Microwave Heating

915 MHz · 2,450 MHz · volumetric · magnetrons

Microwaves heat polar molecules throughout a product instead of conducting heat in from the surface. Industrial lines use 915 MHz because it reaches deeper and one tube delivers about 100 kW.

Comparison of the two industrial microwave frequencies. Free-space wavelength: 915 MHz 32.8 cm, 2,450 MHz 12.2 cm. Maximum power from one magnetron: about 100 kW at 915 MHz, about 30 kW at 2,450 MHz. Magnetron efficiency: about 85% at 915 MHz, about 70% at 2,450 MHz. Longer wavelength also means deeper penetration into wet product, so large industrial lines run at 915 MHz. FREE-SPACE WAVELENGTH, CM 915 MHz 32.8 cm 2,450 MHz 12.2 cm MAXIMUM POWER FROM ONE MAGNETRON, KW 915 MHz ~100 kW 2,450 MHz ~30 kW MAGNETRON EFFICIENCY, % 915 MHz ~85% 2,450 MHz ~70% Longer wavelength penetrates deeper, so large industrial lines run at 915 MHz.
ISM bands
915 / 2,450 MHz
Largest tube
~100 kW
Heating mode
Volumetric
Hub
Industry

Finding

Microwave heating is proven for tempering, drying and rubber curing, while its use in battery materials and minerals is still at pilot scale

A magnetron converts grid power to microwaves that a waveguide delivers into a cavity or tunnel; water and other polar molecules absorb the energy throughout the product. Frozen meat and fish blocks are tempered at 915 MHz in minutes instead of days, and continuous lines cure EPDM rubber profiles, dry pasta, wood and pharmaceuticals.

Microwave and induction are separate tools: induction couples to electrically conductive metals, microwave to dielectric materials such as water, ceramics, polymers and many mineral and battery powders. Microwave sintering of advanced ceramics shortens cycles because heat is generated inside the part. In battery and mineral processing, microwave-assisted calcination of cathode precursors and spodumene, and microwave chemistry for plastic recycling (Microwave Chemical Co. in Osaka, with Mitsui Chemicals) are moving from lab to pilot.

Scale-up is the constraint. Even at 100 kW per tube, a gigafactory-scale calciner would need dozens of generators, uniform fields are hard to hold in large cavities, and thermal runaway in materials whose absorption rises with temperature has to be controlled. Solid-state RF power amplifiers (Sairem and others) give finer frequency and phase control than magnetrons at lower power.

Applications

Where microwave heating is used

Maturity ranges from decades-old food and rubber lines to pilot plants for battery materials.

Industrial microwave applications
ApplicationFrequencyRoleMaturity
Food tempering and thawing915 MHzRaises frozen blocks to just below freezingCommercial for decades
Rubber vulcanization2,450 MHzContinuous curing of extruded EPDM profilesCommercial
Drying (pasta, wood, pharmaceuticals, minerals)915 / 2,450 MHzRemoves water volumetrically, often under vacuumCommercial
Advanced ceramics sintering2,450 MHz and upDensifies parts with internal heatingNiche commercial
Cathode and precursor calcination915 / 2,450 MHzFaster calcination of battery powdersPilot
Ore pretreatment and spodumene conversion915 MHzCracks ore, converts alpha to beta spodumenePilot
Plastic recycling and chemicals915 / 2,450 MHzDrives depolymerization and reactionsPilot to early commercial

Suppliers

System and generator makers

China builds most of the world's domestic microwave ovens and many low-cost industrial dryers; high-power industrial systems come from a small group of specialists.

Industrial microwave makers
CompanyCountryFocus
Ferrite Microwave TechnologiesUnited States915 MHz high-power systems
Thermex-ThermatronUnited StatesMicrowave and RF systems
SairemFranceMagnetron and solid-state generators
Muegge, Fricke und Mallah, PuschnerGermanyGenerators and industrial systems
Microwave Chemical Co.JapanMicrowave chemical processes
Shandong Loyal IndustrialChinaIndustrial microwave dryers and sterilizers
Galanz, MideaChinaMagnetrons and ovens at very high volume

Sources

Sources and scope

Scope
Industrial Microwave Heating
Sources
Supplier specifications; FCC Part 18; published pilot announcements
Updated
October 2026