Abstract
This paper describes how to protect power devices of the transmitter against transient voltage and current due to load changes.
When the load condition of the transmitter changes because of antenna-induced lightning surges, large transient voltage and current, which can damage the power devices, occur in the transmitter.
These transient votages and currents are analyzed using computer simulation. If the load impedance seen from the power amplifier with the grounded antenna base is extremely small, both voltage and current can be very large to exceed the ASO of the power device.
This paper also shows that in order to protect the power devices, the load impedance seen from the power amplifier with the grounded antenna base should be approximately equal to (inductive load), or twice (capacitive load) the absolute value of the matched load impedance.
