The frequency characteristics of microwave
     High-frequency characteristics include three aspects: the magnetic effects , radiation effects and phase lag due to its decadent microwave frequency electromagnetic He rates than higher, so the radiation effect is more obvious. It means that if ordinary metal conductors in the microwave along with energy continuously to the surrounding space radiation, passive transfer will quickly decay . This microwave radiation effects within the microwave transmission speed to bring different characteristics of electromagnetic wave propagation high collar , as well as transmission speed components with special requirements , the formation of micro technology transfer theory uniqueness. For example ;
    (A ) using a circular or rectangular cross-section metal pipes delivering microwave , rather than using an ordinary metal wire . If a metal wire , then also need to be specially designed double wire saw , or a shielded cable with Ron . Namely common TV antenna signal feeding the same coaxial feeder Shao flat cord.
    (B ) can not be applied when the transmission frequency to be parameters , such as current , voltage, and resistance , " circuit" is to discuss the concept of drag characteristics of microstrip . It required an alternating electromagnetic field theory "field" concept. At this condition, the skin effect , radiation effects and phase lag and other high-frequency characteristics will not allow arbitrary suddenly bribe . The reason is: the circuit size and low frequency electromagnetic field is much smaller than the operating wavelength , can be considered low frequency circuits throughout the system steady state voltage and current effects are created at the same time , therefore , the voltage and current in the low frequency circuit has a clear the physical significance. However, the operating wavelength of the microwave band of electromagnetic waves with its circuit size is comparable , or even hours, the electromagnetic wave phase lag phenomenon has been very clear , can not be omitted . It is therefore only used disposable low-frequency circuit " circuit " concept and pinch pass parameters .