Patent ID: 8643449

Claim:
An impedance matching circuit for use at an output stage of a power amplifier, the impedance matching circuit comprising: an input port for receiving a frequency band signal; and a plurality of paths, each path being allocated with a principal band signal to be transmitted therethrough and including a path on-off network and a fixed-value impedance matching network, wherein, depending on a type of the received frequency band signal, the path on-off network is configured to activate a selected one of the plurality of paths by rendering an input impedance of the selected path to have a lower absolute magnitude so that the signal is transmitted therethrough, and to deactivate the remaining paths of the plurality of paths by rendering the input impedance thereof to have a higher absolute magnitude so that the signal is not transmitted therethrough, and the fixed-value impedance matching network matches a load impedance of each path to the input impedance thereof, thereby rendering the input impedance thereof to have a prescribed reference value with respect to the principal band signal when said path is activated by the path on-off network.