The basic concept of microwave
 The so-called " microwave " usually refers to the frequency of electromagnetic waves from 300000000Hz to 300000000000Hz . Where less than 300000000Hz , and refers commonly referred to as radio waves , including the long-wave , medium wave and FM . Where more than 300000000000Hz, belongs infrared or visible light .
 According to the electromagnetic wave propagation velocity in vacuum C and the frequency f, the relationship between the wavelength of a few . 300000000Hz 300000000000Hz respect to the microwave frequency range of the microwave wavelength range lm to about 1mm .
 Thus, the microwave frequency is high , the wavelength is short, so the name suggests , is called microwaves.
 In the microwave band , and is divided into four sub-bands .
    For convenience, the microwave band again more finely divided into a number of bands and expressed with the corresponding symbols .
 Considering the standardization of microwave devices and equipment , and to avoid the use of frequency caused by too much interference with radar and microwave communications , now commonly used in the microwave heating frequency of 0.915GHz and 2.45GHz, which corresponds to a wavelength of 0.330 m , respectively and 0.122m.