Microwaves are a form of high frequency electromagnetic waves (app 12 cm wave length) similar to those used by a radio. Electricity is converted into microwave energy by the magnetron tube. The microwaves travel from the magnetron tube to the oven cavity where they are reflected, transmitted or absorbed.
Reflection Microwaves are reflected by metal just as a ball is bounced off a wall. A combination of stationary (interior walls) and rotating metal (turntable or stirrer fan) helps assure that the microwaves are well distributed within the oven cavity to produce even cooking.
Transmission Microwaves pass through some materials such as paper, glass and plastic much like sunlight shining through a window. Because these substances do not absorb or reflect the microwave energy, they are ideal materials for microwave oven cooking containers.
Absorption Microwaves are absorbed by food. They penetrate to a depth of about 2 to 4 cm. Microwave energy excites the molecules in the food (especially water, [at and sugar causes them to vibrate very quickly. The vibration causes friction and heat is produced. In large foods, the heat which is produced by friction is conducted to the center to finish cooking the food
Grilling
Grilling is done at high temperatures with the food close to the heat. This gives meat a rich brown appearance. Only use highquality, well-marbled meats for grilling since the high temperatures can dry out the less choice meats.
Combination Cooking Combination cooking is ideal for roasting meats and poultry. Combination cooking automatically alternates between grill and microwave heating. The advantage to combination cooking is that it gives the browning of grill and often shortens the conventional cooking time. Combination settings are automatic: there is no need to set grill temperature or microwave power level.