Typical MW reactors that were used in various studies.

Equipment name		Advantages	Application field	Ref.
Monomode MW reactors	Annular MW cavity	The sample can be irradiated equably.	Studying the thermal properties that are associated with phase changes and sintering and annealing characteristics of ceramic materials.	Chen et al.12
	Corridor-like MW cavity	The electrical fields and magnetic fields can be divided by choosing the position of the reactor.		Yamada et al.13
	Hybrid single-mode cavity	It can realize the automatic control of the sample temperature via control of the surrounding air temperature.	Examination of phase changes via examination of the thermal properties.	Binner et al.16
	Setup of an integrated MW/photoreactor system	The operating frequency is not just a single frequency of 2.45 Hz.	On the influence of the MW thermal and nonthermal effects in titania photoassisted reactions. (Chemical)	Horikoshi et al.15
Polymode MW reactors	Ridged waveguide with a glass pipeline	It can avoid interference with the uniform distribution of the electric field in the ridged gap area and unnecessary MW energy coupling.	Water structure stability and structural properties of field-dependence with variations of MWs in NaCl aqueous solution. (Chemical)	Liu and Jia,19
	Constant temperature system	The irradiation power of the MW was set at 45 W and ensured the temperature constancy.	The MW-/photo-assisted degradation of BPA in aqueous TiO2 dispersions. (Environmental)	Horikoshi et al.53
	Full open system	The light colour and intensity are controllable.	The nonthermal effects of weak-intensity millimetre waves on physicochemical properties of water and water solutions. (Chemical)	Ayrapetyan et al.18
	Open system and safe system	Ensures that the pressure in the reaction vessel stays in the safe range. The reaction vessel is cooled actively by automatically turning on/off a stream of compressed air when the reaction vessel's temperature exceeds the present value.	MW-induced degradation of NDMA that is sorbed in zeolites. (Environmental)	Hu et al.49
	Exposure apparatuses	The unexposed cells were not affected by the MMWs.	It is the exposure apparatus for cell proliferation measurements.	Yaekashiwa et al.11
Other	MW irradiation equipment	—	Germicidal effects of MW irradiation on microbial agents. (Microbial)	Kang et al.14