Abstract: A device and a method for combining outputs of a plurality of linear power amplifiers while preventing loss of signals.

Abstract: A linear power amplifier and method for removing the intermodulation distortion with a predistortion system and a feed forward system. The linear power amplifier having a main power amplifier includes: a predistortion system for firstly suppressing the intermodulation signal generated upon amplification of an RF signal in the main power amplifier, by generating a harmonics corresponding to the input RF signal and a predistortion signal with coupling the RF signal to the harmonics; and a feed forward system for secondly suppressing the intermodulation signal by canceling the input RF signal and the output of the main power amplifier, extracting an intermodulation signal distortion, error-amplifying the extracted intermodulation signal distortion, and coupling the amplified intermodulation signal with the output of the main power amplifier.

Abstract: A radio frequency power combiner includes a plurality of transmission lines connecting a plurality of input terminals to an output terminal. An RF switch is positioned between each of the input terminals and a transmission line connecting the output terminal to the input terminal. The electrical length between each RF switch and the output terminal is preferably one half of a wavelength at a central frequency, which may be realized by two transmission lines of different impedances in each path, each a quarter wavelength long. When the switches are on, the signal power applied to all of the input terminals is combined at the output terminal. When any given switch is turned off, the RF power incident to the switch is reflected, and the transmission lines connected between that switch and the output terminal appear as an open circuit. The power combiner can also operate as a power divider.