Page 99 - Microsoft PowerPoint - Foundation Licence Training [Compatibility Mode]

Section 5 Antennas and Transmission Lines u Antenna impedance is measured in ohms u Impedance can be considered AC resistance u Most modern transmitting equipment has an output impedance of 50 or 75 ohms u The output impedance of the transmitter should be matched (have the same impedance) as the transmission line and the antenna. u Mismatched transmitter outputs, transmission line and antenna will cause power to be reflected back and forth along the transmission line u The reflected wave is called a standing wave 24 November 2009 TrainSafe Australia 99