Solid State Technology Reinvents Microwave Heating

Rathindra Nath Biswas

Abstract

Since magnetrons first came into widespread commercial use in microwave ovens in the early 1970s solid state technology has evolved relatively slowly to be used in industrial heating, consumer cooking, drying, automotive applications etc. Recently, RF energy utilizing solid state devices has appeared in the market as a viable replacement for magnetrons as the heating engine. This route offers many advantages like better energy direction control, longer life, enhanced reliability, precise power level control and smaller device size. The good news is that magnetrons, a bulky component with a short life can finally be retired. Replacing magnetrons with solid state electronics promises microwave heating and other applications that can do their jobs like cooking, heating more consistently, more efficiently and more evenly. The solid state technology using gallium nitride (GaN) and laterally diffused metal oxide semiconductor (LDMOS) has now competing with the power levels that can be provided by magnetron. Many innovations have been implemented and many are in the anvil, due to which it has been found that there is about 3 % power efficiency increase in solid state devices every 2 years. Its cost also has been reducing. A magnetron has a life of about 5000hours, whereas life expectancy of a solid state device is more than 30 years. These electronic devices can operate below and above 4 GHz and are ideally suited for industrial heating, domestic cooking and other appliances.

Abstract

Keywords