converter  that directly transduces power and frequency by bidirectional switches has been expected to be an ultimate AC-to-AC converter because it eliminates limited-lifetime capacitors and achieves high efficiency power conversion even without PFC (Power Factor Control) circuits. However, it has not been practically realized due to the following issues resulting from the abundant components it includes. There has been no existing monolithic bidirectional switch that offers a high blocking voltage with current-handling capability and no compact isolated gate driver that provides a gate signal against a positive/negative voltage reference at every moment. Consequently, the matrix converter with discrete components makes the system large and complicated because of numerous power switches and isolated drivers. Relevant to this discussion, GaN devices  are very attractive in power applications since the GaN bidirectional power switches with a high blocking voltage can be monolithically implemented by using its lateral device structure . Additionally, a GaN Drive-by-Microwave (DBM) isolated gate driver  is the best candidate for a matrix converter, because it is very compact being both photo-coupler and transformer free and co-integratable with GaN power devices. These GaN integration technologies are very valuable in terms of a high-speed switching with less inductance among lines as well as offering a small system size.